Improvements in or connected with Pneumatic Tyres for the Wheels of Cycles and other Vehicles, and in Charging Valves for Pneumatio Tyres.
Year: 1896

page_text: Date of Application, 24th Apr., 1896
Complete Specification Left, 24th Feb., 1897-Accepted, 24th Apr., 1897.
PROVISIONAL SPECIFICATION.
Improvements in or connected with Pneumatic Tyres for the
Wheels of Cycles and other Vehicles, and in Charging Valves
for Pneumatio Tyres.
I, ANTHONY PULBROOK, of 8 Unwin Mansions, Queen's Club Gardens, West
Kensington, London, Solicitor, do hereby declare the nature of this invention to
be as follows:-
In making pneumatic tyres with laminated tubes having air spaces between
the laminations as described in the Specifications of Patents granted to me and
numbered respectively 17,931, .18,512 and 21,080 of the year 1893, and 15,172
of year 1894, it is sometimes difficult to adjust the inner tube in position, when a
cover is used, in consequence of the space occupied in the cover by the transverse
distance pieces and air spaces, and it is also sometimes difficult to retain a sufficient
quantity of air in the air spaces before joining the open ends of the material
enclosing thein. To obviate these difficulties I fold the inner tube into as small a
space na possible, and keep it confined to that small space by means of strips or
wrappings of paper or other suitable matorial which casily breaks or tears across
whon the tube is being inflated after it has been placed in position in the tyre. To
assist the inner tube to expand and break the strips or wrappings I sometimes use
lubricants, each as French chalk for example, which prevent adhesion of the folds
of the tube to one another or to the cover, aud I fold the tube in such manner ag
will prevent the sides of the tube from becoming janimed by the expansion of the
air. Sometimes 1 cement, solution, or otherwise lasten the inuer tube at intervals
to the cover.
When hollow transverse distance pieces are used to create air spaces between
the laminations they are necessarily bent into a ring shape, and the inner diameter
of the rings being much smaller than the outer the material forms folds or puckers
on the internal circumferences of the rings, I therefore sometimes use longitudinal
hollow distance pieces, or longitudinal and transverse distance pieces combined.
I also use bags of paper or other thin and light material in which to confine the
air at atmospheric pressure between the laminations before joining the ends of the
distance pieces; these assist in filling the air spaces with air and prevent the escape
of air while joining the ends of the air-tight material.
I sometimes enclose the material which is inore or less difficult to puncture, and
which is used to protect the pneumatic tube against puncture, in separate airtight
bage or tubes, and place these, one over the other, between the outer cover and the
pneumatic tube.
I sometimes make a laminated tyre with air spaces between the laminations as
described in the Specifications of my aforesaid Patents Nos. 17,921 and 18,512 of
1893, and No. 15,172 of 1894 in the following manner:- mould or otherwise
shape a sheet of indiarubber of a sufficient width to form, when rolled round a
mandril, the required number of laminations, and on the said sheet | secure
longitudinal or transverse solid or hollow distance pieces, at such distance apart as
will ensure their coming in their right places when the sheet is rolled into a tube
as hereinafter described. 1 sometimes form the distance pieces by corrugating the
sheet of indiarubber at the proper points, and then solution over these corrugations

page_text: an airtight thin material thereby forming hollow chambers. I then lay the sheet
flat on a table and coat the back of the material which is to form the outside of the
inner tubes with cement or solution so that when the sheet is wound round a
mandril the apex of each corrugation or distance piece may come against a
cemented or solutioned part of the material. Wheu ready to make into tubular
form I take a mandril of the size of the inner tube, and roll the sheet round it, and
us cach cemented or solutioned corrugation is reached it adheres to the side of the
preceding convolution forming an air-tight space. I then join the two ends air-
tight, so that each convolution forms a longitudinal air-tight tube, enclosing but
not communicating with the next inuer convolution. If necessary before rolling
up the sheet on the mandril I first place in the spaces left by the corrugations any
suitable material more or less difficult to puncture in order to protect the pneumatic
tube in the manner now well known and understood and I may also insert in such
spaces bags filled with air as before described.
