Improvements in or connected with the Valves of Steam or other Fluid Pressure Engines.
Year: 1891

page_text: Date of Application, 21st Mar., 1891
Complete Specification Left, 19th Dec., 1891-Accepted, 23rd Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with the Valves of Steam or other
Fluid Pressure Engines.
I DAVID JOY of 17 Victoria Street in the City of Westminster, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention has for its object to reduce the size and consequently the weight
of the valves of steam or other fluid pressure engines where double or multiple
ports are used or what is known as the "trick port is introduced. According to
my invention I employ a double or multiple port valve which may be of ordinary
construction but instead of carrying the "trick port" along and through the back
of the valve, the ports at each end are carried through the valve and are put in
communication with each other by a passage over the valve through the balance
plate which rests on the valve or through an equivalent part against which the
back of the valve slides so that the metal hitherto required for "trick port" in the
valve itself is not present and so I save the weight of the said metal in the valve
and transfer it to the balance plate or equivalent part which is stationary. The
trick port arranged according to my invention as aforesaid may be made so as
both to double the moment of entry of the motive fluid and also to connect the
two ends of the cylinder just before exhaust. Or a single port only may be made
in the valve face and an outer "trick port" may be provided in the balance plate
or equivalent part to double the moment of entry of the motive fluid a second or
minor trick port being provided in the balance plate or equivalent part to perform
the same office for the exhaust fluid. The whole valve is thus very much shortened
and friction is reduced as well as the weight of the valve being very much lessened.
The same arrangement also admits of the single port in the valve face being
employed and instead of the trick port being carried in the balance plate or
equivalent part over the back of the valve it may be led out at each end of the
balance plate or equivalent part and so give communication with the motive fluid
spaces, the laps being arranged accordingly. Or whilst still retaining the single
port in the valve face I provide the double motive fluid opening as before and I
provide two exhaust ports in the balance plate or equivalent part which by the
extra exhaust ports provided in the valve (one at each side of the centre) pass the
motive fluid back again through the middle of the valve. The division between
these ports may be formed by a loose bar kept to its face by spring pressure and I
connect these two exhaust ports in the balance plate or equivalent part so
connecting the two ends of the cylinder, the moment before exhaust by a short
reversed "trick port" in the exhaust.
D
01-4 ML 1001
J. H. JOHNSON & Co.,
A gents.
COMPLETE SPECIFICATION.
Improvements in or connected with the Valves of Steam or other
Fluid Pressure Engines.
I, DAVID JOY, of 17 Victoria Street Westminster, 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:—
My invention has for its object to reduce the size and consequently the weight
of the valves of steam or other fluid pressure engines where double or multiple
ports are used or what is known as the "trick port" is introduced.

