Improvements in Retaining Cases and Protectors for Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 29th Aug., 1893-Accepted, 2nd Dec., 1893
COMPLETE DIECIFICATION.
Improvements in Retaining Cases and Protectors for
Pneumatic 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 inven-
tion 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 the manufacture of retaining cases of pneumatic tyres
and to the protection thereof.
It is a well-known fact that fibres of any character are more easily cut or abraded
when under tension than when in a state of relaxation, and I propose to apply
this principle to pneumatic tyres by the application to the retaining case of one or
more layers of fabric or fibres in a relaxed or slack condition, and so disposed as
to least impair the flexibility and resiliency of the tyre. To do this I prefer to
lay the threads at right angles to the circumferential line as in that position they
will interfere least with the longitudinal flexibility of the tyre though their
direction may be varied without departing from the spirit of my invention. The
preferred method of manufacture will be the incorporation of threads or fabric of
any suitable fibre into rubber by pressure, the raw rubber being warmed for the
purpose; a sheet thus prepared will be cut into strips of sufficient width to cover
the surface desired with the threads lying practically at right angles to the
direction of the length of the tyre. The protecting device may be secured to the
tyre in any suitable manner, outside the retaining case, and may be a separate
sheet or strip, or the fibres may be incorporated into the ordinary outer covering of
rubber but outside the strain-resisting fabric, or it may be vulcanized or otherwise
secured directly to the retaining case. It is further apparent that these threads
will offer greater resistance to cutting or abrasion, if there is a rubber or other soft
cushion interposed between them and the strain-resisting fabric or fibres in the
cover and it is understood that this is included in my invention.
In the accompanying drawings Figures 1 and 2, I have illustrated a cover
constructed according to this part of my invention, Figure 1 being a cross section
of such a cover and Figure 2 a plan with portions removed to more clearly
demonstrate the construction. In these figures A represents the lining of the cover
which may be of ordinary canvas if the cover be made in the ordinary manner,
B the rubber, and C the slack threads incorporated therein. In Figure 2 the same
letters represent the same parts as in Figure 1 each superposed layer being broken
away to show their relative positions.
When employing the fabric manufactured according to my British Patent
Specification No. 4926 of 1893 the strain-resisting threads or fibres A instead of
lying merely upon the inner face of the cover would as set forth in the said Speci-
fication No. 4926 of 1893 be embedded in the rubber the slack threads C being
outside the strain-resisting threads and preferably with some of the rubber between
so as to form a cushion behind the slack threads."
This device is not intended as a material bar to the puncturing of the tube by
pointed instruments, it is designed simply as a protection against cutting or abrasion
of the cover by stones etc. upon the roads.
In the case of a solid-wall or single tube tyre where no separate outer cover is
employed this protecting device would be incorporated in the substance of the tube
outside the strain-resisting threads or fabric.
In the manufacture of the retaining cases I employ the fabric described in my
British Specification No. 4926 of 1893 in which independent parallel threads out

page_text: of contact with each other are laid in the rubber, a double sheet or two single
sheets being employed when threads running in different directions are required.
By the term retaining case I mean that part of a pneumatic tyre which has to
resist the pressure of the compressed air in the tyre whether such case be incor-
porated in the air-tube or be separate from it as an independent cover.
In making the retaining case in the form of a tube open on the inner side, I first
make a straight length of tubing on an ordinary mandrel of suitable length and
diameter, by winding the two layers of fabric spirally upon the same, one super-
imposed upon the other, and wound at a different angle. I remove this tube from
the straight mandrel and slip it onto a ring of corresponding section having a
removable piece or provided with any suitable means of allowing the ring to be
opened, and after slipping the tube of fabric upon it, restore its continuity. This
being done, 1 continue the spiral winding of the strips until they meet, the ends
of the strips cut at an angle to the direction of the threads meeting on the inner
side of the ring in the line of its circumference as clearly shown in Figure 3 of the
drawings in which D represents the tube and 1-2 the junction line of the two
With this joint
ends E and F of the strip G which is wound spirally as shown.
the tube is of the same thickness throughout; even if the ends E and F be over-
lapped the tube will still be of the same thickness throughout upon its outer side.
For full particulars of the joints fabric and tube reference is made to my prior
British Specifications Nos. 14919 of 1893 and 4926 and 4926A of 1893. Owing to the
nature of the material used it readily adapts itself to its change of curvature and
presents a perfectly smooth and even appearance upon the ring. It may or may not
be vulcanized but may be split on the inner side circumferentially of the ring and
removed therefrom. It will be understood that this tube of fabric may be removed
from the mandrel without departing from the spirit of my invention by cutting a
slit upon the inner side of the ring where the removable section of the mandrel is
located, taking out the said section and slipping the mandrel out through the slit
in the tube; or the tube itself may be built up upon a ring of unbroken continuity
and removed by cutting longitudinally as described.
Where the retaining case is merely slit in one place it may be retained as a
complete tube an air-tube being introduced through the slit-or the retaining case
may be built up outside the air-tube-and the slit closed up in any convenient
manner, say by lacing. Where the tube is split all round or in the making is wound
so as to be open circumferentially all round on the inside it may be secured to the
rim by any of the well-known methods commonly adopted the edges being provided
with beads, wires hooks or other device for this purpose.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I wish it to be understood
that I am aware that it has before now been proposed to mix up promiscuously in
the rubber while in a state of "dough" silk and cotton fibres, and I make no claim
to such a mixture which moreover differs fundamentally from the slack threads or
fabric which 1 employ. What I claim is ;-
1. A protecting device for a pneumatic tyre consisting of slack threads or fibres
substantially as described.
2. Protecting the containing case of a pneumatic tyre against cutting or abrasion
by embedding threads or fibres in a sheet of rubber and so applying them that they
will remain in a relaxed condition when the tyre is inflated.
3. In a retaining case for a pneumatic tyre the combination with the strain-
resisting threads of slack threads or fabric between the strain-resisting threads and
the outside of the case substantially as and for the purpose described.
4. An endless tubular retaining case for a pneumatic tyre in which the continuity
of each thread in its spiral course over the whole tyre is unbroken except at one
place the entire tube being of unvarying thickness throughout on the outer side
and a short slit upon the inner side allowing of the introduction of a removable
air tube.

page_text: 5. A retaining case for a pneumatic tyre consisting of a tubular ring of fabric of
the nature described presenting a uniform thickness throughout on the outer side
and open or split open circumferentially on the inner side.
6. Making a tubular ring of the fabric described by winding the said fabric
upon a mandrel as set forth transferring it to a ring having a removable section
making the joint as described and afterwards removing the tube by slitting it
circumferentially on the inner side either wholly or in part.
7. A cover or open retaining case for a pneumatic tyre made of the fabric
described in British Patent Specification No. 4926°³.
soll
f Anout 1803
JOHN F. PALMER.
W. P. Thompson & Boult,
Agents for the Applicant.