A Compound Engine and Compressing Pump.
Year: 1889

page_text: Date of Application, 25th Nov., 1890-Accepted, 27th Dec., 1890
COMPLETE SPECIFICATION.
A Compound Engine and Compressing Pump.
I, GEORGE WESTINGHOUSE Junior, of Pittsburgh, Pennsylvania, in the United
States of America, 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 :-
The object of my invention is to provide a pumping-engine for the compression of
air and other gases simple in construction and economical in action. For this
purpose I combine a compound non-rotative direct acting engine with a compound
compressing pump, having an initial compression cylinder and a smaller final
compression cylinder, the pistons of which are directly connected to those of the engine
cylinders.
Fig. 1 of the accompanying drawings is a vertical central section through the
cylinders and valves of a compound pumping engine according to my invention, and
Fig. 2 a transverse section on the line xa of Fig. 1.
The compound direct acting engine has its high pressure cylinder 1, and its low
pressure cylinder 2, fitted respectively with pistons 3 and 4, the piston rods 5 and 6
The alternation
of which pass through stuffing boxes 7 and 8 in the usual manner.
of supply and exhaust of steam is effected by a single set of piston valves, which
reciprocate within a valve chest or casing 11 having a nozzle 12 for the connection
of the steam supply pipe. The valve chest communicates near its upper and lower
ends, with an exhaust chamber 13 having a nozzle 14ª, for the connection of an
exhaust pipe. The four pistons 15, 16, 17 and 18 are secured upon a common
rod 19, a fifth piston 14 being fixed upon a separate stem, and working in a
chamber 20, which communicates on one side of the piston 14, with the exhaust
chamber 13, and on the other with a chamber 21, into which a passage 22 leads from
the middle of the valve chamber 11. An auxiliary slide valve 23 works in the
chamber 21, and controls ports 24, 25 and 26 leading from the chamber 21 to the
chamber 20, the port 26 communicating with a port 27 leading from the chamber 20
to the exhaust chamber 13.
The valve 23 is fixed upon a stem 28, which fits freely within a central bore in
the piston rod 5 of the high pressure cylinder, and is provided with a collar 29
on its lower end, and a shoulder 30 near the upper end of the high pressure
cylinder.
A slotted plate 31 fixed upon the high pressure piston 3 meeting the shoulder 30,
as the piston approaches the upper end of its stroke, and meeting the collar 29 as it
approaches the lower end effects reciprocation of the valve 23.
Ports 32, 33 lead from the upper ends of the high and low pressure cylinders 1
and 2 respectively, to chambers enclosing a sleeve or bushing 34 which is fitted in
the valve chamber and has ports 35 communicating with the high pressure cylinder
port 32, ports 36 communicating with the low pressure cylinder port 33, and ports 37
communicating with the exhaust chamber 13.
Similarly ports 38 and 39 lead from the lower ends of the high and low pressure
cylinders, respectively, to chambers enclosing a sleeve or bushing 40 which has
ports 41 communicating with the high pressure cylinder port 38, ports 42 com-
municating with the low pressure cylinder port 39, and ports 43 communicating with
the exhaust chamber 13.
The pistons 15 and 16 work in the bushing 34 and the pistons 17 and 18 which are
smaller work in the bushing 40.
The compound compressing pump has an initial compression cylinder 44, and a
final compression cylinder 45 of smaller diameter, these cylinders being in line with
those of the engine and having their pistons fixed on the same rods. Both sets of

