Improvements in and relating to Pneumatic or Air-inflated Tyres for Wheels.
Year: 1891

page_text: Date of Application, 26th Oct., 1891
Complete Specification Left, 19th Dec., 1891-Accepted. 30th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in and relating to Pneumatic or Air-inflated Tyres
for Wheels.
I, WILLIAM GOLDING of No. 4 Portman Street, Moss Side, Manchester,
Inventor and Patentee, do hereby declare the nature of this invention to be as
follows:-
It relates to modifications in the construction of, and processes for constructing a
puncture closing tube.
1. A thin tube of rubber has a strip of canvas or some other similar flexible
material cemented to it on opposite sides, the strip of canvas, preferably cut on the
cross, is cemented, for a width sufficient to securely hold it, along each edge,
the middle part of the rubber tube, under the canvas, and the middle part of the
canvas strip, taken in cross section, being free from each other, though they may
be solutioned together when the rubber tube is inflated. In fixing the canvas strip,
the sides of the rubber tube are drawn towards each other, causing the rubber to
The tube is made
be puckered up or to be more full at that part than the canvas.
preferably smaller in diameter than the hollow of the outer tyre or casing and is
placed in it with the canvas side next the tread. Upon inflation, the main amount
of stretch takes place in the part of the tube not covered by the canvas.
other part is driven down upon the canvas strip. by which its extension is restrained.
The canvas strip stretches, somewhat, laterally, but the amount of stretch is
arranged to take out only a part of the surplus wall of the tube embraced by it.
The lateral stretch of the canvas causes it to contract lengthways. The result of
this arrangement is that a portion of the rubber tube, preferably about half, is
compressed laterally, longitudinally, and radially.
The
2. (a.) To construct such a tube as just described, I prefer to shape the tube of
unvulcanized rubber on a mandrel, but instead of the tube surrounding the mandrel
in the usual way, it is folded into itself, forming two segments of circles, one inside
the other and concentric with each other, and partly surrounding the mandrel.
The surfaces of the folded tube which are to be kept separate are coated with chalk
or soapstone or other well known means are employed to prevent them adhering
together during vulcanization. The folded edges are then joined together by a
strip of canvas solutioned on, which passes over the mandrel at the side not covered
by the folded rubber tube. The whole is then wrapped and vulcanized in the usual
way. In some cases, particularly where the tube is comparatively large with thin
walls, I attach a strip of rubber along the inside of the tube upon the side which
will be covered by the canvas, at the time the tube is formed. Preferably this
strip consists of pure rubber without the addition of sulphur or other vulcanizing
material.
(b.) When the rubber tube is already vulcanized and it is required to make it
puncture proof, I place it over a mandrel in the way just previously described
and join the folded ends in the same manner by the canvas strip. In this case
when it is required to reinforce the tube towards the road side, it is turned inside
out, before affixing the canvas, and the strip of rubber is solutioned to the wall of
the tube. It is then turned back and the canvas strip attached.
(c.) In an alternative arrangement, a rubber strip is formed into a tube with the
edges largely overlapped so that the wall will be double for a considerable extent,
preferably from one-third to a half of the circumference. A reinforcement,
consisting preferably of a thin strip of pure rubber, is solutioned between the over-
lapped parts when forming the tube. A mandrel of much smaller diameter than

page_text: the tube is covered by a strip of canvas, preferably cut on the cross, joined tubular
and the outer surface coated with rubber solution. The rubber tube is then turned
back upon itself and placed over the mandrel double, in the position previously
described. It is then wrapped or placed in a hollow mould and vulcanized, the
canvas tube is split up and the whole removed from the mandrel. Alternatively,
the main rubber strip is not first joined into a tube (or only joined along the
extreme edge of the inner fold for convenience in fixing), but is folded back over the
canvas covered mandrel and the surfaces of the four laminæ of which it is composed
when on the mandrel are prevented, by the usual means, from adhering together
during vulcanization. The strip with the canvas attached along one edge, is
removed after vulcanizing, and a strip of thin pure unvulcanized rubber is solutioned
on the side of the rubber opposite the canvas. This method secures it against
partial vulcanization. The other side of the rubber strip is then solutioned in position
over this, forming a complete tube with the thin reinforcing strip between the
overlap, and the canvas outside it. The canvas strip may be solutioned to the
rubber tube before it is placed upon the mandrel. The result of these arrange-
ments is a tube which when uninflated takes the shape of two concentric rings or
parts of rings in cross section, and owing to its small size is easily inserted and
withdrawn from the outer restraining envelope of the tyre. Upon inflation it
expands into a complete ring, in cross section, the wall of the canvas covered part
which was concave outwardly is now convex, the substance of the wall being
powerfully compressed both radially and laterally. The action of the canvas band
causes it to be compressed longitudinally as well. The effect of this compression is
that immediately a hole is made and the puncturing object withdrawn, the walls
round the hole shut together and close it up so that the tube remains airtight.
