Improvements in Gas Engines.
Year: 1891

page_text: Date of Application, 21st Oct., 1591
Complete Specification Left, 19th July, 1892-Accepted, 20th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvements in Gas Engines.
We, JAMES SHAW, of Mulberry Walk, Richmond Hill, Leeds, Engineer, and
JAMES ROBERT ASHWORTH, of Castlelaw, York Road, Chorlton-cum-Hardy,
Lancashire, Bank Manager, do hereby declare the nature of this invention to be
as follows:-
The improvements relate to gas engines, of what are known as the two cycle
type, of horizontal formation, and have for object the better utilization of the
pressure within the cylinder, produced by the explosion of the mixture of air and
gas.
To accomplish this, and to effect the improvements, we form at the end of the
cylinder, and external thereto, a chamber for the admission of air and gas, and an
exhaust chamber.
In the former, the admission of gas is arranged at a point nearer the cylinder,
than the opening for the admission of air; and the latter chamber is connected with
the exhaust pipe, as will be well understood. These two chambers communicate
with the cylinder through ports arranged one above the other, and between such
ports there projects, from the cylinder cover, a shelf or baffle plate, which extends
very nearly to the point where the piston arrives when it is at the extent of the
inward portion of the stroke. This shelf or baffle plate thus measures off the
portion of the cylinder, over and above the length of stroke, which forms what
may be termed the combustion chamber, and which is, by preference, of a cubical
capacity of about one fifth of the cubic measurement behind the piston when at the
extent of the outward portion of its stroke.
The object of the shelf or baffle plate is to assist the products of combustion on
their passage to the exhaust, and to separate them in some measure from the
incoming air and gas.
The complete cycle of operations is as follows:-
During the time the crank is moving from the inner dead centre for about 40° of
its revolution, the air valve is open; then, while the crank makes about another 80°
of its revolution, the gas valve is open, in addition.
At that point the gas valve shuts, and the exhaust begins to open. The air valve
is kept open until 180°, or the forward stroke of the piston, is completed; and the
exhaust remains open until the crank arrives at 260° of the revolution, or 80° of the
inward stroke, when the exhaust shuts dead, and the charge is compressed up to and
fired at or about the dead point.
The operations during the revolution following the explosion are of the ordinary
character; hence, there is an exhaust at every revolution of the engine.
The valves, and apparatus for controlling the same, together with the firing
arrangements, and other accessories, may be of the ordinary, or any suitable
description.
Variations in detail may be made without departing from the peculiar character
of the invention.
Dated this 20th day of October 1801,
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester, Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Gas Engines.
We JAMES SHAW, of Mulberry Walk, Richmond Hill, Leeds, Engineer, and
JAMES ROBERT ASHWORTH, of Castlelaw, York Road, Chorlton-cum-Hardy,
Lancashire, Bank Manager, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The improvements relate to gas engines, of what are known as the two cycle
type, of horizontal formation, and have for object the better utilization of the
pressure within the cylinder, produced by the explosion of the mixture of air and
gas.
In order that the invention may be better understood, and more readily carried
into effect, we have hereunto appended a sheet of drawings, wherein :-
Fig. 1. is a longitudinal section, and Fig. 2. is a transverse section through
line A. B. of a cylinder of a gas engine, arranged in accordance with our improve-
ments, while 5 diagrams, V. W. X. Y. Z. illustrate the position of the engine crank
at various operations during the cycle.
The same letters indicate corresponding parts wherever they occur.
To accomplish our object and to effect the improvements, we form at the end of
the cylinder a. a, and external thereto, a chamber b. b. for the admission of air and
gas, and an exhaust chamber c. c. In the former, that is to say b. b, the admission
of gas is arranged by means of the valve d. d. at a point nearer the cylinder than
the opening or valve e. e. for the admission of air, and the latter chamber c. c. is
connected with the exhaust pipe f. f, as will be well understood. These two
chambers b. b. and c. c. communicate with the cylinder a. a. through ports g. 9.
arranged one above the other, and between such ports there projects, from the
cylinder cover, a shelf or baffle plate h. h, which extends very nearly to the point
where the piston j. j. arrives when it is at the extent of the inward portion of the
stroke.
This shelf or baffle plate h. h. thus measures off the portion of the cylinder, over
and above the length of stroke, which forms what may be termed the combustion
chamber, and which is, by preference, of a cubical capacity of about one fifth of
the cubic measurement behind the piston when at the extent of the outward portion
of its stroke.
The object of the shelf or baffle plate is to assist the products of combustion on
their passage to the exhaust, and to separate them in some measure from the incoming
air and gas.
The complete cycle of operations, which will be seen on reference to the diagrams,
is as follows :-
. During the time the crank is moving from the inner dead centre (0) for about 40°
of its revolution, (1) the air valve is open; then, while the crank makes about
another 80° of its revolution, the gas valve is open in addition.
At that point, (2), the gas valve shuts, and the exhaust begins to open.
The air valve is kept open until 180° at point (3) or the forward stroke of the.
piston, is completed; and the exhaust remains open until the crank arrives at 260°
of the revolution, point (4,) or 80° of the inward stroke, when the exhaust shuts
dead, and the charge is compressed up to and fired at or about the dead
point (5).
The operations during the revolution following the explosion are of the ordinary
character; hence, there is an exhaust at every revolution of the engine.
The valves, and apparatus for controlling the same, together with the firing
arrangements, and other accessories, may be of the ordinary, or any suitable
description.
Variations in detail, such as the form and construction of the engine, and the

page_text: means for actuating the various valves and parts may be made without departing
from the peculiar character of the invention.
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. In gas engines of the
type and character indicated, the gas and air chamber b. b.
fed by air and gas by the valves e. c. and d. d. combined with the exhaust chamber c. c.
and exhaust and valve, f. and with the projecting diaphragm h. h. within the
cylinder, all arranged for the purposes and in manner substantially as herein set
forth and as illustrated in the accompanying drawings.
2. In gas engines of the type and character indicated, the cycle of operations,
wherein there are two revolutions of the crank, one of which is actuated by the
sequence of operations shewn and described, and illustrated by the diagrams V. W.
X. Y. Z., and the other or explosive revolution is of the ordinary character; and
which are arranged to take place for the purpose and in manner substantially as
herein shewn and described.
Dated this 18th day of July 1892
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester, Agent.