Improvements in Single Acting High Speed Engines.
Year: 1892

page_text: Date of Application, 9th Jan., 1892
Complete Specification Left, 8th Oct., 1892-Accepted, 3rd Dec., 1892
PROVISIONAL SPECIFICATION.
.Improvements in Single Acting High Speed Engines.
We, WILLIAM HENRY ALLEN, RICHARD WRIGHT and RICHARD, WILLIAM
ALLEN, all of York Street Works, Lambeth in the County of Surrey, Engineers,
do hereby declare the nature of this invention to be as follows:-
Our invention relates to single acting high-speed engines.
We construct such engines in such manner that the piston maintains a constant
thrust upon the crank; and this condition is so efficiently fulfilled that the engine
may be worked noiselessly with a condenser aud at high speed. We make such
engines preferably with inverted cylinders.
The steam passages to and from the ends of the cylinder terminate in ports within
a valve chest in the walls of which also a steam inlet port and an exhaust port are
formed.
The valve chest is of cylindrical form and contains two double piston like valves
fast upon the same rod receiving movement from an eccentric upon the crank shaft.
The cavity of the upper valve between its piston like ends is in constant communi-
cation with the steam inlet port and from time to time also with the upper cylinder
port. The cavity of the lower valve in like manner is in constant communication
with the exhaust port and from time to time with the lower cylinder port.
The valve chest is contained within a steam chamber or receiver and there is free
communication between the interior of the valve chest and the receiver excepting
those parts of the valve chest which are covered by the valves.
The valves operate in the following manner :-When the piston is at the top of
the cylinder the descent of the steam valve has commenced to open communication
between the steam inlet and the space above the piston; at the same time. the
exhaust valve admits of the free escape of steam from below the piston.
When the stroke is say half completed the ascent of the steam valve causes its
foot to cover the upper cylinder port. The stroke is then completed by the expan-
sion of the steam already in the cylinder above the piston; the exhaust remaining
open throughout the down stroke of the piston.
When the piston is at the bottom of its stroke or thereabout the continuance of
the upward movement of the steam valve uncovers the upper cylinder port and
allows the steam to return from the cylinder and to enter the receiver. About at
the same time the corresponding movement of the exhaust valve places the lower
end of the cylinder also in communication with the receiver and the steam is free to
pass from one side of the piston to the other side through the receiver.
When the piston has risen to about half stroke, the downward movement of the
exhaust valve causes the foot of the valve to close the passage from the receiver to
the underside of the piston and compression commences in the upper part of, the
cylinder and in the receiver whilst the steam below the piston expands.
When a further rise of the piston has taken place the upward movement, of the
steam valve closes the upper cylinder port and then during the completion of
the stroke the remaining steam in the cylinder is further compressed until about
the initial pressure is attained. The exhaust commences to be opened: again by the
descent of the valve shortly before the end of the upward stroke.
Dated this 8th day of January 1892.
W. H. ALLEN.
R. WRIGHT.
R. W. ALLEN.

