See also : CONSTANTINESCO, George : Transmission ( II )
Newton Burke: Popular Science Magazine (February 1924)
Ian Constantinesco: George Constantinesco -- His Torque Converter and Other Inventions (Chapter 5)
George Constantinesco: US Patent # 1, 542,668; Method and Means for Transmitting Power
G. Constantinesco: US Patent # 1,582,734; Power Transmission
G. Constantinesco: US Patent # 1,591,471; Power Transmission Mechanism
G. Constantinesco: US Patent # 1,613,344; Power Transmission
G. Constantinesco: US Patent # 1,617,410; Clutch and Unidirectional Driving Device
G. Constantinesco: US Patent # 1,715,816; Driving Gear for Motor Vehicles
Popular Science (Feb. 1924)
Ingenious Automatic Power Control Does Away with Nuisance of Shifting
A marvelous new type of automobile is now running through the streets of Paris. In appearance it resembles the thousands of small cars that throng the French capital. And yet this car is capable of performing such remarkable feats that it has aroused the intense interest of automotive engineers in all parts of the world.
The car has no transmission of the conventional type. There are no gears and no gear shift lever. Automatically and without attention on the part of the driver, it adjusts itself to the load, so that in any kind of a test or demonstration the driver has nothing to do except steer and press on the throttle with his foot until the desired results are obtained, whether he is towing a 5-ton truck up a steep hill or traveling at high speeds on an open country road. George Constantinesco, well-known automobile engineer, has perfected in this new gearless car a transmission along radically new lines.
If you ever have tried to push a stalled automobile along a road or to shove a heavy motor boat away from a dock you know how hard it is to get a heavy object into motion and how relatively easy it is to keep it going once you have it started. You have also found that it takes a lot more energy to get it started quickly than if you take your rime with the job.
The ease with which an object can be set in motion if you do the job at slow speed, and the extra effort required when you try to speed up the operation, is taken advantage of in the new gearless automobile. How this is accomplished is shown in the simplified drawing of the most important parts. It shows what happens when the crank is rotated by the engine.
When the motor is started and un slowly and the automobile is stationary, the weight of the car keeps the drive shaft on which the ratchet wheel is mounted from turning, and the motion of the rotating crank is transmitted to the inertia wheel, which consequently oscillates back and forth. When the driver steps on the throttle the motor starts to speed up, and if the inertia wheel weighed practically nothing it would oscillate back and forth at increased speed. But the inertia wheel is made heavy and consequently it offers resistance to being oscillated back and forth with any great amount of speed.
This resistance tends to hold the differential lever attached to it from making the full motion imparted through the connecting rod by the crank and forces the other end of the lever to move back and forth slightly when the increase in speed first starts, and more rapidly as the engine develops more power. Note that the ratchets are so arranged that the ratchet wheel is turned in the same direction both on the forward and and backward motion of the link operating through the drive rods. At high speed the inertia wheel remains practically stationary and all of the motion is transmitted directly to the rear wheels.
The drawing, of course, does not show the parts as they actually are arranged in the automobile. For the sake of clearness the parts have been spread out and simplified. The ratchet wheel, for instance, really consists of a pair of over-running clutches that accomplish the same result without lost motion. Of course this mechanism can drive the car only in the forward direction, and consequently a reverse gear is fitted to facilitate backing the car around in the garage and to make turns on the road.
The control of the new car is much more simple than any of the standard automobiles. There being no clutch or gear shift lever, the driver does not have to worry about changing speeds. When he wants to stop he takes his foot off the throttle and puts on the brake. The motor slows down and the small amount of energy still being generated is used to rock the inertia wheel back and forth.
When he wants to start he throws off the brake and steps on the throttle and the car starts up without a jerk, automatically increasing speed until a balance is obtained between the speed of the car and the amount of power developed by the motor.
Hills present no difficulties. The car simply slows down in proportion to the steepness of the hill. Consequently it will climb any hill as long as the rear wheels can obtain traction. Weird results can be accomplished by the remarkable infinite ratio transmission. If the back wheels are block with heavy logs when the car is standing and the driver steps on the throttle, the wheels rise up over the obstacle with a slow and gradual movement that suggests the running and jumping figures seen by a slow motion camera. It also enables a light demonstrator car fitted with a low-powered motor to tow a loaded 5-ton truck up a steep hill without laboring.
This simplified diagram shows how the gearless transmission passes the power from the motor to the drive shaft in proportion to the motor speed and the load. As the crank runs faster, the weight of the inertia wheel resists this speeding up process, and the other end of the differential lever starts to move back and forward, rotating the drive shaft by means of the ratchet wheel.
His Torque Converter and Other Inventions
George Constantinesco was born in Romania and arrived in London in November 1910. By 1913 he had already applied for eighteen British Patents related to improvements in internal combustion engines and their ancillaries such as carburettors, fuels and transmission elements as well as early patents on methods of transmitting power by pulsating waves of energy through liquids. He formulated the Theory of Sonics --- the science dealing with the transmission of power by periodic forces and motions through liquids, solids and gases. He discovered that these phenomena had their analogies not only with the properties of sound waves and the laws of harmony, but also with AC electrical circuits. Prototypes of rock drills working on the percussion system and polyphase rotary systems were already being demonstrated by 1913. The most important application of his theory of sonics was a "synchroniser gear" which allowed to fire a machine gun through the aircraft propeller. This gear was employed on all allied aircraft during WWI and on some aicraft during WWII. After WWI Constantinesco had an idea for a low cost "peoples' car'' which would travel 100 km miles on 2.5 litres of petrol at the most commonly used road speeds of 50 to 70 km per hour. He considered that this performance and low cost could be achieved by using a cheap 500 cc single cylinder two stroke air cooled engine together with his unique Torque Converter transmission which would eliminate the conventional gear box and clutch. Experience in this field could then be applied to the transmission of much higher powers in heavy vehicles such as railway locomotives. The car was displayed at London and Paris Motor shows in 1925 and attracted more than one hundred articles in world press. General Motors acquired a licence to build the car in 1926. Unfortunately development of the transmission stopped as there was no need for infinitely variable transmission while car engines were large (4-5 litres) and had plenty of torque. His torque converter was however used in self propelling railcars. Constantinesco died in 1965 at the age of 94, and only few years before his death he presented a paper on Power Transmission at the Institutiom of Mechanical Engineering. Constantinesco had 133 British patents to his credit in the fields of automobile engineering, fluid power, mechanical transmissions and others. The following pages describe his career and his various inventions. We hope that you will enjoy reading this fascinating story.
1. Early Days in Romania - the Conception of Sonics // 2. England - Birth of Sonics // 3. Firing between the Props // 4. The Admiralty Backs Sonic Research //
5. The Torque Converter // 6. Other Applications of Sonics // 7. Laboratory at Coniston // 8. Epilog // 9. Acknowledgments // 10. References // 11. Bibliography
Chapter 5 The Torque Converter
With the war over and the Sonic Works at West Drayton disbanded, George was no longer compelled to apply his Sonic principles to engines of destruction. He had for many years shown an interest in motor cars and other vehicles for road and rail transportation. The first practical indications of this interest appeared in his patent for a monorail system in 1910, followed by others relating to components of internal combustion engines and transmission elements. Among these there was a paraffin vaporizer patented in 1911 which was tested in a car fuelled by crude paraffin oil on a journey from London to Brighton and back - at a cost of one shilling for the fuel for the round trip! During the war years George had already made an in-depth mathematical analysis of infinitely variable transmissions and had arrived at a concept for a mechanical Torque Converter. He claimed that such a device could be universally applied in industry, motor vehicles, railway locomotives, ships, military tanks and agricultural tractors. The exigencies of the war had interfered with further development, but now there was an opportunity to return to the theme.
Of the various possibilities which came to mind George concluded that the most fruitful and marketable line of approach to start with should be improvement in the efficiency and ease of operation of the transmission train of motor cars. He was concerned at the wasteful use of fuel inherent in existing engines and their transmission systems, the inconvenience of manual gear changing, and clutch operation, with consequent shocks to the engines and transmissions. Also there was the high price of motor cars, which only a minority of people could afford to buy. His idea was to produce a low cost one hundred guinea "peoples' car'' which would travel 100 miles on one gallon of petrol at the most commonly used road speeds of 30 to 40 miles per hour. George arrived at this figure after conducting a comprehensive survey of average car road speeds and designed his car to benefit the most people, rather than a car of higher speed which would only benefit a minority. He considered that this performance and low cost could be achieved by using a cheap 500 cc single cylinder two stroke air cooled engine together with his Torque Converter transmission which would eliminate the conventional gear box and clutch. Experience in this field could then be applied to the transmission of much higher powers in heavy vehicles such as railway locomotives.
