Improvements in and connected with Pneumatic Tyres.
Year: 1897

page_text: Date of Application, 9th Apr., 1897
Complete Specification Left, 9th Feb., 1898-Accepted, 2nd Apr., 1898
PROVISIONAL SPECIFICATION.
Improvements in and connected with Pneumatic Tyres.
I, PHILIP BRAHAM, of 18, Leigh Street, Burton Crescent, London, W.C.,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to pneumatic tyres, and it consists mainly in the com-
bination with a pneumatic tyre of a device which automatically effects the
inflation of the pneumatic tyre from a state of partial or total deflation, and also
maintains the proper degree of inflation of the inflated tyre during the travel of
the wheel to which it is fitted.
According to one way of carrying out this invention I provide inside a pneu-
matic tyre a hollow body preferably of elongated lenticular form.
This hollow body may be formed in one piece or may be composed of two
normally dished plates or discs of rubber or other suitable material having suffi-
cient resiliency or elasticity for the purposes of my invention. These two discs
or plates are placed together with their concave surfaces facing each other and
are connected together at their meeting edges in an air tight manner. The said
hollow body is provided with one or more slit-like orifices, each orifice being
formed by flexible edges or lips which are adapted to act after the manner of
a non-return valve such for example as a Perreaux valve, that is to say, the said
edges or lips can open to allow of the passage of air from the interior of the
hollow body but will close and prevent the return or passage of air into the said
hollow body.
The inne: disc or portion of the hollow body is provided with a tubular neck
which extends through the wall of the tyre and projects beyond the wheel rim
into the atmosphere. This neck is open at its inner end to the interior of the
hollow body and at its outer end it is provided with edges or lips which con-
stitute a non-return valve, in such wise that the said edges or lips can open to
allow of air passing into the hollow body, but when closed will not allow air to
pass from the hollow body into the atmosphere.
The operation of my improved device is as follows:-When a wheel fitted with
a pneumatic tyre provided with this improved device is made to travel along the
ground, the hollow body, which is normally expanded by reason of its inherent
resiliency, will be compressed each time it is brought by the revolution of the
wheel between the wheel rim and the ground. This compression will have the
effect of forcing the air contained in the hollow body out through its first
described orifice or orifices into the interior of the pneumatic tyre. By the con-
tinued revolution of the wheel the hollow body becomes relieved of load, and will
expand by reason of its resiliency; and as the lips or edges of its orifice or orifices
will not allow of air passing back into it, a partial vacuum will be produced in
its interior.
In consequence, air from the atmosphere will force open the edges or lips of
the tubular neck aforesaid and will pass through the said neck into the interior

page_text: of the hollow body to be forced out of the latter into the pneumatic tyre when
the body is again brought next to the ground by the continued revolution of the
wheel, the edges or lips of the neck closing so as to prevent the air from escaping
back into the atmosphere.
The operation of the valve like edges or lips, as also the resiliency of the
material of the hollow body may be aided if necessary by the provision of springs
inside or outside of the material of said edges or lips or body, or by mechanical
appliances such as levers inside the tyre operated by the movement of the
periphery of the tyre as it is compressed and expands."
The tubular neck is preferably provided with a protective cap or cage to pre-
vent the entrance of grit and dust.
Dated the 9th day of Anril 1807
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, W.C., Chartered Patent Agents.
Improvements in and connected with Pneumatic Tyres.
I, PHILIP BRAILAM, of 18, Leigh Street, Burton Crescent, London, W.C.,
Mechanical Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
This invention relates to pneumatic tyres, and it consists mainly in the com-
bination with a pneumatic tyre and within the same of a device which automa-
tically effects the inflation of the pneumatic tyre from a state of partial or total
deflation, and also maintains the proper degree of inflation of the inflated tyre
during the travel of the wheel to which it is fitted.
According to one way of carrying out this invention I provide inside a pneu-
matic tyre a hollow body preferably of elongated lenticular form.
