Improvements in Valves for Pneumatic Tyres.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Valves for Pneumatic Tyres.
I, JULIUS MOHS, of Brandenburg on Havel, Kingdom of Prussia, Empire of
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:
In the manufacture of rubber tube valves for the pneumatic tyres
of cycles and other vehicles, of the kind described in the Specification of
another application for Letters Patent filed by me No. 18179 of 1897, difficulty
is found in producing the small slit rubber tubes, of a uniform thickness of wall.
This uniform thickness is of importance in order to enable the longitudinal slits,
which are arranged in an annular zone, or those parts of the tube situated between
the longitudinal slits, to be expanded simultaneously and uniformly by the com-
pressed air, and to be closed again simultaneously and uniformly by the com-
pressed air collecting around the rubber tube for the purpose of preventing the
escape of the surrounding air.
The want of uniformity in the thickness of the tube results in a faulty closure
of the slits, and also causes unequal compression of the tube by the surrounding
air, so that the tube becomes flattened in parts, which is objectionable.
In order to obviate this drawback I provide a supporting pin, which
preferably extends from a closing plug (that closes the rubber tube
at the bottom) upwards into the zone of the longitudinal slits and
which is of such thickness as not to completely fill the interior of the rubber tube
in the annular zone in which the slits are situated, but to leave, between the sup-
porting pin and the inner surface of the rubber tube, when the valve is in a state
of rest, an annular air space which allows the air pumped in to flow through the
rubber tube along the supporting pin and also allows the escape of the air
through the longitudinal slits.
The supporting pin comes into operation only when the pressure of the air
surrounding the rubber tube has a tendency to compress the tube. Then this
compression takes place in such a manner that the slits close up, and the tube is
pressed tightly against the supporting pin so that there is no possibility of the
rubber tube being flattened.
The valve then operates with the greatest certainty and exactness.
The use
of the supporting-pin allows of the use of any desired number of longitudinal slits,
for instance only one, or two, because by its use no compression of the rubber
tube or canting of the lips of the slits in closing can take place.
The external pressure will always press the rubber tube in every part of the
zone (whether there is or are, only one or two slits, or more) uniformly against
the supporting pin.
It will be readily understood that according to the present invention a coiled

page_text: spring can be arranged within the casing which surrounds the rubber tube to
support the latter elastically in the direction of its length.
Dated this 13th day of October 1897.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C
Agent for the Applicant.
Improvements in Valves for Pneumatic Tyres.
I, JULIUS Mous, of Brandenburg on Havel, Kingdom of Prussia, Empire of
Germany, 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:―
In the manufacture of rubber tube valves for use in supplying air to the pneu-
matic tyres of cycles and other vehicles, of the kind described in the Specification of
another application for Letters Patent filed by me No. 18179 of 1897, difficulty
is found in producing the small slit rubber tubes of a uniform thickness of wall.
This uniform thickness is of importance in order to enable the longitudinal slits,
which are arranged in an annular zone, or those parts of the tube situated between
the longitudinal slits, to be expanded simultaneously and uniformly by the com-
pressed air, and to be closed again simultaneously and uniformly by the com-
pressed air collecting around the rubber tube, for the purpose of preventing the
escape of the surrounding air.
The want of uniformity in the thickness of the tube results in a faulty closure
of the slits, and also causes unequal compression of the tube by the surrounding
air, so that the tube becomes flattened in parts, which is objectionable, because it
will interfere with the regular filling of the pneumatic tyre.
In order to obviate this drawback I provide a supporting pin, which
preferably extends from a closing plug (that closes the rubber tube
at the bottom) upwards into the zone of the longitudinal slits and
which is of such thickness as not to completely fill the interior of the rubber tube
in the annular zone in which the slits are situated, but to leave, between the sup-
porting pin and the inner surface of the rubber tube, when the valve is in a state
of rest, an annular air space which allows the air pumped in to flow through the
rubber tube along the supporting pin and also allows the escape of the air
through the longitudinal slits.
The supporting pin comes into operation only when the pressure of the air
surrounding the rubber tube has a tendency to compress the tube. Then this
compression takes place in such a manner that the slits close up and the tube is
pressed tightly against the supporting pin, so that there is no possibility of the
rubber tube being flattened.
As
In the accompanying drawings Fig. 1 shows a vertical central section of a
rubber tube valve by way of example in accordance with this intention.
shown it comprises an outer casing a over which a cap or closing party is screwed.
This part y has another small cap z that can be removed for the pressure pipe of
an air pump to be applied. Between the cap y and the casing a piece w is
inserted, which by means of suitable packing rings closes tightly on the
casing x.
O is a filter of sponge or other suitable material for retaining particles of dirt
or grease which may be introduced by the air pump, so as to prevent such
particles from being caught in the slits of the tube.

page_text: The piece w has a tube like part that extends into the casing x. This exten-
sion is suitably formed externally to allow the rubber tube a to be fitted over it
and firmly held thereon. The tube a is provided with slits b, all arranged on one
annular zone. At the end the tube a is closed by a plugs and from this plug the
pin s extends upwardly and preferably a small distance beyond the said annular
slit zone.
The pin s' is smaller in diameter than the inner diameter of the tube a,
so that the air, driven into the tube by a pump, will rush along side or around
the said pin and escape through the slits by expanding the wedge shaped parts
of the tube between said slits. If pressure in the tyre increases, the air in the
tyre will act on the outside of the tube and will compress the wedge shaped parts
of the tube, so that the slits become closed. If now the tube by reason of weak-
ness of wall, yields to such pressure on its outside, it will be pressed against the
pin s which will prevent further yielding of the tube.
Thus the valve operates with the greatest certainty and exactness. The use
of the supporting pin allows of the use of any desired number of longitudinal
slits, for instance only one or two, because by its use no compression of the rubber
tube or canting of the lips of the slits in closing can take place. The external
pressure will always press the rubber tube in every part of the zone (whether
there is or are only one or two slits or more) uniformly against the supporting
pin.
Fig. 2 and Fig. 3 are horizontal sections through the casing X, the rubber
tube a at the annular zone and the supporting pin S. Fig. 2 shews the parts of
the rubber tube between the slits expanded by, internal air pressure, so that
the compressed air escapes through the slits b into the casing X and thence into the
tyre, the arrows a¹ indicating the direction of external pressure.
Fig. 3 shews the parts in the position occupied when such external pressure
has acted, the slits b being closed and the tube being pressed against the support-
ing pin S¹.
It will be understood that in the valve herein shown and described a coiled
spring can be arranged within the casing which surrounds the rubber tube to
support the latter elastically in the direction of its length as set forth in my said
former specification.
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:-
A rubber tube valve for use in supplying air to pneumatic tyres comprising a
rubber tube closed at the bottom and in communication with an air supply device,
the said tube having a longitudinal slit or several longitudinal slits on one annular
zone and being provided with an internal supporting pin of less diameter than the
inner diameter of the tube for supporting the tube when external air pressure
acts thereon substantially as described.
Doted this 12th dow of July 1808