George admitted that the mechanics of his automatic variable transmission, or Torque Converter were not easy to explain because the theory of conventional mechanisms did not apply to this invention. It will be recalled from previous chapters that George used a hydrosonic system to operate the aircraft machine guns and the injector system for Diesel engines. His Torque Converter was a sonomechanical application of his theory on the transmission of power by vibrations where the impulses are transmitted through solids instead of liquids. Power is transmitted from the engine to the output shaft through a system of oscillating levers and inertias1 arranged in such a way as to split the alternating motion derived from a primary crank rotating with uniform angular speed and torque into two components. The first component oscillates a mass or any form of inertia. The second component oscillates a set of mechanical valves. The valves are arranged in pairs out of phase at 180°, so that positive and negative impulses are rectified into a unidirectional torque on the secondary. The angular speed and torque on the secondary varies automatically within wide limits according to the resistance to be overcome and the revolutions of the engine.
The Torque Converter was typical of the way in which George Constantinesco worked, the first model emerged from a purely mathematical analysis of the problem to be solved, followed by a mathematical solution translated into a working drawing. The model made from the working drawing performed as predicted without "trial and error'' or modification.
A great deal of interest in the invention was aroused in the popular and technical press, but many of the statements made were inaccurate or misleading. In an attempt to clarify the situation, the Editor of the Automobile Engineer invited George to discuss the whole concept of variable transmissions for motorcars in a series of five articles in that publication from November 1923 to July 1924. These articles, together with the correspondence which arose, were reprinted at George's request, in a volume entitled "Variable Transmissions for Automobiles'' , and issued in quantity from his offices at 7 Grosvenor Gardens in London. This was an indication of George's confidence in the accuracy of his analysis of the problem and his solution provided by his invention, in spite of the criticism and sometimes heated arguments generated in the correspondence. Further criticism and disbelief was silenced when George published a letter in the July 1924 issue of the Automobile Engineer offering a prize of £100 ''to the first individual who will prove that my mathematics are wrong or the interpretation of my formulae are not in strict accordance with logic".
To illustrate the basic principle of the Constantinesco Torque Converter, consider figs 16a and 16b. The impulses are produced by a crank connected to a point distant from the apex of a pendulum, or lever with a weight on the end. This apex is connected by a short link to a fixed point; the apex of the pendulum is connected with links to unidirectional ''mechanical valves" on the secondary shaft, which operate like ratchets, but much more smoothly. When the primary crank rotates slowly, figure 16a, the pendulum swings to and fro about the apex, or fulcrum of the lever, as in a clock and no energy is imparted to the secondary shaft. This corresponds to the ''neutral" position in a conventional gear box with the prime mover ticking over.
Fig. 16 Principle of operation of the Torque Converter
When the revolutions of the prime mover are increased considerably, the frequency of the crank oscillations increases and thus tries to increase the frequency of the pendulum oscillations. At this point a new set of circumstances arises. Due to its inertia the pendulum weight tends to remain stationary fig. 16b. Under these conditions and when the load on the secondary is moderate, the fulcrum of the pendulum, which was at the apex, has been transferred to the position of the pendulum weight. The result is that the apex of the pendulum oscillates instead, to the maximum to and fro motion, permitted by the design. This causes the links to oscillate the valves, which in turn rotate the output shaft to the maximum angular speed permitted by the design. Under these conditions the system is operating in ''top gear" with a 1 to 1 ratio. (The remarkable similarity to the operation of the hydrosonic system for the aircraft firing gear is apparent. As soon as the aircraft engine reached a predetermined number of revolutions, the inertia of the liquid column diverted the high frequency pulses down the pipes connected to the trigger motors.)
At intermediate angular speeds of the input crank the effective fulcrum will take up intermediate positions on the pendulum rod. Consequently there will be more or less swing (or amplitude) of the pendulum weight and more or less travel (or amplitude) of the valve links according to the speed of the input crank and the torque on the secondary shaft, fig. 16c.
In other words, the operation of the mechanism is dependent on the frequency and amplitude of the input impulses to the mechanical valves which automatically increase or decrease according to the load to be overcome on the secondary shaft. The mechanical valves rectify the alternating nature of the impulses into unidirectional impulses which act on the output shaft in a cumulative way. One valve rotates the output shaft on the forward stroke and the other valve rotates the shaft in the same direction on the reverse stroke.
The first model ever made to illustrate the principle of the Torque Converter is shown in fig.17. It will be observed that the mechanism is upside down in relation to the previous description with the ''weight" of the ''pendulum" at the top instead of at the bottom. The construction of this model follows the arrangement shown in fig. 18, where the primary shaft is connected by a rod to the centre of a floating lever. This introduces more elasticity in the system, but in all other respects the model demonstrates the basic principle of the Torque Converter as described.
Fig. 17 Constantinesco Torque Converter, first model ever made
Fig. 18 Alternative arrangement of TC with floating lever
Other models to demonstrate the principle of the Torque Converter were made in Meccano by schoolboys and other enthusiasts during the 1920s, an example of which is shown in figs 19 and 20 applied to a model car chassis. This example follows the same arrangement as in fig. 18, but ratchets had to be used as it was not possible to construct mechanical valves with Meccano parts. This mechanism occupied the space of the former conventional gearbox in the standard Meccano model of a motor car chassis. The Torque Converter mechanism was driven by a Meccano electric motor connected to the input eccentric by a chain.
Fig. 19 Meccano model of Torque Converter
Fig. 20 Underneath view of Meccano Model
George first successfully tested a Torque Converter in a car in May l 923, using an experimental model that had been built only for bench tests. He obtained an old Sheffield Simplex chassis and replaced the big 45 hp engine with a 10 hp "light car'' Singer engine, and built a platform on the chassis. This car was driven around the outskirts of London loaded with 10 people, including the inventor at the wheel, fig. 21, and later towed a lorry up a steep hill. As a further demonstration of the capabilities of the car, six inch wooden blocks were placed in front of the wheels. When the accelerator was depressed the car climbed over the blocks smoothly and without hesitation, to the astonishment of the bystanders. This test was merely to demonstrate the possibilities of the Torque Converter, because even a 10 hp engine was much larger than necessary for the production car envisaged.
Fig. 21 First Converter Car
The next development was to apply the idea of a low cost 500 cc single cylinder two stroke aircooled engine coupled to a Torque Converter installed in a light car chassis. This was exhibited in the Palace of Engineering during the British Empire Exhibition at Wembley in 1924, fig. 22.
Fig. 22 Constantinesco's stand at 1924 Wembley Exhibition
The chassis performed as predicted under test but the disadvantages of the aircooled engine and balancing problems associated with the one cylinder were recognized and subsequently overcome in a completely new design concept for a production car. This comprised an integral balanced power unit of about 500 cc capacity (bore 67 mm, stroke 70 mm) with the Torque Converter mounted between two water cooled cylinders and an improved carburettor, also one of George's patents. The RAC rating was 5.58 hp and the tax was £6. A cross section of the power unit through the converter mechanism is shown in fig 23, where the arrangement of oscillating inertias, links, and valves can be seen. The diagram in fig. 24 shows the position of the inertias in the extreme working condition equivalent to fig. 16b.
Fig. 23 Cross-section of Torque Converter
Fig. 24 Converter in "top gear" position
The general arrangement of a chassis fitted with this power unit is shown in the drawing in fig. 25. A chassis of this design, together with two prototype cars were exhibited at the Paris Motor Show in 1926, fig. 26.
Fig. 25 General arrangement of chassis
Fig. 26 Constantinesco stand at 1926 Paris Motor Show
A demonstration model of the power unit and a similar chassis is housed in the Science Museum in London. A two seater model of the car, with the inventor at the wheel, is illustrated in fig. 27. The performance of the car was exactly as George had predicted, 100 miles per gallon of petrol at 38 miles per hour. Only the originally estimated sale price of 100 guineas was found to be too optimistic for a car fitted with the improved two cylinder power unit and had to be revised to £215, and £315 for the saloon version.
Fig. 27 Constantinesco automatic two-seater in Paris 1926
In addition to the economic virtues of the car, the other outstanding feature was the ease of control, which George often demonstrated in a convincing manner. Here was a car which even a child could drive after a little practice at steering, as proved by his small son Ian, who was taught to drive and demonstrate it at the tender age of eight. Then there was M. Antoine Bourdelle, the famous sculptor, who drove the car around the streets of Paris after only a few minutes tuition, although he had never handled a car before. Another of George's demonstrations was to have somebody leading the car with a thin string attached to the throttle lever on the carburettor. In fig. 28 his wife Sandra is performing the demonstration and George is following on behind.
