Improvements in Air Valves.
Year: 1897

page_text: Improvements in Air Valves.
I, PRESTON WEIR, of 21, Fernbank Road, Redland, Bristol, Schoolmaster, do
hereby declare the nature of this invention to be as follows:-
This invention relates to valves used in compressing, retaining & releasing air.
It comprises inlet, non-return, & release valves, & is intended, if need be, to be
operated by one hand.
It is specially designed for the air brake described in Specification No. 15030
of 1894, but may be used with any similar apparatus for which it is suitable.
My object has been to devise a form of valve which, while compact in itself, can
be cheaply manufactured. This form can be almost entirely made by tools in a
lathe.
The measurements hereinafter mentioned are only roughly relative & are used
simply to avoid circumlocution. They indicate no essential feature of the invention.
Two tubular chambers, each from half an inch to an inch, both in length &
diameter are joined end to end, but separated by a common partition or diaphragm
of appreciable thickness, rigidly attached to each in a plane at right angles to the
long axes, which are in one straight line.
Standing out from one side of the diaphragm (the back) is a hollow stem, about
three-sixteenths of an inch in external diameter, placed eccentrically, but parallel
to the common long axis. The hole through this stem is continued through half the
thickness of the diaphragm, where it is joined at right angles by another hole,
which opens to the air on the nearest point of the periphery of the diaphragm.
From the front of the diaphragm proceeds a similar hollow stem of the same
diameter, but placed centrally in the line of the common long axis of the chambers.
The hole through this stem pierces right through the diaphragm & opens behind it.
Each of these stems is clothed with a close-fitting rubber tube, closed at the distal
end, which, when in position, projects a little way beyond the end of the stem, & in
its projecting portion is partially cut across, so that the closed end beyond the plane
of section forms a lid or cap, hinged by the uncut segment, the elasticity of which
causes the lid to remain normally closed except when it lifted by pressure of
air within or suction without.
The eccentric stem with its rubber tube forms the inlet, the centric stem with its
rubber tube forms the non-return valve.
Over the non-return valve & just out of contact with it there works longitudinally
a rigid tube closed at one end, & ringed round outside, a little way from the closed
end, by a flange. This rigid tube acts as the plunger of the release valve. When
fully depressed, its open end rests on the diaphragm around the foot of the non-
return valve which is completely covered, but not touched by it. A spiral spring
embraces it closely, but not tightly, below the flange, &, pressing also against the
diaphragm raises the hollow plunger from the diaphragm, & forces its flange out-
wards against the internal seating of a cap, screwed into the open end of the front
tubular chamber, the top of this cap being pierced by a hole, less than its own
internal diameter (the difference forming the seating) & just large enough to allow

page_text: the closed end, but not the flange of the plunger to pass. The open end of the cap
when screwed into the open end of the front tubular chamber beds on a shoulder
which runs round the inside of the latter, at a sufficient distance from the diaphragm
to allow a hole to be drilled from the outside between the two, & a lateral hollow
stem (about three sixteenths of an inch in external diameter) to be inserted & to
project externally establishing communication with the front tubular chamber. This
lateral stein is connected with any chamber in which it is desired to collect the
compressed air. The back tubular chamber is connected to the inflator.
The valves herein before described function in exactly the same way as the corre-
sponding parts set forth in my Specification No. 15030 of 1894.
When the inflator expands after compression the valve on the back stem opens &
air is drawn in, the valve closing automatically as soon as the suction ceases.
When
the inflator is compressed the air contained in it is driven through the non-return
valve (its only means of escape), forcing open the lid, which closing automatically,
causes the air to accumulate under pressure in the front tubular chamber & that
connected with the lateral stem. When the head of the hollow plunger is pressed
the imprisoned air escapes between the flange of the plunger & the seating of the
screwed cap.
In making these valves I turn the two tubular chambers with the front central
stem out of a solid rod of metal or other suitable substance in a lathe. The other
two stems, the screwed cap, & the plunger are similarly formed from smaller rods.
The only work that has to be done out of the lathe is the fixing by means of solder
.or otherwise of the eccentric & lateral stems, & the placing of rubber tubes on the
stems & of washers on flanges & seatings, where required to render these perfectly
air-tight.
This form of valves has been devised for its compactness, its accessibility, & the
facility with which it can be almost entirely made in the lathe. Its special feature
is that the most important parts: viz. the non-return & release valves lie in the
central long axis of the system, & that the plunger is made hollow so as to work
over the non-return valve & so save space.
Dated this 15th day of November 1897
I, PRESTON WEIR, of 21, Fernbank Road, Redland, Bristol, Schoolmaster, 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 valves used in compressing, retaining & releasing air, &
is intended, if need be, to be operated by hand.
It is specially designed for the air brake described in Specification No. 15,030 of
1894, but may be used with any similar apparatus for which it is suitable.
My object has been to devise a form of valve, which, while compact in itself, can
be cheaply manufactured. This form can be almost entirely made by tools in a
lathe.
The annexed sectional drawing, in which every part of the invention is shown in
position, will make the following description clear.
C, C are two tubular chambers separated by a partition or diaphragm D.
Projecting from a point (other than the centre) at one face of the diaphragm D
is a metal tube T open to the atmosphere at E. From the opposite face of the