In order to prevent the inner tubes of pneumatic tyres from being damaged by
the spoke holes in the rim, it is customary, in some cases, to solution or otherwise
secure a piece of tape or other material next to the rim, between it and the
pneumatic tube. I prefer to effect this object by solutioning, cementing or
otherwise fastening to the rim, for the pueumatic tube to rest against, a Hexible
hollow material containing a suitable fluid which may be either compressible
or incompressible, and preferably having transverse distance pieces, which may be
either hollow or solid, and cemented or solutioned at intervals inside the chamber
formed by the said hollow material. These distance pieces form corrugations or
projections and depressions with which the pneumatic tube, when inflated, will
engage and be thereby prevented from creeping. The compression of the air in
the inner or pueunatic tube causing the latter to expand imparts a corresponding
pressure to the fluid in the aforesaid hollow material and the same tube is thereby
kept firmly, in position without subjecting any one part to undue strain, and creeping
of the said tube is thereby avoided.
Sometimes I strengthen the aforesaid tape at the parts immediately over the
spoke holes in the rim by means of plates of suitable material, or by projections
dropping into such holes."
Air escapes from the charging valves of pneumatic tubes mostly at the point
where the stem passes through the tube. I prevent this escape by using a trumpet-
shaped piece of rubber or other flexible airtight material secured in the valve stem
and having an aperture passing right through its centre for the valve spindle.
The outer end of this rubber I make fast inside the valve stem, preferably to a
point reaching outside the rim, and I cement or solution it in such a mauner that
no air can escape between it and the valve stem. I may make the stem, or both
stem and rubber, corrugated to more effectually prevent the escape of air.
I solution the trumpet-shaped end of the piece of rubber all round to the inside of
the pneumatic tube, thus the escape of any air or gas is effectually prevented from
the tube except through the central valve opening.
Various methods have been devised from time to time for fastening pneumatic
tyres to the rims of the wheels, some are termed detachable and others non-detachable,
but they all so far as I am aware, have reference to fastening the tyre to the rim
after the latter is completed and made up into a wheel with spokes. Instead of
this lay the foundation for the fastening to the rim before the spokes are put into
place. For this purpose I cement, solution, or otherwise fix to the inside or
back of the rim a broad piece of the material intended to form the outer cover
preferably of sufficient width and so cut that when the edges are brought round
they will encompass, and if necessary overlap a fully inflated pneumatic tubo.
I then make the holes required for the spokes through the material and rin,
pass the spokes through both, and then fasten the latter in the usual manner.
1 thus have the foundation for a tyre which forms part and parcel of the rim,
thereby preventing the tyre from creeping or coming off the rim in case of
deflation.

page_text: Sometimes instead of forming the tyre by lapping over the edges and joining
them I furnish the edges or either of them with hems, selvages, wires, plates, bands,
ribands, studs, hooks, eyelet holes, laces, or any known device for attaching to
them a removable outer cover or flap in case a detachable tyre is required. I some-
times make the sides of airtight longitudinal chambers containing air or gas and
provide corresponding depressions in the rim to receive these airtight sides, aud
any fastenings they may be secured by. The cover may be secured either outside
or inside the rin, or it may be fastened at one side, then passed round the ioner
tube and secured by suitable fastenings at the other side.
It is customary to prevent the undue expansion of the pneumatic tube by using
canvas restraining covers woven in a single thickness of sufficicnt substance or
strength to resist the pressure, or in two or more layers solutioned together with
rubber or by using specially prepared fabrics. I make the restraining cover of
layers of very light and fine textile material such as linen, cambric, long-cloth, or
the material known as gelosine treated with balata or a mixture of balata and
indiarubber or that part of gutta percha or balata which is called alban either
alone or mixed with indian ubber. The various layers may be either cut on the
straight, on the cross, or on the bias, or some on the straight and some on the cross
or bias. I cement the layers together with balata solution or a compound of balata
and indiarubber solutions, and preferably calender the layers together, before they
are fully dried, so that when dry the material forms, as much as possible one
homogeneous whole. Inasmuch as when textile fabric has been treated as above
described it will not take the circular shape so easily as in its natural state,
1 moisten it in the first instance with mineral naphtha or other hydrocarbon which
softens the balata and I then keep it in a mould or shape until dry, when the textile
fabric is found to have taken the desired shape.