Fig. 28 Constantinesco automatic car being led by string attached to throttle lever
In order to appreciate how easy it was to drive this car a description of the method of operation is appropriate. With the car at rest and the handbrake on, the engine would be started and allowed to tick over. To move off, the handbrake would be released in the usual way and the right foot would depress the accelerator pedal. At about 1200 rpm. the car would start to move away smoothly and progressively gather speed, but at the same time the engine revolutions would gradually decrease until maximum speed was attained in the equivalent of "top gear''. Speed control thereafter would be entirely through the accelerator pedal. On reaching a hill it would be noticed that the car would tend to slow down, but the engine revolutions would not decrease as in the case of a conventional gearbox. By depressing the accelerator pedal fully the car would regain speed and continue to climb the hill. On a very steep slope, say 1 in 3, the car would slow down but continue to climb, without loss of engine revolutions. In other words the Torque Converter would automatically select the correct "gear ratio'' under all road conditions encountered. Starting on a steep hill was also very easy, because when the brake was released the car was automatically spragged by the mechanism and could not run backwards. No matter what the conditions were, the engine would never stall due to overload. For example, it was possible to place the front of the car against a wall and fully depress the accelerator, but the engine could continue running at maximum revolutions and exert maximum torque on the driving wheel.
In order to slow down and stop the car, the accelerator pedal would be released and the left foot would depress the brake pedal. The car would soon stop if required, as it had brakes on all four wheels, and then the handbrake would be applied. The only other control in the car was a lever, which actuated a reverse gear in the back axle.
Another novel feature was that the back axle had no differential. It was unnecessary because there was only one driving wheel and the other was free. Since the propeller shaft rotated anticlockwise looking from the rear, the torque on the propeller shaft gave a considerable increase of loading on the driven wheel. Furthermore, as the propeller shaft torque was about five times that commonly encountered in the orthodox chassis, the single fixed wheel had a road adhesion comparable with that provided by a conventional differential axle driving two wheels. A further important feature was that as the direction of rotation of the propeller shaft was the same for both forward and reverse, the road adhesion was the same for both directions.
In addition to motorcars, the railway locomotive offered fertile ground for the application of the Torque Converter transmission. The steam locomotive was still the best practical solution available for long distance heavy haulage, but was admittedly uneconomical. The internal combustion engine could provide greater economy but it had not been possible to employ it at reasonable cost. Although electrification seemed to provide the ultimate long term solution, the conversion from steam to electricity would entail enormous capital outlay and it was thought that many years would pass before the full benefits could be made available. Even then, it would only be applicable to a small percentage of the world's railways.
The use of George Constantinesco's Torque Converter transmission in a locomotive appeared to offer an immediate and economical solution to the problem because of its ability to cope with heavy starting and acceleration torques without overloading or stalling the engine, while the wide and automatically variable gear ratios would enable light weight high speed internal combustion engines to be used. Although George's main effort in the early 1920s was directed to development of the Torque Converter car the prospects for a Torque Converter locomotive appeared to be equally compelling. Consequently, he fitted a locomotive chassis with a six cylinder 250 hp petrol engine and Torque Converter and demonstrated it on his stand at the Wembley Exhibition in 1924, fig. 29. The chassis of this locomotive was a former Great Western Railway ''Armstrong Goods'' 0-6-0 No. 395, which George converted to a 2-4-0, using the leading jack shaft for transmission of power to the other four coupled wheels from the Torque Converter.
Fig. 29 250 hp Locomotive chassis with Constantinesco's converter at 1924 Wembley Exhibition
The first experimental trials of this locomotive hauling a load of goods wagons took place on the Southern Railway in its Longhedge Yard, Battersea, on 30th June 1925, coinciding with the celebrations of the Centenary of Railways. At the same time, it was inspected by members of the International Railway Congress. This considerable publicity and expense did not result in this Torque Converter system being adopted on British railways, but it was adopted by the Romanian State Railways for railcars on their branch lines a few years later.
Apart from cars and locomotives, the possibility of the universal application of the Constantinesco Torque Converter in all cases where automatic adjustment of speed and load would be useful was given due weight in George's advertising material and demonstration models. Some of the more important applications considered included ship propulsion, auxiliary machinery on board ships, winches, cranes, haulage gear, machine tools and heavy duty starters for powerful engines.
Fig. 30 Bench model of torque Converter application for ship propulsion
Bench models of some of these applications were demonstrated on George's stands at Wembley in 1924, Paris in 1926 and at a special conference on George Constantinesco's work at the French Society of Civil Engineers in Paris on 16th December 1926. Fig. 30 shows a model of a marine application to replace clutches, reduction gears and reverse gears. In this model a very high speed petrol engine is driving a slow running propeller through the gearless transmission. The only control is the lever at the top of the converter, which enables forward, neutral and reverse to be obtained without changing the speed of the engine. Fig. 31 shows an example of the use of a constant speed cheap A.C. electric motor to drive machines of any kind, with the same single lever on the converter to obtain the desired variation of speed and load control.
Fig. 31 Constant speed AC electric motor coupled to Torque converter
At the Paris Motor Show in 1926, George had another convincing demonstration of the capabilities of the Torque Converter in the shape of a starter for heavy engines operated by a small electric motor. The output of the starter was connected to a lever with a tractor seat on the end. Members of the public, the heavier the better, were invited to sit on the seat and to their astonishment were lifted effortlessly aloft by the small electric motor, without gears!
The Constantinesco Torque Converter aroused intense interest in the popular and technical press in many parts of the world. The stand at the 1924 Wembley Exhibition alone generated over 300 enquiries from firms and individuals and over 200 articles in magazines and newspapers. Frequent requests came in to 7 Grosvenor Gardens from individuals and firms wanting to be appointed as Agents for the hundred guinea car from such diverse locations as North and South America, Europe, India and Australia, as well as from the British Isles. Unfortunately all these enquiries were premature in that it had not been possible to develop the car to the production stage due to lack of resources. Thus, the enquirers had to be informed that the car was still in the experimental stage, but they were placed on a priority list for eventual delivery on a first come, first served, basis.
As in the past, with wave transmission and the aircraft firing gear, George had the greatest difficulty in obtaining adequate financial backing for the development of the Torque Converter, and the reaction of the motor manufacturers varied from lukewarm interest to active opposition. A case in point was the refusal of the Wembley Exhibition authorities to allow Constantinesco to exhibit the chassis among the cars, due to objections from The Society of Motor Manufacturers and Traders on the grounds that he was not a member of the Society and manufacturing the chassis in quantity. George sued the authorities and lost the case with costs, but was eventually allowed to exhibit in the Palace of Engineering. In the absence of support from the motor industry and following the demise of the Romanian based Company, Industria Sonica, a series of small British Syndicates and Companies were formed to finance research and development of the Torque Converter, the costs of the exhibits at Wembley and Paris and ancillaries such as carburettors, speed indicators and liquid level indicators.
One of the more long standing of these Companies, formed in 1922, was Constantinesco Torque Converters Ltd, with offices in 40 Grosvenor Gardens and works in 130 Wilton Road, London. This Company, with a share capital of £75,000 acquired world rights in the invention. Under the agreement George Constantinesco was appointed the Consulting Engineer at a fixed salary, out of which he was to bear the cost of obtaining British Patents, continue research on behalf of the Company, provide drawings and designs, act in a consultative capacity and supervise development and experimental work. By today's standards and costs for research and development, the funds available were modest and fell far short of requirements. Another Company, Engine Power Ltd was formed to boost finances by disposing of a large stock of 250 hp Ricardo engines stored in the Slough premises, but sales were disappointing.
A breakthrough appeared to be in sight when in February 1925 the General Motors Corporation of Detroit took an option on a licence to manufacture the Torque Converter for use in cars under an agreement with Constantinesco Torque Converters Ltd and George Constantinesco. About $100,000 were advanced against future royalties to cover further research and development costs to meet specifications and $3,000 per month were paid in consideration of the option. The option was to be exercised within three years upon payment of $3 million, or $4 million within four years and a royalty of $2 was to be paid for each converter sold in the U.S.A.
Encouraged by this arrangement and in anticipation of early marketing of the Converter George committed all available funds to research and development, not only for the car but also for new applications. The maintenance of his life style and generosity to family and friends was commensurate with the expected rewards for a hard working and successful businessman, but in the event the potential returns never materialized and the period was marked by a series of domestic and financial difficulties which undermined his health. His first marriage had broken down during this difficult period and ended in divorce. At the same time he was being hounded by the inland Revenue for tax assessed on royalties received during the war before his inventions were taken over by the Government, including the Government award for the synchronizing gear, which he had expected to be free of tax. To add to his frustrations it appeared that General Motors were reluctant to exercise their option within the specified dates but willing to service the fees. This did not suit George, because it meant in effect that the use of his Converter in cars was blocked. He was impatient to see the invention used and personal financial rewards were a secondary consideration, or so it seemed, as the agreement with General Motors lapsed and he tried to make alternative arrangements for the manufacture and marketing of the car.
