Improvements in Fluid-pressure Engines or Pumps.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Fluid-pressure Engines or Pumps.
I, JAN FREDERIK BEINS, of 3, Burgemeester Hoffmanplein, Rotterdam, in
the Kingdom of Holland, (Analytical) Chemist, do hereby declare the nature
of this invention to be as follows:-
This invention relates to apparatus for enabling liquids or gases of insufficient
or too high a pressure for the particular purpose in view to be applied in such
a manner as to enable an increased pressure to be imparted to a portion of the
volume of the operative fluid or to a corresponding volume of another fluid.
Gases or liquids under pressure, such, for instance, as water in service-
pipes and mains, air from compressed-air systems, or gases stored under pres-
sure in receivers, are too expensive to be used as motive agents. For prac-
tical purposes, it is necessary to raise the pressure of water obtained from
a conduit or service-pipe to the desired degree rapidly and in a sufficient
quantity to meet requirements, and this object is attained automatically by
means of this invention. The improved apparatus is, therefore, specially designed
for use where the pressure available would otherwise be wasted, or where the cost
of the motive fluid is a secondary consideration.
The apparatus or transformer, amongst the numerous purposes to which it is
applicable may be utilized in conjunction with mineral water plant in the manufac-
ture of mineral waters, or in raising water to those storeys of a building for which
the initial pressure is inadequate, in which instances a motive fluid whereof the
pressure would otherwise be unsuitable or lost can be utilized. Or in extinguish-
ing outbreaks of fire wherein the loss of a portion of the water taken from the
source of power would be comparatively unimportant.
The apparatus consists essentially of a large and a small cylinder arranged one
above the other and respectively enclosing a large and a small piston, the said
pistons being connected together by a piston-rod. The movements of the pistons
are controlled by automatic valve mechanism which is arranged beneath the
larger cylinder. The space in the cylinders between the two pistons is maintained
in free communication with the atmosphere. Pressure water from the main
is admitted below the larger piston, whilst water from the same source is forced
away from above the smaller piston. The pressure yielded by the latter will
depend upon the relative areas of the two pistons considered in conjunction with
the pressure in the service-pipe. For example, if the ratio between the piston
areas be 1 to 4, and the pressure in the pipe be 2 atmospheres per unit of
area, a pressure of 8 atmospheres per unit of area will be developed above the
smaller viston.

page_text: The times of admission and exhaust of the pressure fluid are regulated by a
piston -slide-valve: while the position of the piston-slide-valve itself is controlled
by the two pistons pertaining to the large and small cylinders mentioned above.
The water-main pressure is employed for driving the two pistons in the upward
direction, for operating the inlet and outlet valves and for driving the two
pistons in the downward direction. Thus, it will be seen that the operation of
the device is automatic throughout.
In constructing the apparatus, the pistons enclosed in the larger and smaller
cylinders are packed with leather, the piston-rod which connects the two pistons
together being hollow for a portion of its length. The larger cylinder is secured
between the flange at the lower end of the smaller cylinder and an end- or base-
plate leather washers being provided to render the joints water-tight. To
the end-plate is secured a valve-chest wherein the inlet and outlet-valves are
arranged in circular chambers disposed one on either side of another circular
chamber wherein the piston-slide-valve works. Through the valve-chest are
also orifices or passages which serve in connection with the admission and exhaust.
The end- or base-plate of the larger cylinder has depressions which correspond with
the chambers pertaining to the inlet- and outlet-valves; while a central passage
which traverses the said plate coincides with the chamber pertaining to the
piston-slide valve.
The inlet-valve chamber is in communication with the admission orifice through
a small port located in the upper part of the corresponding depression in the
end- or base-plate, the outlet-valve chamber being in similar communication with
the exhaust. The inlet and outlet-valve chambers are also provided with ports
which traverse the said base-plate and communicate with the space below the
piston in the larger cylinder. Both the inlet and outlet-valves are moreover
formed as small pistons and each is provided with a leather cup or packing. The
former valve is of a light, whilst the latter is of a heavy construction. These
valves are adapted to slide in the chambers and are each provided with an india-
rubber cap for effecting the closing of the respective ports which communicate
with the larger cylinder. The lower portion of each valve is extended to serve as
a guide.
extremities.
