Improvements in Back-pressure Valves.
Year: 1895

page_text: Date of Application, 14th Oct., 1895
Complete Specification Left, 14th Aug., 1896-Accepted, 19th Sept., 1896
Improvements in Back-pressure Valves.
I, PAUL GIFFARD of 7 Rue Delaborde, Paris in the Republic of France do
hereby declare the nature of this invention to be as follows:-
This invention relates to back pressure valves applicable for various purposes
and amongst others suitable for use with pneumatic tyres for cycles or in pumps
for charging pneumatic tyres; the construction will be substantially the same in
all applications, allowing for differences of size, and modifications to suit special
applications. I will describe the invention in a form suitable for use with a
pneumatic tyre.
The valve case or body consists of a cylindrical portion screwed to receive the
nuts which secure it to the air-tube and to the rim of the wheel, and provided
with a suitable head, preferably rounded on its face and edges so as not to
damage the rubber. This body is hollow and with one or more holes passing
through from the inside to the outer face of the head which in uso would be the
interior of the air-tube. The valve seating is independent of the valve body and
is placed therein and rests against a suitable shoulder, being held in position by
a cap screwed preferably into the open end of the valve body and perforated to
allow of the passage of the fluid through it; this cap may be screwed in the
perforation, or have a nozzle screwed externally or internally for the reception of
the
pump or branch therefrom.
The valve is pressed by a suitable and preferably helical spring upon the seating
face which is at the inner end of the seating, the valve itself being spherical,
conical or otherwise suitably shaped for this purpose. The valve seating may be
tapered if desired.
Various materials may be employed in the manufacture of these valves,
particularly steel,fcopper, or aluminium, or any other material say ebonite, rubber,
paper, horn, celluloid fibre, or other equivalent or suitable material. The valve may
be of metal and the seating of some softer material or vice versa, and the seating
if of metal may be provided with softer material for making a tight joint with
the valve body.
Dated this 14th day of October 1895
BOULT & WADE,
Agents for the Applicant.
I, PAUL GIFFARD of 7 Rue Delaborde, Paris in the Republic of France, 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 relates to back-pressure valves applicable for various purposes
and, amongst others, suitable for use with pneumatic tyres for cycles or in pumps
for charging pneumatic tyres; the construction will be substantially the same in
1

page_text: all applications, allowing for differences of size, and modifications to suit special
applications. I will describe the invention in a form suitable for use with a
pneumatic tyre with reference to the accompanying drawings, wherein Figures 1, 2
and 3 are each a vertical central section of an improved back-pressuro valve.
Like letters indiente like parts throughout the drawings.
In Figure 1 the valvo case or body A consists of a cylindrical portion screwed
at A to receive nuts which secure it to the air-tube and to the rim of the wheel,
and provided with a suitable head, A³, preferably rounded on its face as at A
and edges as at A' so as not to damage the rubber. This body is hollow and lus a
hole B passing through from the insido to the outer face A' of the head A'
which in use would be in the interior of the air-tube. The valve seating C,
centrally perforated at. C is independent of the valve body and is placed therein;
it is slightly coned on its onter circumference as at C and rests in a correspondingly-
tapered part A of the body against a suitable shoulder A being held in position
by a cap D serowed preferably into the open end of the valve body A and
perforated as at D1 to allow of the passage of the fluid through it; this cap D may
be screwed in the perforation, or have a nozzle screwed internally or, as shown
at D, externally for the reception of the pump or branch therefrom. The cap D
is to be screwed home into the valve body A to compress the seating Cagainst
the shoulder A and into the tapered part A of the body so as to ensure such
hermetic closure that no fluid can escape past the seating.
To prevent the casing A from affording any leak, the edge of the cap D at D'
is caulked or set over on the body so that it cannot become unfixed, and to mako
n fluid-tight joint therewith.
The
The valve E is pressed by a preferably helical spring upon the face of the
inner end of the seating. valve itself may be cylindrical as shown, with a
concave face E' and sharp edge E and may if desired have a "tail" E encircled
by the spring F and serving to guide the valve in its rise and fall, the spring
resting at its upper end against tho interior of the head and at its lower end on
a shoulder E' on the valve.
The modifications illustrated in Figures 2 and 3 are substantially similar to that
shown in Figure 1, except that in Figure 2a sphere is substituted for the
cylindrical valve and in Figure 3 the lower end of the valve E instead of being
concaved and sharp-edged is tapered and convex to fit into the central perforation C
of the seating. Figures 2 and 3 a screwed plug ) is substituted for the screwed
cap D of Figure 1.
Various materials may be employed in the manufacture of these valves,
particularly steel, copper, or aluminium or any other material say chonite, rubber,
paper, horn, celluloid fibre, or other equivalent or suitable material. The valve may
be of metal and the seating of some softer material or rice versa, and the seating
if of metal may be provided with softer material for making a tight joint with the
valve body.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is.
1. The improved back-pressure valve substantially as and for the purpose
described and illustrated in Figure 1, or Figure 2 or Figure 3 of the accompanying
drawings.
DJ to
I
LM
BOULT & WADE,
Agents for the Applicant.