Improvements in Valves for Pneumatic Tyres.
Year: 1899

page_text: Date of Application, 22nd Dec., 1899--Accepted, 3rd Feb., 1900
CUMILITE SPECIFICATION,
Improvements in Valves for Pneumatic Tyres.
I, FRANZ RICHTER, of 70, Moltkestrasse, Cologne on the Rhine, Germany,
Decorative Painter, 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:-
The present invention relates to a non-return valve for pneumatic tyres which
is distinguished from all other known valves of this kind chiefly by the fact that
it allows of an exceedingly easy pumping in of the air, and also by a very high
factor of safety against the escape of the compressed air from the tyre.
These advantages are effected more particularly by the suitable construction of
the valve parts which consist mainly of a rubber piece formed in moulds into
a particular shape.
Figures 1 to 4 of the accompanying drawings illustrate a form of construction
(by way of example) of this non-return valve, and it comprises the following
features.
Over the hollow valve-passage of the pin a situated inside the valve casing b,
there is slipped the cylindrical part of a rubber piece c which terminates at its
lower part in the form of a tail, and is jointed by means of the flange e¹ by the
union nut against the casing b. Through the tail-shaped portion (which is
either of rectangular or elliptical shape in cross section) of the rubber piece c
there extends with a slight downward directed taper a through-passage
e of
slightly lens-shaped form. This passage terminates at its lower end at the mouth
of the tail piece in a linear slot which may be likewise slightly lens-shaped as an
alternative. The surfaces e¹ and e² that form the walls of the passage e are of
different thicknesses, so that an external pressure acting upon the thinner wall
will readily press the latter inwards. In inflating the air passes through the
valve passage of the pin a and through the lens-shaped passage e into the interior
of the tyre. The compressed air is prevented from returning by means of its
own pressure acting upon the two tail surfaces of the rubber piece ; the arrange-
ment being such that the weaker wall e' (as shown in cross section in Figure 4
of the drawings) places itself in a concave curve linearly against the inner sides
of the wall so that an extremely secure closure is effected and all possibility
of an escape of the air from the valve is prevented under all circumstances.
Having now particlarly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
(1) A non-return valve for pneumatic tyres, characterised by the fact that the
valve piece which is provided in the valve casing to be fixed to the tyre,
is formed with a central passage e of lens-shaped form having walls and e
of different thicknesses, as set forth,

page_text: (2) A valve for pneumatic tyres constructed and arranged substantially as
hereinbefore described and shown.
Dated this 21st day of December 1899.
BERT E. PHILLIPS, Assoc. M. Inst. C.E., M. I. Mech. E.,
Chartered Patent Agent,.
70, Chancery Lane, London, W.C., Associate Agent.