page_text: diaphragm and in communication with the chamber C¹ is a similar tube T¹, placed
centrally.
Each of these metal tubes is provided with a close fitting cap shaped rubber
tube R, R¹, near the end of which is a transverse slit or knife cut about half way
through, as at M, M¹, the uncut portion forming a kind of hinge the elasticity
of which causes the lid to remain normally closed, except when it is lifted by pressure
of air from within or by suction from without.
The metal tube T with its rubber tube R, forms the inlet valve; the metal tube T¹
with its rubber tube R¹, forms the non-return valve.
Over the non-return valve & just out of contact with it by reason of a greater
diameter & length, there is fitted a metal tube P, closed at the distal end & ringed
round outside near its middle by a flange F. This metal tube acts as the plunger
of the release valve. When fully depressed its open end rests on the diaphragm
around the foot of the non-return valve, which is then completely covered but
not touched by it.
A spiral spring S embraces this hollow plunger closely, but not tightly, below
the flange & pressing also against the diaphragın raises the plunger from the
diaphragmn & forces it outwards, pressing its flange Fagainst the internal seating S²
of a cap K screwed at S¹ into the open end of the chamber C. The top of this cap is
pierced by a hole, less than its own internal diameter (the difference forming the
seating), and just large enough to allow the closed end but not the flange of the
plunger to pass.
The open end of the cap K when screwed into the chamber C beds on a shoulder H,
which runs round the inside of the chamber at a sufficient distance from the dia-
phragin to allow a hole E₂ to be drilled from the outside between the two & the
end of the lateral tube T, to be inserted, establishing communication with the
chamber C. This lateral tube T, is connected with any vessel in which it is desired
to collect the compressed air.
2
A rubber bulb as in dotted lines or other suitable form of inflator is passed over
the outside of the chamber c³, and secured thereto.
The valves herein described function in exactly the same way as the corresponding
parts set forth in my Specification No. 15030 of 1894.
The action is as follows:-
When the inflator expands after compression the inlet valve opens at M & air is
When the
drawn in, the valve closing automatically as soon as the suction ceases.
inflator is compressed the air contained in it is driven through the non-return
valve at M', the lid of which closing automatically when the pressure ceases, causes
air to accumulate under pressure in the chamber C & in any vessel connected
with it by the tube T₂. When the head of the plunger P is depressed the imprisoned
air escapes between the flange F & the seating S².
In making these valves I turn the two tubular chambers c & c¹, with the tube T₁
& the shoulder H as part of the former out of a solid rod of metal or other suitable
substance in a lathe. The tubes T & T₂, the cap K & the plunger P I similarly
turn out of smaller rods.
2"
The only work that has to be done out of the lathe is the fixing by means of
solder or otherwise of the metal tubes T & T the placing of the rubber tubes R R¹
on these metal tubes & of washers W W1, on the flange F & the shoulder H to
render these contacts perfectly air-tight.
Having now particularly described & ascertained the nature of my said
invention, & in what manner the same is to be performed, I declare that what
I claim is
1. A set of three valves comprising inlet, non-return & release valves for com-
pressing, retaining & releasing air, constructed substantially as herein before
described.
2. The grouping of these three valves in one & the same structure, requiring
only one opening in the inflator.

page_text: 3. The arrangement of the hollow plunger to move longitudinally over the non-
return valve, giving greater compactness.
Dated this 12th day of An 1000
PRESTON WEIR,
Applicant.