Finally, this approach failed and towards the end of the decade George again found himself to be in a precarious financial position and without funds to proceed further with the motorcar project.
In the meantime George had met with Eva Litton who was to become his second wife and constant companion for the rest of his life. Eva, with two sons, Richard and Michael by a previous marriage, was of independent means through a legacy from her father, a Lancashire textile mill owner. As well as being highly intellectual and a proficient pianist like George, she had inherited her family's business sense and thrift and soon advised George how to extricate himself from his difficulties in London and Weybridge. He wound up his affairs in London, including the sale of his patent rights in the torque converter car, sold his expensive house 'Carmen Sylva' in Weybridge and with his young son Ian joined forces with Eva at Oxen House, on the shores of Lake Coniston in the English Lake District.
The Romanians had shown interest in the Torque Converter for use in railcars and here surely there was new hope for the further development of the invention. There was a need for inexpensive and cheap to run railcars on branch lines and the use of relatively small internal combustion engines coupled to the Constantinesco Torque Converter appeared to meet requirements. The development work would need George's presence in Romania for some time, so he soon converted the outbuildings at Oxen House into offices and a laboratory and completed plans for the locomotive Torque Converter. Eva accompanied George on his trips to Romania on the development of the railway project.
Testing, development and manufacture was carried out at the former Malaxa Ironworks of Bucharest during the 1930s. Initially, successful tests were carried out with a 10 hp engine and converter mounted in a 10 tonne railcar. These results were very encouraging considering that similar cars in other countries were using 100 to 140 hp engines. The next stage was the establishment of production lines and special machine tools for the building of 30 tonne passenger railcars with 60 seats. These were propelled by two engines of 20 hp each mounted under the chassis. These railcars ran without trouble at about 40 mph, a performance which appeared to be quite suitable for conditions in Romania at the time. Looking to the future more power and faster speeds would be required on main lines as well as branch lines to meet the needs of rapidly growing industry and infrastructure in all countries. Bearing this in mind, George made a survey of requirements and solutions proposed in several other countries, including Germany, Britain and the United States.
In spite of the rapid progress in electrification and the development of Diesel electric power units, George maintained his confidence in his Torque Converter system as a simple and economic power unit but conceded that further development work was needed to cope with higher powers and speeds. The problem was not so much with design parameters as with lack of suitable materials and methods of manufacture. This work was in progress at the Malaxa Works in the testing laboratory together with the production work, when a change in railway policy led to withdrawal of funds. Thus George had to abandon the project in Romania and return to England, where lack of funds and advent of the second world war prevented any further development of an invention meant for peacetime conditions.
George Constantinesco was not the first inventor to have failed to bring an outstanding invention to commercial fruition. The Torque Converter was quite unique and introduced a new concept in mechanics, but perhaps it was too far ahead of its time. The inertia and scepticism of manufacturers committed to conventional transmissions was understandable, particularly during periods of depression between the wars, while economy in fuel consumption was not regarded as of consequence as fuels were plentiful and cheap. Looking to the future, there is an ever increasing need for economy in the consumption of fossil fuels, and for moderate speeds, safety and driver comfort on congested roads. This inevitable situation is resulting in research workers, inventors and manufacturers taking renewed interest in variable gearless transmissions coupled to high efficiency engines for motor cars. Better materials are now available, as well as improved design and manufacturing facilities with computer assistance.
1 -- The inertias are weights used by the Torque Converter and its action depends on their resistance to a change in movement --- their inertia. A pendulum bob acts as an inertia for a clock.
"Method and Means for Transmitting Power"
(June 16, 1925)
The present invention relates to an improved method and apparatus for transmitting power from internal combustion engines or other prime movers adapted to develop limited torque to driven shafts and is particularly applicable to locomotives or other vehicles, or to machinery driven by internal combustion engines, steam turbines, electromotors and the like.
The invention is of general application where the prime mover is an internal combustion engine or other engine adapted to develop limited torque and the torque to be overcome at the driven shaft is variable within wide limits.
The object of the invention is to transmit power from the engine to the driven shaft in such a manner that increased resistant torque at the driven shaft may result in an increase of engine speed, so that the power developed by the engine does not unduly decrease with increased resistance.
The invention further consists in a method and means, of utilizing the inertia of a suitably arranged oscillating or reciprocating mass for transmitting power from a prime mover to a driven shaft in such a manner that the power developed by the engine does not unduly decrease with increased resisting torque.
The invention further consists in a transmission mechanism for the purpose described comprising an oscillating or reciprocating member or floating link connected at two different points to a driving shaft and a unidirectional driving mechanism, the floating link carrying or being connected to a mass capable of oscillation or reciprocation.
The invention also consists in a power unit comprising in combination a prime mover adapted to develop a limited torque whose shaft is connected to one point of a floating link, which at another point carries or is connected to a heavy mass, such floating link being connected to a device converting the oscillating motion to rotary motion.
The invention also consists in a variable resistance power unit comprising an internal combustion engine whose driving shaft transmits motion through a connecting rod to an oscillating link, the link being pivoted to a mass capable of oscillation, and also connected by two connecting rods with two opposed oscillating ratchet devices driving a rotor, such rotor being connected to the driven shaft.
The invention further consists in the improved method and means for transmitting power from prime movers hereinafter described.
In a simple illustration of the principle of the invention there may be provided a floating link one end of which is caused to move by an eccentric mounted on a rotating driving shaft and which carries at its other end a mass. An intermediate point of the lever is connected to two connecting rods actuating a driven shaft through two ratchet devices by which the oscillating movement of the floating link is converted to a rotary movement, the ratchet devices operating at each half revolution of the driving shaft.
With such an arrangement it will be seen that if the resistance to rotation of the driven shaft is small, the mass on the lever will not move far on each side of its mean position at each oscillation, and the length of travel of the ratchets will be a maximum when the resistance to rotation of the driven shaft is zero.
As the resistance to rotation of the driven shaft increases, the travel of the mass increases, and that of the ratchet decreases; consequently at each revolution of the driving shaft, owing to the smaller angular movement of the ratchets when the resistance is high, it can be shown that the torque required from the prime mover does not unduly increase. Consequently with such an arrangement, if the prime mover is an internal combustion engine, for example, a constant or increased speed of revolution of the engine can be maintained, although the torque on he driven shaft is increased. In fact it can be shown mathematically that taking into account the inertia opposed by the oscillating mass the torque on the driven shaft is proportional to the square of the speed of the prime mover.
Many modifications of the arrangement are evidently possible; but in order to effect the object of the invention, it is essential that the driving shaft and the unidirectional driving connection should be connected to an oscillating or reciprocating member such as a floating link, at two different points, the link carrying or being connected to a mass capable of oscillation or reciprocation about a mean position.
In order to obtain stability without special means for maintaining a mean position of the various parts of the gear the forces acting on the oscillating mass should act in a direction away from and not towards its pivot or point of suspension.
Referring to the accompanying diagrammatic drawings:--
Figure 1 to Figure 5 are diagrams showing various possible arrangements for carrying out the invention;
Figure 6 is a diagram showing the forces acting in one form of the mechanism;
Figure 7 is a diagram showing the relative values of the speed of the prime mover, torque on the driven shaft and speed of the driven shaft, when the torque of the prime mover is kept constant;
Figure 8 is a diagrammatic elevation showing one form of mechanism according to the invention;
Figure 9 is a sectional plan of the mechanism;
Figure 10 is a transverse section through the driven rotor;
Figure 11 is an axial section through the same;
Figure 12 is a section through another form of unidirectional driving device which may be employed;
Figure 13 is a section on the line 13-13, Figure 12;
Figure 14 is an end elevation with the ball race removed;
Figure 15 is a section through another form of the apparatus;
Figure 16 is a side elevation partly in section on the line 16-16, Figure 15;
Figure 17 is a section on the line 17-17, Figure 15;
Figure 18 is an elevation of another example of the invention;
Figure 19 is an axial section through the unidirectional drive of the same;
Figure 20 is a plan of the same partly in section;
Figure 21 is a front elevation partly in section;
In the diagram Figure 1 the crank 2 of a driving shaft 1 is directly connected to a floating link 11 carrying a mass 12; and an intermediate point of the link is connected by connecting rods 8, 9 to the two unidirectional driving members actuating the rotor 10.