With such a cover I preferably use a tread of thin leather or fish skin treated
with balata to make it waterproof. When fixing a treat of thin leather or fish
skin to this or other tyres, I have found that the V shaped joint described in the
Specification of my Patent No. 18,600 of 1894 is apt to separate a little, leaving
part of the textile fabric exposed when the tyre is inflated. I therefore prefer to
use a dovetail or interlocking V-shaped joint which prevents the parts separating
when the tyre is inflated, and grit from getting in at the junctions and I preferably
place a piece of thin leather beneath the joint to more effectually prevent the
entrance of grit.
I sometimes combine leather of any kind with the textile fabric and treat either
or both substances with balata as above described, and cement or solution the layers
together in order to form any part of a tyre.
1 sometimes fasten the cover on the rim in the following manner:-I form sleeves
for the ends of the fastening wire to pass through. These sleeves take the curve
of the rim, and are embedded in the edges of the cover in the same way as the
fastening wires. Each sleeve may be in one piece, or in two pieces adapted to
slide into each other, and it may be solid in the centre or hollow, and of any
suitable cross section. These sloeves lie snugly in the rim and the ends of each
fastening wire are passed into its appropriate sleeve and out through openings in
the latter, and through corresponding openings in the side of the rim. The pro-
jecting ends of the wires, which are seren-threaded are then drawn together by
menus of nuts or other suitable devices so as to draw the wires tight. In some
cases I pass the fastening wire twice round the cuver and rim and entirely or partly
through the whole length of the sleeve or cover, and tne sleeve may have a distinct
channel for the ends of the wire to pass through. 1 sometimes tighten the wires
by crossing their ends and drawing or forcing them by screw nuts or other suitable
devices in opposite directions.
1 sometimes place longitudinally under the cover at its sides, a tube or receptacle
containing confined air which may be at atmospheric pressure. The pneumatio
tube placed between these receptacles distends when filled with compressed air and
compresses the air confined in the said side tubes or receptacles and these form

page_text: cushions which protect the air tube from being jammed between the wires and rim.
Sometimes effect the same object by means of flaps of flexible material passing
down from the cover towards the bottom of the rim, so that the pneumatic tube
'bas to force the flap out between the wire and rim before it can get out itself.
According to another arrangement for fastening detachablo tyres I use an endless
wire which goes twice round the tyre, 1 insert this in the cover over an airtight
compartment in a hem or selvage large enough to give the wire room to move
easily. I insert one strand or convolution of the wire in a hem or selvage near the
edge of the cover, and after it has gone completely round I cross the wires and
make a hem or selvage to receive the other strand or convolution of the wires at a
greater distance from the edge. I sometimes use a rim having a channel or gutter
at the side end I sometimes make the sides of the rim of a triangular shape,
preferably with corrugations or depressions corresponding to the positions of the
wires. It will now be understood that the freedom of movement given to the wire
by this arrangement enables the lower strand or.convolution to be extended so that
it will pass over the back of the rim, then by narrowing the circle made by this
part of the wire the necessary play will be given to the other strand or convolution
to enable that to be got over the back of the rim also. When both strands or
convolutions are passed over the rim they can be so adjusted as to fit into the
channels made to receive thein. When the tyre is inflated the cover is drawn
outwards, and the wire strauds or convolutions are tightened, one of them being
drawn out by the cover to the base of the triangular-sided rim forms a larger
circle and tightens the other straud or convolution so that the latter adjusts itself
to the smaller diameter of the apex of the triangle. The tension on the cover
likewise compresses the air in the airtight chambers by its effort to regain its norinal
state, and thereby uniformly tightens the wires preventing the tyre from being
blown off the rim. The projection at the upper part of the rim prevents the wire
being forced inwards and thereby forming a smaller circle which would allow of the
cover getting loose and leaving the rim. This action is also assisted by the rim
being channelled or grooved.
Dated this 24th day of April 1906
A. PULBROOK,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.
ע.
Improvements in or connected with Pneumatic Tyres for the
Wheels of Oyoles and other Vehicles, and in Oharging Valves
for Pneumatic Tyres.
