Improvement in Compound Air Compressing or Pumping Engines.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvement in Compound Air Compressing or Pumping Engines.
I, FRANK MOORE, residing at Braddock Avenue near Forbes Street Pittsburg,
in the County of Allegheny and State of Pennsylvania, United States of America,
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 relates to compound pumping engines of the type which is set forth
in the application of George Westinghouse filed in the United States August 6,
1890, Serial No. 361,175 (English Application No. 1917790) and in an application
filed by me of even date herewith, and its object is to render an engine of such type
adaptable to use as a simple engine whenever and during such periods as a sufficiently
high working pressure for its normal utilization as a compound engine is not
available.
To this end my invention, generally stated, consists in the combination of a
compound pumping engine, a compound compressing pump having its pistons
connected to those of the engine, a distribution valve controlling the admission and
exhaust of motive fluid to and from the cylinders, and a direct admission valve
controlling direct supply to the low pressure piston and equalization of pressure on
opposite sides of the high pressure piston.
The improvement claimed is hereinafter fully set forth.
In the accompanying drawings
Figure 1 is a vertical central section through the cylinders and valves of a com-
pound pumping engine embodying my invention ;
Figure 2 a similar section, on an enlarged scale, through the valve chest, taken
at right angles to Figure 2; and
Figure 3 a front view of the direct admission valve chamber.
The compound pumping engine in which my invention is herein illustrated
accords in its general features of construction with that of the application of
George Westinghouse Jr. aforesaid (English Patent Application No. 19177) and
with the specific improvement thereon set forth in my aforesaid applications, and
need not, therefore, except so far as relates to my present improvement, be fully
and at length described. As in each of said applications, I provide in the
practice of my invention a compound non-rotative direct acting engine having a
high pressure cylinder 1 and a low pressure cylinder 2, whose pistons 3 and 4 are
fixed upon piston rods 5 and 6, passing through stuffing boxes 7 and 8, and are
controlled by a steam actuated distribution valve composed of a series of valve
pistons 14, 15, 16, 17 and 18, the last four of which are fixed upon a common
stem 19, and the piston 14, for convenience of construction, upon a separate stem
bearing upon the piston 15. Steam is supplied to the distribution valve chamber 11
through a pipe connected to a nozzle 12, and is finally exhausted from the low;
pressure cylinder through a pipe connected to a nozzle 14 on an exhaust chamber 13.
The lower port 39 of the low pressure cylinder 2 communicates with ports 42 in a
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page_text: bushing 40, which is also provided with ports 41, communicating with the lower
port 38 of the high pressure cylinder, and with ports 43, communicating with the
exhaust chamber 13. The cylinders 1 and 2 are provided with a flange 9 for
connection to a fixed support, and their lower heads are preferably cast integral
with a frame or casing 10 for connection to a compound compressing pump having
an initial compression cylinder 44 and a final compression cylinder 45, provided
with suitable inlet, outlet, and discharge valves 49, 51 and 54, discharge port 55,
and delivery chamber 56; and, fitted with pistons 46 and 47 are secured upon the
piston rods of the engine, which pass through stuffing boxes 58 and 59 on the pump
cylinders.
The admission and exhaust of motive fluid to and from the engine cylinders are
effected by the distribution valve as controlled by an auxiliary slide valve 23,
which, as in my application aforesaid, is fitted to work in a chamber 21, communi-
cating by a constantly open passage 22 with the valve chamber 11 between the
valve pistons 16 and 17. The chamber of the valve 23 is fixed upon the head of
the low pressure cylinder 2, and the valve is actuated by a slotted plate 31, fixed
upon the top of the piston 4 thereof, the valve stem 28 extending into and fitting
freely within a central bore in the piston rod 6.
In order to admit of the direct supply of motive fluid to the low pressure piston
and the equalization of pressure upon opposite sides of the high pressure piston, so
as to enable the engine to be operated as a simple engine whenever and during such
periods as such operation may be necessary or desirable by reason of insufficient
working pressure or from other causes, I provide a direct admission valve 64, which
is fixed to a stem 65, and is fitted on a valve face in a chamber 60, formed or fixed
upon the front of the main valve chamber 11, the motive fluid supply nozzle or
inlet 12 leading into the chamber 60 instead of into the valve chamber 11, as in the
applications aforesaid. The chamber 60 is closed at top by a suitable cap 66, and
the stem 65 projects through said cap and through a suitable stuffing box therein
and is squared at its outer end for the application of a wrench to effect the rotative
movement of the valve 64 as from time to time required. The valve 64 is provided
with opposite ports 67 and 68, and, accordingly as turned about the axis of the
stem 65 into one or another position, controls communication between the supply
nozzle 12 and chamber 60 and ports 61 and 62, leading from said chamber to the
ports 35 and 41 of the valve chamber 11, as shown in Figure 2, or, as the case may
be, between said nozzle 12 and chamber 60 and a port 63, leading from the
chamber 60 to the valve chamber 11 between the ports 41 and 35.
