rexresearch.com
John SCOTT
Camber Tire
Camber Tire
Quieter, reduced tread wear, more
responsive, improved handling, braking, steering, &
high-speed stability
http://www.etyres.co.uk/news/new-invention-set-to-revolutionise-the-tyres-industry-7330.html
New invention set to revolutionise the
tyres industry
by Oliver Hall
by Oliver Hall
A US inventor claims he has patented a new product which will revolutionise the tyres industry.
And the CamberTire, which includes a trapezoid profile and asymmetical sidewalls into the design of conventional tyres, is getting ready to hit the roads.
Inventor John Robins Scott said: “This advancement will revolutionise the tyre industry and we are ready to bring it to market.
“The benefits this design offers are significant to a traditionally slow changing industry – we have, literally, reinvented the wheel.”
His US based company Optima Sports LLC has just released the patented CamberTire and he believes the benefit it delivers include better handling and braking performance, safety and fuel efficiency.
Camber designs can reportedly be utilised on virtually every tyre category currently available on the market, and a switch over to the production of tyres incorporating CamberTire developments is said to be achievable just by altering the tyre moulds and making adjustments to alignment settings.
Optima Sports claims that: “Introducing camber into a tyre, and eliminating the need to have toe-in alignment settings, brings significant benefits including improved fuel efficiency, enhanced handling and performance and improved safety with decreased incidence of rollovers.
“Environmental benefits are significant as well, with improved realised mileage due to a reduction in rolling resistance and wind profile, extended tyre life and less material usage allowing narrower tyre profiles to achieve desired handling characteristics with less weight.”
The June 2010 issue of US publication ‘Automobile Magazine’ lists camber tyres as being one of the top ten most significant emerging technologies, and likens the importance of Scott’s invention
http://www.cambertire.com/
Cambertire, LLC
Phone: 262.434.7000
info@cambertire.com ;
http://www.cambertire.eu
Technology
On the track, Cambertire technology really shows it brute. Using a 3 or 4 degree tire allows for the suspension to have an aggressive camber stance which is normally done for cornering and handling stability, however, tires without camber built in lose much of their contact patch with this procedure. The Cambertire corrects for this! Racers can camber amounts safely up to 5 degrees without sacrificing tire life, the benefits on the track are nearly endless!
Our innovation didn't stop with just adding camber, we looked deeper into cornering and discovered that tire "roll" also caused a loss of handling ability. To compensate for this, we added in what we call a "rocker" on both the inner and outer corners of the tire tread pattern. As a tire "rolls" side to side from cornering g-forces, the shelf offers extra contact on the rolling edge resulting in skid pad results exceeding 1G on a street legal tire!
Such incredible claims can be difficult to believe, we encourage our guests to visit our "In the media" page to see what professionals around the world think of our tires through road tests! You'll never look at tires the same again.
OVERVIEW
The Cambertire is a revolutionary technology that changes the paradigm of conventional radial tires. Compared to conventional tires, Cambertire technology offers better wet and dry handling, better on-center feel and improved safety during emergency maneuvers. Cambertire technology improves tire wear and reduces rolling resistance improving fuel economy. Another benefit of Cambertire technology is the ability to prevent vehicle rollover, a very important design characteristic for SUVs and mini vans. It is a known fact that reducing un-sprung weight always improves handling and allows suspension systems to operate with improved efficiency. Reducing required tire weight, width, wind profile, and rolling resistance can contribute to increased acceleration and lessen the load on braking systems (reduced throw weight on spin-up and deceleration). Trailer tires are another significant future market for both the Cambertire and tread “rocker” technologies for safety as well as economical reasons. Economical that is for both the truckers who benefit mileage and the taxpayers because Cambertires spread the load more evenly which makes the roads last longer!
Intellectual Property
Currently Cambertire has three pending utility patents that complement the existing Cambertire U.S. Utility Patent 5,975,176, as well as stand-alone. The three pending utility patents include "Methods and Processes for Manufacturing Asymmetrical Tires", "Active Morphing Variable Tread Depth", and "Tire having a Sidewall Extension for Corning Support" aka "tread rockers."