I, ANTHONY PULBROOK, of 8 Unwin Mansions, Queen's Club Gardens, West
Kensington, London, Solicitor, 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, reference being had to the
accompanying sheet of drawings and to the letters and figures marked thereon:-
In making pneumatic tyres with laminated tubes having air spaces between the
laminations, as described in the Specifications of Patents granted to me and
numbered respectively 17,931, 18,512 and 21,080 of the year 1893, and 15,172 of
the year 1894, it is sometimes difficult to adjust the inner tube in position, when a
cover is used, in consequence of the space occupied in the cover by the transverse
distance pieces and air spaces, and it is also sometimes difficult to rotain a sufficient
quantity of air in the air spaces before joining the open ends of the material
enclosing them. To obviate these difficulties I fold the inner tube, when using

page_text: one, into as small a space as possible, and keep it confined to that small space by
means of strips or wrappings of paper or other suitable material which easily
breaks or tears across when the tube is being inflated after it has been placed in
position in the tyre. To assist the inner tube to expand and break the strips or
wrappings sometimes use lubricants, such as French chalk for example, which
prevent adhesion of the folds of the tube to one another or to the cover, an fold
the tube in such manner as will prevent the sides of the tube from becoming
jammed by the expansion of the air. Figure 1 of the drawings shows a cross
section of the tube A before inflation, folled, and continel in that folded position
by a strip or wrapping A' of paper. Sometimes I cement, solution, or otherwise
fasten the inner tube at intervals to the cover.
When hollow transverse distance pieces are usel to create air spaces between
the laminations they are necessarily bent into a ring shape, and the inner lis ueter
of the rings being smaller than the outer the material forms folds or puckers on the
internal circumferences of the rings, I therefore sometimes use longitudinal hollow
or solid distance pieces, or longitudinal and transverse hollow or solid distance
pieces combined.
Figures 2 and 3 show a longitudinal and cross section respectively of a tyre with
longitudinal distance pieces applied thereto, B being the outer lamination of the
tube, CC the longitudinal distance pieces, D the inner lamination of the tyre,
and non-puncturable material placed at the tread part of the tyre. I also use
bags of paper or other thin and light material in which to confine the air at
atmospheric pressure between the laminations before joining the ends of the distance
pieces, as shown by dotted lines in Figure 3.
These bags assist in filling the air spaces with air, nod prevent the escape of air
while joining the ends of the air-tight material.
I sometimes enclose the material which is more or less difficult to puncture, and
which is used to protect the pneumatic tube against puncture, in separato airtight
bags or tubes containing air and place these, one over the other, between the outer
cover and the pneumatic tube as shown in Figure 4, in which D is the pneumatic
tube, E the non-puncturable material enclosed in the air-tight bags F, and G is the
outer cover.
I sometimes make a laminated tyre with air spaces between the laminations, such
as is described in the Specifications of my aforesaid Patents Nos. 17,931 and 18,512
of 1893 and No. 15,172 of 1804; in the following manner :-I mould or otherwise
shape a sheet of indinrubber H, see Figure 5, of a sufficient width to form, when
rolled round a mandril, tho required number of laminations, and on the said
sheet secure longitudiual or transverse solid or hollow distance pieces C, at
such distance apart as will ensure their coming in their right places when
the sheet is rolled up into a tube as shown in the figure and as hereinafter
described. sometimes forin the distance pieces by corrugating the sheet of
indiarubber H or other airtight material at the proper points, ne shown at Cin
Figure 6, and then solution over the hollows of these corrugatious an airtight thin
material H' thereby forming hollow chambers. I then lay the sheet flat on a table
and coat the bark of the material, which is to form the outside of the inuer tubes,
with cement or solution in places and also the projecting part of the distanco pieces
or corrugations so that when the sheet is wound round a mandril the apex of each
corrugation or distance piece may come against a cemented or solutioned part of
the sheet of material. Wheu ready to make into tubular form I take a mandril of
the size of the inner tube I, and roll the sheet H round it, and as each cemented or
solutioned distance piece or corrugation is reached it adheres to the side of the
preceding convolution thereby forming an air-tight space as shown. I then join the
two ends together air-tight, so that each convolution forms a longitudinal air-tight
tube, enclosing, but not communicating with, the uext inner convolution. If
necessary, before rolling up the sheet on the mandril 1 titst place in the space left
by the corrugatious any suitable material E more or less difficult to puncture, in
order to protect the pneumatic tube in the manner now well known and understood,

page_text: and I may also insert in such spacos bags E' filled with air as before described, and
the non-puncturable material E may be inserted in such bags, as shown in the
figure.