It will be seen that in this case there will be a vertical oscillating movement of the mass as well as a horizontal movement, but this is immaterial if the amplitude of the oscillation of the mass 12 is considerable relative to the length of the crank 2. If desired to balance the inertia forces, two or more systems as described may be mounted on the same driving and driven shafts, the phase angles between the cranks being suitably selected.
The form shown in Figure 2 is similar but in this case the driving crank 2 is connected to an intermediate point and the connecting rods 8, 9 to the upper end of the floating link 11.
In the diagram Figure 3, the driving shaft 1 is connected by a crank 2 and connecting rod 3 to the center of a floating link 4 whose lower end is connected to a rod 5 carrying a mass 6 and pivoted and suspended at 7. The other end of the floating link 4 is connected by two connecting rods 8,9 to two unidirectional driving devices operating alternately to drive the rotor 10 in one direction.
In the form shown in Figure 4 the driving crank 2 is connected to one end of a floating link 13 which near it center is connected to a crank 14 on an oscillating flywheel 15 acting as a mass, the other end of the floating link being connected through the connecting rods 8, 9 to the two unidirectional driving devices acting on the motor,
In the form shown at Figure 5, the driving shaft 1 is at right angles to the driven shaft 16, the crank 2 being connected by the rod 3 to one end of the floating link 13, which toward its center is connected to a crank 14 on an oscillating flywheel 15, the other end of the floating link 13 being connected by the rods 8, 9 to the two unidirectional driving devices.
In the diagram Figure 6 the driving crank 2 is connected by the rod 3 to the lower end of the floating link 13 whose upper end is connected to a crank 14 moving with an oscillating flywheel 15. The link 13 is connected towards its center by the connecting rods 8, 9 to the unidirectional driving devices driving the rotor 10.
In all the diagrams the fixed pivots are indicated at 20.
It will be seen that in all the diagrammatic arrangements above described, neglecting the inertia of the oscillating mass, the motion of the driving parts is indeterminate; it is accordingly necessary to consider the stability of the system when in motion, as with incorrect positions of the fixed axis and moving pivots the amplitude of the oscillations of the flywheel or pivoted mass may tend to increase indefinitely the whole system becoming unstable, with the result that jamming and consequent breakage of the linkage will occur.
To illustrate this, the forces acting in the various parts of the apparatus in one example of the invention, are shown in the diagram Figure 6. Considering the equilibrium of the oscillating flywheel 15 it can be shown that the average resultant of the tension forces which are transmitted through the connecting rod 8 will always be between the dotted lines indicated by the arrows a2, a3. It should be noted that the reverse stresses in the connecting rods 8, 9 are due to inertia of reciprocating parts in the unidirectional drive and are very small in comparison with the driving forces referred to. Consequently in the arrangement shown in this figure the resultant forces acting on the oscillating flywheel 15 will always be alternately to left and right and always in the direction away from the axis about which the flywheel oscillated, so that the stability of the system is maintained.
In the diagram Figure 7, if we consider the speed v of driven shaft as abscissae, the torque at driven shaft will be approximately represented by the ordinates of the curve z and the speed of the prime mover by the ordinates of the curve u, the torque of the driving shaft being kept constant.
From these curves it can be seen that as the speed of the driven shaft gets beyond a certain speed, the torque at the driven shaft tends towards a constant value, and the speed of the prime mover varies in linear proportion with that of the driven shaft very much as in ordinary gear of constant ratio. On the other hand when the speed of the driven shaft diminishes below a certain value, the torque at the driven shaft increases very rapidly and similarly the speed of the prime mover also increases.
In carrying out the invention into effect as illustrated in Figures 8, 9, 10, 11, the prime mover drives the shaft a which carries a flywheel b and is connected by the connecting rod c to the center of a floating link d. The upper end of this link is pivoted a t e to a swinging lever f pivoted at x which carries at its lower end a mass g. The lower end of the floating link is connected by two pairs of connecting rods hk to two double arms lm oscillating about the axis of the motor. On the oscillating arms at p1, q1 respectively are pivoted double circular frames pq carrying pivoted friction pads rs, Figure 10, bearing on the rotor on the side of its circumference remote from the pivots of the frames. The pads rs are adapted to bear on the circumference t of the rotor and grip the rotor in turn so as to drive it always in the direction in which the pads tend to approach the rotor owing to the fact that the pivot of each pad on its frame and the pivot of each frame on its driving arm are situated on a line which does not pass through the center of the rotor. Further the angle between the diameters on which these pivots are situated is less than the angle of friction at starting with the particular materials used to form the surfaces of the pad and rotor. The lower connecting rods k are under tension and the upper rods h under compression. The pads are of substantial length occupying nearly a quarter of the circumference of the rotor. The springs u serve merely to keep the friction pads in light contact with the rotor on the idle stroke.
Accurately placed pins might, however, be employed with or without springs for the same purpose, especially where a yielding material such as rubber is used in the pads.
It is desirable in some cases to provide an elastic drive between the rotor and the shaft to be driven as in the two phase form illustrated to torque is intermittent. If considerable inertia on the driven shaft has to be overcome an elastic shaft of some type is of importance.
It will be seen that with the apparatus above described, rotation of the driving shaft causes oscillation of the floating link d and this oscillation can be transmitted either to the mass g through the lever f or through the connecting rods hk to the unidirectional device on the rotor. As the speed of the driving shaft is increased without much load on the driven shaft, the amplitude of the oscillation of the mass g decreases and the stroke of the oscillating members driven by the rods h and k increases, thus increasing the speed of the rotor relative to the speed of the prime mover. If the apparatus is started with a heavy resisting torque acting on the driven shaft the swinging mass immediately starts oscillating at its maximum amplitude producing high alternating forces in the connecting rods hk, the forces being proportional to the square of the speed of the prime mover; so that if the speed of the prime mover is sufficiently increased, the torque on the driven shaft is overcome by the unidirectional mechanism and the driven shaft commences to rotate. Until rotation has started no energy is taken up except the amount absorbed by internal frictions. The driven shaft then rotates with corresponding diminuation of the movement of the swinging lever, the torque to overcome the resistance at the driven shaft being proportional to the square of the speed of the prime mover and directly produced by the forces set up in the connecting rods hk and proportional to the speed of the prime mover. The relative values of speeds and torque produced by the mechanism are shown approximately in the diagram, Figure 7, in which it will be seen that many forms of the invention other than that above described are possible and many other forms of mechanism may be adopted in place of the unidirectional drive mechanism illustrated; for example, three mechanisms as described differing in phase by 120 degrees may be provided acting on the same shaft and in this case almost continuous rotation instead of intermittent rotation would be obtained. The unidirectional drive mechanism employed may be of any suitable type. Further, instead of a swinging lever an oscillating flywheel or mass of any shape may be employed.
It will be seen that with a mechanism constructed as above described, vertical movement of either of the centers, that is either of the axis of the rotor, axis of the mass, or axis of the prime mover, will produce very little effect on the motion. Further, slight horizontal movement of these centers is also permissible. Alternating movement of the rotor center in the horizontal direction will merely serve to slightly increase the speed of the rotor. It is possible, therefore, with such mechanism to allow small variations of the distances between any two of the supporting centers of driving shaft, mass, and driven shaft. This is of extreme convenience in motor vehicles, as parts of the apparatus may be mounted on springs and parts directly on the road wheels if desired.
In the form of unidirectional driving device shown at Figures 12, 13, and 14, the connecting rods from the prime mover are connected to the pins 21, 22 which are carried by sleeve members 23, 24 capable of oscillating about the shaft 25 on ball bearings 27. The friction pads 28, 29 are pivoted at 30, 31 on link members of plate form 32, 33 which are themselves pivoted to the rotor members 34, 35m at 36 and 37, these rotor members being keyed to the rotor shaft 25.
In this form of the unidirectional drive the upper friction pad pivoted on the rotor is gripped and driven when the oscillating member 23 moves in the direction of the arrow, the lower pad on the other part of the rotor being gripped and rotated in the same direction during the return oscillation by the oscillating member 24.
In the form of the invention shown in Figures 15, 16 and 17 the prime mover is connected by a connecting rod 41 to one end of the floating link 42 (which for assembly should be made in two parts) pivoted at 43 to the oscillating flywheel 60, which oscillates about the axis 40. The link is connected at its other end 44 to two connecting rods 45, 46 which oscillate respectively the two drum members 47, 48. The drum members are lined with friction surfaces as shown at 49 which may be of leather, each drum drives one of the two portions 56, 57 of the rotor situated within it; and each rotor carries a pair of friction pads 50, 51 pivoted at the ends of links 52, 53, these links being pivoted on the rotor at 54, 55 and passing through a suitable central space allowed in the rotor.