page_text: COMPLETE SPECIFICATION.
Improvements in Single Acting High Speed Engines.
We, WILLIAM HENRY ALLEN, RICHARD WRIGHT and RICHARD WILLIAM
ALLEN, all of York Street Works, Lambeth in the County of Surrey, 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 :-
Our invention relates to single acting high speed engines.
We construct such engines in such manner that the piston maintains a constant
thrust upon the crank; and this condition is so efficiently fulfilled that the engine
may be worked noiselessly with a condenser and at high speed. We make such
engines preferably with inverted cylinders.
The steam passages to and from the ends of the cylinder terminate in ports within
a valve chest in the walls of which also a steam inlet port and an exhaust port are
formed.
The valve chest is of cylindrical form and contains two double piston like valves
fast upon the same rod receiving movement from an eccentric upon the crank shaft.
The cavity of the upper valve between its piston like ends is in constant communi-
cation with the steam inlet port and from time to time also with the upper cylinder
port. The cavity of the lower valve in like manner is in constant communication
with the exhaust port and from time to time with the lower cylinder port.
The valve chest is contained within a steam chamber or receiver and there is free
communication between the interior of the valve chest and the receiver excepting
those parts of the valve chest which are covered by the valves.
The valves operate in the following manner :- -When the piston is at the top of
the cylinder the descent of the steam valve has commenced to open communication
between the steam inlet and the space above the piston; at the same time the
exhaust valve admits of the free escape of steam from below the piston.
When the stroke is say half completed the ascent of the steam valve causes its
foot to cover the upper cylinder port. The stroke is then completed by the expan-
sion of the steam already in the cylinder above the piston; the exhaust remaining
open throughout the down stroke of the piston.
When the piston is at the bottom of its stroke or thereabout the continuance of
the upward movement of the steam valve uncovers the upper cylinder port and
allows the steam to return from the cylinder and to enter the receiver. About at the
same time the corresponding movement of the exhaust valve places the lower end
of the cylinder also in communication with the receiver and the steam is free to
pass from one side of the piston to the other side through the receiver.
When the piston has risen to about half stroke, the downward movement of the
exhaust valve causes the foot of the valve to close the passage from the receiver to
the underside of the piston and compression commences in the upper part of the
cylinder and in the receiver whilst the steam below the piston expands.
When a further rise of the piston has taken place the downward movement of the
steam valve closes the upper cylinder port and then during the completion of
the stroke the remaining steam in the cylinder is further compressed until about
the initial pressure is attained. The exhaust commences to be opened again by the
descent of the valve shortly before the end of the upward stroke.
In order that our said invention may be fully understood and readily carried into
effect we will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.

page_text: Figure 2 is a section of the valve chest and steam receiver.
Figure 3 shews indicator diagrams such as may be obtained from our engines.
A is the frame of the engine, it carries in bearings B B' the crank shaft C which
is driven by the connecting rod D. The rod D is attached by the rod E¹ to the
piston E which works in the cylinder F. G is the cylindrical valve chest which
contains two double piston like valves H¹. H', I' I' fast upon the same rod K which
receives movement from an eccentric L on the shaft C. A governor of ordinary
type contained within the wheel M controls the lead of the eccentric.
The cavity H of the upper valve is in constant communication with the steam
inlet N and the cavity I of the lower valve in like manner is in constant communi-
cation with the exhaust passage O.
The valve chest G is contained in the receiver P and at its lower end is in free
communication therewith. The valves are so formed as to provide a free central
passage from end to end of the valve chest. The piston valve H' in working over
the upper port of the cylinder places it alternately in communication with the steam
supply and with the receiver. Similarly the piston valve I' working over the lower
port of the cylinder places it alternately in communication with the receiver and
the steam outlet. The cycle of the engine and the operation of the valves has
been already described.
the
The diagrams represented in Figure 3 will be readily understood; the upper one
applies to the top of the cylinder and the lower diagram to the bottom of the.
cylinder. The horizontal line of figures denote percentage of the stroke;
column of figures to the left denote steam pressure in pounds per square inch. The
line marked A T denotes the atmospheric line.
We have shewn and described the engine as arranged with the cylinder vertically
over the crank; this is the position which we prefer nevertheless it may be placed
in other positions.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. A single acting engine substantially as described in which the steam is first.
admitted to the upper side of the piston, is then expanded and at the end of the
down stroke is allowed to pass to a receiver whence during the up stroke it returns
to the cylinder, is expanded and then leaves the cylinder.
2. In an engine in accordance with the preceeding claim affecting the distribution
of the steam by means of two double piston like valves working in a cylindrical
valve chest contained within the receiver.
3 A single acting engine substantially as herein described.
Dated this 21st day of September 1892.
W. H. ALLEN..
R. WRIGHT.
R. W. ALLEN..
W. H. ALLEN..
R. WRIGHT.
R. W. ALLEN..