In order to prevent the inner tubes of pneumatic tyres being damaged by the
spoke holes in the rim, it is customary, in some cases, to solution or otherwise
secure a piece of tape or other material next to the rim over the ends of the spokes,
and hetween the rim and the pneumatic tube. I prefer to effect this object by
solutioning, cementing, or otherwise fastening to the rim, see Figure 7, for the
pneumatic tube D to rest against, n hollow air-tight tube or chamber K of flexible
inaterial rontaining suitable fluid, which may be either compressible or incom-
pressible, and preferably having transverse distance pieces L, which may be either
hollow or solid, and cemented, solutioned or otherwise fastened at intervals inside
the hellow chamber K. These distance picces form corrugations or projections
and depressions with which the pneumatic tube D when inflated, will engage and be
thereby prevented from creeping. The compression of the air in the inner or
pneumatic tube D causing the latter to expand imparts a corresponding pressure to
The fluid in the aforesaid hollow tube or chamber K, and the said tube D is thereby
kept firmly in position without subjecting any one part to undue strain, and creeping
of the said tube is thereby avoided.
When using air-tight chambers instead of tapes as a protection from the spoke
ends I find it unnecessary to use an inner tube at all in some instances, especially
when using longitudinal airtight chambers in the sides of the rim in addition to the
air-tight chamber K over the spoke ends. This is a matter of great importance
when using laminated tyres with air chainbers as before described. For instance I
may use endless wires; plates or other rigid material in, or attached to, an airtight
outside cover as shown, by way of example, at Min Figure 8, such wires being
preferably capable of being tightened up, so that when the said wires, plates or
other like inextensible rigid material are put on the rim J, over the air-tight
chamber K containing fluid, they sink into the said air-tight chamber, and the fluid
enclosed in the chamber causes an equal pressure in all directions, and prevents
the exit of air from the interior of the cover G. In this case I preferably make
the parts of the air chamber under the wires, or the parts of the cover G
surrounding the wires, of leather or strong textile fabric, which I preferably make
fluid-tight by soaking in, or treating with balata or a mixture of balata and
rubber, or soft soap, grease, vaseline, or other compound or substance having the
like effect. By this means not only is wear prevented but the chamber is made
more completely air-tight. When using plates instead of wires I may have pius,
nuts or screws passing from the plates through the rim so as to tighten the plates
down on the air-tight chamber, and prevent the separation of the cover from the
rim. 1 may corrugate the plates so as to form ridges siuking into the fluid-
containing chamber.
Sometimes I strengthen the aforesaid tape at the parts immediately over the
holes made in the outside thickness of the rim opposite the ends of the spokes
(when a hollow rim is employed) by means of plates of suitable material, or by
projections dropping into such holes.
Air escapes from the charging valves of pueumatic tubes mostly at the point
where the stem passes through the tube. I prevent this escape by using a
trumpet-shaped piece of rubber or other suitable flexible airtight material P
secured in the valve stem or body P', as shown in Figure 9, and having an
aperturo P passing right through its centre for the valve spindle P³. The outer
end of this rubber PI make fast inside the valve stem or body P, preferably to a
point reaching outside the rim J, and I cement or solution it in such a manner that
no air can escapo between it and the valve stem or body. I may make the stem or
body, or both stem and rubber, corrugated to more effectually prevent the escape of
air. I solution the trumpet-shaped end of the plate of rubber P, all round to the
inside of the pneumatic tube D, thus the escape of any air or gas from the said
tube is effectually prevented except through the central valve opening.

page_text: Various methods have been devised from time to time for fastening pneumatio
tyres, or the covers thereof, to the rims of the wheels, some are termed detachable
and others non-detachable; but they all, so far I am aware, have reference t
fastening the tyre to the rim after the latter is completed and made up into a wheel
with spokes. Instead of this I lay the foundation for the fastening of the tyre r
cover to the rim before the spokes are put into place. For this purpose I cement,.
Holution, or otherwise fix to the inside or hack of the rim J, see Figure 10, a bro ul
piece of the material Q intended to form part or the whole of the outer cover, su
material being preferably of sufficient width, and so cut, that when the edg
are brought round they will encompass a fully inflated pneumatic tube 1),
and if necessary overlap. I then make the holes required for the spokes througa
the material and rin, pass the spokes R through both, and then fasten the spokes
in the usual manner. I thus have the foundation for a tyre which forms part an
parcel of the rim, thereby preventing the tyre creeping or coming off the rim in
case of deflation, and allowing an inner tube to be readily examined, by opening
the cover, and, if necessary, to be repaired or removed.