In this form the direction of movement in which the oscillating member 47 grips the rotor is shown by the arrow in Figure 15.
In another form of the unidirectional driving device, Figure 18, suitable for use in the transmission, the driving of the rotor is effected through face clutches. The connecting rods 61, 62 from the floating link are pivoted to the oscillating members 63, 64 by pins 65, 66 and drive the rotor 67, 68 through friction plates 69, 70, which are mounted on the spherical members 71, 72. The locking of the device for driving the rotor in one direction is effected by pressure exerted through the slightly inclined rods 73, 74 which press through ball ends against the clutch members 69, 70 and he parts 67, 68 of the rotor which are keyed to the driven shaft by stout pins 75. Springs 76, 77 are provided adapted to keep the members 69, 70 in light contact with the oscillating members 63, 64 during the idle stroke. The actual friction surface may be provided by annular leather, rubber or like pads giving a considerable gripping surface.
In the form of the invention shown in Figures 19, 20 and 21, the shaft 81 of the prime mover carries a flywheel 82 and is connected by the connecting rod 83 with the floating link 84. This link 84 is connected at the other end to the almost vertically moving connecting rods 85, 86 which actuate the oscillating members 87, 88 which are adapted to drive the rotor disks 89, 90 through inclined rods 91, 92, as described above with reference to Figure 18. The lever 84 is pivoted at 93 to a crank 94 keyed rigidly to the vertical levers 95 pivoted at 96 in the fixed standards 97 and carrying at their lower ends masses 98. A certain freedom is permitted for angular movement at the various pivots at the ends of the connecting rods by making the bearings of curved form as illustrated in order to allow angular play.
It will be seen that in this modification the system is in indifferent dynamic equilibrium so that quite a small force is able to keep the oscillating mass in the mean position. As illustrated gravity effects this, and suitable buffers may be provided to prevent excess shifting of the mean position of the oscillating mass to one side or the other.
The same object may be effected by arranging springs tending to hold the end of the floating link connected to the oscillating members in a predetermined mean position.
Also with this form of the invention since all the connecting rods are substantially parallel a unidirectional driving force in either direction could be employed.
The invention described above is suitable for traction purposes. The transmission gear, however, will be seen to be applicable to a large number of other purposes in which it is desired to overcome a torque at the driven shaft variable between very wide limits either with a constant torque prime mover, or a prime mover having other characteristics, for example, using the transmission gear for driving rolling mills by steam turbines, IC engines or electric motors. Also, it can be applied to machine tools such as drilling machines, and as a mechanism for gearing down from high speed shafts for various purposes. Many other examples of transmission for which the gear is suitable will naturally present themselves.
Although in apparatus constructed as above described the movement of the oscillating members is approximately harmonic and the movement of the driven shaft is unidirectional, the shock which would be expected to take place at the instant of gripping will in many cases be sufficiently taken up by the natural give of the system.
I claim: -- [ Claims not included here ]
The present invention is for a power unit in which the transmission gear is used, which gear acts on the principle of the means for transmitting power from a steadily rotating shaft to a shaft subject to a resisting torque as claimed in Serial # 570,986 and # 653,772.
In these specifications a power transmission gear is described in which oscillating motion derived from a prime mover is communicated partly to an oscillating mass and partly to a device which drives a rotor unidirectionally, the motion of the prime mover being distributed between the oscillating mass and the rotor. The proportion in which this motion is distributed depends upon the torque on the rotor. If there is no torque the oscillating mass receives little or none of the motion. If, on the other hand, the torque is infinite so that the rotor cannot move, the oscillating mass receives the whole of the motion of the prime mover.
The power unit in which the present invention consists comprises an internal combustion engine, the piston of which is connected as usual by a rod and crank to a steadily rotating or flywheel shaft. The piston, or any other reciprocating part of the prime mover, is connected directly and independently of the engine connecting rod, to the common pivot of two links which form a toggle. One link of the toggle actuates oscillating masses, while the other link actuates oscillators which cause a driven shaft to rotate unidirectionally. The toggle is so disposed that it oscillates symmetrically or substantially so about a mean position in which the two links are in line, the effect of which is that the oscillating mass or masses and the oscillators perform a complete oscillation for each stroke of the piston, or two for each revolution of the engine shaft.
Referring to the accompanying drawings, all of which show parts of the same machine:--
Figure 1 is a section through the cylinder and crank shaft of a prime mover.
Figure 2 is a plan showing the arrangement of the shafting and parts connected therewith.
Figure 3 is a detail view showing the way in which the unidirectional driving devices are driven from a rocking shaft.
Figure 4 is a detail view showing the way in which inertial masses are driven from a rocking shaft.
In the apparatus shown in the figures, the prime mover consists of a single cylinder engine having a cylinder a in which moves a piston b. The piston is connected by a rod or rods c to a crank d on the primary shaft e, which rotates continuously. The piston is also connected by the rod f, directly and independently of the connecting rod or rods c, with the knuckle g of a toggle hk. The link h actuated an oscillating crank l on rocking shaft o. The shaft m carries a crank u connected by links vw, with heavy masses yz, which are mounted on the rotor shaft t so as to oscillate. The links vw oscillate the masses in opposite phase. The masses are not fixed on the shaft t; they oscillate freely about it. The rocking shaft o carries a crank j which is connected by links pq, with oscillating members rs, which, like the masses yz, are actuated in opposite phase. The oscillators carry ratchets or the like, which give unidirectional motion to a rotor fixed on the shaft t.
It will be seen that the toggle links oscillate symmetrically or substantially so about the position in which they are in line, and thus complete oscillations of the shaft m and o take place for each stroke of the piston, so that each of the driving ratchets make a complete oscillation for each stroke of the piston. In addition to this, it is evident that a distribution of them motion of the piston and of the shaft e between the inertia masses yz and the oscillators rs, takes place in the way described above. Thus if the resisting torque on the rotor is so great as to render it immovable, the oscillators rs, the links pq, and the shaft o and the crank u, are all stationary. The end of the link k remote from the knuckle is therefore fixed, and the whole motion of the prime mover is absorbed in oscillating the masses yz, if, on the other hand, there is no resisting torque on the rotor, the masses yz remain practically stationary by reason of their inertia. This fixes the shaft m, and similarly to the above described action, the whole motion of the prime mover is distributed between the rotor and the masses yz; the greater the torque, the greater the motion of the masses, and the less that of the rotor, and conversely. The principle is precisely the same as that of the invention described in my prior specifications above referred to.
With a double frequency arrangement of this type, long strokes are required, and the arrangement is therefore especially useful in combination with an internal combustion engine.
It will be seen that the combined unit may be applied to internal combustion engines having any number of cylinders. In such case, the different cylinders may be arranged to operate a number of transmission gears working in different phases on the same driven shaft.
The invention is specially suitable for use in motor vehicles. Obviously there need be but one oscillating mass.
What I claim is: -- [ Claims not included here ]
In my prior US Patent # 1,542,668, a power transmission device is described in which reciprocating motion derived from a prime mover is divided between an oscillating mass and reciprocating devices which give unidirectional motion to a rotor, the oscillations or reciprocations of all the parts being of the same frequency. The amplitudes, however, of those of the oscillating mass and the unidirectional driving device bear tone another a ration which is great or less according as the opposing torque on the rotor is greater or less. In my former specification aforesaid the inertial mass was solid; according to my present invention it is liquid.
Figure 1 illustrates my invention, and
Figure 2 is an additional detail.
In the form of the invention shown in Figure 1 the driving crank b of the prime mover, the flywheel of which is shown in dotted lines, is connected by rods cd with pistons ef working in cylinders gh. The cylinders gh are interconnected by a pipe 21 containing the liquid which forms the inertial mass. They are also provided with suction valves k and l leading to a source of supply, but liquid enters through these valves only sufficient to make up for leakage since no fluid is actually pumped. The cylinders gh are also connected with cylinders 31, 32, provided with pistons 33, 34, which actuate a lever 35 pivoted at 36 by means of rods. The lever is connected to a pair of rods 37 and 38,which actuate unidirectional driving devices operating on a rotor 39 pivoted at 40.
This application is particularly suitable for cases in which the prime mover is a machine giving a constant torque, but capable of variation of speed between certain limits. Variation of speed between these limits will produce considerable variation of pressure at the delivery of the cylinders. The apparatus is thus extremely suitable for traction purposes of vehicles; for example, in a traction engine an internal combustion engine may be provided by driving the pistons ef, the two cylinder gh being connected to the double opposed pistons or double acting pistons driving a ratchet motor as above described.
