Improvements in or relating to Air Tubes for Pneumatic Tyres, and for other Purposes.
Year: 1896

page_text: Improvements in or relating to Air Tubes for Pneumatic Tyres,
and for other Purposes.
I, JOHN FORREST WALTERS of 291 Oxford Street, in the County of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in inflatable air tubes suitable for a variety
of purposes, but particularly applicable to pneumatic tyres.
The invention has for its object the strengthening of the air tube and consists in
providing a covering of fabric, canvas or other suitable flexible material upon any
desired portion of the tube.
In applying my invention for instance to the air tube of a pneumatic tyre I may
cover with a suitable fabric that portion of the tube fitting into the rim and which is
at present liable to puncture by protruding spokes or nipples or by being nipped by
the wires or beadings of the outer cover when inflated. This covering may also be
applied to the tread portion of the tube. This partial covering of fabric may be
applied after the manufacture of the tube by solutioning or other suitable means or
may be applied during the manufacture of the tube, the whole being vulcanized
together.
Dated this 19th ....
1000
BOULT & WADE,
Agents for the Applicant,
Improvements in or relating to Air Tubes for Pneumatic Tyres,
and for other Purposes.
I, JOHN FORREST WALTERS, of 291 Oxford Street, in the County of London, Engineer,
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:-
The invention relates to improvements in inflatable air tubes suitable for a variety
of purposes, but particularly applicable to pneumatic tyres.
The invention has for its object the strengthening of the air tube and consists in
providing a covering of fabric, canvas or other suitable flexible material upon any
desired portion of the tube.
In applying my invention for instance to the air tube of a pneumatic tyre I may
cover with a suitable fabric that portion of the tube fitting into the rim which is at
present liable to puncture by protruding spokes or nipples or by being nipped by the

page_text: wires or beadings of the outer cover when inflated. This covering may also be applied
to the tread portion of the tube. This partial covering of fabric may be applied after
the manufacture of the tube by solutioning or other suitable means or may be applied
during the manufacture of the tube, the whole being vulcanized together.
In the accompanying drawings A represents any ordinary rubber air tube and
B the strip of material preferably canvas, so woven that while it will not stretch in the
direction around the tube, i.e. the width of the strip it will stretch circumferentially
around the tyre, say in the direction E to F. I do not bind myself to any precise
width of this strip, although the proportion shown in the drawing I have found to be
suitable in practice.
I prefer to permit the before-mentioned longitudinal extension to facilitate the
easy fitting of the tyre inside the rim, but the invention can be used even if the strip
be inextensible in that direction; in the other direction C D it should be inextensible
as the greater the extensibility in that direction the less the utility of the strip.
As already explained one of the advantages of this strip is to prevent the air tube
from being damaged by spoke ends or holes or roughnesses upon the rim, and for that
purpose the kind of material employed is of little importance.
Another object however is to prevent the tube from being nipped between the
edges of the cover and the rim, and it is in this light that it is desirable to have the
strip inextensible in the direction C D. The reason of this is as follows;-the damage
to the air tube due to nipping is chiefly occasioned by the fact that the portion of the
air tube partially segregated from the rest of the air tube by the pinching or nipping
between the wire and the rim receives some of the inflating air and becomes swelled
up apart from the rest of the tube and is very liable to burst and is sure to be
damaged, the air forming a blister or boil which prevents the inflation of the rest of
the tube from pulling this nipped portion back into its proper place. Now if the
strip B be employed, and being upon the rim side of the tube should the tube be
nipped the strength of the canvas will prevent a boil from forming, and furthermore
the pull of the inflating air upon the canvas cover tube will be sufficient to pull the
nipped portion from between the cover and the rim back into its proper position and
that without damaging the tube. The advantage of this is self-evident.
In use the canvas is required upon the inner or rim portion of the tube and the
tube itself may be moulded or shaped in manufacture so that the canvas naturally
lies upon that part as it is found in practice that even if the tube be moulded with a
curve in the other direction when in place in the tyre the tendency is for the tube to
assume its proper position especially as one part of it is necessarily properly placed as
the valve holds it to the rim.
A similar strip B may also be placed on the opposite tread face of the air tube if
desired, but that does not form part of my present invention.
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. The combination with the air tube of a pneumatic tyre of a strengthening strip
or bead substantially as and for the purposes described.
2. In a pneumatic tyre the employment of a strip such as B substantially as and
for the purposes described.
Dated this 0th day of February 1907
JOHN F. WALTERS.
Boult & Wade,
Agents for the Applicant.