page_text: cylinders are fixed to a hollow middle frame 10 which may form as shewn the covers
for the lower ends of the steam cylinders and the upper ends of the pump cylinders.
Flanges 9 and 48 are provided for attaching the engine to a standard or support,
and suitable stuffing boxes 7, 8, 58 and 59 are provided for the piston rods 5 and 6.
The initial compression cylinder 44 is provided at each end with an inlet or receiving
valve 49, controlling communication between the atmosphere and a port 50 leading
into the cylinder, and the final compression cylinder 45 is provided at each end with
an inlet or receiving valve 51, which acts also as the delivery valve of the initial
cylinder, this valve controlling communication between a port 52, which is always
open to the port 50, and a port 53 leading into the final compression cylinder 45.
The cylinder 45 is also provided at each end with a delivery valve 54 controlling
communication between its port 53 and a discharge port 55 leading into a delivery
chamber 56 having a nozzle 57 to which is connected a delivery pipe leading to a
suitable reservoir for the storage of the compressed air.
The operation of the engine is as follows:-
Assuming the ports to be in the position shown in the drawings, steam passes
from the valve chest 11 through the ports 41 and 38 into the high pressure
cylinder 1 under its piston 3, effecting its upward stroke and that of the piston 47.
The steam which effected the preceding downward stroke of the pistons 3 and 47
passes through the ports 32, 35, 36 and 33 into the low pressure cylinder 2 above its
piston 4, effecting its downward stroke and that of the piston 46. The steam which
effected the preceding upward stroke of the pistons 4 and 46 is exhausted from
the low pressure cylinder 2 through the ports 39, 42 and 43 to the exhaust
chamber 13, and passes thence to the atmosphere or to a condenser. The air to be
compressed is drawn into the initial compression cylinder 44, through its upper
port 50, and the air which was drawn into it through its lower port 50, in the
preceding npward stroke, is compressed to a certain degree, and forced through the
lower port 52 and valve 51 into the final compression cylinder 45. As the pistons 3
and 47 approach the upper limit of their stroke, the plate 31 meets the shoulder 30
of the valve stem 28 and moves up the auxiliary slide valve 23. The upper end of
the chamber 20 above the valve piston 14 is thus put in communication with the
exhaust chamber 13, through the ports 26 and 27 and the exhaust cavity of the
valve 23. The preponderance of steam pressure on the valve piston 16, above that
on the opposite and smaller valve piston 17, thereupon raises the valves admitting
steam to the high pressure cylinder 1 above its piston 3 through the ports 35 and 32,
and effecting the succeeding downward stroke of the pistons 3 and 47. The steam
which effected the up stroke of the piston 3 now passes into the low pressure
cylinder 2 under its piston 4, through the ports 38, 41, 42 and 39, and the steam
which effected the down-stroke of the piston 4 is exhausted from the low pressure
cylinder 2 into the exhaust chamber through the ports 33, 36 and 37. As the
piston 3 approaches the lower end of its stroke, the plate 31 meets the collar 29 of
the valve stem 28, returning the auxiliary slide valve 23 to the position shown in
the drawings, in which position steam is admitted to the chamber 20 above its
piston 14. The preponderance of downward pressure thus produced moves the
valves to the position shown in the drawings, whereupon the actions are repeated
a's described.
By the stroke of the piston 47, the air which was initially compressed in the
cylinder 44,during the preceding stroke of the piston 46, is farther compressed and
passes through the port 53, delivery valve 54, and discharge port 55 into the delivery
chamber 56, and thence through a suitable delivery pipe into the storage reservoir
or to the place where the compressed air is to be used.
In the construction shewn, the piston, of the initial compression cylinder of the
pump is connected to that of the low pressure cylinder of the engine, and the piston
of the final compression cylinder of the pump to that of the high pressure cylinder
of the engine. This arrangement of cylinders might however be inverted, their
areas being suitably proportioned to the pressures acting in them.
Although in what precedes I have spoken of steam as the motive fluid acting in

page_text: the engine and of air as the fluid to be compressed, obviously other elastic fluid
under pressure could be employed as motive fluid, and gases other than air could be
compressed as described.
The engine described, by reason of its simplicity of structure and compactness, is
specially adapted to uses, such as a locomotive compressing pump for air-brake
mechanism, and its easy working results from the fact that, the pistons not being
connected to a crank shaft, their movements are capable of such relative variation
as may suit variations of pressure of the fluids acting and acted on.
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 a compound pumping engine, the combination, substantially as set forth,
of a compound non-rotative direct acting engine, and a compound compressing
pump, having an initial compression cylinder and a smaller final compression
cylinder with their pistons directly connected to those of the engine cylinders.
2. In a direct acting compound pumping engine, the combination, substantially
as set forth, of a high pressure engine cylinder, a low pressure engine cylinder,
an initial compression pump cylinder, a final compression pump cylinder the
pistons of the pump cylinders directly connected to the engine pistons, a single
distribution valve controlling the ports of the high and low pressure engine
cylinders, and an auxiliary valve actuated by the piston of the high pressure
engine cylinder, substantially as set forth.
3. A direct acting compound pumping engine having a single distribution valve
for the high and low pressure cylinders, and an auxiliary valve, which controls
the movements of the distribution valve, said auxiliary valve being actuated by one
of the main steam pistons, substantially as set forth.
Dated this 25th day of November 1890.
ABEL & IMRAY,
Agents for the Applicant.