Improvements in Steam Pumping Engines.
Year: 1893

page_text: Date of Application (in United Kingdom), 4th Apr., 1893
Complete Specification Lert, 4th Apr., 1893—Accepted, 5th Aug., 1893
Complete Specification Lert, 4th Apr., 1990-Accepted, on Aug., 1090
COMPLETE SPECIFICATION.
Improvements in Steam Pumping Engines.
I, HENRY HERMAN WESTINGHOUSE, of Pittsburgh, Pennsylvania, 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 :-
My invention relates to a construction of steam pumping engines which is
simple, has its parts readily accessible for examination or repair, and has a high
operative efficiency, as I shall describe referring to the accompanying drawings.
Fig. 1 is a view, partly in elevation and partly in vertical central section, of a
steam pumping engine embodying my invention;
Fig. 2 is a vertical central section taken on a plane at right angles to the section
in Fig. 1;
Fig. 3 a plan partly in section, on an enlarged scale, on the line a, a, of
Figs. 4 and 5;
Fig. 4 being a vertical section on the line y, y, of Fig. 1;
Fig. 5 a side elevation of the lining of the main valve chamber, and,
Fig. 6 a transverse section on the line z, z, of that lining.
My present invention applies to steam pumping engines of the class or type of
those used for compressing air on trains provided with Westinghouse brake
apparatus, in which the operation of the main steam distribution valve is controlled
by a valve operated by the movement of the main steam piston of the engine or some
part having movement coincident with it.
As shewn in the drawings a main distribution slide valve which controls the
supply and exhaust of steam to and from the main steam cylinder is operated by a
differential piston whose movement is controlled by a single auxiliary valve operated
by the movement of the steam piston. The valve mechanism is simple and compact
being formed entirely within the cover or bonnet of the steam cylinder. This
construction is comparatively inexpensive, and permits the removal or examination
of any of the parts without removing the cylinder head, and, should it be necessary
to remove the cylinder head, this may be done without disturbing or removing the
valve gear from it. The employment of a single auxiliary valve for controlling the
main valve, and the relative arrangement of these parts, admit of short and direct
passages from the auxiliary valve to the differential piston, and there are no outside
connections from one part to another requiring the employment of stuffing boxes or
other packings or tight joints. The form of the main steam cylinder is much
Bimplified, and, when repairs are required of the valve devices, or the parts within
which they operate such as a lining, it is not necessary to remove the main steam
cylinder, but only the cylinder head.
When the engine is used on a locomotive, for which use it is specially designed,
a new head, with its contained valve device, may be quickly substituted for one
requiring repair, and thus a locomotive need not be put out of service, or
substantially delayed for repairs to the valve mechanism of its pump.

page_text: The steam cylinder 1 is placed above the pump cylinder 2, and the steam piston 3,
is connected by the piston rod 4, to the pump piston 13. The piston rod 4 has
a central bore 5, to receive the valve stem 7, which is connected to an auxiliary
valve 8, which may be termed the reversing valve. This reversing valve 8 is fitted
in the lining 12 of a central chamber formed in an upward extension of the cylinder
head 15. The reversing valve 8 is fitted between the shoulders 10 and 11 of the
stem 7 and moves with the stem which passes through a hole 16 in a plate 6 into
the bore 5 of the piston rod 4. When the steam piston 3 ascends, the plate 6 comes
in contact with the shoulder 9 on the stem 7, and moves the valve 8 upwards, and
when steam piston descends, the plate 6 comes in contact with a collar 14, on the
end of the stem 7 and moves the reversing valve down.
The engine being connected to a steam supply pipe by the nozzle or connection 17;
steam passes through the passage 18 formed in the wall of the steam cylinder, the
passage 19 formed in the cylinder head, and the port 20 in the lining 21, into
the chamber 22 in which the main slide valve 23 is fitted controlling the ports 24,
25 and 26, through which steam is admitted to and exhausted from the two ends
of the steam cylinder. The slide valve 23, is fitted between two shoulders on the
stem 27 of the differential pistons 28 and 29, with which the main valve moves.
The larger piston 29 is fitted in one end of the lining 21, and the other piston 28, is
fitted in the cap 30 which closes one end of the chamber 22, but both pistons may
be fitted in the lining 21, or in a chamber 22 without a lining, or, the piston 29 may
be fitted in the cap 31 in the same manner as the piston 28 is fitted in the cap 30.
The outer end of the chamber 32, in the cap 30, is in open communication at all
times with the exhaust passage 26 by means of the passage 33 formed in the cap 30,
the annular passage 34 formed in the inner end of the cap 30; the passage 35 in
the lining 21 (see Fig. 5) and the passages 36 and 37 which open into the exhaust
passage 26 so that the outer side of the smaller piston 28 is exposed at all times to
the pressure in the exhaust passage 26. The space between the two pistons 28 and 29
is at all times exposed to the pressure in the live steam passages 18 and 19; and
the outer end of the larger piston 29 is exposed to the pressure of steam which is
admitted to and discharged from the chamber 22 by the reversing valve 8, this
chamber 22 being always in open communication with the reversing valve
chamber 45 by means of the port 43 in the lining 21, the passage 44, and the
port 46 in the lining 12.
The reversing valve 8 controls the three ports 47, 48, and 49, in the lining 12,
these ports connecting respectively with the passages 36, 40, and 38 formed in the
outer side of the lining 21. The passage 36 in the lining 21 communicates with the
exhaust passage 26 by the passage 37. The passages 38 and 40 both communicate,
by the ports 39 and 41, with the space at that end of the chamber 22 which is closed
by the cap 31. When the reversing valve is down as shown in Fig. 1, the port 49
is closed and the cavity 42 in the face of the reversing valve, by connecting the
port 48 with the port 47, connects the passage 40 with the passage 36, and thereby
opens communication from the outer side of the piston 29 to the exhaust passage 26.
The outer faces of both pistons being then exposed to the pressure in the exhaust
passage 26, and their inner faces to the live steam between them, as the piston 29
has a larger area than the piston 28, the two pistons 28 and 29 and the main slide
valve 23 are moved to the right, as shown in Figs. 2 and 3. Before reaching the
end of its stroke, the piston 29 closes the port 41 and thereby confines a portion of
the exhausting steam between it and the cap 31, this acting as a cushion. The
slide valve, moving with the piston 29 to the right, opens the port 24, admitting
live steam under the main steam piston 3 and allowing steam from above the piston
to exhaust through the passage 25, the cavity 50, in the main valve, and the exhaust
passage 26, thus causing the piston to move upwards.
When the steam piston approaches the upper end of its stroke, the reversing
valve is moved up, first closing the port 48 and cutting off communication between
the port 41 and the exhaust passage 36, and then by its farther movement opening
the port 49 through which live steam enters the passage 38 in the lining 21 and