Inasmuch as if the rim be flat or convex in section the flaps when brought
round would leave an unsupported gap longitudinally at the edges of the rim.
especially when the tube is enclosed in a restraining cover as hereinafter described,
place a longitudinal loose airtight compartment of this air-tight material,
containing air at atmospheric pressure in order t fill up the gap on each side so as
to apply to the inner tube the strength of the outside fold, as shown at K' in
Figure 11.
There being little or no strain to draw the inner flap back from its place round
the tyre, any known simple fastening is alone necessary in respect of that flap, or
even no fastening at all, though when using a canvas pocket round the inner tube
I do not always bring it round the tube or pocket, but solution it to the pocket at
the top or side.
Having completed one flap (the inner tabe being inflated to the size intended) if
I intend bringing the other flap round outside the edge of the rim, I fix an air
chamber at the side as shown in Figure 11 to fill the longitudinal gap, and I then
bring the Hap either wholly or partially round over the air chainler and coment,
solution, or otherwise fasten it; if only partially brought round I bring it beyond
the edge of the tread piece to be solutioned, cemented, or otherwise fastened on.
I may easily repair a puncture in a tyre thus formed, by cementing or
solutioning in the following manner-Having found the puncture I moisten the
outside flap with a bydro-carbon or other solvent of the cement or solution, so that
it can be drawn back to expose the puncture in the inner flap; I then cement a
sinall patch of air-tight material over the puncture, and draw the outside flap or
cover back into its place again. If necessary I sprend some thin solution
between the layers to refix them; then blow up gently and wind a tapo of
flexible materiai flat round the part of the cover that has been removed, and over
the puncture, clinker fashion, and secure the ends, being careful not to allow any
part of the tyre where the repair has taken place, to be unsupported by the tape.
This being done inflate the tube hard, this presses the patch against the
supporting tape, and the tyre can be ridden on at once till the tape is worn out.
By that time the cement or solutioning will have dried, and the tape can be
removed. The patch being enclosed between the flaps makes a perfect air-tight
epair.
When use an inner tube I preferably secure it in a thin restraining tubular
pocket which may or inay uot, he air-tight, and the tube is then inflated until it
attains the size it is intended to be. The flaps of the cover are then brought
round to encircle or partly encirelo the inner tube as before described.
Figure 12 shows a modification of the arrangement shown in Figure 10, in which
the material intended to form the cover, or part thereof, is cemented, solutioned,
or otherwise fixed to the outside or front of the rim J, and the spokes are passed
through the rim and cover and secured inside the latter. Figure 13 shows another

page_text: modification in which the material Q intended to form the cover is folded so that
the spokes R pass through two thicknesses of the material; and Figure 14 shows
yet another modification in which the material Qis folded so that the spokes R
pass through three thicknesses of the material. Sometimes I place a band of steel
or other flexible metal or substance S over the material Q and pass the spokes
through it as well. It will be understood that each of the folds of the material Q
shown in Figures 13 and 14 is preferably cemented or solutioned to the preceding
one, and the first to the rim J, also that the edge Q of the cover is cemented in
each case in Figures 10, 12, 13 and 14 to the flap Q thereof or to the back of
the rim so as to encircle the tube; and that, if desired, the flap Q may be continued
round as shown and may, or may not, be cemented to the inside of the cover, or
to the rim, or it may be held in position by friction only against the other Hap
which is fastened.
Sometimes instead of forming the tyre by connecting the edges of the cover
together as above described I furnish the edges Q Q with hems, selvages, wires,
plates, bands, ribands, studs, books, eyelet-holes, laces, friction bands, or any other
known device for attaching them together, or for attaching to them a removable
outer cover or flap in case a detachable tyre is required; or the edge Q', see
Figure 15, may be provided with a wire T furnished with suitable tightening-up
devires and which is passed into the concavity of the rim J, and holds that edge
of the cover in place in the usual well known way, the other edge Q being held by
friction or cement, and by the spokes R as above described.
In some cases a tyre prepared as shown in Figures 10, 12, 13 or 14 may have a
removable outer cover U applied thereto, secured in place by wires T T in the
manner described in the Specification of a Patent granted to C. K. Welch
No. 14,563 of 1890, as illustrated in Figure 16, or by any other known devices.