°
The piston-slide-valve is provided with a leather cup at its upper and lower
From the guide-like upper extremity of the said valve projects
a stem which works through a cap or nut at the lower end of the hollow piston-
rod and which is provided with an adjustable dise: the outer extremity of the
stem entering a reduced portion of the bore of the hollow piston-rod. Or a
hollow cylindrical body may be fitted in the said bore so as to form a shoulder
for the disc to abut against. This cap or nut, in conjunction with the shoulder
in the hollow piston rod, operates the piston-slide-valve according as the one or
the other comes into contact with the said disc. The annular space in the piston-
slide-valve chamber between the cupped extremities is permanently in communi-
cation with the pressure-fluid by means of a branch pipe extending from the
service-pipe to a port communicating with the annular space formed by the valve
in the valve-chamber. The said piston-slide-valve is perforated so that the spaces
above and below the said valve are in communication with each other. The piston-
slide-valve chamber is in communication by way of suitably disposed ports with
the chamber of the outlet-valve above and below the piston of the latter valve,
and with the chamber of the inlet-valve below the piston pertaining thereto.
At a point near the upper end of the smaller cylinder is an inlet furnished with
a non-return valve and with which the service-pipe is connected. The discharge
orifice is situate at the top of the cylinder and is provided with a pressure-gauge
and a back-pressure-valve.
The operation of the apparatus or transformer is as follows: The starting
valve or cock having been opened, and, assuming the piston-slide-valve to
he in its lowest position, pressure water from the annular space surrounding

page_text: the piston-slide-valve is admitted, by way of the port in the lower portion
of the piston-slide-valve chamber, below the piston of the outlet-valve; the outlet-
valve being thereby raised and the exhaust port of the larger cylinder is closed.
Meanwhile, the port between the piston-slide-valve chamber and the chamber
below the inlet-valve is uncovered; the pressure water being thereby exhausted
from the latter chamber into the space above the piston-slide-valve. From this
space the liquid passes through the port communicating with the space above
the outlet-valve from whence it is finally exhausted. As the water becomes
exhausted, the pressure from the service-pipe which is in direct communication
with the upper end of the inlet-valve chamber causes the inlet-valve to descend and
open the port to the larger cylinder. The pressure liquid now gains access to the
space in the cylinder below the larger piston, raising the two pistons and dis-
charging the liquid from above the smaller piston at an increased pressure,
until the piston-slide-valve is raised by the cap or nut coming into contact with
the dise on the stem of the said valve. The pressure fluid now gains access to the
under side of the inlet-valve from the annular space which surrounds the piston-
slide-valve by way of the port between the slide-valve and the outlet-valve
chamber. At the same time, the pressure liquid is cut off from the under side
of the outlet-valve and the port thereto is opened so as to exhaust, by way of the
passage through the body of the slide-valve, to the upper part of the slide-valve
chamber and from thence as above described. The pressure on each end of the
outlet-valve being in equilibrium this valve falls by its own gravity. The opening
of the outlet-port to the exhaust produces a reduction of pressure in the upper
space of the inlet-valve chamber while the pressure below the inlet-valve, which
is of light construction, effects the rise of the said valve and thereby closes the
inlet-port. The pressure from the service-pipe being now on the upper side of the
smaller piston both pistons descend, the upper cylinder being thereby recharged;
while the liquid from below the larger piston is exhausted to a storage tank.
On the cylindrical body in the hollow piston-rod coming into contact with the
dise on the slide-valve-stem the piston-slide-valve is depressed and the cycle of
operations is repeated.
It will be seen that at each upward stroke of the pistons the water contained in
the smaller cylinder is forced at an increased pressure into the discharge pipe
and that a quantity of water, corresponding to the capacity of the larger cylinder,
is discharge. This water may be collected in a tank or cistern and utilized for
washing. Hushing or other purposes.
The apparatus cas be advantageously applied in the manufacture of mineral
waters, the water herefor being usually forced into the saturation chamber
by the pressure of the carbonic acid gas, a loss in respect of the latter invariably
occurring. Such loss of gas is however obviated by the employment of the herein
described automatic apparatus.
The mineral water machine supposed to be in use is one of the class in which
the water is forced through a porous wall into a chamber containing carbonic
acid gas at a pressure of, say, 5 atmospheres and wherein such water is saturated
with the carbonic acid gas. Assuming that the pressure in the pipe supplying the
water (which pipe is connected by branches to the inlet- and piston-slide-valve
orifices in the valve-chest and to the inlet of the smaller cylinder) be 2 atmos-
pheres, and that the ratio between the piston areas be 1 to 4. the water, under
an increased pressure, will be forced from the transformer into the mineral water
machine and charged with carbonic acid gas.
