31 December 1910
A Portable Collapsible Mast
An Ingenious Device For Many Uses
A German inventor has devised a very ingenious construction of
masts made of steel bands running lengthwise of the mast and
transverse connecting members for holding the steel bands together
to form a tubular structure of square or polygonal cross section.
Our illustrations show several forms of this new mast, together
with very original mechanism employed for erecting the mast and
for taking it down.
While the general principle is the same for all sizes and types of
masts, there are certain differences in construction, according as
the masts are to be portable or stationary. The small cut at the
left shows a portable mast, before erection, and on our front page
other cuts show stationary masts, two of them in course of
construction, and the third finished.
Portable masts are made in heights varying from 6 to 130 feet,
with either four or six steel bands of best quality, their width
being either 1-1/4, or 2-1/2, or 4 inches. The bands are wound on
four or six drums, as the case may be. For very small sizes ( up
to 17 feet ) spring drums are used, and the mast is pushed up or
down by means of two wheels the teeth of which fit into
corresponding holes in the two opposite bands. For larger sizes,
the drums are rotated by means of cranks, and the raising of the
mast is effected by means of a hoisting device of various forms.
In most cases, the hoisting device is operated by one or more
cranks, which control either friction wheels engaging opposite
bands, or toothed hoisting wheels engaging opposite bands, or
toothed hoisting wheels which fit into holes of some of the bands.
With a mast comprising four bands, two are operated in this
manner, while a six-band mast has three of its bands engaged by
toothed hoisting wheels.
In the case of portable masts, the transverse connecting members
consist of plates or frames arranged to surround and brace the
tube formed by the longitudinal steel bands. When the mast is
completely collapsed these numerous plates are stacked one upon
the other ad thus occupy very little space. The uppermost plate is
secured to the top of the mast, and the other plates are held
together loosely by ropes or other flexible connections, so that
the plates will be raised successively and automatically as the
mast is extended upward by turning the cranks. A small ladder may
be attached permanently to the plates to enable a person to climb
up or down readily. In the illustration a seat for the person is
carried by the upper end of the mast; instead of this, there is
provided sometimes a rotary table with a chair and a stand for
holding a telescope.
Stationary masts on this principle are made in heights from 50 to
250 feet, and over, with four or six steel bands up to 11 inches
wide and up to 1/5 inch thick. The masts are raised by means of
simple hoisting devices, which for the smaller sizes are operated
by levers rocked up and down as shown on this page; for larger
sizes the hoisting device is operated by cranks, as shown on the
front page. Instead of being permanently connected with the steel
bands, as in the portable masts, the hoisting device is
detachable, so that the same hoisting device may be used to erect
different masts successively. In fact, the manufacturers will rent
the hoisting device to their customers. The steel bands are not
wound on drums, but simply coiled upon themselves for convenience
in storing and shipping. Their edges have teeth or projections
which interlock, and in some cases they also have perforations in
the center. Instead of connecting plates, two-part clamps are
employed, these being applied individually as the structure rises,
and drwn tight by means of screws to hold the steel bands
together. The clamps may be formed with steps to facilitate
climbing the mast. Stationary masts are set with a suitably
prepared foundation, and are generally braced by guy wires. The
top of the mast may carry an extension made of steel tubing.
These masts are used for a great variety of purposes, as supports
or carriers for electric lamps or searchlights, for wires or
cables, as antennae for wireless telegraphy, as extensible
ladders, as flagpoles, as observation posts, signal masts or
semaphores, for cranes and derricks, posts for scaffolds or
Among the advantages of the new masts the manufacturers mention in
the first place the great strength of the structure, combined with
light weight. The safety of the masts is very great since all
joints are longitudinal, and transverse joints are avoided; even
in the case of overloading the mast will not break, but simply
bend, and the construction is therefore exceedingly durable. The
parts required for erecting the masts are shipped readily, as they
can be divided into a number of parcels, none of which will be
very bulky. Even the coiled steel bands for the stationary masts
need not exceed 5 feet in diameter. the parts are not heavy, so
that they may be readily handled and transported.
All parts of the finished masts are easily accessible, thus
facilitating inspection and repairs. The masts may be put up and
taken down readily and in very short time in any kind of weather (
wind, ice, etc. will not interfere ) by a small working force,
from one to three men being sufficient, and these need not be
skilled workers. In the case of portable masts, the time required
for erection or taking down is only a few minutes; even with
stationary masts, the time is very short, comparatively, four
hours being sufficient for the erection of a mast 100 feet high.
The portable form of the invention presents obvious special
advantages for purposes of rescue work, for firemen, and
railroads, where it will be valuable on account of the quick
erection of the mast, its ready transportability, and the fact
that in the collapsed state it may pass through places where it
could not be brought fully erected. For the same reasons, it will
find ready use in the army and navy for reconnoitering purposes,
signaling, carrying searchlights, periscopes, torpedo nets, sheds
for dirigible balloons and for aeroplanes, etc. The portable mast
may be mounted on a truck, and in this form will provide a very
convenient addition to the equipment of a fire department or army.