Tire having a constantly decreasing diameter
Abstract
A tire having a decreasing profile diameter includes an outside sidewall with a greater height than the inside sidewall. The inner diameters of each sidewall are preferably identical. The outer diameter of the outside sidewall is greater than the outer diameter of the inside sidewall. The cross-section of the width of the tread has a substantially constant thickness from the inside tread diameter to the tread surface of the tire. The depth of the tread is preferably constant across the width of the tread surface.
http://www.youtube.com/watch?v=Z5bT4hJ4B6M
Are current tires the wrong shape?
http://www.automobilemag.com/features/news/1004_scotts_camber_tires/#ixzz39C3L9Dbf
Apr 27, 2010
Camber Tires: Tires Get Tipsy
By Don Sherman
By Don Sherman
In 1839, Charles Goodyear accidentally discovered how rubber could be 'vulcanized.' Since then, the most notable tire advancements can be counted on one hand. Scot Robert Thompson invented the pneumatic tire in 1846. (Forty-two years later, Dr. John Dunlop had to reinvent Thompson's discarded idea.) Michelin patented the steel-belted radial in 1946. Tubeless tires arrived in 1954 followed by the first run-flat designs in 1958 and low-profile sidewalls in 1968.
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Add to this list of fearless pioneers John Scott who recently offered us what he calls a Camber Tire for testing and evaluation. In our June 2010 issue, Automobile Magazine selected this as one of the ten most significant emerging technologies. Now that we've enjoyed a few miles over the road on these tires and had the chance to conduct two preliminary performance tests, we're more convinced that the Camber Tire concept is worthy of our acclaim.
Twelve years ago, Scott -- a successful Wisconsin car dealer and mortgage broker -- was inspired by the sight of a grossly overloaded Lexus sedan exhibiting excessive rear wheel and tire camber. Instead of running vertically, the tops of the rear tires were tipped sharply inward. While most of us would have moved on to the next item in our daily routines, Scott was convinced there was something to be gained by orienting tires in this braced sea-leg manner. With his father's backing he sketched his Camber Tire idea and hired an attorney to conduct a patent search. In 1999, he was issued US Patent 5975176 for a "tire with a constantly decreasing diameter." Scott had invented the asymmetrical profile with an inner sidewall significantly shorter than the outer sidewall. While negative camber angles up to ten degrees might be beneficial, the first experimental tires Scott had made are molded with the tread angled two degrees.
In conjunction with a suspension adjusted to suit this radically different cross-section, Scott's Camber Tire delivers a long list of claimed benefits:
Quieter running
Reduced tread wear
More predictable response during emergency maneuvers
Increased track width
Improved handling, braking, and high-speed stability
Improved straight-line steering
Superior performance during oval track racing
(See Scott's website, www.cambertire.com, for the patent disclosure and detailed list of performance claims.)
This sounds like too much to be true. The skeptic in us wondered why the major tire makers weren't on to this trick if it really paid such handsome dividends. There had to be a hitch. Driving on Camber Tires at the ragged limits of performance was the only way to see if they lived up to Scott's promises. When he offered that opportunity with some experimental tires manufactured by his initial partner M&H, we were the first independent organization to put Camber Tires to the test.
Before adjourning to the track, this primer might be useful. The phenomenon called camber thrust is what a leaning motorcycle uses to assume a curved path. Tipping the tops of both tires towards the center of a bend develops lateral forces at the two points where the bike's tire treads contact the pavement. These lateral forces, in combination with small steering angles, are what allows motorcycles to follow a curved cornering path.
Camber thrust is also useful in four-wheeled vehicles. The main benefit associated with tipping the tires off a perfectly vertical orientation is compensating for the body's outward lean in a corner. Ideally, the entire tire tread should stay firmly and evenly planted against the pavement. Unfortunately, that ideal situation is disturbed by body lean and by the typical suspension system's inability to fully compensate for the tipping body.
