Improvements in or connected with Pneumatic Tyres, and in Charging Valves for the same.
Year: 1895

page_text: Date of Application, 3rd Aug., 1835
Complete Specification Left, 4th May, 1896-Accepted, 1st Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in or connected with Pneumatic Tyres, and in
Charging Valves for the same.
I, ANTHONY PULBROOK, of 14 Victoria House, South Lambeth Road, in the
County of Middlesex, Solicitor, do hereby declare the nature of this invention to
be as follows:-
This invention relates firstly to improvements in methods of joining together the
ends of the tubes of pneumatic tyres described in the Specifications of Patents
granted to me bearing date respectively the 3rd October 1893, No. 18512, and the
27th December 1893, No. 24903, and consists in making the inwardly projecting
part of the socket, at one end of the tube, that takes into the recessed part of the
spigot at the other end of the tube that enters the said socket, of airtight
chambers containing confined air or gas, and having flexible elastic sides so that
when the compressed air in the tyre tube tends to force the parts together, the
confined air in the airtight chamber is compressed and its elasticity causes the
aforesaid inwardly projecting part of the socket to take a firm grasp in the recess
in the spigot end of the tube that is introduced into the socket, and thereby assists
in holding the ends of the tube in place.
Instead of making the shoulder of the spigot end of the pneumatic tube that
comes against the end of the socket, and the said end of the socket itself flat, as
heretofore, whereby a space or gap is sometimes left between the two flat surfaces
when the tyre is bent round into the circular form, and the two ends are brought
together, I make the inside of the socket end conical or trumpet mouthed, and the
part of the spigot end that abuts against the conical or trumpet mouthed end of
the socket of corresponding shape to fit same. By this means I avoid the space
or gap above mentioned, and strengthen the abutting parts. The conical or
trumpet mouthed end of the socket may be made hollow with airtight chambers
containing air as above described, or it may be made of solid material if
preferred.
In order to prevent the socket end of the tube from expanding by the
pressure of the compressed air in the tube, I sometimes solution or otherwise fix
a band of more or less unstretchable material round that part of the tube instead
of relying on the cover of the tyre as heretofore.
The invention relates secondly to improvements in the manufacture of the outer
covers of pneumatic tyres from fish or other skins. In making such covers from
fish-skins, particularly eel skins, the skin is often too narrow to fully cover the
pneumatic tube, and consequently make it up in the following manner :-
I take several pieces of skin preferably as broad as I can obtain them, and
join them together end to end in one long piece which is to form the tread part of
the tyre. I make the joints by cementing or solutioning them with any suitable
water-proof and preferably elastic cement or solution. I then sometimes sew
them together with one or more rows of stitches, such rows being either straight or
curved, and to prevent the stitches being worn by contact with the ground may
solution bands of indiarubber or fish-skin over them. I next take two similar
lengths of slightly narrower skins which I join on either side of the central or
tread piece by sewing and cementing, allowing sufficient width for a hem to hold
the wires or other fastenings.
Inasmuch as when the tyre covering encloses a round tube blown out with

page_text: compressed air the circumference of the tread portion will be greater than that of
the sides, a tyre cover thus made would pucker when made of a more or less
unstretchable skin, I sometimes cut the sides in gores. Sometimes I effect the
like object by solutioning the sides with a solution of indiarubber or balata, which
in drying causes them to contract and prevents their absorbing water.
I then
moisten the central part so as to render it stretchable. Water, or water to which
a little borax is added is a good moistening fluid; benzine also answers, but not so
well. I next fasten the cover while moist on a straight flexible mandril of about
the same diameter as the inner tube, and about the same length as the circum-
ference of the tyre, by winding tapes or bands of strong textile fabric, preferable
cut on the cross, or other more or less flexible and stretchable material, round both
mandril and skin; I then bend the mandril, with the cover on it, round into
a circle till the ends meet, which causes the tread portion of the cover to
stretch and assume the required curved shape. I keep it thus fixed till dry,
when it retains the shape thus imparted. Sometimes before removing the
shaped covering from the circular mandril I saturate the tread part, when
completely dry, with a solution of balata, indiarubber, or other similar gum, or a
mixture of such guns.
