Year: 1886

page_text: Workou by x
I, OLIVER IMRAY, of No. 28 Southampton Buildings, Chancery Lane in the
County of Middlesex, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the construction and arrangement of slide valve gear
for engines or meters in which working fluid has to be alternated at opposite ends
of a cylinder, so as to move a piston to and fro. The object of the invention is to
render the action of the engine or meter automatic, by applying the pressure of the
working fluid itself to move the slide valve which alternates the supply and
discharge at each end of the cylinder. For this purpose, the slide, of the ordinary D
kind, governing the two ports leading to the two ends of the cylinder and the
middle port for exhaust, is placed between two pistons which fit cylindrical parts
formed in the slide case, the slide being free to adjust itself to the facing on which
it works, while it must move to and fro along with the two pistons. The supply
of fluid enters the slide case between the two pistons pressing on them equally.
From the one end, say the left hand end, of the slide case a passage leads to a
lateral opening into the main cylinder a little beyond the middle of its length to
the right of the middle, and, similarly, from the other or right hand end of the
slide case a passage leads to another lateral opening into the main cylinder a
little beyond the middle to the left thereof. There is also at the middle of the
cylinder a lateral opening leading into the exhaust. It is preferred that each of
these three lateral openings should consist of a row of small holes side by side, as
a single wide opening might catch and derange the packing of the main piston as
it travels to and fro across the opening. The main piston is made to occupy a
little more than half the length of the cylinder in which it works, so that at
neither extreme of its stroke does it uncover the middle lateral opening to the
exhaust, but at each extreme of its stroke it uncovers one of the other lateral
openings.
:
In the piston itself, on that side of it which is presented towards the lateral
openings, there are formed two grooves, each, near one end of the piston, so

page_text: situated that when the piston is at one extreme of its stroke, say to the left, one
of these grooves puts the middle lateral opening in communication with that which
is to the left of the middle, and when the piston is at the right extreme of its
stroke the other groove puts the middle lateral opening in communication with
that which is to the right of the middle. The action is as follows:-
The slide being in such a position as to supply fluid to the left end of the
cylinder, while fluid is being discharged from the right end, the piston moves from
left to right. As it approaches the end of its stroke to the right, it uncovers the
lateral opening on the left of the middle thus putting the right end of the slide
case in communication with the left end of the cylinder, at the same time one of
the grooves in the piston puts the left end of the slide case in communication with
the exhaust. The right hand piston in the slide case is thus subjected to the
pressure of the fluid acting in the main cylinder, and the left hand piston in the
slide case is relieved of pressure. Owing to the excess of pressure on the one
piston over that on the other, the two pistons move to the left, moving the slide
so that it uncovers the port leading to the right of the cylinder and puts the left
port in communication with the exhaust. The main piston is now caused to make
its stroke to the left, and, as it approaches the end of its stroke, it makes communi-
cations through the lateral openings whereby the slide is again moved to the right.
Thus as long as the slide case is supplied with fluid at sufficient pressure to
overcome friction, the supply and discharge of the two ends of the cylinder are
automatically alternated and the piston is caused to reciprocate.

page_text: Self Acting Slide Valve Gear for Reciprocating Engines or Meters
Worked by Fluid Pressure.
I, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane, in the
County of Middlesex, Fellow of the Institute of Patent Agents 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 the construction and arrangement of slide valve gear
for engines or meters in which working fluid has to be alternated at opposite ends
of a cylinder, so as to move a piston to and fro. The object of the invention is to
render the action of the engine or meter automatic, by applying the pressure of the
working fluid itself to move the slide valve which alternates the supply and
discharge at each end of the cylinder. For this purpose the slide valve and ports
and passages are arranged as will be described referring to the accompanying
drawings. Fig. 1 is a longitudinal section of a cylinder and slide valve, and Fig. 2
is a plan of the piston shewing the relation of the several passages arranged for
the working of the slide valve. The piston P, which is made a little longer than
half the length of the cylinder C, has sunk into one side of it two grooves G
and G. The slide valve S which is of the ordinary D kind is fitted between the
pistons V V which work in a cylindrical slide case supplied about its middle by a
pipe F with the working fluid, which after acting in the cylinder passes away by
the exhaust passage E. Near the ends of the slide case are apertures A A' which
respectively communicate by passages with ports B B¹ opening into the cylinder,
each of these ports being preferably formed as a row of small holes so as not to
catch the packings of the piston P as might be the case if the boles were elongated
ports. The holes B B₁ are in such positions that when the piston P is at one end
of the stroke, the one set of holes B¹ is uncovered, while the other set B coincide
with the one piston groove G. In like manner when the piston P is at the other
end of its stroke the holes B are uncovered, and the holes B¹ coincide with the
other piston groove G¹. There are also holes e opening from the middle of the
cylinder into the eduction passage E. As shewn in the figures, the piston P is at
the right extreme of its stroke and the slide valve S is at the left extreme, the
piston being about to commence its stroke to the left. When it is reaching the
left end of the cylinder it uncovers the holes B and brings the groove Glinto
coincidence with the holes B. Working fluid flows by the holes B and opening A
into the left end of the slide case pressing on V, whilst by the opening A', holes B¹,
groove G¹ and holes e, fluid escapes from the right end of the slide case to the
eduction passage E, the pressure on V₁ being thus relieved. Owing to the excess
of pressure en V the slide valve is moved to the right so as to admit fluid, to the
left end of the cylinder and allow its escape from the right. The piston now
makes its stroke towards the right, and, as it reaches the end of the stroke, it
uncovers the holes B' and brings the holes B into communication with e, where-
upon V₁ is subjected to pressure and the pressure on V is relieved, the slide valve S.
thus being moved to the left as shewn in Fig. 1. Thus, as long as the slide caso

page_text: is supplied with fluid at sufficient pressure to overcome friction, and there is
exhaust open from E, the supply and discharge at the two ends of the cylinder are
automatically alternated and the piston is caused to reciprocate.
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:-
The construction and use of self acting slide gear for recipfocating engines or
meters worked by fluid pressure, the cylinder piston and slide case having passages
so arranged that as the piston approaches each end of its stroke it makes com-
munication by which the pressure is alternated on the pistons that work the
alide valve, substantially as herein described and illustrated by the drawings.
1
220
2
1
1000
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings, London, W.C.
O med TO COD DOART