The object of using the thin strip of pure rubber is that the hole so made may be
cemented across by it, owing to the adhesiveness of the pure rubber acting under
the pressure to which it is subjected laterally, in order that a number of holes may
not interfere with the process of inflation by allowing an escape of air when the
tube is collapsed and the wall is not under compression. The amount of compression
to which the canvas coated side of the tube will be subjected when fully inflated
depends upon the relative dimensions of the mandrel, tube, and thickness of wall.
The canvas strip may be made into a tube and solutioned to the outside of the
folded rubber, and completely surround the rubber and mandrel. When it is
required to form a complete tubular tyre in one piece with the tube just described,
I form it upon a ring-shaped mandrel having a loose segment which is afterwards
pushed out through a slit in the tube or casing, the remainder of the mandrel being
withdrawn in the same manner. The rubber tube is folded on the inner curve of
the mandrel. It is surrounded by a canvas and rubber tube or casing to which it is
solutioned and the whole is wrapped and vulcanized.
or
The reinforcement may be a complete tube instead of a strip, but a strip is
and
sufficient for the purpose. The tube may be built up of two or more tubes strips,
or the relative positions of the rubber tube and strip of rubber may be reversed.
3. A modification of the process to obtain the same result, but with reduced
compression, is to form a tube upon a straight hollow mandrel, which tube may
consist of one thick sheet of rubber only, or of successive layers of vulcanized or
unvulcanized rubber placed or formed concentrically with each other and solutioned
or vulcanized together, with or without canvas insertion, and afterwards turning
the tube inside out. This may be effected by passing a cord through the mandrel,
tying it to the end of the rubber tube and drawing the tube through the mandrel.
The interior of the tube is then under compression, the amount of such compression
depending upon the relative diameter of the tube and the thickness of the wall.
4. Such a puncture proof inflatible tube as hereinbefore described may be used
inside an outer tyre or casing in which it may be loose or to which it may be
solutioned, vulcanized, or otherwise attached, or it may in some cases form a tyre
of itself when suitably secured to the rim of the wheel.

page_text: 5. Any of the methods, processes, or details hereinbefore described may be
combined together, where practicable, in order to obtain the same result.
Dated this Twenty-third day of October 1891.
COMPLETE SPECIFICATION.
Improvements in and relating to Pneumatic or Air-inflated Tyres
for Wheels.
I, WILLIAM GOLDING, of No. 4, Portman Street, Moss Side, Manchester,
Inventor and Patentee, 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 :-
It relates to the construction of, and to processes for constructing, a puncture-
closing tube.
1. A thin tube of rubber has a strip of canvas or some other similar flexible
material secured to it on opposite sides, the strip of canvas, preferably cut on the
cross, is secured, for a width sufficient to safely hold it along each edge, the middle
part of the rubber tube, under the canvas, and the middle part of the canvas strip,
taken in cross section, being free from each other, though they may be solutioned
together when the rubber tube is inflated. In fixing the canvas strip, the sides of
the rubber tube are drawn towards each other causing the rubber to be puckered
up or to be more full at that part than the canvas.