Car and tire designers avoid significant camber angles because, if one front tire runs at a camber angle and the other doesn't, the car can feel twitchy and unpredictable on a straight path. Also, uneven tread wear occurs with tires rolling at steep camber angles.
The beauty of the Camber Tire is that its tread runs flat. Scott claims that his prototype tire treads showed normal life in long-mileage tests. But the more important benefit is the camber thrust available to enhance cornering ability without waiting for body roll or suspension deflection.
Forty years ago, racing driver-engineer Mark Donohue was so intrigued by the possible benefits of cambered tires that his crew constructed an experimental AMC Javelin for the Trans Am series combining cambered wheels with a live rear axle. Today, Goodyear is exploiting cambered tires in NASCAR. Since Sprint Cup cars only turn left on oval tracks, it's beneficial to have the outboard tires running at steep negative (top towards the car) camber angles while the inboard tires operate at steep positive (top away from the car) camber. In the middle of a high-speed corner, when the body rolls a few degrees, this setup provides the ideal upright orientation, allowing all four tires to generate maximum adhesion.
The tests we conducted at the Bosch proving grounds in Flat Rock, Michigan, over south-eastern Michigan public roads, and at the Tire Rack's testing facilities near South Bend, Indiana, were rudimentary by design and intent. The goal was to determine if the Camber Tire could deliver Scott's phenomenal claims. We used two Mitsubishi Lancer Evolution test cars - one with standard Yokohama Advan A13 original equipment tires and factory camber settings (see results chart), one with front and rear suspensions reset with negative camber. Scott's Optima Sports enterprise supplied two sets of Camber Tires for evaluation -- one molded with a 140 tread wear rating, the other with R compound tread rubber. (The reference Advans have a 180 tread-wear rating -- higher is better. R compound rubber is intended for gymkhana or race track use where traction is a much higher priority than tread wear. We owe a special thanks to Automobile Magazine reader Jermaine Holland who generously provided the reference Evo test car and OE tires.)
Our results confirm that Camber Tires do provide measurable advantages over conventional rubber designs. Optima's standard-tread design (second on the results chart) is a fairly close performance match with the original equipment Yokohama Advans. (After 23,000 miles of use, one Tire Rack customer rated these tires "simply the best tire an Evo driver can get.") The R-compound Camber Tire delivered remarkable gains: versus the reference Advans, it shortened stopping distance by 11 feet and increased cornering grip by more than four percent (left and right lateral acceleration average).
Tire engineers would kill for any one-percent gain. Trimming braking distance by six percent while increasing cornering grip by four percent constitutes a major breakthrough.
We were also impressed at the subjective observations we noted with the Camber Tires. They turn in smartly with a purely linear and predictable response. The Evo's drift angle was significantly reduced over what was demonstrated by the Evo on Advans. At the limit of cornering grip, minor changes in steering or throttle position were enough to hold the car on the desired line. The feedback provided to the driver through the steering wheel and the car's minor movements were both clear and concise. The extra grip available here should be easy for any driver to use.
Even more amazing is how these radical tires performed on tattered Michigan back roads. They showed an uncanny ability to traverse pavement imperfections and potholes with much less trauma transmitted through the car's chassis. Instead of reverberating through the suspension and body structure, each bump was of short duration. The Camber Tires ride as if they're filled with marshmallows instead of cement.
Where from here? Scott is collaborating with M&H to construct more molds so that experimental Camber Tires can be evaluated in additional sizes. He also hopes to produce what he calls 'square' tires -- radials with identical compounding and construction, minus the camber feature -- to facilitate more equitable comparison tests. Plans are afoot for Optima Sports to sell some Camber Tires in the size we tested here to early adopters such as SCCA Solo competitors, track day users, and fanatic street drivers. But Scott's ultimate intention is to license this technology to major manufacturers with the means to further develop his concept. If and when the Camber Tire idea takes hold, John Scott will have earned his place next to the true tire heroes -- Goodyear, Dunlop, and Michelin.