I preferably make the solution, especially when using balata, with warm mineral
naphtha, or petroleum ether; and when the solution is made with mineral naphtha
I prefer to add petroleum ether to the mixture and to agitate until the mixture
becomes homogeneous. When I use ordinary leather in a tyre, or its cover, I shape
it in the same way and by the same means, and when I use tubes of fish-skin or
thin leather for an outer covering for inner tubes, or for inner tubes themselves, as
described in the Specification of two Patents granted to me dated respectively the
3rd October 1893, No. 18512, above referred to, and the 6th November 1893,
No. 21080, I likewise shape them in the same manner.
The invention relates thirdly to improvements in the manufacture of the airtight
tubes used in pneumatic tyres. I make a compound tube consisting of an outer
covering of the grain part of skived or thin leather, made airtight as above
mentioned, and having solutioned, or otherwise connected to it (especially when
the leather happens to be thinner or weaker at some parts than at others) a fabric
cut on the cross to allow of expansion when inflated, so that when not inflated the
contraction of the textile fabric, cut on the cross, to its normal state will act on
the outside leather covering, and cause that to contract also by reason of the two
being connected together.
I also sometimes make more or less stretchable airtight tubes of fibrous
materials, such as thin leather, silk and so forth, in the following manner :-
1 first make a tube of thin indiarubber, and stretch it equally in all directions.
This may be effected by filling it with compressed air or other fluid. Whilst in
this condition I cement, solution, or otherwise fix on it an outer covering of the
thin fibrous material such as thin split or skived leather, or silk or other textile
fabric. I then allow the tube to resuine its normal condition,, when the contraction
of the indiarubber contracts the fibrous covering as well, and thus an exceedingly
strong elastic tube is made. Sometimes I treat the leather with diarubber or
balata, or a mixture of the two as hereinbefore described. Sometimes instead
of making a tube of indiarubber in the first instance I stretch a sheet of
indiarubber in all directions, and whilst in that condition cement
or solution
the aforesaid material to it, and make the whole into the tube form afterwards.
The invention relates, fourthly, to improvements in the method of fastening the
covers of tyres when such covers are formed of the rough skins of fishes. I have
found that a creeping action sometimes occurs with such skin coverings, and to
prevent this, when wires are used for fixing the tyres, I corrugate such wires or
otherwise form them with projections and depressions, or knobs or like alterations
of size at intervals, and the rims may, or may not, have corresponding depressions
and projections, and where hooks or similar tastenings to the rim are used I make
depressions in the rim at intervals to receive them.

page_text: The invention relates, fifthly, to improvements in the charging valves of
pneumatic tubes, and these improvements consist in using for the valve a hollow
cylinder, cone, globe, or other airtight receptacle made of thin flexible or elastic
material, such as indiarubber, and containing a compressible fluid such as air or
gas, at or above atmospheric pressure. When this cylinder, cone, globe or other
airtight receptacle is pressed against the valve opening or seating the contained
elastic air or gas is compressed, and the effort of the air or gas to regain its
Dormal pressure causes a uniform equal and lasting pressure over the orifice of
the valve and effectually prevents the escape of any air or gas through the outlet
closed by it. I also employ hollow airtight elastic receptacles as packing for the
glands of cbarging valves, and for washers used in making the airtight joints of
such valves.
Sometimes I effect the same object in the following manner :-I employ a hollow
stem passing from the inside of the tube through the rim in the usual way. I make
a tube of indiarubber or other like elastic material the lower part of which is of
less diameter than the stem so as to allow the outside of the tube to be surrounded
by an air space between it and the stem at this part. The upper part of the tube
I make however of the same diameter as the internal diameter of the stem, the
internal diameter of the tube being the same throughout. I then cement or
solution the tube at the upper part, where it is of the same diameter as the internal
diameter of the stem at that point,.to the stemn so as to prevent the escape of any
air or gas, except through the central opening. I screw, or otherwise fix a nozzle
or cover at the top of the stem having a central opening corresponding to the size
of the internal diameter of the tube, or a little less. Through this opening I pass
a spindle having at its lower end a metallic, rubber or other ball, cone, or
cylinder, which may be one of the herein before described hollow receptacles
containing compressed air; the pressure of the internal air forces the ball, cone,
or cylinder against the sides of the tube and effectually closes the outlet of the
valve, and at the same time the compressed air between the tube and stem forces
the tube on to the ball. cone, or other compressed air receptacle.