The action is in all cases the same as that described in my prior specification above referred to. If, for instance, the torque on the rotor is so great that it cannot move, the pistons 33 and 34 remain stationary, and the whole motion of the prime mover is taken up in causing liquid to surge backwards and forwards in pipe 21. If the torque is zero liquid in this pipe has little or no motion on account of its inertia, and all the motion of the prime mover is communicated to the unidirectional driving devices operating on a rotor 39 pivoted at 40.
This application is particularly suitable for cases in which the prime mover is a machine giving a constant torque, but capable of variation of speed between certain limits. Variation of speed between these limits will produce considerable variation of pressure at the delivery of the cylinders. The apparatus is thus extremely suitable for traction purposes of vehicles; for example, in a traction engine an internal combustion engine may be provided driving the pistons ef, the two cylinders gh being connected to the double opposed pistons or double action piston driving a ratchet motor as above described.
The action is in all cases the same as that described in my prior specification above referred to. If, for instance, the torque on the rotor is so great that it cannot move, the pistons 33 and 34 remain stationary, and the whole motion of the prime mover is taken up in causing liquid to surge backwards and forwards in the pipe 21. If the torque is zero liquid in this pipe has little or no motion on account of its inertia, and all the motion of the prime mover is communicated to the unidirectional driving devices. Intermediate torques produce intermediate effects; the greater the torque on the rotor, the greater the surging in the pipe 21 and the less the movement of the driving devices; and conversely.
A variable inertia may be provided as shown in Figure 2. The apparatus consists of a casting comprising two branches 62, 63, which are placed in communication by means of a slidable U-shaped pipe 64 which is connected to the ends of the branches 62, 63, suitable glands 65, 66, being provided to make liquid tight joints at the junctions. The pipe 64 is embraced by a socket 67 connected to a rod 68 which can be raised or lowered by turning the nut 69 by means of the handle 70. The branches 62 and 63 can be connected up to any point of the pipe 21 by passages 60 and 61. With this device the inertia of the liquid column can be increased or decreased by merely turning the handle 70 to raise or lower the U-shaped pipe 64.
A variable inertia device of the pipe type may be obtained by using telescopic tubes which will permit the length of liquid column to be lengthened or shortened. By using variable inertia devices as above described, the maximum pressures in the system may be varied without varying the speed of the prime mover.
What I claim is: [Claims not included here]
In my British patent Specification # 185,022 I have shown a new method of transmitting power from a prime mover to a shaft which is to be rotated against a variable resisting torque by splitting alternating or sinusoidal motion derived from a steadily rotating shaft into component alternating motion of the same frequency; one component motion being caused to give alternating motion to a mass, while another is caused to give alternating motion to a pair of unidirectional driving devices working in opposite phase and rotating a shaft.
The main features of the invention are the ode in which reciprocating motion is derived from the prime mover and the way in which this reciprocating motion is apportioned between the two inertial masses which take the place of the single inertial mass as described in my prior specifications. The uniform motion of the prime mover is according to my invention split between the center of gravity of these two masses and the driven shaft, according to the torque on or the speed of, the shaft. For example, the prime mover causes an unbalanced mass to gyrate about an axis which is suspended by links from a fixed point. This axis is linked to a second mass which is capable of oscillating about another fixed point. The result, as will be explained hereinafter, is that the motion of the prime mover is distributed between the center of gravity of the two masses and the driven shaft. If, for instance, the torque opposing the motion of the driven shaft becomes infinite so that the shaft does not rotate, the travel of eh center of gravity of the two masses is a maximum. If there is no torque the motion of their center of gravity is a minimum.
Referring to the accompanying drawings:--
Figure 1 shows one form of the invention in which a rotating mass is provided;
Figure 2 shows another modification utilizing a rotating mass;
Figure 3 shows a modified form;
Figure 4 shows another form of the invention utilizing a rotating mass and giving quadruple frequency impulses in the rotor.
Figure 5 shows a form in which a rotating mass is employed in combination with a ratchet moving at double the frequency of the prime mover;
Figure 6 shows the application of the invention to transmission gear combined with a single cylinder combustion engine.
In the form of the invention shown in Figure 1 a rotating mass 21 at the end of a crank 22 is caused by a Cardan joint or other suitable means to gyrate or revolve about a pivot 23 suspended by a link 24 from a fixed pivot 25. The pivot 23 is connected by a rod 26 to a pivot 27 on a swinging lever 28 pivoted at a fixed point 29 and carrying at its end a mass 30. A second pivot 31 on the lever 28 is connected by a rod 32 to a pivot 33 supported on a stabilizing link 34 pivoted at fixed point 35. The driving pivot 33 is connected to a pair of oscillating members 36, 37 carrying ratchet devices 38, 39 driving a rotor 40 pivoted at a fixed point 41.
The gyrations of the mass 21 set up by the prime mover, which is connected to the pivot 23 by the Cardan joint or other flexible coupling, cause this pivot to oscillate. These oscillations are communicated to the mass 30 and the motion of the prime mover is thus split between the center of gravity of the masses 30 and 21 and the unidirectional driving devices connected to the driving pivot 33, the splitting or division taking place according to the torque on or the speed of the rotor 40. Thus, for example, if the torque against the rotor 40 becomes infinite so that the rotor cannot rotate, the lever 28 and the axis 23 becomes fixed. But the mass 21 continues to gyrate about this axis, and the lateral motion of the center of gravity of the masses 21 and 30 is at its maximum. If, however, this torque vanishes, the mass 21 still gyrates, but the lever 28 now swings. The lateral motion of the center of gravity of the masses 21 and 30 is then zero or nearly so, and the whole motion of the prime mover is transferred to the rotor. The same action in principle occurs in all the succeeding embodiments of the invention. According to my prior specifications the motion of the prime mover was divided between a single periodically moving mass and a rotor; in the present case it is divided between the center of gravity of two periodically moving masses and a rotor.
In the form of the invention shown in Figure 2 the mass 51 is rotated about the pivot 52 on a lever 53 pivoted at a fixed point 54 and carrying at its lower end a mass 55. The pivot 52 is directly connected by the rods 56, 57 with the oscillating members 36, 37 driving the rotor 40.
A further form is shown in Figure 3 where the rotating mass 51 rotates about an axis 52 at which is also situated a mass 61. The mass 61 is carried by an arm 62 pivoted at a fixed point 63. The connecting rods 56, 57 which drive the oscillating members 36, 37 are directly connected to the pivot 52.
In the form of the invention shown in Figure 4, the rotating mass 51 is rotated about the axis 52 at which is also situated the mass 61 carried by an arm 62 pivoted at a fixed point 63, so that the mean position of the mass 61 is situated in the line between the pivot 63 and the driving pivot 64. The driving pivot is connected by a link 45 with the pivot 52 and drives the oscillating members 36, 37 through connecting rods 56, 57 giving four impulses to the rotor for each revolution of the driving shaft.
The dotted lines in this case show the extreme lower point of the pivot 52.
The form of the invention shown in Figure 5 is similar to that shown in Figure 4 with the exception that the arm 70 carries a single ratchet device 71 so placed that two impulses are given to the rotor at each oscillation of the mass 61, the pivot 52 being directly connected to the oscillating member by the connecting rod 72.
In the form of the invention shown in Figure 6, the crankcase 140 of a single cylinder internal combustion engine is supplied by links 141, 142 from fixed points 143, 144 and is connected through the pivot 145 by connecting rods 146, 147 with oscillating members 148, 149 carrying ratchet devices driving the rotor 150 which turns about the fixed axis 151. The piston 152 of the engine is connected by the usual connecting rod 153 with a crank 154, a balancing mass 155 being provided to balance the crank. In this case the motion of the prime mover is split between the total mass of the engine acting at its center of gravity and the ratchet devices driving the rotor 150.
I claim: -- [ Claims not included here ]
The present invention relates to clutches and unidirectional driving devices for various purposes, particularly to devices for converting an oscillating motion to an intermittent motion in a new direction.
The invention is applicable to many types of ratchet devices particularly to such devices as are described in my US specification # 653,774.
In the said specifications I have described a clutch comprising a sliding member and a rotating member and arranged so that relative movement of rotation between said sliding member and said oscillating member causes a movement of said sliding member at right angles to the movement of rotation with consequent engagement and jamming together of the three members, said sliding member having teeth or the equivalent on one side and smaller teeth or a friction surface on the other side brought into close engagement by the movement of said sliding member at right angles to the direction of rotation. In such device unless the clearance between the friction surface and the slider is extremely small, in the free position there is a certain relative movement between the oscillating member and the slider which gives rise to shocks when the slider overruns the oscillator at the end of the driving stroke and if a rubber or other pad is employed as the friction surface, this relative movement increases as the pad becomes worn, so that the gear is apt to become noisy owing to shocks produced when the slider overtakes the oscillator.
