Improvements in Air Valves for Pneumatic Tyres, Pneumatic Hubs, and Compressed Air Cushions.
Year: 1897

page_text: Date of Application, 26th Feb., 1897
Complete Specification Left, 26th Nov., 1897-Accepted, 19th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in Air Valves for Pneumatic Tyres, Pneumatic Hubs,
and Compressed Air Cushions.
We, ROBERT Gow WATSON, of Ferndean, Bruce Road, Pollokshields, in the
City of Glasgow, and PETER FYFE, of 1, Montrose Street, in the City of Glasgow,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object to provide a valve for pneumatic tyres, pneumatic
hubs and compressed air cushions, which can be maintained air tight without the
aid of a screw down nut or cap on the outside end of the valve tube. The improved
valve comprises a tubular casing, with or without the usual flange and nuts for
attachment to the rim of a bicycle. Within the tubular casing a circular piece
or rod of rubber or other elastic material is fitted of the same diameter as the bore
of the tube, and almost the full length of it, having ball head or rounded face at
its lower end. This ball head or face forms the valve and fits upon an annular seat
formed to receive it at the lower end of the tubular casing. The body or rod
part of this valve is grooved its whole length to allow of air passing from the
pump.
At its top end the body of the valve has a small metal cap fitted to it. This cap
has a cone shaped hole drilled in the centre of it which permits the point of the
screwed metal plug above it to enter. When this plug is screwed down it puts
compression upon the cap and upon the valve without tending to exert any torsional
strain, and so the valve is held tightly upon its seat without any risk of its face
being abrased by turning upon it.
The amount of pressure required to keep the valve on its seat is regulated by the
depth to which the plug is screwed down into the upper end of the tubular casing,
and the elasticity of the body of the valve.
In order to let the pumped air escape freely into the tyre or cushion a small hole
is bored through the screwed plug above the metal cap. While the head of the
valve is thus held air tight on its seat, there is still sufficient elasticity left in the
circular body of the valve to permit of the head being raised off its metal seat by
the nose of the pump coupling, and so to permit of air being pumped through the
tubular casing. When the pump coupling is unscrewed the compression put upon
the elastic body of the valve, together with the back pressure of the air acting upon
the top of the metal cap before mentioned shuts the ball headed or round nosed end
of the valve firmly on its seat and holds it air tight.
A screwed dust cap may then be fitted on if desired.

page_text: Improvements in Air Valves for Pneumatic Tyres, Pneumatic Hubs,
and Compressed Air Cushions.
We, ROBERT Gow WATSON, of Ferndean, Bruce Road, Pollokshields, in the
City of Glasgow, Iron Founder, and PETER FYFE (formerly of No. 1, Montrose
Street), now of No. 23, Montrose Street, in the City of Glasgow, Sanitary Inspector,
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 has for its object to provide a valve for pneumatic tyres, pneumatic
hubs, and compressed air cushions which can be maintained air tight without the
aid of a screwed nut or cap on the outside end of the valve tube.
This
As illustrated in vertical section in Figure 1 the improved valve comprises a
tubular casing B formed with a flange to be inserted into the inner tube of a pneu-
matic tyre.
At the opposite end the thimble or casing S, is screwed on.
casing has a diaphragm at its centre which enables an air tight joint J, to be made
between it and the tubular casing B. The lower end of the thimble S, is recessed
as shewn at M, and contains a seat for the valve V, V. Within the casing B, is
fitted loosely the spring or cushion valve V,V, of india rubber or other elastic
material, having a cap C, and the screwed plug P. The tubular casing B, is also
fitted with the usual rim piece A and the tightening jam nut N. The spring or
cushion valve V,V, has a groove g, g, extending longitudinally from its upper end
to the shoulder at the ball shaped head which rests on the valve seat.
The pointed plug P, has a small air escape hole H, bored through it. D, is an
ordinary dust cap. Y, is a screwed coupling to which the air pump connection U,
is fitted. X is a small perforated nose piece perforated at the end of U, which goes
through the apperture at 0, 0, and lifts the valve off its seat previous to pumping in
the air.
When the plug P, has been screwed down sufficiently to make the valve V,V,
bear air tight on the seat 0, 0, the valve casing is secured to the tyre and rim in
the usual manner. To inflate the tyre the coupling Y, is screwed on, when the nose
piece, pushes up the ball head of the valve. The air is then pumped through the
recess M up the groove g, g, through the holes H, into the tyre. When the pump
is uncoupled the valve V, V, closes the aperture 0, 0, air tight.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. An air valve constructed in such a manner as to be self closing and air tight
without the aid of extraneous springs or extraneous screws.
3. A valve constructed substantially as described with reference to the annexed
drawing.
Dated this 25th day of November 1897
ROBERT GOW WATSON.
PETER FYFE.