Improvements in Cylinder Valves for Direct Acting Fluid Pressure Engines and Pumps.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Cylinder Valves for Direct Acting Fluid Pressure
Engines and Pumps.
We, JAMES MACARA CHRISTIE, of No. 57, Wigram Street, Glebe Point, near Sydney,
in the Colony of New South Wales, Engineer Turner, and RICHARD ROCK, of Stanley
Street, Burwood, near Sydney, in the said Colony, Engineer Turner, do hereby declare
the nature of this invention to be as follows:-
-
This invention relates to improvements in cylinder valves for direct acting fluid
pressure engines and pumps or those valves which control the supply and exhaust of
working fluid for the cylinders of engines which impart a reciprocating and not a
circular motion to the object actuated such as the piston of a pump.
Cylinder valves for such direct acting fluid pressure engines and pumps accord-
ing to the present invention are made in two parts, namely a main reversing
valve, hereinafter termed the main valve, for controlling the supply and exhaust
of the fluid at the opposite ends of the main or power cylinder, and a secondary
reversing valve, hereinafter termed the secondary valve, for controlling the supply and
exhaust and cushioning of the fluid at one end of the main valve. Both the main
and the secondary are piston valves and fit in their respective cylindrical casings
provided with suitable ports and passages.
The main valve is arranged on the cover of the main cylinder with its axis at right
angles to that of the cylinder, and the secondary valve, according to our invention, is
situated at the side of the main valve, its axis being parallel to that of the main
cylinder and therefore at right angles to that of the main valve.
The secondary valve has three pistons on one stem which is actuated by the main
piston of the power cylinder at each end of its stroke. The casing of this secondary
valve has a port by which the space between its two outer pistons is always kept
charged with the working fluid under pressure the outermost of these pistons prevent
ing this fluid from finding its way into the main cylinder.
Another port
communicates with the exhaust passage of the main valve and a third port communi-
cates with the casing of the main valve by a port at cushioning distance from its
inner end. A fourth port of the secondary valve casing, alternately opened and closed
by the central piston, communicates with a port at the inner end of the casing of the
main valve. The stem of the secondary valve is hollow or channelled to form an
exhaust passage from the inner end of the secondary valve casing, and it protrudes
through the head or upper end of the main cylinder so that it is moved one way by
the main piston at that end of its stroke pushing against it. The secondary valve
has also a rod passing through the main piston rod, and terminating in a collar which
the main piston acts on at the other end of its stroke so as to reverse the position of
the secondary valve. Thus the motion of the secondary valve is such that fluid under
pressure is supplied at one end of the casing of the main valve at the proper moment
to move that valve the one way, and then again at the proper moment the steam

page_text: supply port is closed and the exhaust port from that end of main valve casing is
opened relieving the pressure on the main valve so that it moves the other way until
the cushioning takes place.
The main valve. also a piston valve having four pistons on one stem. Two of
these governing central ports for the supply and exhaust of the main cylinder are
balanced in pressure having always the working fluid between them and having a
passage through them for exhaust. The working fluid is supplied to the space
between the pistons through the stem from one end of the valve casing which is
always in communication with the source of fluid pressure. The other two pistons
which are at the ends of the valve have different areas, the piston at the inner end,
which is acted on by fluid as controlled by the secondary valve, having the larger
area.
When the larger piston at the one end of the main valve has the fluid under
pressure admitted behind it by the action of the secondary valve, the pressure on it
overcomes the same pressure which always is on the smaller piston at the other end
of the valve, moving the valve the one way, and when by the action of the secondary
valve the fluid behind the larger piston is exhausted, then the excess pressure on the
smaller end piston moves the main valve the other way.
These motions of the main valve control the supply and exhaust of the main
cylinder.
Dated this 15th day of October 1898.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Cylinder Valves for Direct Acting Fluid Pressure
Engines and Pumps.
We, JAMES MACARA CHRISTIE, of No. 57, Wigram Street, Glebe Point, near Sydney,
in the Colony of New South Wales, Engineer Turner, and RICHARD ROCK, of Stanley
Street, Burwood, near Sydney, in the said Colony, Engineer Turner, 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 improvements in cylinder valves for direct acting fluid
pressure engines and pumps or those valves which control the supply and exhaust of
working fluid for the cylinders of engines which impart a reciprocating and not a
circular motion to the object actuated such as the piston of a pump.
Cylinder valves for such direct acting fluid pressure engines and pumps according
to the present invention are made in two parts, namely a main reversing valve, here-
inafter termed the main valve, for controlling the supply and exhaust of the fluid at
the opposite ends of the main or power cylinder and a secondary reversing valve,
hereinafter termed the secondary valve, for controlling the supply and exhaust and
cushioning of the fluid at one end of the main valve. Both the main and the
secondary are piston valves and fit in their respective cylindrical casings provided
with suitable ports and passages as will be described with reference to the accom-
panying drawings.
Fig. 1 is a vertical section of the main valve and its cylindrical casing.
Fig. 2 is a sectional plan of the main and secondary valves and their casings.
Fig. 3 is a vertical section of both valves on a plane at right angles to that of the
section Fig. 1

