Improvements in Valves applicable for Pneumatic Cycle Tires and other purposes.
Year: 1892

page_text: Date of Application, 1st Nov., 1892-Accepted, 17th Dec., 1892
COMPLETE SPECIFICATION.
Improvements in Valves applicable for Pneumatic Cycle Tires and
other purposes.
A communication by WILLIAM EDWIN GIBBS, of 111, Liberty Street, New
York, in the County and State of New York, United States of America,
Mechanical Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester both in the County of Lancaster, and 323 High Holborn in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention although relating to an improved construction of valves, is
specifically devised to be utilized in connection with hollow rubber tires or what is
known as t pneumatic" tires for bicycles.
In the inflation of these hollow tires, it is necessary to provide means for
securing a suitable cut-off or valve for the back pressure of the atmospheric air
and in connection therewith, to secure a permanent shut-off for the preventing of
leakage during service.
In these valves as hitherto constructed, it had been found difficult to make them
retain the air within the hollow tire, a gradual leakage taking place which neces-
sitates frequent inflations of the tire. This leakage is due partly to the dust on
the rubber of the tire getting between the valve and its seat, causing thereby an
imperfect closure and partly to the ordinary leakage through the metallic joints.
This invention aims to overcome these difficulties and to provide an air tight
valve which shall be effectual against dust, leakage and corrosion and which shall
not be loosened by the continual vibration and jar to which such valves are
subjected.
Referring to the accompanying drawings which form a part of this Specifi-
cation:-
Figure I represents a cross-section of a pneumatic tire with the improved valve
attached. In this figure, a temporary cap is shown illustrating the method of
filling the tire with compressed air.
Figure II is a vertical section of the improved valve with the permanent cap in
place, the temporary cap having been removed.
In Figure 1, A, represents a tube of metal, vulcanite, celluloid or other substance
not easily corroded by india rubber, or the materials contained in it, having an
internal shoulder a inserted as shown in Figure I in the hollow tire T.
B is a plug having a screw thread 6 6' at its ends; it is further provided with a
centrally located enlarged portion N which may be constructed in the form of a
nut or it may be milled on its periphery so that it may be utilized for screwing
the plug B into the tube A by hand; it is further provided with a centrally
located conduit or opening O bored axially as shown. At C is a spindle somewhat
smaller in cross section than the opening Ó of the plug B. This spindle is provided
with a screw thread E at its outer end and an enlarged head or button H at its
inner end. D is a tubular piece or collar of soft rubber, cork or other elastic and

page_text: yielding material and fitting closely as a sleeve on the spindle C, its outer end
abutting against the head or button H. The tubular collar D is inserted in the
tube A with an annular space w between the collar and the tube.
F is a removable temporary coupling provided with a screw thread adapted to
screw on the thread b of the plug B and to be employed during the process of
pumping air into the hollow tire. The coupling is hollow and is provided with an
interior chamber J and is adapted to receive a pipe P leading from the air pump.
When filling the hollow tire with air for the purpose of distending it, the temporary
cap is screwed on to the plug B as shown and air from the pump is forced into
the chamber J and thence passes down through the conduit or port O of the plug B.
At the end of this conduit it reaches the rubber valve D and the pressure being
sufficient to force the valve inwardly, the air will enter the chamber A¹ of the
tube A and from thence pass into the hollow tire T. The air is prevented from
returning by the immediate closure of the rubber valve on its seat upon the inner
end of the plug B.
The required internal pressure in the pneumatic tire having been obtained, the
pump U is disconnected by unscrewing the coupling. F on the plug B. The valve
is then ready for the reception of its permanent cap. This permanent cap shown
at G in Figure II and consists of a skirt 9 having smooth, interior surface, an
annular rim or flange R and stem S. Stem S is hollow and is threaded on its
interior surface and is adapted to screw upon the screw threaded portion E at the
upper end of the spindle C.
When the temporary cap F as aforesaid, has been removed and the permanent
cap G is applied, it will be seen that by screwing it on the spindle and over the
nut B the said spindle will be drawn up through the port O of the plug B, thereby
compressing the rubber valve or thimble D longitudinally and between the
button H and the valve seat thus causing the said sleeve like valve (being formed
of rubber as aforesaid) to extend laterally until it fills the entire space to between
the interior walls of the tube A, the button H and the valve seat on the plug B
providing thereby an air tight plug. The parts are shown in this position in
Figure II.
As before stated, one of the difficulties heretofore unsatisfactorily contended
with in respect to valves upon pneumatic tires, has been the fact that the dust
which sheds from the interior surface of the rubber tire has crept in between the
valve and its seat, thereby causing an uneven positioning of the valve allowing
leakages of air; it will be seen from the above description and the drawing that
any small particles of dust or grit which may have entered the valve will, by the
pressure, be embedded in the rubber; this important drawback is therefore removed
in this manner.
In addition to the above parts, a coiled spring K is provided which will, upon
removal of interior atmospheric pressure, keep the valve against its seating.
The skirt of the permanent cap G fits down and over the screw threaded
portion 6 of the plug B and serves as a guard therefor preventing abrasion or
breakage of the screw thread.
In case of accident to the valve or rubber sleeve, all the working parts may be
removed by loosening the screw cap G and unscrewing the plug B at b.
It will be seen that the valve when expanded as shown in Figure II constitutes
a complete check to the escape of air and forms a cut-off which lies nearer the tire
than any joint, and as a consequence, no great care is required in making these
joints especially perfect or tight.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that I am well aware that some of the general
principles on which this Patent is based are well known, such as for instance the
lateral expansion of a washer by compression between its faces so as to close up an.
orifice. This is found in the Specification of Letters Patent, granted to Preston Davies

page_text: No. 18259 of 1891 and I make no claim to that or any other general principle, but
what I do claim is :-
1. The combination of a hollow tire or other chamber adapted for the reception
of compressed air with a combined valve and plug provided with an elastic packing
or gland adapted to operate as a valve during the filling of the chamber and as a
plug when permanently compressed longitudinally and expanded laterally, substan-
tially as shown and described.
2. In a combined valve and plug, the combination of a tube A, a tubular
collar D of yielding material inserted in the tube A whereby a space is formed
between the said tubular collar and tube A so that the parts will operate as a valve
and means substantially as shown and described for transforming the valve into a
plug by compressing the collar D longitudinally and expanding it laterally so as to
fill the space between it and the tube A as set forth.
Dated this 21st der of Datahar 1000
WM. P. THOMPSON & Co.,
Agents for the Applicant.