Improvements in or relating to Pneumatic Tyres.
Year: 1896

page_text: I, JAMES GORDON MALCOLM of 12, Fairview Avenue, Dublin, Painting Contractor
&c., do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in connection with pneumatic tyres, and
is intended to provide a simple means by which the tyre may be automatically
inflated as the wheel revolves.
In carrying out my invention I propose to employ two elastic vessels preferably of
india-rubber and of spherical or egg shape. These vessels are connected together
by a tube fitted with a valve, which allows air to pass from one chamber to the
other, but prevents its return. One chamber or vessel is provided with a tube or
inlet which extends through the rim or tyre, and opens to the atmosphere. A
non-return valve is also placed at this inlet allowing the air to enter, but preventing
it escaping from the chamber. As the wheel revolves, air is forced from the first
chamber through the valve into the second, the latter being also furnished with a
valve which allows the compressed air to escape into the tyre, thus keeping the
latter inflated to a certain pressure. To keep the first chamber or vessel open,
a spiral spring may be employed placed within it, and causing it to expand
immediately the pressure is released.
This arrangement does not in any way alter the action of the machine, and does
not add appreciably to the weight, but will be of service in the case of a slight
puncture, automatically supplying the loss of air.
DJ of 1.... 1000
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Tyres.
I, JAMES GORDON MALCOLM, 24 Eden Quay, Dublin Painting Contractor &c.
late of 12 Fairview Avenue Clontarf 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 :-
A simple means by which the Tyre may be automatically inflated as the wheel
revolves.
In carrying out my invention I propose to employ two or more elastic vessels
preferably of India rubber. The first of these I make of a cylindrical shape, with top
and bottom rounded to fit inside the air tube as shown in Section Fig. 1. A is
the air tube as it would appear inflated. The upper and lower parts of India rubber

page_text: cylinder would be thick so as to form caps B in Fig. 1. Inside the cylinder and with
the ends resting on these caps I place a helical spring S Fig. 1, preferably of steel
and sufficiently strong to keep the cylinder well expanded. One of the caps I make
with a flange like a pill box lid so as to put the spring in and then fix with India
rubber solution, in the lower cap B 2, Fig. 1, I place a Valve V, Fig. 1, firmly
cemented into the seat and also into a hole of the air tube, and passing through the
rim of the wheel. This valve is of an ordinary air pump description a strip or
filament placed across a flat surface with a hole in the centre of the brass, that will
resist the air from inside passing out, but will admit the air from the outside
atmosphere to the interior. When the cylinder has been compressed and then
released, the spring in opening the cylinder causes the air to rush in. On the side
of the Cylinder I place another valve V 1, Fig. 2, in a channel leading into a
spherical or egg shaped ball of stouter rubber than the air tube. So as to prevent
the air returning to cylinder but allowing it to be forced through into the ball, when
the cylinder is compressed and released, I may use two or more elastic balls each
connected by a valve to the other, the final valve passing the air into the air tube,
which is received from the one before it. The apparatus shown in Fig. 2, works thus.
A, Fig. 2, is the air tube viewed from the side, C, Fig. 2, the cover, and R, the rim,
O, being the cylinder containing the spring. B, the elastic balls and V the
communicating valves. When the portion of the wheel outside the cylinder O, Fig. 2,
comes to the bottom, the weight on machine presses in the spring, which being
released as the wheel is moved sucks in a charge of air through the valve attached to
the rim, the next time the wheel presses, the air in this cylinder is transmitted into
the ball or balls and finally into the air tube, this keeps filling until the tyre is so
hard there is not enough elasticity to further compress the cylinder.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is
The Automatic inflating of the Tyre by combination of elastic vessels and
valves substantially as described.