I provide by any suitable means for inflation or deflation and sometimes I have
two valves for those purposes. I sometimes use two cylinders, cones, or balls one
under the other, and of the same or different sizes, and sometimes I fit them into
collars or projections in the tube, so that the compressed air passing up between
the stem and tube compresses the latter on to the balls, cylinders or cones whereby
the greater the pressure of the air or gas the greater the power of the valve to
retain it. Sometimes I join the tube airtight at top and bottom to the stem in
order to have an air or gastight chamber. The ball, cone, or cylinder being forced
up by the pressure of the compressed air in the tyre compresses the air between
the tube and the stem which air in its effort to regain its normal pressure causes
the sides of the tube to tightly grasp the balls, cones or hollow receptacles
containing compressed air or gas, and the latter in turn in its efforts to expand
forces the sides of the receptacle against the sides of the tube with such an equal
and continuous pressure as to preclude the escape of any air or gas.
The invention relates, sixthly, to improved means of fastening the outer cover
to the rim of the wheel. For this purpose I make the rim of any suitable shape
in the centre but with one or more grooves or channels on either side. The
bottom of these channels may be plain or corrugated or provided with depressions
and projections. The cover may be of any suitable shape and material, but
preferably provided with a thickened flexible selvage or flange at each side adapted
to take into the grooves or channels at the sides of the rim. I fasten the
cover on the rim by any suitable means, for example I may wind round the
selvages or flanges of the cover, when placed in the grooves or channels of
the rim, wires, cords, tapes or any other suitable flexible material tightened on,
and fastened to the rim, or otherwise, by any convenient means. The flexible
material for fastening the cover may form part of the latter or be separate
therefrom as may be preferred. The selvages or flanges of the cover may be

page_text: made bollow, so as to form airtight chambers, the air contained in which will be
compressed by the pressure of the fastening wires or cords, and the surfaces of
the selvages or flanges will thereby be forced into close contact with the grooves
or channels in the rim, and the entrance of water between the cover and the
pneumatic tyre completely prevented.
1
A. PULBROOK,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.
Improvements in or connected with Pneumatic Tyres, and in
Charging Valves for the same.
1, ANTHONY PULBROOK, formerly of 14 Victoria House, South Lambeth Road,
in the County of Middlesex, at present of 8 Unwin Mansions, Queen's Club
Gardens, West Kensington in the County of Middlesex, 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, firstly, to improvements in the methods of joining
together the ends of the tubes of pneumatic tyres described in the Specifications of
Patents granted to me bearing date respectively the 3rd October, 1893, No. 18512,
and the 27th December 1893 No. 24903, and consists in making the inwardly
projecting part of the socket, at one end of the tube, that takes into the recessed
part of the spigot at the other end of the tube which enters the said socket, of
air-tight chambers containing confined air or gas, and having flexible or elastic
sides, so that when the compressed air in the tyre tube tends to force the parts
together, the confined air in the airtight chamber is compressed, and its elasticity
not only adds to the resiliency of the tyre, but causes the aforesaid inwardly pro-
jecting part of the socket to take a firm grasp in the recess in the spigot end of the
tube that is introduced into the socket, and thereby assists in holding the ends of
the tube in place.
Instead of making the shoulder of the spigot end of the pneumatic tube that
comes against the end of the socket, and the said end of the socket itself flat, as
heretofore, whereby a space or gap is sometimes left between the two flat surfaces
at the outside or tread part which forms the largest diameter of the tube when the
tyre is bent round into the circular form, and the two ends are brought together,
I make the inside of the socket end conical or trumpet-mouthed, and the part of
the spigot end that abuts against the conical or trumpet-mouthed end of the socket
of corresponding shape to fit same.
Figure 1 of the accompanying drawings represents a longitudinal section
showing the two ends of a pneumatic tyre joined together in the manner above
referred to, and with the first part of my present invention applied thereto.
The left hand end E of the tube E is made with an inwardly projecting
part E2 extending circumferentially round the interior of the end of the tube,
such part E2 being made hollow as shown, so as to form airtight chambers
containing confined air or gas, and having flexible elastic sides, the other end E3
being made of corresponding shape so as to fit into the other end E¹ of the tube
as shown in the figure. When compressed air is forced into the tube E in the
usual way it expands the end E3 in the end E', and the shape of the parts
prevents them from being drawn one out of the other so long as the air pressure is
maintained. By making the outer end of the part E 2 conical or trumpet-
mouthed as shown I avoid the space or gap above mentioned, and strengthen the
abutting parts. The part E 2 may be made hollow with airtight chambers

page_text: containing air or gas as described, and as shown in the drawing, or it may be made
of solid material if preferred.
