IMPROVEMENTS IN THE SLIDE VALVES OF STEAM AND OTHER MOTIVE POWER ENGINES "
Year: 1882

page_text: LETTERS PATENT to James Emery of 66 Crayford Road Erith in the County of
Kent for an invention of "IMPROVEMENTS IN THE SLIDE VALVES OF STEAM
AND OTHER MOTIVE POWER ENGINES
"
PROVISIONAL SPECIFICATION left by the said James Emery at the Office
of the Commissioners of Patents on the 19th May 1882.
JAMES EMERY of 66 Crayford Road Erith in the County of Kent.
"IMPROVE-
MENTS IN THE SLIDE VALVES OF STEAM AND OTHER MOTIVE POWER ENGINES
وو
The chief object of this invention is to neutralize the pressure on the back of
sliding valves of steam or other engines. This slide I form as a hollow box with a
tube at one end which dips into a hollow chamber at the bottom end of the
cylinder. On the back of the slide I place an adjusting bar, with two adjusting
screws so as to keep the slide up to its facing. This improved slide valve can be
worked expansively by placing another slide under the said valve.
The expansion valve is similar to an ordinary slide valve excepting that the
admitting ports are open right through This improved slide valve admits
regularly with the stroke of the piston; while the hollow slide admits and cuts
off at any part of the stroke. On the face of the hollow chamber above mentioned
I place a moveable stuffing box which can be shifted either way so as to allow of
the adjusting of the valves.
This improved slide valve can be worked either with or without a cover on the
back. If worked with a cover it prevents any leakage of the valve from escaping.
This improved slide valve can be worked without the tube at one end of it; by
forming a hollow chamber under the valve seat. This chamber is divided into two
parts one for the inlet and the other for the outlet. The face has double ports so
that the steam passes up one side of the valve and down through the other.
This improved slide valve can be worked with or without an expansion; or
can be worked expansively with a single valve by means of a shifting eccentric
sheave.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Emery in the Great Seal Patent Office on the 18th November
1882.
JAMES EMERY of 66 Crayford Road Erith in the County of Kent
"IMPROVE-
MENTS IN THE SLIDE VALVES OF STEAM AND OTHER MOTIVE POWER ENGINES
"
The chief object of this invention is to neutralize the pressure on the back of
sliding valves of steam or other motive power engines. This slide I form as a
hollow box with a tube at one end which dips into a hollow chamber at the bottom
end of the cylinder. On the back of the slide I place an adjusting bar, with two
adjusting screws so as to keep the slide up to its facing. This improved slide
valve can be worked expansively by placing another slide under the said valve.
The expansion valve is similar to an ordinary slide valve excepting that the
admitting ports are open right through. This slide valve admits regularly with
the stroke of the piston; whilst my improved hollow slide admits and cuts off at
any part of the stroke. On the face of the hollow chamber above mentioned
I place a moveable stuffing box which can be shifted either way so as to allow of
the adjusting of the valves.
This improved slide valve can be worked either with or without a cover on the
back; If worked with a cover it prevents any leakage of the valve from escaping.
This improved slide valve can be worked without the tube at one end of it; by
forming a hollow chamber under the valve seat. This chamber is divided into two
parts one for the inlet and the other for the outlet. The face has double ports so
that the steam passes up one side of the valve and down through the other.
This improved slide valve can be worked with or without an expansion; or
can be worked expansively with a single valve by means of a shifting eccentric
sheave.
And in order that my Invention may be better understood and readily carried
into practice I will proceed to describe the drawings hereto annexed.
DESCRIPTION OF THE DRAWINGS
There are three methods of carrying my invention into practice.
The first method is represented in Figures 1 and 2 of the drawings annexed in
which the same letters in both figures refer to the same or similar parts.
The action of my improved slide here represented may be thus explained.
The steam after passing through an ordinary fixed steam pipe a passes through
the sliding steam pipe b to the slide valve d and while so passing is prevented
from escaping into the atmosphere by means of the gland or stuffing box c
through which the sliding steam pipe b moves backwards and forwards the back
of slide valve d being boxed over. The steam is distributed as in other engines
into the ports f¹, f2, alternately by means of the slide valve d the inner portion
of which acts precisely as an ordinary slide valve and the outer portion by what
I term a moveable valve chest.
The steam is also conducted by the valve d into the exhaust port f³ as in
ordinary steam engines.
In order to keep the valve tight to its face and prevent any leakage of steam,.its
back is pressed upon by means of four set screws k, l, which work in the cross
pieces g, g, which extend over the back of the valve and are bolted to pro-
jections h, h, cast solid with cylinder.
The ends of set screws k, l, are in recesses in a brass bar against which the slide