Where no pressure water from a main is available, water from any other source,
or in fact any fluid, may, by means of this transformer, be brought to the desired
pressure.
The pressure of carbonic acid gas at say, 20 atmospheres--may be employed as
motor power the transformer being so arranged that water from a higher level
is first admitted under the larger piston, to raise the same, while carbonic acid

page_text: gas is ultimately admitted above the smaller piston. Water is thus forced from
below the larger piston of the transformer at a pressure of 5 atmospheres where
the ratio of the piston areas is 4 to 1.
This latter arrangement may also be adapted to operate automatically, and
without loss of carbonic acid gas; the gas exhausted from the transformer being
employed to saturate the water in the mineral water machine.
The transformer above described may be employed in all cases where a low
pressure is available and where it is desired to develop a higher pressure.
In large towns where a system of water mains exists, but where the pressure in
such mains is sometimes insufficient to carry the water to the upper storeys of the
buildings. this apparatus will be found advantageous. The transformer in this
instance is introduced into the water-pipe system at a conveniently low level to
raise the water in the said system to the required pressure. The moment such
pressure becomes reduced in consequence of water being drawn from any
part of the system, or from the cistern served thereby and which may be at the
highest point of such system, the apparatus will operate automatically until the
required pressure is restored. The water which has been used in obtaining this
increase of pressure may be utilized in the lower storeys for flushing and other
purposes.
This apparatus is further adapted for use in extinguishing outbreaks of fire as
it enables a supply of water to be at any time ready for use so that an incipient
fire may be suppressed as soon as detected; and if such water be first saturated
with carbonic acid gas, the extinguishing effect on the fire will be increased. If
carbonic acid gas under pressure be employed for actuating the transformer, the
exhaust gas may be discharged upon the fire with the water.
Total 411.
A 1
1004
G. G. M. HARDINGHAM,
Chartered Patent Agent.
Clun House, Surrey Street, London, W.
Improvements in Fluid-pressure Engines or Pumps.
I, JAN FREDERIK BEINS, of 3, Burgemeester Hoffmanplein, Rotterdam, in
the Kingdom of Holland, (Analytical) Chemist, 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 apparatus for enabling liquids or gases possessing
insufficient or excessive pressure for the particular purpose in view to be applied
in such a manner as to enable an increased pressure to be imparted to a portion
of the volume of the operative fluid or to a corresponding volume of another
fluid; energy which, under the existing mode of working, is incapable of employ-
ment or is lost being thereby rendered serviceable.
Gases or fluids under pressure, such, for example, as water in service pipes
and mains, are too expensive for use as motive agents. The object of the present
invention is to provide means for automatically raising the pressure of water
from a conduit or service pipe to a higher pressure rapidly, and, in sufficient
quantities, to meet requirements; and the apparatus is especially serviceable in
cases where the pressure available would otherwise be wasted or where the cost

page_text: of the same is of slight importance. The apparatus being designed more par-
ticularly for use in converting a low pressure into a higher one, or rice corsa, for
brevity it may be termed a transformer.”
"
The purposes to which the apparatus or transformer may be applied are
Dumerous. For example, it may be utilized in connection with mineral water
plant in the manufacture of mineral waters or in raising water to those storeys of a
building for which the initial pressure is inadequate, in which instances a motive
fluid is utilized, whereof the pressure would otherwise be unsuitable
lost. Or it may be used in extinguishing fires, in which instance the loss of a
portion of the water taken from the source of power would be comparatively
unimportant.
or
Apparatus adapted for carrying my invention into effect is illustrated in
the accompanying drawings whereof Fig. 1 is a vertical section. Fig. 2 is an
elevation, at right angles to Fig. 1: the upper portion of the smaller cylinder
and the inlet thereto being shown in section. Figs. 3, 4 and 5 are horizontal
sections taken on the lines A-A, B-B and (--C respectively in Fig. 1. Fig. 6
is a diagrammatic view illustrating the application of the device in the manufac-
ture of mineral waters.
The apparatus comprises a small cylinder and a large cylinder 2, arranged the
former above the latter, wherein are respectively located a small piston 5 and a
large piston 3, the said pistons being connected together by a hollow piston-rod 4.