I sometimes continue the end of the tube beyond the conical or trumpet-
mouthed part in the form of a cylindrical sleeve, as shown at E4 in Figure 2,
adapted to fit over the part of the spigot end E 3 of the tube E which lies
behind the recess into which the part E2 of the socket end enters. This sleeve E4
may be made hollow with air chambers like the part E 3, or solid as shown in the
drawing.
In order to prevent the socket end of the tube from expanding by the pressure
of the compressed air in the tube, I sometimes solution or otherwise fix a band of
more or less unstretchable material around that part of the tube instead of relying
on the cover of the tyre as heretofore.
The invention relates. secondly, to improvements in the manufacture of the
outer covers of pneumatic tyres from fish or other skin. In making such covers
from fish skins, particularly eel skin, the skin is often too narrow to fully cover
the pneumatic tube, and I consequently make it up in the following manner :-
I take several pieces of skin A, see Figure 3, preferably as broad as I can
obtain them, and join them together end to end in one long piece which is to
form the tread part of the tyre. I make the joints as at A¹ for example by
bevilling the two ends that come together in opposite directions, and then cement
or solution the pieces with any suitable water-proof and, preferably, elastic cement
or solution on to the usual canvas or other textile backing B, preferably cut on the
bias or cross. In making the joints the overlapping ends which are to be
cemented or solutioned together may be rubbed down with sand paper or other
similar abrading material to form the bevils and make the skin of the same
thickness at the joint as at the other parts of the tread. I then sometimes sew
the pieces together side by side with one or more rows of stitches, such rows being
either straight, angular or curved, and to prevent the stitches being worn by
contact with the ground I may solution bands of indiarubber or fish-skin C over
them, preferably making the joinings of such bands intermediate between the
aforesaid joinings A' of the cover, and preferably using the dovetail joint shown
at D, which joint may be made by means of a tool or cutter of corresponding
shape driven through the overlapping ends. I preferably water-proof the band of
fish-skin with balata solution, or with mixed indiarubber and balata solutions,.
shaping them as hereinafter described, and fastening them to the cover when the
latter is distended. 1 next take similar lengths of slightly narrower skins which I
join on either side of the conical or tread piece by cementing to the textile fabric,
when one is used, sometimes allowing sufficient width for a hem to hold the
wires or other fastenings.
When using a textile backing I prefer to use one having the same, or about the
same, stretchable power as the skin, so that when combined and subjected to
tensile stress they may both be strained to the same extent.
When the stretching
powers of the two materials are different the strain is unequally divided, and is
thrown mostly on the least stretchable, and when this happens to be the skin it
cracks. In ordinary tyres the canvas bears nearly all the strain without damaging
the indiarubber with which it is combined.
Inasmuch as when the tyre covering encloses a round tube inflated with
compressed air, the circumference of the tread portion will be greater than that of
the sides, a tyre cover would pucker when made of a more or less unstretchable
skin or leather, I sometimes cut the sides in gores as shown at B¹ in Figure 3.
Sometimes I effect the like object in the following manner:
I make the skin or leather waterproof by treating it with balata or indiarubber
solution, or a mixture of the two as hereinafter described. I then moisten the skin
or leather with water, or with water to which a little borax is added, so as to
render it stretchable. I next shape the skin or leather so moistened and made
stretchable on a straight flexible maudril of about the same diameter as the inner
tube when inflated, and about the same length as the circumference of the tyre,

page_text: and keep it in position by winding narrow overlapping tapes or bands of strong
textile fabric, which may be made or cut on the cross or bias, or other more or
less flexible or stretchable material, round both mandril and skin; I then bend the
mandril, with the cover on it, round into a circle till the ends meet, taking care
that the skin or leather cover occupies the like position on the mandril that it will
on the tyre. I keep it thus fixed till dry, when it retains the shape thus imparted.
Instead of using a straight mandril I soinetimes use one having the circular form
before placing the skin or leather on it.