page_text: valve rubs and the ends of the set screws k¹, k', are in similar recesses in a similar
bar. This bar can be renewed from time to time.
The proper motion is given to the slide valve by means of the slide valve rod e
worked by a suitable eccentric rod and eccentric keyed on engine shaft as is well
5 understood.
Figure 2x shows the slide valve enclosed by a cover.
The second method in which I obtain the same result as that previously
described is by means of a double ported slide valve.
The action of this improved slide valve may be explained by reference to Figures
3, 4, 5, 6 and 7 of the drawings hereto annexed where the valve is shown working
as an expansion valve over a main slide valve.
Figure 3 shows a longitudinal section through the valve and cylinder mid-way
between centre line of valves and its side and Figure 4 shows a longitudinal
section through valves mid-way between the centre and other side. Figure 5 is a
section through the valves in a plane whose section at right angles to face of
paper in Figure 3 is shown by the line B B and Figure 6 represents a section
through valves parallel to that shewn in Figure 5 and its position is shown in
Figure 3 by line A A. Figure 7 represents a cross section through cylinder
through centre line of steam pipe and shews how the exhaust port conveys steam
to exhaust pipe.
The actions of the valves are as follows.
The steam from the steam pipe a enters the inlet port a', and passes into the
steam passage b in the main valve m and in the position shown in the figures
passes through the large port b into the ordinary cylinder port c and by it into the
cylinder d.
The steam which is exhausting from the cylinder & through the other ordinary
port centers the upward exhaust port e¹ in the main valve m and passes into the
cross port f, g, in the expansion valve n and into the downward exhaust port h¹
in the main valve m and thence through the cylinder exhaust passage kl, in
cylinder body to the exhaust pipe and thence to atmosphere or condenser.
When the large steam passage in the valve m has been moved over port c, and
ports e, f, are in apposition and also to ports h and g the steam is exhausting from
the port now taking steam and the port now exhausting is taking steam.
Another method of conducting the steam to the slide valve is by having the
slide valve shewn in Figures I and 2 to move or rock in the arc of a circle and
the valve face turned to receive it and the steam pipe instead of sliding in a gland
rocks in one and is bent twice at right angles and jointed to back of slide valve.-
Or the pipe may be bent once at right angles and brought in at the side of the
valve.
Having thus described the nature of my invention and the manner of performing
or carrying the same into practice I would remark that I make no claim to any of
the mechanical parts separately which are well known and in common use but
what I claim is:-
-:
First. The improved arrangement and construction of the slide valves of steam
and other motive power engines whereby the pressure on the back of the slide
valve is neutralized by taking the steam or other pressure from the back and
exposing it to the atmosphere substantially in the manner herein-before described
and represented in Figures 1-2 and 2* of the drawings hereto annexed.
Second. I claim the improved arrangement and construction of slide valves in
which the steam is brought through the face of the cylinder slide the ordinary
exhaust port being made the steam inlet port only, two new exhaust ports being
made in the cylinder slide the valve being arranged to act either as an ordinary
slide valve or as an expansion valve in conjunction with a main slide valve sub-
stantially in the manner and for the purpose hereinbefore described and represented
n Figures 3-4-5-6 and 7 of the drawings hereto annexed.
Third. I claim the improved arrangement and construction of the slide valves
n which the steam or other motive power agent is introduced through a sliding

page_text: steam pipe working in a gland direct into the body of the steam valve to be filled
with steam and thus expose the back of the valve to air thereby reducing the
pressure thereon substantially in the manner represented in Figures 1-2 and 2× of
the drawings annexed.
Fourth. I claim the improved arrangement and construction of slide valves in
which the steam is introduced through a rocking steam pipe rocking in a gland
and after passing twice through a right angle passage is introduced to the back of
the valve or after passing once through a right angle passage is brought into the
side of the valve substantially in the manner and for the purpose herein before
described.
Fifth.—I claim the improved arrangement and combination of parts for keeping
the slide valve to its face by means of set screws substantially in the manner and
for the purpose hereinbefore described and represented in Figures 1, 2 and 2* of
the drawings annexed.
In witness whereof I the said James Emery have hereunto set my hand and
seal this sixteenth day of November in the year of our Lord One thousand
eight hundred and eighty two.