The tube is made preferably smaller in diameter than the hollow of the outer
tyre or casing and is placed in it with the canvas side next the tread. Upon
inflation, the main amount of stretch takes place in the part of the tube not covered
by the canvas. The other part is driven down upon the canvas strip, by which its
extension is restrained. The canvas strip stretches, somewhat, laterally, but the
amount of stretch is arranged to take out only a small part of the surplus wall of
the tube embraced by it. The lateral stretch of the canvas causes it to contract
lengthways. The result of this arrangement is that the wall of a portion of the rubber
tube, preferably about half, is compressed laterally, longitudinally, and radially.
The invention will be best understood from the following description in reference
to the accompanying sheet of drawings in which
Figure 1 is a cross section of a mandrel, and an end elevation of a tube upon it,
in process of construction.
Figures 2 and 3 are similar views illustrating alternative methods of
construction.
Figure 4 is an end elevation of two strips of thin sheet rubber formed into a tube
by widely overlapping the edges of the wider strip previous to placing it on the
mandrel as shewn in Fig. 2.
Figure 5 is an end elevation of a strip similarly formed into a tube and shewn on
the mandrel in Fig. 3.
Figure 6 is a cross section of the completed tube, shewn in Fig. 2, in an uninflated
state.
Figure 7 represents the next step in the process of construction of the tube shewn
in Fig. 3.
Figure 8 is a cross section of the completed tube, illustrated in Figs. 5, 3, and 7,
shewn in an uninflated state.
Figure 9 is a cross section illustrating the tube shewn in Fig. 1, in a state of
inflation, and
Figure 10 is a cross section illustrating the tube shewn in Fig. 8 in a state of
inflation.
In all the figures the solid black sections and end elevations are intended to
represent strips or layers of unvulcanized or partly vulcanized rubber which is in its
substance, more or less, in an adhesive condition.

page_text: The same letters of reference relate to the same parts throughout.
The mandrel is indicated at m, t is the rubber strip which constitutes the wall of
the inflatible tube, r is a thin strip or layer of rubber in an adhesive state, and
o is the restraining band of canvas or other suitable material, hereinafter called
canvas.
2. (a.) To construct such a tube as just described, I prefer to shape the tube of
unvulcanized rubber on a mandrel, see Fig. 1, but instead of the tube tt being
placed. around the mandrel, that is with the mandrel inside the tube, in the usual
way, it is folded into itself forming two segments of circles, one inside the other and
concentric with each other, and partly surrounding the mandrel. The inner surfaces
of the folded tube which are to be kept separate are coated with chalk or soapstone
or other well known means are employed to prevent them adhering together during
vulcanization. The folded edges are then connected together by a strip of canvas cc
solutioned on, which passes over the mandrel at the side not covered by the folded
rubber tube. The whole is then wrapped and vulcanized in the usual way. In
some cases, particularly where the tube is comparatively large with thin walls, I
attach a strip of rubber along the inside of the tube upon the side which will be
covered by the canvas, at the time the tube is formed. Preferably this strip
consists of pure rubber without the addition of sulphur or other vulcanizing
material. This strip of unvulcanized rubber is shewn at r, Fig. 9, placed
between the tube and the canvas restraining strip c c. It may be cemented or
solutioned to the canvas strip in this position previous to the vulcanization of the
tube or it may be affixed to the wall of the tube or to the canvas after vulcanization
by turning the tube or canvas inside out for the purpose.
If the tube is then
expanded inside an inextensible tube or casing in a warm temperature the wall of
the tube, the pure rubber strip r, and the canvas strip become firmly united together.
(b.) When the rubber tube is already vulcanized and it is required to make it
puncture closing, I place it over a mandrel in the way just described and join the
folded ends in the same manner by a canvas strip solutioned on. In this case when
it is required to reinforce the tube towards the road side, the strip of rubber is
solutioned to the wall of the tube before affixing the canvas.