Instead of water I may use benzine, but it does not answer so well.
In that case
I do not waterproof the leather or skin until afterwards. When dry I paint the
leather or skin with a solution of balata, or a mixed solution of balata and india-
rubber. I then solution the inner side of the shaped skin and also the canvas or
other backing to receive it, and having inflated the pneumatic tube until the said
backing is quite hard I fix the shaped skin to it. I then wind strong tapes round
both rim and tyre, and inflate the tyre as hard as possible; the uniform pressure
thereby obtained causes the skin to adhere to the canvas or other backing closely
and without pucker. I preferably make the solution, when using balata, with warm
mineral naphtha, but I sometimes use a mixed solution of indiarubber and balata.
In that case I make the solutions with the same hydro-carbon solvent and then mix
the solutions together; but when using warm mineral naphtha for the balata I may
use petroleum ether for the indiarubber, and then intimately mix the two solutions
when warm.
In the case of the mixture 1 preferably use that portion of balata
which when dissolved and cold remains at the top and forms a white jelly-like
substance. When I use ordinary leather in a tyre, I shape and waterproof it in
the same way and by the same means, and when I use fish-skin or thin leather for
an outer covering for inner tubes, or for inner tubes themselves as described in the
Specifications of two Patents, granted to me dated respectively the 3rd October 1893,
No. 18512, above referred to, and the 6th November 1895 No. 21080, I likewise
shape them in the same manner.
The invention relates, thirdly, to improvements in the manufacture of the
airtight tubes used in pneumatic tyres. I make a compound tube for pneumatic
tyres of an outer covering either of the grain part of skived or of thin leather made
airtight with india rubber or balata solution, or with a mixture of such solutions as
hereinbefore described, and then solution to the same a textile fabric cut on the
cross or bias to allow of expansion when inflated. The contraction of the textile
fabric to its normal condition when deflated will art on the outside leather covering,
and cause that to contract also by reason of the two being closely solutioned
together. I also roake an outside cover for the pneumatic tube in the same manner.
Sometimes I form a tube of textile fabric cut on the cross or bias, and stretch it
by inflating a rubber tube inside it, and then solutiou the leather to it.
I also sometimes make more or less stretchable airtight tubes of fibrous materials,
such as silk or other textile fabric or thin leather, but I prefer to use eel skins or
skins of the shark species, because the fibres of such skins cross each other at acute
angles and therefore take more easily the tubular form. And for this purpose
I proceed in the following manner :-I first make a tube of indiarubber and stretch
it equally in all directions. This may be effected by filling it with compressed air
or other fluid. Whilst in this condition I cement, solution, or otherwise attach to
it an outer covering of the thin fibrous material, such as split, skived, or thiu
leather, or dressed skin, or silk, or other textile fabric, preferably cut on the cross
or bias.
I then allow the tube to resume its normal condition, when the contraction
of the indiarubber causes the fibrous covering to contract also, and thus an
exceedingly strong and light elastic tube is made. Sometimes I treat the leather
or textile fabric with indiarubber or balata, or with a mixture of the two as
hereinbefore described. Sometimes, instead of making a tube of india rubber in
the first instance, I stretch a sheet of indiarubber in all directions, and whilst in
that condition cement or solution the aforesaid material to it, and make the whole
into the tube form afterwards.

page_text: When I use vulcanized indiarubber I rub the tube or sheet with sand paper or
like abrading material in the usual manner, and I also treat that part of the fibrous
material which is solutioned to the indiarubber with a solution of indiarubber,
balata, or a mixture of indiarubber and balata in the well known manner to make
them adhere.
The invention relates, fourthly, to improvements in the method of fastening the
covers of tyres. When such covers are formed of the rough skins of fishes I have
found that the grip caused by their use sets up a creeping action or draws the
wires, when such are used, from the rin, thereby allowing the pneumatic tube to
force itself between the rim and the wires and to get nipped by the latter; and to
prevent any such action when wires are used for fixing the tyres, I corrugate such
wires or otherwise form them with projections and depressions, or knobs, or like
alterations of size at intervals, and the rims may, or may not, have corresponding
depressions and projections, and where hooks or similar fastenings are used I make
depressions in the rim at intervals to receive them, or I may place between the
corrugated wires, or wires with projections and depressions or knobs, and the rim
having similar corrugations, projections, depressions or knobs, an airtight compart-
ment containing air, and made of flexible material for the corrugations, projections,
depressions or knobs to embed themselves into. In this case the rim may be plain,
and the flexible material may, or may not be connected or solutioned to it. This
airtight compartment may form part of the edge or side of the cover.
