Improvements in Balanced Valves for Steam Engines.
Year: 1891

page_text: Date of Application, 24th Mar., 1891-Accepted, 16th May, 1891
[Communicated from abroad by HOBART CANFIELD, of Moristown, New Jersey,
United States of America, Mechanical Engineer.]
Improvements in Balanced Valves for Steam Engines.
I, HENRY HARRIS LAKE of the firm of Haseltine Lake & Co., Patent Agents,
45 Southampton Buildings in the County of Middlesex 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 balanced valves of the piston class employed in compound
marine, locomotive and stationary engines and it consists in the construction whereby
the arrangement of ports is such that the communication between the high and low
pressure cylinders is made by the movements of one valve, and in a single steam
chest common to both the high and lower pressure cylinders.
In the accompanying drawing,
Figure 1 is a longitudinal section of a cylinder steam chest and valve embodying
my improvement.
Figure 2 is a transverse section through cr of Figure 1.
Figure 3 is a transverse section through the line
Figure 4 shows the valve.
of Figure 1.
of Figure 4, and
of Figure 4.
Figure 5 is a section through either of the lines
Figure 6 is a section through either of the lines
Similar letters of reference indicate like parts in all the figures of the drawing.
Referring by letter to the drawing, A designates the high pressure cylinder and
A is the low pressure cylinder on the same centre line with the first named cylinder.
The cylinder A is provided with a piston A and the cylinder A' has the piston A³.
These pistons are connected together in the usual manner and may be provided with
the usual packing rings a.
It may be here stated that the construction of the pistons and cylinders may be
other than that shown, or in other words, my invention may be applied to high and
low pressure cylinders either horizontal or vertical, and of the various constructions
now in use.
B designates the pistons valve consisting essentially of the hollow cylinder b and
the piston rings B. For the cylinder I preferably employ steel or similar hard
metal and the piston rings B' are preferably of softer metal, such as wrought iron,
shrunk into the cylinders. Each of the piston rings B may be provided with
annular channels into which metal packing rings are fitted and properly doweled
to break joints.
Port openings 62 extend
rings B¹. The openings
than the other openings b².
ends of the cylinder b.
through the cylinder
between certain of the piston
for the passage of live steam are shown as larger
Closures or heads are provided at the respective
From the closure 63 a valve rod a' extends through a head of the valve casing B²
to connect with any well known driving mechanism whereby a reciprocating longi-
tudinal movement is imparted to the piston valve. From the closure & a tail piece
or rod a extends through the other head of the valve casing B². The casing heads
may be provided with stuffing boxes and glands within which the rods a' a² operate.
designates the steam chest into which steam may be admitted through the
opening or openings e. As shown in the drawing, the steam chest C is located over
or opposite the high pressure cylinder A, and a steam chest C' is located over or
opposite the low pressure cylinder A'.
The steam chest C has communication for live steam with the steam chest Ci
through a small duct or pipe c', and the latter steam chest is provided for the purpose
DC

page_text: of receiving steam to bear against the head or closure while steam in the chest C
bears against the opposite end of the valve whereby an equal pressure is established
at both ends of the valve to maintain a perfect balance.
In the drawing, I have shown the tail rod a as of larger diameter than the rod a',
thus reducing the bearing arca at that end of the valve and thus compensating for
the weight of the valve and valve rod. This construction, however, need be
employed only when the valve is used with a vertical compound engine. In a
horizontal cylinder the tail rod and valve rod may be of the same diameter and its
main use is to keep the valve central and relieve the weight on the packing rings of
the piston rings.
DD' D D designate steam ways or ports providing for the entrance of steam to
the high pressure cylinder and for the exhaust therefrom to the low pressure
cylinder. The liner, E, is also provided with ports communicating with the
ports D D'D² D³.
In the drawing (Fig. 1) it will be seen that the pistons A A³ are about to be
moved in the direction indicated by the arrow adjacent to the piston A² and the
various arrows show the course of the steam and exhaust. For instance, steam is
admitted to the high pressure cylinder through the port D, the exhaust passes
from the high pressure cylinder through the port D' to the interior of the valve by
way of ports and through the port D into the low pressure cylinder, and the
exhaust from the low pressure cylinder escapes through the port ³ to an exhaust
outlet E. Of course when the direction of the valve movement is reversed the live
steam is admitted to the high pressure cylinder through the port D' and the exhaust
is through the port D into the low pressure cylinder through the port. D³, the
exhaust therefrom being through the port D.
By reference to Figures 2 and 3, it will be seen that the requisite increase of area
for the admission of low pressure steam, is gained by enlarging the ports D² D³
transversely to the length of the cylinders.
Having now particularly described and ascertained the nature of my invention, and
in what manner the same is to be performed, as communicated to me by my foreign
correspondent I declare that what I claim is:
1. The combination with high and low pressure cylinders having ports substantially
such as described, of a steam chest arranged above or opposite the high pressure
cylinder, another steam chest arranged above or opposite the low pressure cylinder
and communicating with the first named steam chest, through a conduit of reduced
area, and a reciprocating hollow piston valve having ports allowing the passage
of steam through its interior, substantially as specified.
2. The combination with the cylinders, the valve casing and the steam chests, of
the reciprocating hollow valve having the end closures, a valve rod extending from
one of said closures and a tail rod extending from the other of said closures, the said
tail rod having a greater diameter throughout its length than the valve rod whereby
the pressure area on that end of the valve is decreased, substantially as specified.
Dated this 24th day of March 1891
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.