(c.) An alternative arrangement is illustrated in Figs. 4 and 2, which is more
suitable than the one previously described when the rubber strip of which the tube
is to be formed is thinner, say from th to sth of an inch in thickness. A rubber
strip to is formed into a tube by largely overlapping the edges t¹ and t* so that the
wall will be double for a considerable part, preferably from one-third to a half of
the circumference. A reinforcement consisting preferably of a thin strip or layer
of pure rubber r without vulcanizing ingredients is attached between the over-
lapped parts when forming the tube. A mandrel m, Fig. 2, of much smaller
diameter than the tube is covered by a strip of canvas c, preferably cut on the bias
or cross, joined tubular and the outer surface coated with rubber solution. The
rubber tube is then curled back upon itself and placed round the mandrel double.
It is then wrapped, or placed in a hollow mould, and vulcanized. The canvas tube
is split up at c and the whole removed from the mandrel. The shape it assumes in
cross section is shewn in Fig. 6.
(d.) A modification of the above is illustrated by Figs. 5, 3 and 7. The main
rubber strip is not first joined into a tube, or only joined along the extreme edge of
the inner fold, see x, Fig. 5. It is then folded over the canvas covered mandrel, as
just described, and the surfaces between the two lamina t and t, and the remainder
of the surfaces between and are prevented by the usual means from adhering
together during vulcanization. After vulcanization, a strip of thin unvulcanized
rubber is inserted between the laps of t¹ard t'. This is conveniently effected by
turning over the tubular part t,, as illustrated in Fig. 7, and solutioning the
strip to the overlap t' while it is still on the mandrel. The outer surface of the
strip r is then solutioned and the tubular part returned into position over it
and pressed down so as to firmly join the strip to the inner and outer folds of the
overlap. This method secures the strip r against partial vulcanization, The canvas

page_text: strip may in some cases be solutioned to the rubber tube before it is placed upon
the mandrel.
The result of these arrangements and processes of manufacture is a tube which
when uninflated takes the shape of two concentric rings or parts of rings in cross
section, as illustrated by Figs. 6 and 8, and which owing to its small size is easily
inserted and withdrawn from the outer restraining envelope of the tyre. Upon
inflation it opens out into a complete ring in cross section, as illustrated by Figs. 9
and 10, the part of the wall shewn uppermost at y uz, which is on the inuer curve
towards the rim, stretches if necessary under inflation so as to expand to the full
extent the restraining envelope and outer tyre or casing. The wall of the canvas
covered part round y sz is on the outer curve towards the tread, and this part
which had a concave shape outwardly given to it by vulcanization is, under infla-
tion, convex, and the outer surface being held under restraint by the canvas strip,
the whole substance of the wall is powerfully compressed both radially and laterally.
The action of the canvas band, when cut on the cross, causes it to be compressed
longitudinally also. The effect of this compression is that immediately a hole is
made and the puncturing object withdrawn the walls round the hole shut tightly
together and close it up so that the tube remains airtight.
The object of using the thin strip or layer of pure or unvulcanized or partly
vulcanized rubber is that the punctured hole may be automatically cemented across
by it, owing to the adhesiveness of such rubber acting under the strong lateral
pressure to which it is subjected. This is in order that the punctured holes may
not interfere with the process of inflation by allowing an escape of air when the
tube is collapsed and the wall is not in a state of compression, and also for the
purpose of preventing loss of air through the punctured holes when the tube is
bent inwards while being ridden over stones or other obstacles or unevennesses of the
road. The purpose of the canvas band is to maintain the outer curve of the tube
in a state of compression when inflated. When the canvas is cut on the cross, the
tube is elastic and flexible and may be stretched in parts during the process of
insertion or under the action of riding without affecting the amount of compression
in such parts. The amount of compression to which the canvas coated side of the
tube will be subjected when fully inflated depends upon the relative dimensions of
the mandrel, tube, and thickness of wall. The proportions shewn in the drawings
represent an amount of compression to about three-fifths of the superficial area of
the surface of the interior of the tube where the compression is greatest, and a
corresponding thickening of the wall. This in practice is found to be about the
most desirable amount and is sufficient to cause the wall to close up and remain
airtight after being punctured by a pointed object to the extent of a hole one-
eighth of an inch in diameter and after a cut a quarter of an inch long caused by a
knife blade thrust in in any direction. The whole of the protected wall of the tube
may be pierced in this way without discharging the contained compressed air.
