Improvements in or relating to Pneumatic Wheel Tyres.
Year: 1892

page_text: Date of Application, 7th June, 1892-Accepted, 9th July, 1892
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Wheel Tyres.
I JOHN FULLERTON PALMER, of Riverside, County of Cook, State of Illinois,
United States of America, Gentleman, 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 :-
My invention relates to an improved method of manufacturing the inner canvas-
covered air-tube of pneumatic bicycle-tires, whereby the rubber shall be compressed
or densified to an extent that will render it self-sealing in the sense of self-closing
in case of puncturing.
My invention also relates to the canvas-covered pneumatic-tire. tube as a new
article of manufacture.
Generally stated, to practice and produce my improvement, I proceed as follows:
The rubber is first molded over a suitable mandrel wrapped, partially with canvas
or some analogous material suitable for a "back,” and which is preferably inelastic
and unyielding like canvas. Thus a rubber hose is produced, which is, subsequently,
properly vulcanized, thereby fastening the canvas, or the like, as an internal lining,
which extends only part-way around the bore. I then turn the hose inside out by
drawing it lengthwise through itself, as it were, whereby the lining is transposed to
the exterior of the rubber. If canvas or an equally inelastic or unyielding material
is used for the lining, the bore of the hose, when thus turned inside out, will be
materially reduced in diameter compared with what it was before so turning it,
when it was defined by the lining, since the latter, being practically unyielding and
thus essentially maintaining its initial diameter, must compress the rubber
surrounded by it, in being reversed to surround the rubber to form the hose with
an external diameter equal, or approximately equal, to its former internal diameter.
The rubber portion of the hose is thus, obviously, compressed to a degree of density
which enhances its imperviousness and, also, causes any puncture or break in the
hose to be immediately closed.
My improvement is illustrated, in the accompanying drawing, in which-
Figures 1 and 2 are cross sections respectively showing the hose before & after
it is turned inside out, but showing a modified construction, in which the canvas
extends only partway around the rubber;
Figure 3 is a view in elevation representing the inner air-tube of a pneumatic
bicycle-tire constructed in accordance with my improvement;
Figure 4 is a broken perspective view of a rubber tube, in the nature of a
diagram, representing an attachment, and the manner of applying it, to avoid the
requirement of the usual air-valve for inflating a pneumatic tire for bicycles; and
Figure 5 is a view like that presented in Figure 4, but showing the aforesaid
attachment as applied.
A (Figures 1 and 2) denotes material suitable for the back, and hereinafter
referred to as canvas, though it is to be understood that it may be, and that the
term is intended to include, any suitable material analogous to canvas in its non-
stretching quality, and even though it be susceptible of slight stretching in the
direction longitudinally of the hose, as would be a fabric cut on the bias or woven
with the threads crossing each other diagonally. The canvas is applied around a

page_text: suitable (preferably straight) mandrel, about which and the canvas a strip of soft
rubber B is molded. On removing the canvas-lined hose, thus formed, from the
mandrel and suitably vulcanizing it, I turn it inside out, by drawing the hose
through itself, thereby, bringing the canvas A outside the rubber B and com-
pressing the rubber inside the canvas to an extent that will render the external
diameter of the hose equal to, or approximately equal to, its former internal
diameter.
1
The inner canvas-covered air-tube C of a bicycle-tire produced in the manner
described, and by joining the ends together, need not have the canvas A extending
transversely entirely around the rubber B primarily inside, nor eventually outside,
the hose, it being sufficient for practical purposes if it be only on the tread-portion
of the tire, to do which does not require that it extend more than half-way around,
(as represented in Figures 1 and 2,) or thereabout, since it would be only in that
portion that the tire would be liable to be punctured and require, therefore, the
self-sealing function of the compressed rubber to be exercised. It may be here
stated, that the endless tube C, to produce a complete tire has an additional
covering of rubber, outside the external covering of canvas A; and that if only
one-half the tire in cross-section is, as provided for, covered with the canvas A, the
uncompressed portion of the rubber B should be confined, but not compressed, in a
canvas covering.
With a bicycle-tire constructed in accordance with my improvement, charging it
with the fluid contents (as air under pressure) it is designed to hold may be effected
by merely puncturing it with the supply-medium (as a pointed nozzle) of the fluid
and introducing the supply into the tire through the puncture by a suitable force-
pump; since, on withdrawing the nozzle, the aperture through which it was
inserted will close itself. Thus an air-valve, through which to fill the tire, may be
dispensed with.
The principle of thus densifying and compressing india rubber, may be utilized
in the form indicated in Figures 4 and 5 on rubber tubing B generally, (thus
whether compressed and densified in the manner described or otherwise, or not).
To so utilize it I provide a piece of rubber D, molded into the concavo-convex
form illustrated in Figure 4, with a back E, on the concave side, of canvas,
'extended beyond the rubber to form flaps r. The rubber D is placed with its
convex side against the exterior of the tube B, at a desired point, as represented in
Figure 4, and bent, in the direction contrary to its curve, against the tube, around
which the flaps r are extended and cemented, with the rubber D, in place, as
represented in Figure 5, thereby compressing and densifying the rubber attachment,
so that if punctured (as by inserting a fluid-supply nozzle through: it into the
tube B) it will be self-sealing and thereby also close the puncture in the uncom-
pressed tube.
Having now particularly described & ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
_
...
1. As a new article of manufacture, the self-closing inner air-tube of a pneumatic
bicycle-tire, formed of rubber and provided with a covering, extending over only
its tread-portion, of canvas confining, compressing and densifying the said rubber
at the tread-portion of the tire, substantially as described.
2. As a new article of manufacture, the self-closing inner air-tube of a pneumatic
bicycle-tire, formed of rubber and having the tread-portion, only, permanently
confined, compressed and densified, independently of the inflating medium by a
canvas covering, substantially as described.
Dated this 7th day of June 1892
W. P. THOMPSON & BOULT,
Agents for the Applicant.