Improvements in Pneumatic Tyres for the Wheels of Cycles and other Vehicles.
Year: 1892

page_text: Date of Application, 7th Nov., 1892—-Accepted, 10th Dec., 1892
COMPLETE SPECIFICATION.
[Communicated from abroad by FRANCIS TAYLOR CHAMBERS, of 712, Walnut
Street, in the City and County of Philadelphia, State of Pennsylvania,
United States of America, Lawyer.]
Improvements in Pneumatic Tyres for the Wheels of Cycles and
other Vehicles.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had to the
accompanying drawings and to the letters and figures marked thereon, that is
to say:
My invention relates to pneumatic tyres such as are used for bicycle and racing
sulky wheels, the object of my invention being to provide a tyre which will be
simple and durable, and which will when inflated, automatically grip and hold fast
to the wheel rim upon which it is placed. I accomplish these results by forming
the tyre proper of an inner expansible and air tight tube (preferably rubber) and
enclosing the tube in a tubular jacket formed of a fabric made up of oppositely
inclined spirally running lines of threads, similar in character to the well known
braided whip covers, the threads being so inclined, and being also free to move on
each other, that the diameter of the jacket can be increased by decreasing its
length. Such a tire uninflated or but partially inflated can be readily slipped over
the edges of a grooved wheel rim and will lie loosely in the groove thereof, but
when in this position if more air is forced into the inner expansible tube, said tube
will expand and the braided jacket will expand freely with it while at the same
time decreasing in length as the pitch of the spiral threads decreases. In this way
the braided jacket will decrease in length until its further contraction is arrested
by the rim which will be firmly gripped by it, and which by arresting its longi-
tudinal contraction will also prevent further expansion in diameter; the expansible
jacket thus becoming non-expansible and preventing further expansion of the inner
expansible tube.
Reference being now had to the drawings which illustrate my invention, and in
which-
-
Figure 1, is a side elevation of a portion of a wheel rim provided with my
improved tyre, the parts of which are shown cut away in steps so as to show each
of the constituent parts.
Figure 2, is a cross-section on the line x-x of Figure 1.
Figure 3, shows a section of my tubular jacket pulled out longitudinally.
Figure 4, is a similar section showing the jacket expanded and the spirals of the
threads decreased in pitch.
Figure 5, is a side elevation showing a wheel rim and deflated tyre placed around
it, and
Figure 6, is a similar view showing the effect of inflating the tyre.
A, is the wheel rim which is made concavely grooved as shown, and may have, a
groove of any desired depth. B, is the inner expansible tyre tube, preferably of
rubber. C, is the braided expansible jacket which is formed of two spirally
running sets of threads. Cand C the spirals running in opposite directions as
shown. D, is the wearing shoe which is used to prevent injury to the tyre proper
and is usually formed of rubber having a thickened tread as shown. I have shown
the edges D'D' of the shoe as lapped over the inside of the wheel rim and covered
by a finishing strip E, but the shoe can lie throughout in contact with the jacket C,
and need not extend to the inside of the rim. I have shown the rim A, as provided

page_text: with a wrapping of fabric F, which should be cemented to the rim, and I have also
shown the jacket C, as cemented to the rim or its wrapping, but while this increases
the holding power of the tyre it is not essential.. G, is the non-return air valve
through which the tyre is inflated and deflated.
The tyre made up of tubes B and C is, in a wholly or partially deflated con-
dition, placed around the rim as shown in Figure 5, the threads of the braided
jacket C, being pulled out so that their spirals will make long turns around the
tube, then the tyre is inflated contracting around the rim as it increased in sectional
diameter until it tightly grips the rim as shown in Figure 6; being unable to
further contract in length the jacket C can no longer expand in sectional
diameter and the tyre can be made as hard as may be desired by forcing air into
it. Of course when it is desired to remove the tyre it is only necessary to let the
air escape when the length of jacket C can be increased so that it can readily be
removed from the rim.
Having now particularly described and ascertained the nature of my said inven--
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. In a pneumatic wheel tyre the combination of an inner expansible air tight
tube with a tubular jacket formed of a fabric, the threads of which run in
opposite spirals as described, and so that said tubular jacket can expand by
shortening its length.
2. In a pneumatic wheel tyre, the combination of an inner expansible air tight
tube with a tubular braided jacket, the oppositely inclined spirally running threads
of which can move freely on each other so that said tubular jacket can expand by
decreasing in length.
3. The combination with a grooved wheel rim of a pneumatic tyre having an
inner expansible air tight tube of circular form and an outer tubular jacket of
braided fabric surrounding the air tight tube and resting in the groove rim the
oppositely running spiral threads of said jacket being loosely braided so that said
jacket can expand freely by contracting in length.
Dated this 7th day of November 1892.