page_text: According to my invention I employ a double or multiple port valve which may
be of ordinary construction (otherwise than as hereinafter explained) but instead of
carrying the "trick port" along and through the back of the valve the ports at
each end of the valve are carried therethrough and are put into communication
with each other by a passage made through the balance plate which bears on the
valve or through an equivalent part against which the back of the valve slides so
that the metal hitherto required for the "trick port" in the valve itself is not
present and so I save the weight of the said metal in the valve and transfer it to
the balance plate or equivalent part which is stationary. The "trick port,"
arranged according to my invention as aforesaid may be made so as both to double
the moment of entry of the motive fluid as well as to connect the two ends of the
cylinder just before exhaust. Or a single port only may be made in the valve face
and a "trick port" may be provided in the balance plate or equivalent part to
double the moment of entry of the motive fluid another "trick port "being provided
in the balance plate or equivalent part to perform the same office for the exhaust
fluid. The whole valve is thus very much shortened and friction is reduced as well
as the weight of the valve being very much lessened. The same arrangement also
admits of the single port in the valve face being employed and instead of the trick
port being carried in the balance plate or equivalent part over the back of the
valve it may be led out at each end of the balance plate or equivalent part and so
give communication with the motive fluid spaces, the laps being arranged
accordingly. Or whilst still retaining the single port in the valve face I provide
the double motive fluid opening as before and provide two exhaust ports in the
balance plate or equivalent part which, by extra exhaust ports provided in the
valve (one at each side of the centre) pass the exhaust motive fluid back again
through the middle of the valve. The division between these ports may be formed
by a loose bar kept to its face by spring pressure, and I connect these two exhaust
ports in the balance plate or equivalent parts for putting the two ends of the
cylinder into communication as aforesaid at the moment before exhaust by a short
reversed "trick port" in the exhaust.
And in order that my invention may be well understood I will describe with
reference to the accompanying drawing the best methods with which I am
acquainted for carrying the same into effect.
In Figure 1 1 illustrate a double port steam valve A with the ordinary exhaust
passages therein. B is the valve casing and C the valve face. The "trick"
passage has hitherto been carried round through the back of the valve being cast
in it. According to my invention I make short ports a a passing directly through
the valve A and opening into another port d putting them into communication with
each other and formed in a plate D bearing on the back of the valve A and
forming the balance plate. Thus the trick passage is formed partly in the valve
and partly in the balance plate a large part of the material for forming this port
being so transferred from the moving part of the valve A and embodied in the
balance plate D which is stationary, thus relieving the strains on the valve gear by
that amount of weight.
The trick passage may be used for doubling the steam admission, and may also
be employed to unite the two ends of the cylinder by leaving a negative lap of
opening on the exhaust side as shewn at a².
In the example shewn in Figure 2 I use the short ports a a through each end of
the valve for doubling the steam admission in conjunction with the ports d' d' in
the balance plate above, these two being connected by the small "trick" passage d
for uniting both ends of the cylinder as in Figure 1. For doubling the exhaust
areas, two additional ports a³ a³ are provided through the valve opening into
another and distinct port d³ in the balance plate which allows the exhaust steam to
pass back through the opening d and through the valve to the exhaust port.
The valve face itself has only two ports C¹ C³ for connection to the two ends of
the cylinders.
In the example shewn in Figure 3 I illustrate another modification according to

page_text: my invention by which I reduce both the weight and surface of the valve so
relieving the driving strains and friction whilst maintaining the proper port
opening. In this case I use only one wide port (C¹ C²) for each end of the
cylinder, but there are four through ports (a a as a³) in the valve, combining with
other ports d d³ on the balance plate bearing on the back of the valve, the
ports a a in the valve in conjunction with the ports dd in the balance plate serve
to double the admission of steam into the main cylinder ports C'C' whilst the
ports as as in the valve in conjunction with the ports d³ d³ in the balance plate
serve to double the passage for the exhaust from each end of the cylinder through
the opening in the back of the valve. There is a small passage a round each
end of this port shewn dotted in Figure 3 (and separately in section in Figure 3A
by which, at the middle position of the valve, the steam is allowed, for a moment,
to pass round from one end of the cylinder to the other. If this passage a¹ be not
employed then the laps at f may be omitted as they are not then required. The
division between the ports a³ a³ may be formed by a loose bar E (as shewn at
Figure 3) extending across the port openings and kept to its face by spring
pressure, say by two springs as at e.
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. In or for motive power engines a slide valve with the "trick" port partly in
the valve and partly in the relief or balance plate or equivalent part against
which the valve slides substantially as and for the purpose hereinbefore
described.
2. In or for motive power engines the combination of a relief or balance
plate on the back of the valve with ports as herein described in combination
with ports passing through the valve itself and providing double steam admission
and exhaust, and with a supplemental passage in the valve to connect both ends of
the cylinder all arranged substantially as herein before described.
3. The several constructions or arrangements of slide valves and ports as herein-
before described and shewn in Figures 1, 2 and 3 of the drawings.
4. In combination with slide valves and a balance plate bearing on the back
thereof a loose bearing bar E extending across the port openings and kept in
contact with the valve by spring pressure substantially as explained with regard to
Figure 3B of the accompanying drawings.
Dated this 19th day of December 1891.
J. H. JOHNSON & Co.,
Agents.