Improvements in and relating to Pneumatic Tyres.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c., Act, 1883), as required by the
decision of the Chief Examiner of the 18th day of August 1897
Date of Application, 21st May, 1896
Complete Specification Left, 19th June, 1896-Accepted, 21st Nov., 1896.
SIONAL
Improvements in and relating to Pneumatic Tyres.
I, AI BERTRAM SHAW, of Medford, Massachusetts, United States of America,
do hereby declare the nature of this invention to be as follows:-
My invention relates to pneumatic tyres containing means for closing such
punctures as are commonly incident to pneumatic tyres during use.
The main object of my said invention is to provide simple, reliable, practical, and
otherwise improved means whereby the positive closure of punctures in pneumatic
tyres can be readily effected by a simple manipulation of the tyre by the rider,
without the necessity of using any tools or implements, and without the necessity
of removing the tyre from the wheel or the air-tube from its cover or sheath.
Further objects of my said invention are, to avoid materially increasing the weight
of the tyre; to avoid impairing the resiliency of the same; to provide for the
closing of punctures without deadening the tyre at the point or points of closure;
to permit the successful closure of punctures in close proximity to each other; to
render the contained puncture-repairing means effective even in cases where a new
puncture is made in close proximity to a puncture previously closed by such
repairing means; to utilize such puncture-closing means as an auxiliary for
fortifying an inner air-tube against leakage should porous places exist in the
rubber; and to secure other useful ends.
Various devices have been heretofore proposed for attaining the above-
mentioned results; for example, the employment of a lining of unvulcanized
india-rubber in the tyre or in the air-tube thereof or between the air-tube and the
sheath or cover, the said lining being intended to automatically close punctures
formed therein and in the air-tube or tyre; or the making of the air-chamber with
a suitable envelope having enclosed therein one or more tubes of larger dimensions
than the said envelope and which, when the tyre is inflated, will not be in a state
of tension, and having a lubricating liquid or a mixture of a lubricating liquid and
a powder interposed between the said inner tube or tubes and the envelope, the
object being to permit freedom of movement of the inner tube relatively to its
envelope or of the inner tubes relatively to. each other and to the said envelope,
so that punctures may be closed by the automatic shifting of one tube relatively to
another. But so far as I am aware, such devices have not proved successful or
satisfactory in practice, and the last-named is open to the objection that, should
one tube be displaced relatively to another so as to close a puncture, it may
automatically return to its original position and thus permit leakage.
Now the essential feature of my invention consists in making the tyre or the air-
tube thereof with an inner repairing skin or fabric inpermeable to air, between
which inner skin or fabric and the outer tube is provided a layer composed of a

page_text: substance of an adhesive or sticky nature, such as melted raw or crude india-rubber
with or without other ingredients, which substance will prevent automatic relative
movement of the said inner skin or fabric and the outer tube whilst permitting
relative movement thereof when the tyre or, air-tabe is manipulated as hereinafter
mentioned, and will keep the said skin or fabric and the outer, tube in close contact
throughout their surface and thus prevent accidental detachment of the said skin
or fabric from the outer tube in places, when the tyre is deflated.
While my said invention can be applied to both single or multiple or double
tube pneumatic tyres, its principal use is in connection with inner air-tubes for
pneumatic tyres. With reference to this last-mentioned application, the inner air-
tube is provided with an adjustable flexible repairing skin or fabric which is
suitable for closing punctures as by patching, and which is caused to adhere to the
tube by means of an intervening layer of the aforesaid adhesive or sticky substance,
which, while sufficiently adhesive to cause the opposing surfaces of the tube and
skin to hold together and oppose their accidental relative movement or displace-
ment, is also of such a nature as to permit of such relative movement or displace-
ment being easily effected by manually kneading or similarly working the tyre
containing such air-tube, while the sane is deflated or partially deflated. When,
therefore, a puncture is made through the air-tube and through the repairing skin,
the latter can be shifted so as to bring the punctures out of register and thereby
permit the repairing skin to positively close the puncture in the air-tube, as by
patching. The conditions of adherence between the two fabrics comprising the
repairing skin and the air-tube are, however, maintained throughout, and hence,
when any portion of the repairing skin has been shifted as a result of the manipu
lation of the tyre for such specific purpose, it will be securely held against
accidental independent movement, which is particularly desirable after shifting the
skin and before fully inflating the tyre, as, when the tyre is inflated, the internal
air-pressure will assist in holding the repairing skin against accidental shifting.
This adherence also opposes improper creeping of the skin during the use of
the tyre.
The repairing skin is, if desired, somewhat fulled, wrinkled or folded, so that it
can be moved freely at any particular point on the body of the tube, and such skin
may cover the entire inner surface of the tube or be restricted principally to the
portion thereof which is adjacent to the tread of the tyre.
The adhesive or sticky substance employed, in addition to possessing the above-
mentioned properties, should be of a nature to maintain such properties for a
considerable period, and not to dry or harden. As an effective preparation for the
purposes of my invention I prefer to use melted raw or crude india-rubber, to
which I sometimes add some substance, such as paraffine wax, to render it of a
proper consistency, although I find that some kinds of india-rubber, when melted
down, will form an adhesive semi-liquid substance having sufficient body for the
purpose of my invention, and also that the adhesive semi-liquid formed by thus
inelting the rubber, will inaintain its condition of adhesiveness and semi-liquidity
for a long time. I can also use other ingredients, such as tar or molasses, for
giving more body to the melted rubber.
In forming this adhesive semi-liquid substance, the raw or crude india-rubber is
subjected to a high degree of heat, far in excess of that required in vulcanizing,
whereby the rubber is melted into a. liquid state; and, if necessary, a substance
such as paraffine. wax, is added to this melted rubber to increase its body or
stiffness. These ingredients are mixed while hot. The composition thus formed
may be readily applied with a brush and will remain in a semi-liquid state and
maintain its consistency and sticky qualities for an indefinite length of time.
My improved air-tubes for pneumatic tyres can be conveniently and advan-
tageously made as follows, vis. :-The inner repairing skin or fabric is placed upon.
a suitable mandrel and solution or cement is applied to it for a short distance from
each end. The preparation of melted crude india-rubber or the like is then
applied to the said skin or fabric throughout nearly the entire length thereof so