The invention is also applicable to other type of ratchet devices and particularly to ratchets which are employed in combinations in which it is desired to maintain a definite mean position of the oscillating parts when there is no torque to be overcome at the driven shaft.
The invention consists in interconnecting the pawls, sliders or the like in two phase or polyphase operating unidirectional devices so that the sliders drive each other through a suitable connection anchored to an external point so that an external force may be applied to the interconnecting means.
The invention further consists in providing means whereby the mechanism can be reversed so as to produce rotation of the driven rotor in either direction as desired.
The invention further consists in the improved mechanism for converting oscillating motion into intermittent rotary motion hereinafter described.
Figure 1 shows a diagrammatic arrangement in which the pawls are hydraulically interconnected, the fluid pressure being regulated by fluid pressure produced by any external means (not shown);
Figure 2 shows a side elevation of a form of the invention in which the sliders or pawls are mechanically interconnected; also parts of an apparatus by which power is applied to the oscillators;
Figure 3 is a sectional view of the same, while
Figure 4 is a side elevation partly in section;
Figure 5 is a detailed view showing part of the reversing apparatus;
Figure 6 is a side elevation of the reversing apparatus, while
Figure 7 is a plan of the same.
In the form of the invention shown in Figure 1, the oscillating driving pivot 71 is connected by rods 72, 73 to oscillating members 74, 75 carrying ratchet devices 76, 77, these ratchet devices being capable of acting in either direction. The ratchet devices are connected by links 78, 79 to the piston rods 80, 81 of pistons 82, 83 moving in cylinders 84, 85 which are interconnected by pipes 86, 86 and which are connected through a reversing valve 88 with a source of fluid pressure connected at 89 and an outlet for fluid at 90. The fluid pressure applied to the nozzle 89 may be obtained by any external means desired.
Figures 2 to 7 show a form of the invention in which the grippers or pawls are mechanically interconnected. In these figures the invention is applied to the clutch described in my prior US specification # 653,774. They also sow by way of illustration the application of this clutch modified according to my invention to a device for dividing the motion of a prime mover into two components which operate respectively upon an inertial mass and unidirectional driving devices which actuate a rotor the ratio of the two components varying as the torque opposing the motion of the rotor. As the principle of this mechanism is fully explained in my former US specification # 653,774 and it forms no part of the present invention it is not necessary to describe it in great detail. The prime mover drives a main shaft 101 having an eccentric 102 driving on to the central pivots 103 of the floating lever 104 by means of the strap 105. The floating lever 104 is connected at its ends to a pair of links 106, 107 which are pivoted to levers 108, 109 whose upper ends have their movement restrained by stops 110, 111 one of these steps or the other coming into operation according to the direction of rotation of the driven rotor on the shaft 112. The levers 108, 109 are pivoted in the frame of the machine and one end of the floating lever 104 is connected by links 116, 117 with a pair of oscillating members 18, 119 each of which acts through a sliding member 133 having large teeth on one side and a friction surface 134 on the other side to grip rotary members 135 on the driven shaft 112 alternately. The construction and operation of these gripping or sliding members is described in my US specification 653,774 referred to above. Fixed on each sliding member there are provided bosses 120, 121 connected by rods 122, 123 with a bell crank lever 124 which is pivoted on a link 125 capable of movement about a fixed pivot 126. Threaded through the link 125 there is provided an actuating rod 127 carrying flanges with buffers 128, 129 between them and the link 125. The rod 127 is connected to an eccentric 130 on shaft 131 pivoted in the frame of the machine and the handle 132 is provided on this shaft by which either one or the other of the buffers 128, 129 may be brought in contact with the link 125. By this means the pull in one direction or the other may be exerted on the two sliders so that by merely moving the handle 132, the direction of rotation may be reversed, as explained in my prior US specification # 653,477, already referred to.
I claim: -- [ Claims not included here ]
"Driving Gear for Motor Vehicles and for Other Purposes"
The relation relates to driving gear mainly for motor cars by which the usual differential gear is dispensed with.
It consists in driving each wheel of the axle of a motor vehicle independently by two shafts each of which received unidirectional impulses fro a single engine driving one primary shaft. Alternating motions derived from this shaft are split between one or more oscillating masses and unidirectional driving mechanism which actuates the two independent shafts by power transmission means acting on the principle of the subject matter of my prior US Patent # 1,542,668. The invention, however, is applicable not only to motor vehicles but to any other purpose where it is desired to drive more than one shaft form a single engine.
The invention provides a method by which the engine may be kept running at a steady speed while two or more shafts automatically drive independently variable loads. For instance, all four wheels of a vehicle may be driven from one engine by this method, thereby dispensing with complicated differentials.
According to one embodiment of my invention the rear wheels are mounted independently and driven by reverse mitre gearing, each wheel having a gear to itself. The middle or driving pinion of each gear is mounted on a shaft, the two shafts being actuated preferably in opposite directions by separate unidirectional driving gears, each of which received a step-by-step motion from an oscillator. The oscillators are connected together by a rod so that they move together and one of them is driven from a prime mover through an inertia device on the principle explained in my prior specification above referred to.
In a modification, the oscillators may be stabilized for no load conditions by resilient or other suitable links, for example, they may be connected together by a spring link in addition to the above mentioned connecting rod.
The invention may be embodied in a great variety of forms of which the above are examples, and the arrangement may be made polyphase by multiplying the number of cranks in the prime mover and the unidirectional driving devices.
Referring to the accompanying drawings, which show embodiments of my invention,
Figure 1 shows in diagram a form in which the oscillating members of the unidirectional driving devices are connected by a rod.
Figure 2 shows in diagram a modification in which the oscillating members are in addition connected by a spring link.
Figure 3 shows in diagram a device similar to that shown in Figure 1 with a modified form of inertial mass.
Figure 4 and Figure 5 are detail views of the back axle of a motor vehicle showing means for reversing.
Referring to Figure 1, 1 represents in diagram a flywheel of an engine, not shown, with a mass 4 which is thus oscillated. The mass 4 is carried on an arm5 pivoted at 6 to a lever 7 which is loosely mounted upon it and connected to the lever 7 by a rod 11. The shafts 8 and 9 are parallel and are mounted in fixed bearings indicated diagrammatically at 12 and 13. The lever 7 and arm 10 drive the shafts on which they are mounted unidirectionally by any suitable means indicated by arrows 14 and 15 which represent pawls after the manner described in my prior specification above cited. If, for example, the torque on either shaft becomes excessive so that lever 7 and arm 10 cannot oscillate, the point 6 becomes fixed and the whole motion of the engine is absorbed by the inertial mass. If, on the contrary, there is no torque, the point 6 can move freely and the motion of the inertial mass is little or nothing. Intermediate torques produce intermediate results, the motion in all cases being split between the unidirectional devices and the inertial mass in proportions varying with the torque as fully described in my prior specification.
Figure 2 shows a modification in which corresponding parts are correspondingly numbered. The modification consists in connecting the lever corresponding to the lever 7 of Figure 1 and here shown as a bell crank lever 7’ and the arm corresponding to arm 10 of Figure 1 and here shown as a bell crank lever 10’ by a spring 18’ as well as by the connecting rod 11’, the spring giving additional stability to the motion. The straight lever 7 and the arm 10 are replaced by bell-crank levers 7’ and 10’
Figure 3 is a view similar to Figure 1, in which the inertial mass corresponding to the inertial mass 4 in Figure 1 and here indicated as 4’ is in different form and is differently mounted.
Figures 4 and 5 show the arrangement of, for example, the rear wheels of a car adapted for operation by the gearing above described. 8 and 9 are the twin shafts as before. They terminate in sleeves 19 within which are splined stub shafts 20 each of which carries a mitre-wheel 21. The sleeves are carried by ball bearings 22 and each sleeve is surrounded by a stuffing box 23 in the housing 24. The mitre wheel 21 gears with corresponding pinions 25 and 26 which are loose on the axle 27, either being brought into engagement for forward or reverse drive with the axle 27 by a sliding clutch member 28 which is splined on the axle. Both clutch members are actuated from the same central rod 29 by links 30 disposed toggle-wise. The mechanism for actuating the clutch members 28 is shown more particularly in Figure 5. Each link 30 is connected to a lever 31 which is mounted on a shaft 32 carrying a pair of arms 33. The arms engage with a half-collar 34 which is recessed into the clutch member 28. The axle 27 is mounted in ball bearings 35 and passes through a stuffing box 36 and it carries at its outer end the wheel 37 and brake drums 38 in the usual way.
It will be understood that the above described arrangements are illustrative only and may be modified in many ways. All four wheels may be independently driven by an obvious multiplication of the device,