The movements of the pistons are controlled by automatic valve mechanism
arranged beneath the larger cylinder. The space in the cylinders between the
pistons 5 and 3 is maintained in free communication with the atmosphere through
the vent or port 51. Water under pressure from the service pipe or main is
admitted below the larger piston and water from the same source is forced away
from above the smaller piston 5 through the port 45. The pressure of the liquid
yielded by the latter piston will depend upon the relative areas of the two
pistons considered in connection with the pressure in the service pipe. For
example, if the ratio between the piston areas be as 1 to 4 and the pressure in the
service pipe be two atmospheres per unit of area, a pressure of eight atmospheres
per unit of area will be developed above the smaller piston 5.
The admission and exhaust of the pressure fluid are controlled by the piston
slide 28, while the position of the piston slide itself is controlled by the two
pistons 5 and 3.
The pressure of the water from the service pipe or main is employed for moving
the pistons 5 and upwards, for operating the inlet and outlet valves 27, 26
and for effecting the downward movement of the said pistons. Thus, it will be
seen that the operation of the device is automatic throughout.
In constructing the apparatus, the pistons 5 and 3 are packed with leather, the
piston-rod 4 which connects these pistons together being hollow for a portion of
its length. The larger cylinder 2 is secured by bolts 22 between the Hange 48,
at the lower end of the smaller cylinder 1, and an end- or base-plate 6; leather
washers being provided to render the joints water-tight. To the end-plate 6
is secured a valve-chest 12, the latter being provided with five perforations or
chambers 14, 15, 33, 35, 37, and closed by a cover or lid 13. The chambers 35
and 33 wherein the inlet and outlet-valves 27 and 26 are respectively located are
disposed one on either side of a central chamber 337 within which the piston-slide-
valve 28 works. The remaining orifices or passages 15 and 14 are utilized as
passages in connection with the admission and exhaust. The end- or base-plate G
of the larger cylinder has depressions 60 and 61 which are in line with the
chambers 35 and 33 pertaining to the inlet- and outlet-valves; while a central
passage 62 which traverses the said plate 6 coincides with the chamber 37 pertain-
ing to the piston-valve.
The inlet-valve chamber 35 is in communication with the admission orifice 15
through a small port 36 located in the upper part of the corresponding depres-
sion 60 in the end- or base-plate 6, the outlet-valve chamber 333 being in similar

page_text: communication through the port 34, with the exhaust 14. The inlet and outlet
valve chambers 35 and 33 are also provided with ports 11 and 10, respectively,
which traverse the said base-plate and communicate with the space below the
piston in the larger cylinder 2. Both the inlet and outlet-valves 27 and 20
are moreover formed as small pistons, and each is provided with a leather cup or
packing 23. The inlet-valve 27 is of a light, while the outlet-valve 26 is of a
heavy construction. These valves are adapted to slide in the chambers 35 and 33
and are each provided with an india-rubber cap 63 for effecting the closing of
the respective ports 11 and 10 which communicate with the larger cylinder 2.
The lower portion of each valve is extended to serve as a guide.
The piston-slide-valve 28 is provided with a leather cup 64 at its upper and
lower extremities. From the guide-like upper extremity of the said valve projects
a stem 29 which works through a cap or nut 9 at the lower end of the hollow
piston-rod 4 and which is provided with a disk 30, the outer extremity of the stem
entering a reduced portion of the bore of the hollow piston-rod. Or a hollow
cylindrical body 31 may be fitted in the said bore so as to form a shoulder for
the disk 30 to abut against. This cap or nut 9 in conjunction with the shoulder 31
in the hollow piston-rod operates the piston-slide-valve 28 according as the one
or the other comes into contact with the said disc 30. The disc 30 is
made adjustable on the stem 29 so that the stroke of the valve 28 may be
accurately regulated. The annular space in the piston-valve chamber, between
the cupped extremities 64 of the valve, is permanently in communication with
the pressure fluid by means of a branch pipe 17 extending from the service-pipe
to a port communicating with the annular space formed by the valve in the valve-
chamber and having a nozzle 50 thereon. The said piston-slide-valve 28 is per-
forated at 32 so that the spaces above and below the said valve are in communi-
cation with each other. The piston-slide-valve chamber is in communication,
by way of the port 23, with the space above and by way of the port 24, with
the space below, the piston of the outlet-valve 26; and by way of the port 25 with
the space below the piston of the inlet-valve 27.
At a point near the upper end of the smaller cylinder 1 is an inlet 65 furnished
with a non-return or check valve 19 and with which the service-pipe 18, is con-
nected. The discharge orifice 38, is situated at the top of the cylinder 1, is
provided with a pressure-gauge 20 and is in communication with a discharge
pipe 45 which is provided with a back pressure valve 21.