page_text: C is the cover of the engine cylinder C¹ which is assumed to be vertical. On this
cover in one piece with it is formed the cylindrical casing C2 of the main valve the
axis of this casing being horizontal and the casing being bushed with a lining C³
through which there are holes or ports which put the interior in communication with
two annular ports C and C5. Of these C communicates directly with the upper
end of the main cylinder C¹ and C³ communicates with a pipe or channel C leading
to the lower end of the main cylinder.
There is an inlet C7 for the steam or working fluid leading by a channel Cs to the
right end of the main valve casing and by a channel C to the secondary valve
casing. From the main valve casing there is an outlet C10 for exhaust this com-
municating by a channel C with the secondary valve casing.
The main valve consists of a tubular stem A on which are three portions A¹ A² A³
of equal diameter and a smaller piston A4 working in a smaller cylindrical part
formed in the cover of the valve casing. The interior of the tubular stem has two
lateral openings A5 into the space between the pistons A2 and A³ and through these
and a widened part of the stem are channels A for passage of exhaust.
The casing B of the secondary valve is also cylindrical having its axis vertical.
From it besides the channels C and C already referred to there are two other
channels B¹ leading to the extreme left end of the main valve casing behind the
piston A¹ the other B opening into the main valve casing a little further from its
end. The stem D of the secondary valve is tubular and has on it three
pistons D1 D2 D3 the middle one D2 of which governs the ports B1 and B2 and
between the pistons D1 and D2 there is the exhaust port C. Through the tubular
stem passes a rod E which extends into the tubular rod of the main piston and has
on it collars at each end the one bearing on the top of the secondary valve the other
meeting an internal shoulder of the main piston rod as it is approaching the end of
its down stroke so that the secondary valve is then drawn down to the position
shown in Fig. 3 being afterwards pushed up by the main piston as it approaches
the end of its upstroke acting on a prolongation of the valve stem D. The rod E
has a groove along its side so that there is free passage to the upper part of the slide
case B, and therefore the pressure on both pistons D¹ and D³ is always the
same.
The operation of the valve is as follows:
When the main piston has ascended bringing the secondary valve up, fluid under
pressure passes by the port B₁ to the left end of the main valve case C and acts on
the piston A¹ propelling the main valve to the right. Fluid thereupon passes by the
port C to the top end of the main cylinder while exhaust from the lower end of the
cylinder passes by the port C5 to the space between the pistons A¹ and A2 thence
through the channels A" to the exhaust channel C. The main piston is thus
propelled downwards. As it approaches the end of its downstroke it draws down the
secondary valve, the port B¹ is thus closed and the port B2 is put in communication
with the port C leading to the exhaust and then the pressure on the piston A*
causes the main valve to make its stroke to the left being cushioned by the fluid
imprisoned behind the piston A¹ when it passes the port B2. By this movement of
the main valve fluid is admitted by the port Co to the lower end of the main
cylinder, while the upper end is put in communication through the channel C¹ with
exhaust Co. Thereupon the main piston makes its upstroke after which the opera-
tion is repeated.
Having now particularly described and ascertained the nature of this in-
vention and in what manner, the same is to be performed, we declare that what we
claim is :-
In combination with the cylinder of a direct acting fluid pressure engine a main
slide valve having two pistons adapted to govern ports leading to the two ends of the
cylinder, and having at its ends a larger and a smaller piston, the smaller always
subject to the pressure of the working fluid and the larger subjected to that pressure
as determined by the movement of a secondary valve which has three pistons and is

page_text: adapted to be moved up and down by the piston of the main cylinder as it approaches
the ends of its stroke and thus to govern ports communicating with the main valve
casing substantially as described.
ABEL & IMRAY,
Agents for the Applicants.