Improvements in Slide Valves.
Year: 1890

page_text: Date of Application, 7th May, 1890
Complete Specification Left, Sth Feb., 1891-Accepted, 14th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Slide Valves.
We, JAMES MARSHALL and REGINALD WIGRAM, of the Steam Plough Works,
Leeds, in the County of York, Engineers, do hereby declare the nature of this
invention to be as follows:-
This invention relates to expansion valves, working in connection with ordinary
er so called main valves and used in controlling the inlet and outlet of steam from
the cylinders of any engine. The invention is applicable whether the valves are
automatically controlled by the governor, or varied in their action by hand. The
object of the invention is to relieve the said main and expansion valves from the
whole or any portion of the friction caused by the pressure of steam upon the valves.
For this purpose we make the main valve of a box section like valves now in use in
engines automatically controlled by the governor. The steam ports on the back of
the valve may be made at right or at any other angle in relation to the centre
line of the valve spindle. The expansion valve is of a box section, not as is
usual of a flat section. The steam ports of this valve are formed in one face only of
the box. The balance or relief of this valve is obtained by admitting the steam
used in working the engine through the valve between its two larger Inces, either
through the ends or sides of the box. The steam chest cover has its inner face
grooved in any convenient form; and into this groove or recess is received a
packing capable of adjustment. The inner face of this packing bears upon the back
of the expansion valve. Or the packing may be arranged upon the back of the
valve travelling with it and bearing against the steam chest cover.
The space enclosed between the slide valve, the steam chest cover and the packing
is connected with either the condenser or the receiver of the engine, or with the
external atmosphere, as may be desirable; thus reducing or relieving the pressure
on the back of the valve.
Dated this 6th day of Mar 1890.
REGINALD WIGRAM.
Carpmael & Co.,
Agents
COMPLETE SPECIFICATION.
Improvements in Slide Valves.
We, JAMES MARSHALL and REGINALD WIGRAM, of the Steam Plough Works,
Leeds, in the County of York, Engineers, 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 expansion valves, working in connection with ordinary or
so called main valves and used in controlling the inlet and outlet of steam from the
ylinders of any engine. The invention is applicable whether the valves are
automatically controlled by the governor, or varied in their action by hand. The
object of the invention is to relieve the said main and expansion valves from
the whole or any portion of the friction caused by the pressure of steam upon the
valves. For this purpose we make the main valve of a box section like valves now
in use in engines automatically controlled by the governor. The steain ports on
the back of the valve may he made at right or at any other angle in relation to the
centre line of the valve spindle. The expansion valve is of a box section, not as is
usual of a flat section. The steam ports of this valve are formed in one face only

page_text: grammpraren
पत्र
of the box. The balance or relief of this valve is obtained by admitting the steam
used in working the engine through the valve between its two larger faces, either
through the ends or sides of the box. The steam chest cover has its inner face
grooved in any convenient form; and into this groove or recess is received a packing
capable of adjustment. The inner face of this packing hears upon the back of the
expansion valve.
The space enclosed between the slide valve, the steam chest cover and the packing
is connected with either the condenser or the receiver of the engine, or with the
external atmosphere, as may be desirable; thus reducing or relieving the pressure
on the back of the valve.
In onler that our said invention may be fully understood and reality carried into
effect we will proceed to de cribe the drawing hereunto annexed.
DESCRIPTION OF THE DRAWINGS,
Figure 1 is a longitudinal section through the valve chest of a steam engine in
which the valves are arranged in accordance with our invention and so as to avoid
undue pressure of the valves the one on the other and against the valve face,
Figure 2 is a transverse section; in this figure the valves are seen in end
elevation.
Figure 3 shows the inner face of the cover of the valve chest.
Figure 4 shows a detail to a larger scale.
a is the valve face upon the eylim the engine. a'd' are the steam port-
and is the exhaust port in this fa.. is the main valve and are the
ports in it. In the back of this valve there are other ports. As represented
in the drawing these ports may be supposed to be obliquely cut but they might
he otherwise. e is the main valve spindle and a rectangular frame, of a piere with
the spindle and surrounding the valve. The spindle is actuat:-1 in the usual
manner by the main eccentric. d is the expansion valve and is the valve spinille
which also is moved by an eccentric or it may be otherwise. The valve dis hos
like in form it has openings in it at d by which steam enters freely within it.
This valve on its face next the main valve has oblique or other ports ad for the
passage of the steam into the main valve when these ports correspond with other
like ports in the back of the main valve, are the walls of the valve chest and
is the valve chest cover. is a back plate fixed upon the cover. There is a circular
recess in the cover into which spring packing rings ji are fitted. At Figure 4 a
transverse section of the rings is seen and the sertion is so taken as to show the
joint tongues in the rings. is an endless coil spring ring at the back of the
packing rings by it they are pressed against the back of the expansion valve (which
is a plane surface) and against the sides of the circular recess in which the rings
are lodged. is a brass ring supporting the endless coil k. At the back of the
ring there are six coiled springs in lodged in recesses provided for them in the
nn are adjustable screws serving as abutments for the springs mom they
pass through the back plate of the cover which has bushes let into it at to
receive the screws n. The space in the cover y within the packings rings ii is
relieved from pressure, being either open to the atmosphere or to the condenser, or
other enclosure in which a relatively low pressure is maintained. is a connecting
passage which serves also as a drain to lead of water resulting from condensation, ag
are openings in the cover g by which the adjustment of the parts may be observed
before the back plate & is put on.
cover .
h
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is—
1. The combination of parts consisting of the main valve b with ports corresponding
to those in the valve face against which it works and other ports in the back; the
- expansion valve ₫ of box like form on the back of the main valve and having vorts

page_text: corresponding with the ports therein by which steam passes from the interior of the
expansion valve into ports in the back of the main valve and the cover plate g with
packing rings i bearing upon a plane surface at the back of the expansion valve and
enclosing a space from which the steam in the valve chest is excluded and which is
thus relieved from pressure.
2. The apparatus substantially as represented by the annexed drawings.
CARPMAEL & Co.,
Agents for the Applicants.