The invention relates, fifthly, to improvements in the charging valves of
pneumatic tubes, and these improvements consist in using for the valve a closed
hollow cylinder, cone, globe or other airtight receptacle made of thin flexible
material, or may use thin elastic material, such as indiarubber, containing a
compressible fluid, such as air or gas, at or above atmospheric pressure.
When
this cylinder, cone, globe, or other airtight receptacle is pressed against the valve
opening or seating, the contained elastic air or gas is compressed, and the effort of
the air or gas to regain its normal pressure causes a uniform, equal, and lasting
pressure over the orifice of the valves, and effectually prevents the escape of any
air or gas through the outlet closed by it. I also employ hollow airtight elastic
receptacles as packing for the glands of charging valves, and for washers used in
making the airtight joints of such valves.
Figure 4 of the drawings is a longitudinal section of a charging valve constructed
in accordance with this part of my invention, and Figure 5 is an elevation of a cap
intended for use with the same.
F is a metal stem or valve body screwed externally as usual and provided with
the usual securing out F' and base or flange G to enable the pneumatic tube H
to be compressed in order to prevent leakage in the usual way. F2 is the rim of
the wheel. The stem F is passed through a hole in the tube H, and through the
washer plate I and is secured by the nut J in the usual way. Sometimes I place
a hollow airtight washer containing a fluid between the washer plate I and the base
or flange G of the stem. To make the arrangement still more effectual I sometimes
make an airtight compartment in connection with the tube H itself outside the same
and under the washer plate I. The upper part of the stem F is provided with a
screw thread K to receive the inflating pump. I fit into the stem F a tubular
piece of indiarubber L trumpet-mouthed at its lower end, and 1 cement the upper
part of this tubular piece to the inside of the stem F to prevent the passage of air
between the rubber and the stem, and I make the lower or trumpet-mouthed end of
the tubular piece L of thin rubber, and larger than the base or flange G of the stem
as shown at L, and 1 cement the edge of this larger part to the inside of the
pneumatic tube H round and beyond the edge of the flange G of the stem, whereby
the escape of air, except through the central opening of the tubular piece L, is still
more effectually prevented. I preferably shape the trumpet end of the tubular
piece L so that when cemented or solutioned as above described to the pneumatio
tube H there will be formed an airtight chamber, containing air, between the solid
part that passes into the stem F, and the edge which has been cemented or

page_text: solutioned to the pneumatic tube; but I may make the trumpet-mouthed part
without such confined air space relying on the elasticity of the rubber itself to
prevent leakage of the contained air. I sometimes solution or cement the edge
of the trumpet shaped part to the base or flange G of the stem F. The valve M
is provided with a spindle N which passes up through the central opening in the
tubular piece L, and may either be inade an easy fit in such central opening or
be made flat on one or more sides to allow of the entrance, or escape of air.
I preferably interpose between the valve M and its scat a ring P made either of
hollow indiarubber, or other flexible airtight material, having confined air in its
When the
hollow space, or of solid rubber or other flexible airtight material.
valve M has been put in place, as shown in Figure 4, 1 secure a diaphragm Q to
the inside of the pneumatic tube H by cementing or solutioning it at intervals
round its edge, leaving uncemented or unsolutioned spaces through which air can
pass to the interior of the tube H. This diaphragm may be made of stretchable
or non-stretchable material, or partly of one and partly of the other, and is
preferably provided with a circular or otherwise shaped airtight chamber R placed
immediately below the valve M, and with an annular or ring shaped airtight
chamber S. These chambers R and S contain a confined fluid, and the centre
one R is so adapted that it presses the valve M normally outwards, and the outer
one S so that it presses normally against the edges of the trumpet shaped opening,
but clear of the valve M.