US5975176
Tire having a constantly decreasing diameter
Tire having a constantly decreasing diameter
Inventor(s): SCOTT JOHN R [US] +
A tire having a decreasing profile diameter includes an outside sidewall with a greater height than the inside sidewall. The inner diameters of each sidewall are preferably identical. The outer diameter of the outside sidewall is greater than the outer diameter of the inside sidewall. The cross-section of the width of the tread has a substantially constant thickness from the inside tread diameter to the tread surface of the tire. The depth of the tread is preferably constant across the width of the tread surface.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to tires and more specifically to a tire having a decreasing profile diameter which has an outside sidewall with a greater height than the inside sidewall to provide increased vehicle performance.
2. Discussion of the Prior Art
There have been numerous attempts at optimizing the handling and braking performance of tires through the variation of tread designs and profiles. One method of modifying the profile of a tire is to decrease the outer diameter of the tire from one sidewall to an opposite sidewall. Some examples of this tire profile modification can be found in U.S. Pat. No. 3,435,874 to Mirtain et al., U.S. Pat. No. 4,840,210 to Kukimoto, and U.S. Pat. No. 4,848,429 to Mezzanotte. Each of these patents disclose a tapered or sloping tire profile. However, none of these patents disclose a tire profile which has a substantially constant cross-sectional thickness across the width of the tread surface. Some of these patents also disclose a thread depth which is non-constant.
Accordingly, there is a clearly felt need in the art for a tire having a decreasing profile diameter which has a substantially constant cross-sectional thickness across the width of the tread surface, and a substantially constant tread depth.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a tire having a decreasing profile diameter which has a substantially constant cross-sectional thickness across the width of the tread surface, and a substantially constant tread depth.
According to the present invention, a tire having a decreasing profile diameter includes an outside sidewall which has a greater height than the inside sidewall. The inner diameters of each sidewall are preferably identical. The outer diameter of the outside wall is greater than the outer diameter of the inside sidewall. The cross-section of the width of the tread has a substantially constant thickness from the inside tread diameter to the tread surface of the tire. The depth of the tread is preferably substantially constant across the width of the tread surface. The decreasing profile is preferably flat as opposed to a crown shape. Yet, a crown may still be formed at substantially the middle of the tread surface if warranted by a particular application.
Accordingly, it is an object of the present invention to provide a tire having a decreasing profile diameter which improves handling of a vehicle, because of the tire's increased contact patch with a road surface.
It is a further object of the present invention to provide a tire having a decreasing profile diameter which improves braking of a vehicle, because of the tire's increased contact patch with a road surface.
It is yet a further object of the present invention to provide a tire having a decreasing profile diameter which allows more extreme negative camber adjustments to be made to the wheel than that of normal tires.
It is yet a further object of the present invention to provide a tire having a decreasing profile diameter which widens the track of vehicle.
It is yet a further object of the present invention to provide a tire having a decreasing profile diameter which allows a wider tire to fit in a wheel well.
Finally, it is another object of the present invention to provide a tire having a decreasing profile diameter which provides for more consistent temperatures across the width of the tread surface when the temperature of the tire increases.
These and additional objects, advantages, features and benefits of the present invention will become apparent from the following specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a standard tire design mounted on a rim and in contact with a road surface;
FIG. 2 is a cross-sectional view of a tire having a decreasing profile diameter mounted on a rim and in contact with a road surface in accordance with the present invention; and
FIG. 3 is an enlarged cross-sectional view of a tire having a decreasing profile diameter in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings, and particularly to FIG. 2, there is shown a cross-sectional view of a tire having a decreasing profile diameter 1. FIG. 1 shows a standard tire design. Only a small amount of negative camber is allowed for optimal handling performance without prematurely wearing out the tread near the inside wall of the tire. The tire having a decreasing profile diameter 1 includes an outside sidewall 10 which is greater in height than the inside diameter sidewall 12. The outside sidewall inner diameter "OI" is preferably equal to inside sidewall inner diameter "II." It would also be possible to fabricate the tire having a decreasing profile diameter 1 for a rim that has an outside sidewall inner diameter which is different than the inside sidewall inner diameter, while maintaining nearly the same performance characteristics. Preferably, the distance "OS" from the inner diameter "OI" to the outer diameter "OO" of the outside sidewall 10 is greater than the distance "IS" from the inner diameter "II" to the outer diameter "IO" of the inside sidewall 12. However, outer diameter "OO" is greater than outer diameter "OI" whether inner diameter "OI" is equal to inner diameter "II" or not. It is preferable that angle A between the outside sidewall 10 and the tread surface 14 be 90.1 degrees or greater.