The hoisting device may be operated by a motor, thus saving time
and labor in extending and collapsing the mast.
Load - handling appliances. - Comprises a telescopic tubular mast
for lifting and other purposes, in which the sections are raised
progressively by a flexible steel band and are automatically
locked in the extended position. Fig. 2 shows a detail view, and
Fig. 3 is a sectional elevation of the apparatus. The tubes are
raised by a band a which is stepped to correspond with the various
diameters of the tubes so that it always fits the diametrical
section of each tube and is thus kept rigid. The band is wound on
a drum l and passes between two rolls h, i the drum being driven
from the roll i by chain gearing k. Projections on the rolls
engage with perforations in the band and keep it central. Each
tube is locked, until the one inside it has been raised, by a pin
d carried by a lever b the lower end of which is actuated by the
shoulders on the band a and thus the tubes are released in turn.
As the tubes are extended each section is locked to the next by a
split clamp q which is tightened by an arm o actuated by a pin m
on a fixed bracket n. When the band is lowered, the sections are
released in order as they come down, so that the band is always
rigid in the tubes. In a modification, the band a may be tapered
instead of stepped.
I, EARL NITSCHKE, Engineer, of 43, Waldemarstrasse, Berlin S.O.
26, Germany, do hereby declare the nature of this invention and
in- what manner the same is to be. performed, to be particularly
described and ascertained in and by the following statement:
In known telescopic lifting gear it has been proposed to extend
the tubular sections by means of a jointed rack passing up the
inside and wound on a drum.
Now according to my invention the tubes are operated by means of a
steel band which is preferably stepped to correspond in width to
different sections of the telescope so that it always fits the
largest sectional dimensions of the different tubes.
My lifting gear can be employed for lifting loads of all kinds,
people, antenna for radiotelegraphy. projectors, and also as a
mast for signalling purposes, phototelegraphy, and the like.
Some illustrative embodiments of my invention are represented by
way of example in the accompanying drawings, wherein : -
Figure 1 is a vertical section through part of my lifting gear,
three different forms of the steel band being indicated therein;
Figure 2 is a vertical section showing means for guiding
the steel band and mechanism for securing the tubes;
Figure 3 is an elevation, partly in section, showing the
lifting gear with the tube elevating and fixing devices, and
Figure 4 shows the automatic fixing device in elevation.
Referring to the drawing, the telescopic tubes 1,2, 3,4 are driven
positively by the steel band a wound on a drum (Figure 3) being
guided by two press rolls h pressed together by a screw i and
driven upwardly or lowered by turning the crank-handle g secured
to one of the rolls, which roll is geared to the drum by a chain
k. The band is kept most rigid and most suitable for raising loads
when it occupies the entire section of the tubes, as shown at f in
Figure 1, but is also sufficiently rigid when it is cut tapered,
as shown at u, and occupies the largest section of the tube at
places, whereas, when the band has rectilinear, parallel sides as
shown at viz, and therefore its breadth is only equal to the
section of the top telescope tube, it must be made correspondingly
I prefer to use a steel band which is recessed or shaped step-like
as at f, fills the entire diametral section of the tube, and thus
cannot move out of position, such a band being able, although
relatively weak, to lift considerable loads, namely i acts in the
tube like a rigid connecting-rod.
In order that the steel band may always have its shoulders in the
tubes suitable for the same, the tubes must not be raised or
lowered irregularly, but in order.
The tubes are elevated in order by means of the spring-pulled pawl
b (Figure 2) pivoted on tube 3 ; this pawl carries a pivoted pin d
which can enter into the tubes 1, 2,3 and thus lock the same; the
pin d is withdrawn the thickness of a tube by the shoulders f of
the rising band coacting with the pawl, whereby one tube is
released after another.
The tubes are caused to descend in order by the spring shackles or
clamps Q (Figures 3 and 4) in a manner as previously used in
telescopic apparatus for wireless telegraphy and these clamps are
automatically released by the pin m, of the bracket n, by which
the shackles are automatically tightened as the tubes are
elevated. The construction and operation of the shackles will be
readily understood from Figures 3 and 4 ; the top ends of the
tubes are slotted and each carries a shackle q, whilst, the
largest tube carries a support or bracket n carrying a pin m. A
bolt s having on the right a head and on the left a nut passes
through the ends of each shackle ; outside one end of the shackle
is secured a block p having a slanting face through which bolt s
passes, and loose on the latter is an arm o having a projection r
with a slanting face which corresponds to the slanting face on the
block p. When the shackle is locked the arm o is opposite, the pin
m , so that when the tube 2 for example moves upwards, the shackle
q is tensioned and the inner tube is fixed, whereas when the tubes
descend till they are unlocked, at the moment when one tube abuts
on the head of another.
In order to keep the band always in the middle of the rollers I
provide a row of perforations in the band (Figure 2), into which
the teeth w provided in the middle of the rollers enter.