This hollow body may be formed in one piece or may be composed of two
normally dished plates or discs of rubber or other suitable material having suffi-
cient resiliency or elasticity for the purposes of my invention. These two discs
or plates are placed together with their concave surfaces facing each other and
are connected together at their meeting edges in an air tight manner. The said
hollow body is provided with one or more slit-like orifices, each orifice being
formed by flexible edges or lips which are adapted to act after the manner of
a non-return valve such for example as a Perreaux valve, that is to say, the said
edges or lips can open to allow of the passage of air from the interior of the
hollow body but will close and prevent the return or passage of air into the said
hollow body.
The inner disc or portion of the hollow body is provided with a tubular neck
which extends through the wall of the tyre and projects beyond the wheel rim
into the atmosphere. This neck is open at its inner end to the interior of the
hollow body and at its outer end it is provided with edges or lips which con-
stitute a non-return valve, in such wise that the said edges or lips can open to
allow of air passing into the hollow body, but when closed will not allow air to
pass from the hollow body into the atmosphere.
The operation of my improved device is as follows:-When a wheel fitted with
a pneumatic tyre provided with this improved device is made to travel along the
ground, the hollow body, which is normally expanded by reason of its inherent
resiliency, will be compressed each time it is brought by the revolution of the
wheel between the wheel rim and the ground. This compression will have the

page_text: effect of forcing the air contained in the hollow body out through its first
described orifice or orifices into the interior of the pneumatic tyre. By the con-
tinued revolution of the wheel the hollow body becomes relieved of load, and will
expand by reason of its resiliency; and as the lips or edges of its orifice or orifices
will not allow of air passing back into it, a partial vacuum will be produced in
its interior.
In consequence, air from the atmosphere will force open the edges or lips of
the tubular neck aforesaid and will pass through the said neck into the interior
of the hollow body to be forced out of the latter into the pneumatic tyre when
the body is again brought next to the ground by the continued revolution of the
wheel, the edges or lips of the neck closing so as to prevent the air from escaping
back into the atmosphere.
The operation of the valve like edges or lips, as also the resiliency of the material
of the hollow body may be aided if necessary by the provision of springs inside
or outside or embedded in the thickness of the material of said edges or lips or
body, or by mechanical appliances such as levers inside the tyre operated by the
movement of the periphery of the tyre as it is compressed and expands.
The tubular neck is preferably provided with a protective cap or cage to pre-
vent the entrance of grit and dust.
Various arrangements of this improved device for automatically inflating a
pneumatic tyre during the travel of the wheel to which said tyre is fitted are
shown in vertical longitudinal section in the accompanying illustrative drawings
in which:
Figure 1 shows the improved device in its simplest form in which the expansion
of the hollow body is aided by the provision of springs inside the hollow body.
Figure 2 shows an arrangement of the improved device in which the expansion
of the hollow body is aided by a lever operated by the movement of the tread of
the tyre as it is compressed and expands.
Figures 3 and 4 show an arrangement in which the expansion of the hollow
body is aided by the provision of a spring outside the hollow body, and the com-
pression of the hollow body is effected through the medium of a lever operated
by the tread of the tyre and Figure 5 shows a modification of that shown in
Figures 3 and 4.
In all these figures only so much of the wheel and tyre is shown as will enable
the invention to be properly understood. It is also to be understood that this
invention is shown applied to a double-tube pneumatic tyre, by way of example
only, and that the improved device can be readily used also with single tube
tyres.
In the arrangement shown in Figure 1, 1, 1^ is the pneumatic tyre to be auto-
matically inflated, composed in this case of an inner air tube 1, enclosed in an
outer cover 1, and 2 is the rim of the wheel on which the tyre is mounted. 3 is
the hollow body of approximately elongated lenticular form composed of elastic
material and provided at one end with a slit-like orifice 4 formed by flexible
elastic edges or lips 4,.4, which act in the manner of a non-return outlet valve,
that is to say the lips 4ª can open to allow of the passage of air from the interior
of the hollow body 3 but will close and prevent the return or passage of air into
the said hollow body. The hollow body 3 is connected at its other end by means
of a tubular neck 5 to the casing G of a suitable non-return inlet valve consisting
preferably of a slit-like orifice formed by flexible elastic edges or lips 7 which will
open to allow air to enter the hollow body 3 but will close to prevent air from
passing back from said hollow body. The valve casing 6 is provided at its inlet
with a dust-filter cap 6º.