(e.) The canvas strip may be made into a tube solutioned to the outside of the
folded rubber, and completely surrounding the rubber and mandrel. When it is
required to form a complete tubular tyre in one piece with the tube herein before
described, I form it preferably upon a ring-shaped mandrel having a loose segment.
The inner, puncture closing, rubber tube is folded on the inner curve of the mandrel.
It and the mandrel are surrounded by a canvas and rubber tube or casing to which
it is partially solutioned and the whole is wrapped and vulcanized. The loose
segment is withdrawn through a slit in the tube or casing. The tyre is then with-
drawn from the mandre! by passing the remainder of the mandrel through the slit
which is afterwards made up.
3. A modification of the process to obtain a similar but less effective result with
reduced compression, is to form a tube preferably upon a straight hollow mandrel,
which is placed inside the tube in the usual manner which tube may consist of one
sheet of vulcanized rubber with a strip or tube of unvulcanized or partly vulcanized
rubber, or of successive tubes or layers of vulcanized or unvulcanized or partly
vulcanized rubber placed or formed concentrically with each other and solutioned

page_text: or vulcanized together, with canvas or other strengthening insertion or lining, and
afterwards turning the tube inside out. This may be effected by passing a cord
through the mandrel, tying it to the end of the rubber tube and drawing the tube
through the mandrel. The interior of the tube is then under compression, the
amount of such compression depending upon the relative diameter of the tube and
the thickness of the wall.
4. Such a puncture closing inflatible tube as hereinbefore described may be used
inside an outer tyre or casing in which it may be loose or to which it may be
solutioned, vulcanized, or otherwise attached, or it may in some cases form a tyre
of itself, when suitably secured to the rim of the wheel.
5. Any of the methods processes or details hereinbefore described may be
combined together, where practicable, to obtain the same result.
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 or air-inflated tyre for wheels, a separate inner inflatible tube
constructed along the outer curve so as to possess the property of closing punctured
holes and to be of smaller size in cross section when uninflated than the hollow of
the restraining envelope of the tyre, substantially as hereinbefore described and
illustrated by the accompanying drawings.
2. A separate inner inflatible expansible tube for pneumatic or air-inflated tyres
for wheels, the wall of which on the outer curve is cons sted to be in a state of
lateral compression throughout its substance, and in which is incorporated a strip
or layer of rubber in an adhesive state, in the manner and for the purpose substan-
tially as hereinbefore described and illustrated by the accompanying drawings.
3. In a separate inner inflatible tube for pneumatic or air-inflated tyres for
wheels, the combination with a laterally compressed wall on the outer curve, of a
strip or layer of unvulcanized or partially vulcanized rubber, and an outer
restraining band of canvas or other suitable material, all arranged in the con-
struction of the tube so as to operate in conjunction for the purpose of automatically
and permanently closing up punctured holes, substantially as hereinbefore described
and illustrated by the accompanying drawings.
4. In a pneumatic tyre for wheels, in combination with a restraining envelope
and an outer tyre or casing, an inflatible inner tube constructed with laterally
compressed walls containing a layer or tube of rubber in an adhesive state in the
manner and for the purpose substantially as hereinbefore set forth.
5. The method of and processes for effecting and maintaining a lateral com-
pression of the substance of the wall along the outer curve of an inflatible rubber
tube for pneumatic tyres, substantially as herein before described and illustrated by
the accompanying drawings.
6. The method of and processes for constructing an inner inflatible tube for
pneumatic tyres which shall possess the property of automatically and permanently
closing punctured holes, substantially as set forth with reference to Figures 1
and 9.
7. The method of and processes for constructing an inner inflatible tube for
pneumatic tyres which shall possess the property of automatically and permanently
closing punctured holes, substantially as set forth with reference to Figures 4, 2,
and 6.
8. The method of and processes for constructing an inner inflatible tube for
pneumatic tyres which shall possess the property of automatically and permanently
closing punctured holes, substantially as set forth with reference to Figures 5, 3, 7,
8 and 10.
Dated this 17th day of December 1891
WILLIAM GOLDING.