The operation of the apparatus or transformer is as follows: The starting
valve or cock (indicated by the reference numeral 16) having been opened, and,
assuming the piston-slide-valve 28 to be in its lowest position, pressure water
from the chamber 37 is admitted by way of the port 24 into the chamber 33 below
the outlet-valve 26, thereby raising the said valve and closing the exhaust port 10
of the cylinder 2. Meanwhile, the port 25, between the piston-slide-valve
chamber 37 and the space in the chamber 35 below the inlet-valve 27, is un-
covered the pressure water being thereby exhausted from the said chamber 35
into the space above the piston-slide-valve 28. From this space the liquid passes
through the port 23 communicating with the space above the outlet-valve 26
As the
from whence it is finally exhausted through the port 34 and orifice 14.
water becomes exhausted, the pressure from the service-pipe 18 which is in direct
communication through port 36 with the upper end of the inlet-valve chamber 35
causes the inlet-valve 27 to descend and open the port 11 to the cylinder 2.
pressure liquid now gains access to the space in the cylinder 2 below the piston 3.
raising the two pistons 3 and 5, and discharging the liquid from above the smaller
piston through the passage 38, check valve 21 and pipe 45 at an increased
pressure, until the piston-slide-valve 28 is raised by the cap or nut 9 coming
into contact with the disk 30 on the stem 29 of the said valve. The pressure
fluid now gains access to the under side of the inlet valve 27 from the chamber 37
pertaining to the piston-slide valve 28 by way of the port 25 between the
piston-slide-valve 28 and the inlet-valve chamber 35. At the same time, the
The

page_text: pressure liquid is cut off from the under side of the outlet-valve 26 and the port 24
thereto is opened so as to exhaust, by way of the passage 32, through the body of
the slide-valve 28 to the upper part of the slide-valve chamber 37 and from
thence, as above described, through the port 233 and passage 34 to the discharge
orifice 14. The pressure on each end of the outlet-valve 26 being in equilibrium,
this valve falls by its own gravity. The opening of the outlet port 10 to the
exhaust 14 produces a reduction of pressure in the upper space of the inlet-valve
chamber 35 while the pressure below the inlet-valve 27, which is of light con-
struction, effects the upward movement of the said valve and the closure of the
inlet-port 11. The pressure from the service-pipe 18 being now on the upper
side of the smaller piston 5, both pistons and descend, the upper cylinder 1
being thereby recharged: while the liquid from below the larger piston is
exhausted. On the cylindrical body 31 in the hollow piston-rod 4 coming into
contact with the disk 30 on the slide-valve-stem 29, the piston-slide-valve 28 is
depressed and the cycle of operations is repeated.
It will be seen that, at each upward stroke of the pistons 5 and 3, the water
contained in the smaller cylinder is forced at an increased pressure into the
discharge pipe 45 and that a quantity of water, corresponding to the capacity
of the larger cylinder 2 is discharged. This water may be collected in a tank
or cistern and utilized for washing, flushing or other purposes.
The apparatus is capable of being advantageously applied in the manufacture
of mineral waters, the water herefor being usually forced into the saturation
chamber by the pressure of the carbonic acid gas, a loss in respect of the latter
invariably occurring. Such loss of gas is, however, obviated by the employment
of the improved automatic apparatus. -
The mineral water machine, illustrated in Fig. 6, is one of the class in which
the water is forced through a porous wall into a chamber containing carbonic acid
gas at a pressure of say five atmospheres and wherein such water is saturated with
the carbonic acid gas. Assuming that the pressure in the water supply pipe 41,
which pipe is connected to pipe 18 of the transformer, be two atmospheres, and
that the ratio between the piston areas be 1 to 4, the water, under an
increased pressure, will be forced from the cylinder 1 of the transformer through
the pipe 45 into the mineral water machine 39 and charged with carbonic acid gas.
The carbonic acid gas enters the mineral water machine 39 under the requisite
pressure, say, five atmospheres, from the receiver 44, by way of the pipe 16;
the gas-charged water being withdrawn by way of the pipe 47.
The waste water from the exhaust 14 of the transformer flows into a recep-
tacle 43 being conducted hither by the pipe 42, and may be utilized for any
purpose.
Where no pressure water from a main is available, water from any other source,
or, in fact, any fluid, may, by means of this transformer, be brought to the desired
pressure.