The expanding tendency of the hollow body 3 may be aided by or may be
wholly due to the elasticity of a pair of springs 8 which are arranged in the
hollow body 3 in such a manner as that, the said springs have a constant tendency
to open out or expand the said hollow body so as to press the lower or outer
wall 3 of the latter against the inner tread portion of the tyre.

page_text: The operation of this arrangement is as follows:-The hollow body 3 which is
normally expanded will be compressed each time it is brought by the revolution
of the wheel between the wheel rim and the ground, with the result that the air
contained in the hollow body will be forced out through the outlet orifice 4 into
the interior of the air tube 1. By the continued revolution of the wheel, the
hollow body becomes relieved of load and will expand by reason of its resiliency
aided by the elasticity of the springs 8; and as the lips 4" of the orifice 4 will
close so as not to allow air to pass back into the hollow body, air from the atmos-
phere will pass in through the valve casing 6, and forcing open the lips of the
non-return inlet valve 7, will pass into the interior of the hollow body 3 to be
forced out of the latter through the non-return outlet valve 4, 4", into the air
tube 1 when the hollow body is again brought next to the ground.
In all cases where a non-return inlet valve of the kind indicated at 7 is
employed, a separate valve (not shown) may be provided for deflating the tyre if
required.
In the arrangement shown in Figure 2, the hollow body 3 is provided with a
slit-like non-return outlet valve 4, 4" at each end and it is connected by means of a
central aperture 5 in its upper or inner portion 3b to the valve casing G of the
non-return inlet valve 7. The expanding tendency of the hollow body 3 is in
this arrangement effectively aided by the operation of a lever 8 which is pivoted
forwards by the hollow body. 3 at 8 to the wheel rim 2 through the air tube 1.
The lever 8 engages with one end 8b in the lower or outer portion 3 of the hollow
body 3, and at its other end it bears with a spoon-shaped part 8 against the inner
part of the tread of the tyre. The arrangement of the parts is such that when
the hollow body 3 has been compressed so as to force its contained air out through
the outlet orifices 4 into the tyre, the continued revolution of the wheel will bring
the spoon-shaped end 8 of the lever S to bear upon the ground, with the result
that the said end 8 will be forced inwards whereby the other end 8b will be
forced outwards, and so forcibly expand the hollow body 3 as indicated in dotted
lines in the Figure.
In the arrangement shown in Figures 3 and 4 the hollow body is made in the
form of cylindrical bellows 3 of elastic material adapted to be compressed by the
reaction of the ground transmitted through the medium of a lever 8 which is
fulcrumed at one end at 8ª to a metal piece 9, that is curved to suit the curvature
of the wheel rim 2. At its other end the lever 8 bears with a spoon-shaped part 8°
against the inner tread portion of the tyre. The metal piece 9 is continued rear-
wards in the form of a cylinder 9 which is fixed in a socket forming part of the
valve casing 6, and in which cylinder 9, the cylindrical bellows body 3 is
capable of longitudinal movement in its expansion and contraction. The bellows
body 3 is fixed at its rear end 3 to the lower part of the valve casing 6 with
which it communicates through a central inlet and outlet orifice 5.
ward end 3 the bellows body 3 is attached to a guide piece 10 which is adapted
to slide in and out of the cylinder 9". This guide piece 10 is connected by means
of a link 11 to the lever 8 at 8b, and it is also attached to one end of a tension
spring 12 adjustably fixed at its other end to the metal piece 9. This spring 12
has a constant tendency to expand the bellows body 3.