FIG. 3 shows an enlarged cross-sectional view of a tire having a decreasing profile diameter 1. It is preferable that the cross-section of the tread have a substantially constant distance from the inside tread diameter 16 of the tire to the tread surface 14. Dimensions A, B, and C are preferable equivalent to each other. Tread depth is also preferably substantially constant. Dimensions D, E, and F are preferable equivalent to each other. The decreasing profile of the tread surface 14 is preferably flat as opposed to a crown shape of many prior art tire designs. The flat shape will provide an improved contact patch with a road surface. It is preferable that the belts 20 are substantially parallel to the tread surface 14 to enhance the performance characteristics previously mentioned.
The substantially constant distance from the inside tread diameter 16 to the tread surface 14 would be alter if a crown were formed in substantially the middle of the tread surface 14. The distance between the inside tread diameter 16 and the tread surface 14 would be least at the edges of the tread surface 14 and would be greatest at substantially the middle of the tread surface 14.
It is preferable that the outside sidewall 10 be stiffer than the inside sidewall 12 of the tire having a decreasing profile diameter 1. The outside sidewall 10 can be made stiffer than the inside sidewall 12 by adding at least one extra belt or bias ply to the outside sidewall. The stiffer outside sidewall 10 can improve cornering performance.
The belt and internal construction of the tire having a decreasing profile diameter 1 is preferably that of prior art tires, such as radial belt and bias ply constructions. Also, the material which the belts are constructed from should include steel, aramid, nylon, and kevlar. The tire having a decreasing profile diameter 1 may be fabricated from state of the art rubber compositions being presently used in tire construction such as natural rubber, and synthetic rubber. The tread pattern can also be that of prior art tires. The fabrication of the tire can utilize state of the art molding processes. The tire having a decreasing profile diameter 1 is preferably of a tubeless design, but could be of a tube, or nonpneumatic design.
It is preferable that the suspension system of the vehicle be adjusted to add negative camber as shown in FIG. 2 such that the tread surface 14 is substantially parallel to the road surface 18. The tire having a decreasing profile diameter 1 is intended only for a suspension system which may be adjusted to add negative camber. The tire having a decreasing profile diameter 1 should not be used on solid axles, but can be used in front wheel applications as well as rear wheel independent suspensions where negative camber can be added or adjusted.
The tire having a decreasing profile diameter 1 has many secondary advantages which result from its unique design. Heat generated during extreme cornering is more evenly distributed across the tread surface because the tire deforms less than a normal tire during cornering. The tire having a decreasing profile diameter 1 will afford the vehicle better cornering performance, because it allows the vehicle suspension to be set at extreme angles of negative camber. Increased negative camber can improve cornering performance.
The tire having a decreasing profile diameter 1 increases the track width of the vehicle, because the tire protrudes further from the width of the vehicle than a normal tire. The tire having a decreasing profile diameter 1 allows a wider tire to be placed in a wheel well, because the top portion of the tire 1 leans into the wheel affording greater clearance or extra clearance for a wider tire. The tire having a decreasing profile diameter 1 affords greater protection to rims than that of the prior art; the tire protrudes horizontally further from the rim to protect against getting too close to a curb and scraping the rim surface.
The increased control which the tire having a decreasing profile diameter 1 provides, makes a vehicle safer to drive. The wide track helps prevent high center of gravity vehicles from tipping over. Improved cornering increases the chances of retaining control of a vehicle during a swerve maneuver. The improved braking increases the chances of stopping sooner to avoid hitting an object.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The invention should not be limited to racing cars or high performance cars, but should include passenger cars, vans, sport utility vehicles, busses, and semi tractor trailers.