I sometimes place at the sides air-tight longitudinal chambers K' containing air or
gas, and may provide corresponding depressions in the rim to receive these
air-tight chambers, as shown in the figure, and I may secure such chambers by
fastenings, cement or other meaus.
The arrangements shown in Figures 10, 12, 13 and 14 may be used without inner
or pneumatic tubes when the material Q of the outer cover is air-tight, and care is
taken, as in the arrangement shown in Figure 13 for example, to cover the ends of
the spokes with air-tight material to prevent leakage of air through the spoke
holos in the rim.
It will be understood that when I bring one air-tight flap Q round to the outer
periphery of the rim and then bring the other over it and fix or fasten it to the
other side of the tyre or rim by any means, on forcing air into the interior through
a non-return valve in the usual manner the inner flap will be forced by the air
against the previously secured outer part, and the pressure of the air will close
them together so as to form an air-tight compartment, even if the inner flap has
not been cemented or solutioned to the inside of the fixed part of the cover.
I may
assist this by placing over the joint a thin sheet of smooth indiarubber, balata, or
a mixture of these, as described in the Specification of my Patent No. 14839
of 1895, or by placing between the flaps an air-tight bag or compartment containing
air or other compressible or incompressible fluid."
It is customary to prevent the undue expansion of the pneumatic tube by using
canvas restraining covers woven in a single thickness of sufficient substance or
strength to resist the pressure, or in two or more layers solutioned together with
rubber, or by using specially prepared fabrics. I make the restraining cover of
layers of very light and fine textile material such as lineu, cambrio, long-cloth, or
other fabric made of suitable fibre treated with balata, or a mixture of balata and
indiarubber, or that part of gutta percha or balata which is called alban either
alone or mixed with indiarubber. The various layers may be either cut on the
straight, on the cross, or on the bias, or some on the straight and some on the cross
or bias, cement the layers together with balata solution, or a compound of
balata and indiarubber solutions; and preferably calendar the layers together,

page_text: before they are fully dried, so that when dry the material forms, as inuch as
possible, one homogeneous whole. Inasmuch as when textile fabric has been
treated as above described it will not take the circular shape so easily as in its
normal state. I moisten it in the first instance, with mineral naptha or other
hydrocarbon which softens the balata, and I then keep it in a mould or shape:until
dry, when the textile fabric is found to have taken the desired shape.
With such a cover I preferably use a tread of thin leather or fish skin treated
with balata, or balata and indiarubber, to make it water-proof. When fixing a
tread of thin leather or fish skin to this or other tyres, I have found that the
V-shaped joint described in the Specification of my Patent No. 18600 of 1894 is
apt to separate a little, leaving part of the textile fabric exposed when the tyre is
inflated. I therefore prefer to use a dovetail or interlocking V-shaped joint, as
shown in Figure 17, which prevents the parts separating when the tyre is
inflated, and grit from getting in at the junction, and I preferably place a piece
of thin leather beneath the joint to more effectually prevent the entrance
of grit.
I sometimes combine leather of any kind with the textile fabric, and treat
either or both substances with balata as above described, and cement or solution
the layers together in order to form any part of the tyre.
When using textile fabrics in combination with leather I reduce the stretching
capacity of the fabric by cutting it on the straight or cross, or partly on the bias.
60 as to make it as nearly as possible equal to that of the leather in order that
each material may take its proportion of the strain.
When using leather or fish skin which stretches less than the textile fabric, I make
the tyre up with the textile fabric in the first instance and then, when the tyre is.
inflated hard, cement or solution the shaped leather or fish skin as described in the
Specification of my Patent No. 14788 of 1895 on to the tread of the tyre.