It will now be understood that when the air pump is screwed on to the top of the
stem F and is operated, the air supplied by it passes down the side of the spindle N,
opens the valve M and enters the hollow space formed by the diaphragm Q and
issues thence through the spaces left uncemented at the edge of the said diaphragm,
into the pneumatic tube H. When the down stroke of the pump is completed the
compressed air contained in the pneumatic tube presses the diaphragm against
the inside of the said tube and prevents the egress of the air, at the same time the
pressure of the air on the centre of the diaphragm is transmitted through the air
chamber R to the underside of the valve M and forces the latter against its seating,
the same pressure also forces the annular air chamber against the part L' of the
tubular piece L, thereby forming a second non-return valve.
as
of the
is adapted
For the purpose of deflating the tyre when necessary, I provide a
shown in Figure 5, one end T of which is adapted to screw on to
stem F to prevent escape of air in the usual way, and the other
to effect the deflation, and for that purpose is provided with a pin U¹, which presses
on the end of the valve spindle N when the end U of the cap is screwed on to the
stem F, whereby the valve M is pressed inwards and forces the diaphragm Qaway
from the inside of the tube H allowing the air to escape therefrom through the
holes U2 in the cap. T₁ is the milled collar by which the cap may be screwed on
and off the stem F, and T2 is a chain by which the cap may be secured to the
stem in the usual way.
At
In some cases it is not convenient to allow sufficient inward motion of the valve
to enable it to press the diaphragm Q away from the tube H sufficiently to enable
deflation to take place. In this case I do not allow the edge of the diaphragm to
extend beyond the air chamber S, but cement or solution to the diaphragm one or
more tapes Q the outer ends of which I solution to the inside of the tube H.
the air chambers S these tapes may be looped, as shown at Q2 and be left
unsolutioned to the diaphragm at those parts. Under these circumstances, when
the valve M.is pressed inwards the diaphragm Q stretches at the parts Q2, and the
air chamber S is thereby drawn away out of contact with the part L', and the air
can then escape between the surfaces thus separated.
When the hollow airtight elastic chambers or receptacles are to be used as
packing for glands or as washers they may be made in the shape of hollow rings
or otherwise as may be best suited to the purpose for which they are to be
-employed.
The invention relates, sixthly, to improved means of fastening the outer cover to

page_text: the rim of the wheel. For this purpose I make the rim at the tread part of any
suitable shape, convex, flat, or concave or hollow in the centre, but with one or
more grooves or channels on either side. The bottom of these chanuels may be
plain or corrugated or provided with depressions and projections. The cover may
be of any suitable shape and material, preferably fish-skin or thin leather to stand
the wear of the fastenings, but preferably provided with a thickened flexible selvage
or flange at each side adapted to take into the grooves or channels on each side of
the rim. I fasten the cover on the rim by any suitable means, for example I may
wind round the selvages or flanges of the cover, when placed in the grooves or
channels of the rin, wires, cords, tapes, or any other suitable flexible material
tightened on, and fastened to the rim, or otherwise, by any convenient means.
The flexible material for fastening the cover may form part of the latter, or be
separate therefrom as may be preferred. The selvages or flanges of the cover inay
be made hollow, so as to form airtight chambers, the air contained in which will be
compressed by the pressure of the fastening wires or cords, and the strain occasioned
by the inflation of the pneumatic tube will force the surfaces of the selvages or
flanges into close contact with the grooves or channels in the rim; the entrance of
water or grit between the cover and the pneumatic tyre will be thereby completely
-prevented.
Figure of the accompanying drawings is a transverse section of a rim and tyre
constructed in accordance with this part of my invention, Figure 7 is a transverse
section of a rim and tyre somewhat different from that shown in Figure 6, and
Figure 8 shows how the ends of the fastening wires may be connected together.
V represents the rim of the wheel provided with side channels V' with a lip or
projection V 2 at its inner edge. W is the outer cover of the tyre provided
preferably with hollow air-tight sides W₁ charged with air or gas. W✶ is the
pneumatic tube. ✗ are short plates or distance pieces preferably made of a non-
oxidisable metal having three, more or less, eyelets X for the fastening wires ✗2
to pass through. These plates X are preferably made of such a depth that when
standing opposite the opening into the channels, as shown in Figure 6, they cannot
be drawn out through such openings, though they can readily be introduced
diagonally or by slightly bending them. The ends of each fastening wire are
secured to angle plates Y see Figure 8, provided with a tightening screw Y', an
have a bed plate Y 2 of non-oxidisable metal placed under them to prevent
friction of tightening up damaging the cover. Any other known meang
tightening up the wires may, however, be employed.