valve 64 is in the former position, motive fluid will be admitted directly to the low
pressure piston and an equilibrium of pressure will be effected upon opposite sides
of the high pressure pistou, the engine operating under such conditions as a simple
engine. When the valve 64 is turned into the latter position, motive fluid will be
admitted initially to the high pressure cylinder, exhausted therefrom to the low
pressure cylinder, and finally exhausted from the low pressure cylinder, as in the
applications aforesaid.
When the
In operation as a compound engine, assuming the high pressure piston 3 to be at
the lower extremity of its stroke, motive fluid is admitted from the supply nozzle 12
and chamber 60 to the valve chamber 11 through the port 63 and from the valve
chamber through the ports 41 and 38 to the high pressure cylinder 1 on the lower
side of its piston 3, effecting the upward stroke of said piston and of the connected
pump piston 47. These pistons remain stationary at the termination of the upward
stroke until the low pressure piston 4 has made a complete downward stroke, (its
initial downward stroke being effected by the slight leakage of motive fluid past the
high pressure piston 3) when the slotted plate 31 of the low pressure piston 4 strikes
the collar 29 of the stem of the auxiliary slide valve 23 and moves said valve
downwardly, so as to place the interior of the chamber 20 above the valve piston 14
in communication with the exhaust chamber 13 through the ports 24 and 26, and
the exhaust cavity of the valve. The preponderance of motive fluid pressure in the
valve chamber 11 on the valve piston 16 above that on the opposite valve piston 17

page_text: thereupon raises the distribution valve, admitting motive fluid 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 admission and exhaust
of motive fluid from the high pressure cylinder 1 to the low pressure cylinder 2
and from the low pressure cylinder to the atmosphere or to a condenser are effected
by the distribution valve, as in the applications aforesaid, and, not having special
reference to my present invention, need not be herein again described. When
it is desired to operate the engine as a simple engine, the direct admission valve
is turned into the position shown in Figure 2, in which its ports 67 and 68 register
with the ports 61 and 62, leading to the valve chamber 11, and the port 63 is
closed. Motive fluid will then, in the position shown in the drawings, be admitted
directly to the low pressure cylinder 2 above its piston 4 through the ports 35, 36
and 33, effecting the downward stroke of said piston and of the connected pump
piston 46, and will likewise be admitted through the ports 35 and 32 to the high
pressure cylinder 1 on the upper side of its piston 3 and through the ports 41 and 38
to said cylinder on the lower side of its piston, thereby instituting an equilibrium
of pressure on the opposite sides thereof. Upon the elevation of the distribution
valve by the auxiliary slide valve at the termination of the stroke of the pistons
motive fluid will be correspondingly admitted directly to the low pressure cylinder
below its piston and to the high pressure cylinder on opposite sides of its piston,
as required for the succeeding upward stroke of the low pressure piston, upon
which the entire available working pressure is exerted in this position of the direct
admission valve.
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. The combination, substantially as set forth, of a compound pumping engine, a
compound compressing pump having its pistons connected to those of the engine,
a distributing valve controlling the admission and exhaust of motive fluid to and
from the engine cylinders, and a direct admission valve controlling direct supply to
the low pressure piston and equalization of pressure on opposite sides of the high
pressure piston.
2. The combination, substantially as set forth, of a high pressure cylinder, a low
pressure cylinder, a compound compressing pump having its pistons connected to
those of the engine, a distribution valve controlling the admission of motive fluid to
the high pressure cylinder and the exhaust thereof into and from the low pressure
cylinder, a chamber having a supply inlet, a passage leading from the supply
chamber to the distribution valve chamber in such relation to the ports thereof and
of the cylinders as to effect admission initially to the high pressure cylinder and
secondarily from the high to the low pressure cylinder, passages leading from the
supply chamber to the distribution valve chamber in such relation to the ports
thereof and of the cylinders as to effect admission initially to the low pressure
cylinder and to establish equilibrium of pressure in the high pressure cylinder on
opposite sides of its piston, and a direct admission valve controlling the passages
from the supply to the distribution valve chamber.
Dated this 14th day of February 1891.
ABEL & IMRAY,
Agents for the Applicant.