page_text: that the parts not covered thereby are covered with the said solution or cement.
The outer tube is then applied by fastening one end of this tube on the mandrel
and the other on the end of a tubular carrier, which carrier is adapted to be filled
with air under pressure and is provided with a safety-valve to prevent excess of
pressure. The air-pressure expands the said tube, and, while it is thus expanded,
the said tubular carrier is noved towards and over the said mandrel. In this
movement, the said tube is turned inside out and pressed uniformly against the
inner skin or fabric on the mandrel by the air-pressure. When nearly the whole
of the tube has thus been applied to the skin or fabric on the mandrel, the said tube
is detached from the tubular carrier and the remainder of its length is turned
inside out and pressed against the inner skin or fabric on the mandrel. The air-
tube thus made is then removed from the mandrel, and its ends either united to
form an endless air-chamber, or else pinched together so as to form flattened
closed ends, which are also vulcanized if desired.
When the inner repairing skin or fabric is only to be of segmental form in
transverse section, the outer tube is placed on the inandrel and a sheet of the said
skin or fabric of the requisite size is applied to the outer tube on the mandrel and
secured thereto along its edges by solution or cement, after the aforesaid
preparation has been applied to the said outer tube as required. The air-tube thus
made is then removed from the mandrel and turned inside out, thus bringing the
repairing skin or fabric inside the air-tube so that it will be adjacent to the tread
of the tyre.
Dated
נnet ei
day of May 1896.
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, AI BERTRAM SHAW, of Medford, Massachusetts, United States of America,
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:-
This invention relates to the manufacture of pneumatic tyres containing means for
closing such punctures as are commonly incident to pneumatic tyres during use The
tyre comprises an inner repairing skin, a layer of adhesive material and an outer
tube.
Figure 1 is a sectional side elevation illustrating one mode of manufacturing my
improved tyres as hereinafter described, and
Figure 2 is a sectional side elevation illustrating a later stage of such
manufacture.
The air-tubes for pneumatic tyres can be conveniently and advantageously made
as follows, viz.:-The inner repairing skin or fabric 6 is placed upon a suitable
nandrel f, Figure 6,and solution or cement is applied to it fora short distance from each
end, as at d. The preparation of melted crude india-rubber or the like is then applied
to the said skin or fabric, as at c, throughout nearly the entire length thereof so that
the parts not covered thereby are covered with the said solution or cement. The
outer tube a is then applied by fastening one end of this tube over the end of the tube
on the mandrel and the other on the end of a tubular carrier g, which carrier is
adapted to be filled with air under pressure through a suitable valve h, and is provided
with a safety-valvej to prevent excess of pressure. The air-pressure expands the said

page_text: tube, and, while it is thus expanded, the said tubular carrier is moved towards and
over the said mandrel. In this movement, the said tube is turned inside out and
pressed uniformly against the inner skin or fabric on the mandrel by the air-pressure,
as illustrated in Figure 7. When nearly the whole of the tube has thus been applied
to the skin or fabric on the mandrel, the said tube is detached from the tubular
carrier and the remainder of its length is turned inside out and pressed against
the inner skin or fabric on the mandrel. The air-tube thus made is then removed
from the mandrel, and its ends either united to form an endless air-chamber, or
else pinched together so as to form flattened closed ends, which are afterwards
vulcanized if desired. This method or process is very expeditious and has the
further advantage that the air-pressure, acting uniformly all around the outer tube
while applying it to the inner tube, forces all the air out from between the tubes
and prevents the formation of air-bubbles between them.
When the inner repairing skin or fabric is only to be of segmental form in
transverse section, the outer tube is placed on the mandrel and a sheet of the said
skin or fabric of the requisite size is applied to the outer tube on the mandrel
after the aforesaid preparation has been applied to the said outer tube as required,
and is secured to the outer tube along its edges by solution or cement. The air-
tube thus made is then removed from the mandrel and turned inside out, thus
bringing the repairing skin or fabric inside the air-tube so that it will be adjacent
to the tread of the tyre.
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 manufacture of an air-tube for a pneumatic tyre by a process in which
air-pressure is employed for applying one elastic tube over another while the latter
is held upon a mandrel, substantially in the manner hereinbefore described.
2. The improved method or process of making an air-tube for a pneumatic tyre,
wherein an inner tube is placed upon a mandrel and coated with an adhesive semi-
liquid material and with india-rubber solution or cement, and an outer tube is then
secured over one end of the inner tube and is then turned inside out and uniformly
applied to the inner tube by air-pressure, substantially as herein before described.
Dated this 19th day of June 1896.
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.