It will now be understood that when the tyre is deflated the edges of the cover W
can be easily placed in the channels V', the plates X applied, and the fastening
wires threaded through the eyelets X'. By then screwing up the wires by means
of their tightening screws Y, the wires being kept even by the plates or distance
pieces X and eyelets X', the air in the hollow air spaces W₁ is compressed and the
cover is thereby forced tightly against the rim, effectually preventing the introduc-
tion of water or grit. Moreover the air in the hollow spaces W₁ assists by its
reaction to tighten the wires, and this action is increased when the tyre is inflated.
The air tube, cord, leather or wire W' at the edge of the cover projecting beyond
the tightened wire prevents any yielding of the cover, and retains it in place, and
in the same manner the strain caused by the friction of the tyre on the road drags
the other wire against the projection in the rim and prevents movement of the
cover.
The airtight chambers in the cover passing by the sides of the lateral projections
in the rim adds to the resiliency of the tyre, and assists in preventing puncture.
In order to obtain access to the pneumatic tube W the tightening screws Y₁ of
the wires are slackened and the plates X moved sidewise, the edge of the cover
can then be drawn out and the tube W* got at easily.
Figure 7 shows the application of a cover having the airtight chambers at its
edges for the fastening wires to bear against, to a rim of well known construction,
similar letters of reference relating to like parts in both Figures 6 and 7.
A

page_text: Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. In a spigot and socket joint for joining together the ends of a pneumatic
tyre tube, making the part of the socket which projects inwards and takes into a
recessed part of the spigot with airtight chambers containing confined air or gas,
substantially as described with reference to Figure 1 of the drawings.
Second. In a spigot and socket joint for joining together the ends of a pneumatic
tyre tube, making the inside of the end of the socket conical or trumpet-mouthed,
with or without a cylindrical sleeve extending beyond the said conical or trumpet
mouthed part, and the part of the spigot end that abuts against the conical or
trumpet-mouthed end of the socket of corresponding shape to fit same, substantially
as described with reference to Figures 1 and 2 of the drawings.
Third. In a spigot and socket joint for joining together the ends of a pneumatic
tyre tube, the use of a band of more or less unstretchable material solutioned or
otherwise fixed round the socket, substantially as, and for the purpose specified.
Fourth. A cover for a pneumatic tyre made of fish skin substantially as described
with reference to Figure 3 of the drawings.
Fifth. The method of shaping skin or leather for pneumatic tyres which consists
in moistening the material, shaping it on a mandril and waterproofing, either before
or after application to the mandril, by treating it with a solution of balata or
indiarubber, or with a mixture of such solutions, substantially as described.
Sixth. An airtight tube for pneumatic tyres, or a cover for same, consisting of
leather or fish skin made airtight with a solution of balata or indiarubber, or with
a mixture of such solutions, and cemented or solutioned to textile fabric cut on the
cross or bias, substantially as described.
Seventh. An airtight tube for pneumatic tyres constructed by first stretching an
indiarubber tube in all directions, as by filling the same with compressed air or
other fluid for example, then cementing, solutioning, or otherwise attaching to such
stretched tube au outer covering of thin fibrous or textile material, substantially as
described.
Eighth. In connection with a charging valve for pneumatic tyres the use of
hollow elastic chambers charged with air or gas and adapted to act as valves to
prevent the escape of air from the pneumatic tube, substantially as described with
reference to Figure 4 of the drawings.
Ninth. The use of flexible hollow airtight chambers charged with air or gas as
packing for the glands of charging valves, and for washers to make the airtight
joints of such valves, substantially as described.
Tenth. The improved devices for fastening the outer cover of a pneumatic tyre to
the rim of the wheel, which consist of a rim constructed with one or more grooves
or channels on either side, plates or distance pieces adapted to fit into the said
grooves or channels and to bear against the sides of the cover contained therein,
and fastening wires passed through eyelets on the aforesaid plates or distance
pieces, combined and arranged substantially as described with reference to Figure 6
of the drawings.
Eleventh. In a cover for a pneumatic tyre, the use of hollow airtight chambers
charged with air or gas, at the sides or edges of the cover, substantially as described
with reference to Figures 6 and 7 of the drawings, and for the purposes specified.
Dated this 4th day of May 1896.
A. PULBROOK,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.