page_text: passes through the port 39 into the space at the right side of the piston 29. The
steam thus admitted behind the piston 29 balances the pressure on its left side and
as the pressure of the live steam on the right side of the smaller piston 28 is opposed
only by the pressure in the exhaust passage 26 acting on its left side the pistons
and the valve 23 move toward the left and put the passage 24 from the lower end
of the main steam cylinder in communication with the exhaust passage 26 through
the cavity .50 in the valve 23 while at the same time the port, 25 is opened
permitting live steam to pass from the chamber 22 to the upper end of the main
steam cylinder causing the piston to make its downstroke.
When the piston approaches the end of its downstroke the plate 6, meeting the
collar 14, on the stem 7, moves the reversing valve down to the position shown in
Fig. 1. The supply of steam to the space at the right side of the piston 29 is then
cut off and that space is put in communication with the exhaust passage 26; the
pressure of the live steam on the left face of the piston 29 thereupon moves the
pistons 28 and 29 and the valve 23 so as to first cut off the exhaust from under
the main piston, and then to open the port 24 admitting live steam under the piston,
and at the same time to connect the passages 25 and 26 through the cavity 50, so
as to open the space above the main piston to the exhaust passage. The main
piston 3 then moves upwards as before.
In order to hold the reversing valve down in the position shown in Fig. 1 and
prevent it from being moved before the plate 6 meets the shoulder 9, the stem 7 has
its upper end in a chamber 51 in which it is subjected to steam pressure when the
piston 3 is moving upward, this chamber 51 communicating by a passage 52 with an
annular groove 54 formed around the outside of the upper edge of the lining 12.
This annular groove is connected by a longitudinal groove, formed in the outside of
the lining 12, with another annular groove 55, which is formed around the lower end
of the lining, and is connected with the passage 24 by a passage 56 formed in the
cylinder head, see Fig. 3. The chamber 51 is therefore, always subject to the
pressure in the passage 24 and under the main piston 3, and so that as the piston
moves up the stem is held down by the steam pressure in the chamber 51, acting
on its upper end, against the pressure of the exhaust acting on the other end. When
the piston 3 is moving down the chamber 51 and the space under the piston 3 are
exposed to the pressure in the exhaust passages, the reversing valve is then in its
upper position and is held up by the pressure in the space above the steam piston
acting on the lower end of the stem against the pressure of the exhaust to which the
upper end of the stem 7 is then exposed.
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 steam pumping engine, in combination with the steam cylinder, a cylinder
head, having formed in it a chamber containing the main valve and a second
chamber containing the reversing valve and a shouldered stem of the reversing
valve passing through the main steam piston so that the reversing valve is moved
both ways by the piston, substantially as set forth.
2. In a steam pumping engine, in combination with the steam cylinder, a cylinder
head, a main distribution valve working in a chamber of the head, and connected to
two pistons of different areas, one of these pistons being always subject on its one
side to the pressure in the exhaust passage of the engine, and the other piston being
exposed alternately to live steam pressure and to pressure in the exhaust passage, a
reversing valve controlling the ingress and egress of steam to act on the latter
piston, this reversing valve having a shouldered stem passing through and moved
by the main steam piston at each extremity of its stroke substantially as set
forth.
3. The arrangement of passages whereby the stem of the reversing valve is
subjected to the pressure of live steam and of exhaust steam at its opposite ends

page_text: alternately so as to be held in position until it is moved by the piston, substantially
as set forth.
ABEL & IMRAY,
Agents for the Applicant.