Improvements in and connected with Direct-acting Steam Pumps.
Year: 1896

page_text: Date of Application, 26th May, 1896-Accepted, 18th July, 1896
COMPLETE
SPECIFICATION.
Improvements in and connected with Direct-acting Steam Pumps.
I, JAMES WEIR, of Holm Foundry, Cathcart, in the County of Renfrew,
North Britain, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described aud
nscertained in and by the following statement, that is to say:
My said invention has for its object to improve and render more efficient the
distribution valve for the steam cylinder of a direct-acting non-rotating pump.
The improvements are applicable to steam valves of the kinds described in my
Patent Specifications No. 1208 of 1881, and No. 3723 of 1894, the main slide
valve being controlled and operated by means of an auxiliary slide valve deriving
its motion from the piston rod and working on a port face on the main slide
valve in a direction opposite or at a right or other angle to the movement of the
main valve.
The improved valve is suitable for very high pressures as well as for ordinary
pressures.
Several modifications of valves as made according to my invention are shown on
two accompanying sheets of explanatory drawings,
Figures, 1, and 2, on Sheet, 1, thereof being sections, as at right angles to each
other, of one modification.
Figure, 3, on Sheet, 2, is a plan of part of the main and auxiliary valves of the
modification shown in Figures, 1, and 2.
Figures, 4, and 5, are sections, as at right angles to each other, of a second
modification.
Figure, 6, is a plan (drawn to a larger scale) of part of the main and auxiliary
valves of the modification shown in Figures, 4, and 5.
Figure, 7, is a cross section of the main slide valve of a third modification.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
In the modification shown in Figures, 1, 2, and 3, the main steam ports, A, B,
and the main exhaust port, C, are formed in a flat face in the steam chest, D, which
may be jointed to or formed in a piece with the cylinder, E. The main slide
valve, F, is externally rectangular in cross section, and is made with an internal
cylinder, F1, which is bisected by a partition, F2, so as to form two cavities
which fit and work on pistons or plugs, G, G 1, held apart by a distance bar, G 2,
(movable in a central hole in the partition) and held in position by stops, G 3, fixed
in the sides of the valve chest, D. Each stop, G 3, consists of a washer inside and
a washer outside of the valve chest, D, into which they are suitably recessed and
jointed and held by a screw. On the face of the main slide valve, F, ports, H, J,
(communicating with the expansion cavities, H 1, J 1) and the exhaust cavity, C1,
are formed these ports also working in connection with the steam ports, B, A, and
exhaust port, C, in the steam chest, D. On the side of the main valve, F, opposite
to the ports, H, J, the auxiliary steam ports K, L, communicating with the
cylindrical cavities between the plugs, G, G 1, and the valve partition, F 2 are
formed, there being also on this face the expansion ports, H2, J 2, and
ports, C2, C3, communicating with the exhaust cavity, C1. The auxiliary slide
valve, M, works across the main, slide valve, F, that is at right angles to its
motion, and on the face of the auxiliary valve the auxiliary exhaust cavity, M 1, is
formed.

page_text: When the auxiliary valve, M, is moved by the valve spindle, M 2, to the end
of its stroke, the auxiliary exhaust cavity, MI, puts one port, K, in communication
with one exhaust port, C'3, and thereby with the main exhaust cavities, C 1, and C.
Pressure being thereby relieved between one piston, G, and the partition, F 2,
steam entering by the other uncovered port, L, between the other piston, G I, and
the other side of the valve partition, forces the main valve, F, to the other end
of its stroke. The expansion port, H2, is by the travel of the auxiliary
valve, M, uncovered and communicates with the corresponding steam port, B, in
the valve chest, D, and the main piston is made to complete a stroke. On the
auxiliary valve, M, being again moved the port, I, communicates by means of
the exhaust cavity, M 1, and the passage, C 2, with the exhaust cavities, C 1, and C,
and pressure is thereby relieved between the piston, G 1, and the valve
partition, F 2.
Steam enters by the uncovered port, K, between the other
piston, G, and the valve partition, F 2, and forces the main valve, F, to the
opposite end of its stroke, and the expansion port, J 2, which communicates with
the main steam port, A, being uncovered the main piston is again moved to the
opposite end of its stroke. Ports, N, N 1, are formed in the valve face of the
steam chest, D, communicating with cavaties, N 2, which communicate by means
of by-pass valves, N 3, N4, with their corresponding steam passages, A, B.
When the auxiliary valve, M, has closed either expansion port, H 2, J 2, either
by-pass port, N, N1, is uncovered, and the valve, N 3, or N 4, is regulated to
allow of a little steam entering the steam passage to insure the main piston
completing its stroke without jarring. Either port, N, N 1, is covered by the
valve, F, when the steam port, A, or B, at the same side is open to the exhaust
cavities, C, C 1. To prevent lateral movement the main valve, E, slides between
guides, D 1, formed in the valve chest, D.
In the modification shown in Figures, 4, 5, and 6, the steam ports, A, and B, and
the exhaust port, C, are in a plate, Q, fixed in the steam chest, D, and having a
concave face, the main valve, F, being circular in [cross section. In this case the
pistons, G, G 1, are fitted with packing rings, G 4, and are each held by a
screw, G5, against the sides of the valve chest. The valve, F, is also provided
with guide pieces, F 1, to prevent it from rocking. The valve, F, is not provided
with expansion cavities, or ports to be closed or opened by the auxiliary valve, the
steam entering the main ports, A, B, at the ends of the valve. With the exception
that the valves, F, and M, cannot be worked expansively, their action is the same
as the action of the modification previously described.
In Figure, 7, a third modification is shown in which the main valve, F, is
cylindrical and works on a concave face on a plate in the steam chest, and is
provided with side guides, F1, to prevent rocking. It is also provided with
expansion cavities, H 1, J1, and ports, H 2, J 2, and with a flat face for the
auxiliary valve, M, to slide upon. Its action is precisley the same as the action of
the modification first described.
With my improvements an increased area in the ports leading to the cylinder is
obtainable, likewise a large face on which the auxiliary valve may move thus
permitting larger openings through the expansion ports and a longer travel to the
auxiliary valve. My improvements also allow of a simpler arrangement of
by-passes admitting steam to the cylinder passages.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The construction, arrangement and combination of parts constituting 'the
improved valve apparatus for direct-acting steam pumps substantially as herein-
before described with reference to Figures, 1, 2, and 3, of the accompanying
drawings.
2. In direct-acting steam pumps an improved distribution valve made with
cylindrical cavities and moving on pistons or plugs held and guided substantially

page_text: in the manner hereinbefore described with reference to Figures, 1, 2, and 3, of the
accompanying drawings.
3. In direct-acting steam pumps combining with the main steam distribution
valve by-pass ports passages and valves. substantially as and for the purposes
hereinbefore described with reference to Figures, 1, 2, and 3, of the accompanying
drawings.
4. The construction, arrangement and combination of parts constituting the
improved valve apparatus for direct-acting steam pumps substantially as herein-
before described with reference to Figures, 4, 5, and 6, of the accompanying
drawings.
5. In direct-acting steam pumps an improved distribution valve made with
cylindrical cavities and moving on pistons or plugs held and guided substantially
in the manner herein before described with reference to Figures, 4, 5, and 6, of the
accompanying drawings.
6. In direct-acting steam pumps, the improved construction of steam distribution
valve substantially as herein before described with reference to Figure, 7, of the
accompanying drawings.
Dated this Twenty-third day of May 1896.
EDMUND HUNT,
Applicant's Agent.