The pressure of carbonic acid gas--at say, 20 atmospheres may be employed
as motive power, the transformer being so arranged that water from a higher
level is first admitted under the larger piston to raise the same, while carbonic
acid gas is ultimately admitted above the smaller piston. Water is thus forced
from below the larger piston of the transformer at a pressure of 5 atmospheres
where the ratio of the piston areas is 4 to 1.
This latter arrangement may also be adapted to operate automatically, and
without loss of carbonic acid gas: the gas exhausted from the transformer being
employed to saturate the water in the mineral water machine.
The transformer above described may be employed in all cases where a low
pressure is available and where it is desired to develop a higher pressure.
In large towns where a system of water mains exists, but where the pressure in
such mains is sometimes insufficient to carry the water to the upper storeys of
the buildings, the above described apparatus will be found advantageous. The
transformer” in this instance is introduced into the water-pipe system at a con-

page_text: veniently low level to raise the water in the said system to the required pressure.
The moment this pressure becomes reduced in consequence of water being drawn
from any part of the system, or from the cistern served thereby and which may
be at the highest point of such system, the apparatus will operate automatically
and effect the restoration of the pressure. The pressure water which has been
used in obtaining this result may be employed for flushing and other purposes
in the lower storeys of the buildings.
This apparatus is further adapted for use in extinguishing out-breaks of fire
as it enables a supply of water to be at any time ready for use so that an incipient
fire may be suppressed as soon as detected, and if such water be first saturated with
carbonic acid gas the extinguishing effect on the fire will be increased. If
carbonic acid gas under pressure be employed for actuating the transformer, the
exhaust gas may be discharged upon the fire with the water.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim:-
1. For use in connection with fluids under pressure as motive agents for
enabling an increased pressure to be imparted to a portion of their volume or to
a corresponding volume of another fluid, apparatus arranged or operating substan-
tially as herein described and comprising a pair of cylinders of different dimensions
or diameters enclosing pistons and disposed tandem-wise, the one above the otlier,
one of the cylinders being furnished with valves capable of being automatically
operated and whereby the pressure fluid is admitted to and discharged from the
apparatus.
2. In apparatus of the character indicated in the preceding claiming clause, the
employment of two cylinders, one larger than the other, pistons connected to each
other operating therein, an opening between said pistons in communication with
the atmosphere, a conduit for supplying fluid under pressure to the smaller
cylinder provided with a check valve, a discharge pipe leading from the smaller
cylinder also provided with a check valve, and a conduit for supplying fluid under
pressure to the larger cylinder behind the piston therein.
3. In apparatus of the character indicated in the first preceding claiming clause,
the employment of two cylinders, one larger than the other, pistons connected
to each other and operating therein, an opening between said pistons in com-
munication with the atmosphere, a conduit for supplying fluid under pressure,
whereof one branch communicates with the smaller cylinder and is provided
with a check valve, while another branch leads to the larger cylinder, a discharge
pipe leading from the smaller cylinder, also provided with a check valve, and
valve mechanism for controlling the pressure on the piston in the larger cylinder.
4. In apparatus of the character indicated in the first preceding
claiming clause, the employment of two cylinders, one larger than the other,
pistons operating therein, an opening between said pistons in communication
with the atmosphere, a hollow piston-rod connecting said pistons, a conduit for
supplying fluid under pressure, whereof one branch communicates with the
smaller cylinder and is provided with a check valve, while other branches
of said conduit communicate respectively, with the inlet chamber and with the
piston-valve chamber, the branch entering the latter at a point opposite the
pocket in the piston-slide-valve, a discharge pipe from the smaller cylinder
provided with a check valve, a valve-chest secured to the larger cylinder having
inlet and exhaust passages or orifices and inlet-valve, outlet-valve and piston-valve
chambers formed therein, the inlet passage and inlet-valve chamber, and the
exhaust passage and outlet-valve chamber being in communication with each
other respectively, passages being provided between the piston-valve chamber
and the inlet-valve chamber, and between the piston-valve chamber and the outlet-
valve chamber, the latter passages being located adjacent to the ends of the
chambers with which they communicate, and ports being provided between the
larger cylinder and the inlet and outlet-valve chambers, inlet- and outlet-valves

page_text: adapted to close said ports, a piston-slide-valve having a passage therethrough
and provided with a closed annular pocket in its outer surface, a stem on the
said slide-valve working through the nut on the larger piston and extending into
the said hollow piston-rod, a disk on said stem adapted to be engaged by said nut
and by a shoulder in the hollow piston-rod.