At its for-
In this arrangement the valve stem 13 is formed with a central inlet perfora-
tion 14 terminating at its lower end in a transverse through passage 14 the ends
of which are controlled by non-return inlet valves 7 formed by a rubber sleeve 15
slipped over the valve stem 13. The rubber sleeve 15 is slit vertically on each
'side as shown (or it may be on one side only) between the two ends of the trans-
verse passage 14" with the object of facilitating the operation of the inlet valve-
portions 7 on the suction-stroke of the bellows-body. Below the aforesaid trans-
verse passage 14" and approximately opposite to the central passage 5 of the
bellows body there is formed in the valve stem a passage 4 leading into a trans-
verse hole the ends of which are controlled by non-return outlet valves 4" con-
stituted by the lower portion of the rubber sleeve 15. Permanent communica-

page_text: tion is established between the passage 5 and the passage 4 by cutting away the
rubber round the inlet orifice of passage 4.
The mode of operation of this arrangement is as follows:-
:―
At every revolution of the wheel when the part of the tyre next the lever end 8°
is compressed or flattened by contact with the road the lever end 8" is automati-
cally pushed inwards together with the link 11. This inward movement is trans-
mitted through the sliding piece 10 to the outer end 3 of the bellows body 3
which is consequently pushed inwards (as shown in Figure 4) towards the end of
the cylinder 9, whereby the air is forced out of the bellows body through the
passage 5 and through the passages 4 into the tyre, the valves 4" opening. When
the part of the tyre next the lever end 8° leaves the road and expands to its normal
form the spring 12 draws back the bellows body 3 which then becomes filled with
air through the inlet passages 14, and 14", and the passage 5 the inlet valves ī
opening. The spring 12 also returns the lever 8 and link 11 to the position shown
in Figure 3. The same action is repeated at every revolution of the tyre until
the latter has become inflated to the required extent. The maximum or required
extent of inflation is regulated by the spring 12, the strength of which can be
adjusted by means of the adjusting screw 12" in such a manner that until the
required air pressure in the tyre has been reached, the spring 12 will still be able
to draw back the bellows body 3 in opposition to the air pressure acting upon the
bellows body in the reverse direction. The whole device can be inserted in the
tyre through the usual hole for the inflating valve as ordinarily usually fitted.
The device will serve for deflating the tyre if required by removing the cap 16
and withdrawing the valve stem 13 with the rubber sleeve 15; this withdrawal
of the valve stem also allows of the non-return valves to be examined and repaired
in case of need.
Figure 5 illustrates a modification in which the cylindrical guide piece 10 of
Figures 3 and 4, is made to fit air-tight in the cylinder 9. In this case, the
bellows body 3 may be dispensed with, and the drawing in of the air into
the cylinder 9 and its expulsion from the latter into the tyre will be effected in the
same manner by means of the cylindrical guide piece or piston 10. In all other
respects the construction and mode of operation of this arrangement is the same
as described with reference to Figures 3 and 4.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is:-
1. The employment within a pneumatic tyre of a device operated upon directly
or indirectly by the flattening or compression of the tread of the tyre while travel-
ling and provided with air outlets and air inlets through which respectively the
device alternately forces out air into the tyre and draws in air from the outer
atmosphere, substantially as and for the purpose herein before described.
2. In combination with a device such as specified in Claim 1, a spring or springs
inside or outside the same for the purpose of aiding or producing the movements
of the device and automatically limiting the maximum pressure produced sub-
stantially as and for the purpose set forth.
3. In combination with a device such as specified in Claim 1, a lever or levers
for the purpose of aiding or producing the movements of the device substantially
as and for the purpose set forth.
4. The particular construction of apparatus substantially as hereinbefore
described and illustrated in Figure 1 for automatically inflating and maintaining
the inflation of pneumatic tyres.
5. The particular construction of apparatus substantially as hereinbefore
described and illustrated in Figure 2 for automatically inflating and maintaining
the inflation of pneumatic tyres.
6. The particular construction of apparatus substantially as herein before

page_text: described and illustrated in Figures 3 and 4 for automatically inflating and main-
taining the inflation of pneumatic tyres.
7. The particular construction of apparatus substantially as hereinbefore
described and illustrated in Figure 5 for automatically inflating and maintaining
the inflation of pneumatic tyres.
Dated this Oth dov of Tohm 1000
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.