1 sometimes fasten the cover on the rim in the manner shown in Figures 18..
and 19, in which V V represent sleeves for the ends of the fastoning wires V' to
pass through. These sleeves V take into the rim J and are embedded in the
edges of the cover G in the same way as the fastening wires V. Each sleeve.
may be in one piece, or in two pieces adapted to slide into each other, and it may
be solid at the middle part of its length or hollow, and of any suitable cross.
section. These sleeves lie snugly in the rim J, and the ends of each fastening
wire V are passed into its appropriate sleeve V and out through openings V' in
the latter, and through corresponding openings Vs in the side of the rim J. The
projecting ends of the wires V', which may he secrew-threaded, are then drawn
together by means of nuts or other suitable devices, not shown in the drawings,
Fo na to draw the wires tight. In some cases I pass the fastening wire twice
round the cover and rim and entirely or partly through the whole length of the
•sleeve or cover, and the sleeve may have a distinct channel for the ends of the
wire to pass through. 1 sometimes tighten the wires by crossing their ends and
drawing or forcing them by screw nuts or other suitable devices in opposite
directions.
I may use incurved rims with the sleeves above described, but in that case I
need not bring the ends of the wires through the rim as they may remain loose
and free to move longitudinally inside the sleeves.
1 sometimes place. longitudinally under the cover G, (seo Figure 20) at its sides,
tubes or receptacles W containing confined air which may be at atmospheric
pressure. The pneumatic tube D placed between these receptacles distends when
filled with compressed air, and compresses the air confined in the said tubes or
(receptacles, and these form cushions which protect the air tube D from being
jammed between the wires S S and the rim J, and, when an inner tube is not used,
prevent the escape of the compressed air. Sometimes I effect the same object by
menns of flaps of flexible material G', see Figure 21, passing down from the
wires SS of the cover G towards the bottom of the rin J, so that the pueumatio
tube D has to force the flaps G' out between the wire and rim before it can get

page_text: out itself. Sometimes I join together, for the same purpose, the side air
chambers W shown in Figure 22 by a connecting flap X as shown in Figure 22.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to he performed, I declare that what I
claim is :-
First. The method of confining the inflatable tube of a pneumatic tyre in a
comparatively small space, which consists in folding it and wrapping it round with
paper or other suitable material which is easily broken or torn by the inflation of
the tube, substantially as described with reference to Figure 1 of the drawings.
Second. In a tyre made of laminated tubes the use of longitudinal hollow or
solid distance pieces placed between the laminations, substantially as described
with reference to Figures 2 and 3 of the drawings.
Third. Constructing the laminated tube of a pneumatic tyre with air-tight
compartments containing air or other fluid by forming corrugations or distance
pieces on, or securing the same to, a suitable sheet of flexible material, and then
rolling the sheet so prepared on to a mandril, substantially as described with
reference to Figures 5 and 6 of the drawings.
Fourth. In a pneumatio tyre the use of a hollow air-tight tube or chamber
containing a fluid, which may be either compressible or incompressible, such tube
or chamber having solid or hollow distance pieces, or not, placed between the
inflatable tube and the rim, substantially as described with reference to Figure 7
and 8 of the drawings.
Fifth. In a charging valve for pueumatio tyres, the use of a trumpet-shaped
piece of indiarubber, or other suitable flexible air-tight material, secured in the
valve stem or body and to the inflatable tube, substantially as described with
reference to Figure 9 of the drawinge.
Sixth. In a pneumatic tyre the means for securing the tyre, or the cover
thereof, to the rim, which neaus consist in securing the outer casing to the rim
and passing the outer ends of the spokes through or partly through such outer
casing, substantially as described with reference to Figures 10, 12, 13, 14 and 15
of the drawings.
Seventh. In a pneumatic tyre the use of hollow air-tight tubes or chambers,
containing air or other fluid, at the sides of the cover and rim, substantially as
described with reference to Figures 11, 20 and 22 of the drawings.
Eighth. In pneumatic tyres the use, as restraining material for preventing the
undue expansion of the inflatable tube, of textile fabrics treated with and cemented
together by balata solution or a compound of balata and indiarubber solutions,
substantially as described.
Ninth. In pneumatic tyres the use of a combination of leather and textile
fabric treated with balata solution, or with a compound of balata and indiarubber
solutions, substantially as described.
Tonth. In connection with the fastening of pneumatic tyres to their rims, the
use of hollow sleeves adapted to receive the ends of the fastening wires, substantially
as described with reference to Figures 18 and 19 of the drawings.
Eleventh. In a pneumatic tyre the use of longitudinal air-tight tubes or chambers
containing air interposed between the inflatable tube and the cover, substantially
as described with reference to Figures 20 and 22 of the drawings.
February
TOOS
A. PULBROOK,
Per W. H. Beck,
116 Cannon Street, London, E.C., Agent.