IMPROVE- MENTS IN GAS MOTOR ENGINES
Year: 1884

page_text: I, FRANCIS WILLIAM CROSSLEY of Openshaw Manchester in the county of
Lancaster, Engineer do hereby declare the nature of my invention for " IMPROVE-
MENTS IN GAS MOTOR ENGINES" to be as follows:-
In the Specification to Letters Patent No 2177 of 1877 granted to me and
W. J. Crossley (being partly a communication from N. A. Otto) were described
various arrangements for enabling the slide of a gas motor engine to be pressed
against the engine face during the working stroke of the piston by means of the
gaseous pressure existing in the cylinder at that time, while at other times the
slide was kept up by a slight spring pressure only, the object being to obviate
the wear of the parts which results if the slide is kept continually pressed against
the engine face with the force requisite for withstanding the pressure during the
working stroke.
According to my present invention, I employ for the above purpose an elastic
diaphragm, on one side of which is an enclosed space or chamber that is put into
communication with the interior of the cylinder, so that the enclosed side of the
diaphragm is subject to the gaseous pressure existing in the cylinder while the
outer face of the diaphragm is pressed against a stop and the enclosed back of its
chamber against the slide cover or, the diaphragm itself presses directly against the
cover, the chamber being suitably secured. When no gaseous pressure is being
exerted, the pressure of the stop or stops used for securing the diaphragm in
position causes this to exert a sufficient elastic pressure upon the slide cover and
slide to keep the latter in gas tight contact with the engine face. The diaphragm
with its chamber and stops may be variously arranged for effecting the above
purpose. In one arrangement, the chamber is secured to the back of the slide cover
in such a manner that the ordinary slide rod worked by its crank can pass between
the two. The diaphragm forming the one face of the chamber is secured in any
suitable known manner thereto so as to form a gas tight joint therewith and has at
its centre a projecting pin which bears against a cross bar constituting the before
mentioned stop, and which is carried by rods attached to the engine cylinder, such
rods having screw nuts, by which the cross-bar can be made to press with more or
less force upon the pin of the diaphragm thus causing the latter to exert a greater
or less elastic pressure upon the slide cover.

page_text: But this arrangement may be reversed as the diaphragm in certain cases can be
more advantageously placed on the inner side of the chamber and press directly on
the slide cover.
The chamber may be made to communicate with the interior of the engine
cylinder either by a small pipe or by a passage formed through the slide cover and
slide, or it may be formed in one piece on the back of the slide cover itself instead
of in a separate casting. Or two thin plates or diaphragms may be used, pressure
being admitted between them instead of one thin plate placed over a rigid
chamber.
For twin engines worked by one and the same slide, I provide two such
diaphragms the chambers of which communicate respectively with one of the
cylinders, and which both act on the slide cover.

page_text: I, FRANCIS WILLIAM CROSSLEY of Openshaw, Manchester in the County of
Lancaster do hereby declare the nature of my invention for "IMPROVEMENTS
IN GAS MOTOR ENGINES" and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :-
In the Specification to Letters Patent N° 2177 of 1877 granted to me and
W. J. Crossley (being partly a communication from A. N. Otto) were described
various arrangements for enabling the slide of a gas motor engine to bo pressed
against the engine face during the working stroke of the piston by means of the
gaseous pressure existing in the cylinder at that time, while at other times the
slide was kept up by a slight spring pressure only, the object being to obviate
the wear of the parts which results if the slide is kept continually pressed against
the engine face with the force requisite for withstanding the pressure during the
working stroke.
According to my prosent invention, I employ for the above purpose an olastic
diaphragm, on one side of which is an enclosed space or chamber that is put into
communication with the interior of the cylinder, so that the enclosed side of the
diaphragm is subject to the gaseous pressure existing in the cylinder while the
outer face of the diaphragm is pressed against a stop and the enclosed back of its
chamber against the slide cover or the diaphragm itself presses directly against the
cover, the chamber being suitably secured. When no gaseous pressure is being
exerted the pressure of the stop or stops used for securing the diaphragm in
position causes this to exert a sufficient elastic pressure upon the slide cover and
slide to keep the latter in gas tight contact with the engine face. The diaphragm
with its chamber and stops may be variously arranged for effecting the above
purpose. In one arrangement, the chamber is secured to the back of the slide cover
in such a manner that the ordinary slide rod worked by its crank can pass between
the two. The diaphragm forming the one face of the chamber is secured in any
suitable known manner thereto so as to form a gas tight joint therewith and has at
its centre a projecting pin which bears against a cross bar constituting the before
mentioned stop, and which is carried by rods attached to the engine cylinders, such
rods having screw nuts by which the cross bars can be made to press with more or
less force upon the pin of the diaphragm thus causing the latter to exert a greater
or less elastic pressure upon the slide cover.
But this arrangement may be reversed as the diaphragm in certain cases can be
more advantageously placed on the inner side of the chamber and press directly on
the slide cover.
The chamber may be made to communicate with the interior of the engine
cylinders oither by a small pipe or by a passage formed through the slide cover and
slide, or it may be formed in one piece on the back of the slide cover itself instead
of in a separate casting. Or two thin plates or diaphragms may be used, pressure
being admitted between them instead of one thin plate placed over a rigid
chamber.
For twin engines worked by one and the same slide, I provide two such
diaphragms the chambers of which communicate respectively with one of the
oylinders, and which both act on the slide cover,

page_text: Fig 1 of the accompanying drawings is an elevation of the ends of the two
cylinders of a twin gas motor engine with pressure apparatus according to my
invention applied thereto. Fig. 2 is a plan partly in section, and Fig. 3 is a side
view also partly in section of the pressure apparatus. C is a cross piece made with
two circular hollows over each of which an elastic diaphragm A made of steel or
other suitable plate is held by a piece E that is bolted to G. Through each of two
holes in the piece E passes free to slide a circular boss G from which two feet B B
project and bear against the slide cover H. The cross piece C is held to the
cylinders by bolts having nuts K by turning which more or less strain may bo
imposed on the diaphragms A against which the bosses G bear. From each cylinder 1
a pipe F leads to the hollow behind each diaphragm A. When there is littlo
pressure in the cylinders, the slide cover H is held up to the slide only by the
elasticity of the diaphragms A. But when there is great pressure in the cylinder
tending to force away the slide and its cover H, then the pressure being
communicated by the pipe F tends to bulge the diaphragm A and so strain 1
the feet B, the slide cover H and the slide against the cylinder facing.
Fig. 4 is an end view of apparatus for a single cylinder, and Fig 5 a vertical
section thereof. In these figures the parts corresponding to those described with
reference to Figs 1, 2 and 3 are marked by similar letters. It is often necessary to
provide for passing a-rod-across the end of the cylinder. In order to allow for this, 2
the strain in the arrangement-shewn by Figs 1, 2 and 3 is transmitted from the
diaphragm A to the slide cover H by two pressing feet B B between which a rod
is free to pass. In Figs. 4 and 5 a single pressing foot B is shewn, but should it be
necessary to provide for the passing of a rod, the boss G may have two pressing
-feet B B as shown in the end view Fig 6 and side view Fig. 7. In the arrangement 2
shewn by the end view Fig-8-and-plan Fig 9, the pieces C and E which hold the
diaphragm A-are-placed between the slide cover H and a cross head-N, the piece_C
having a pressing foot M. bearing against-the-slide-cover H and the boss G having
its pressing foot-B-bearing against the crosshead N.
:
Having now particularly described and ascertained the nature-of-my-invention 3
and in what manner the same is to be performed, I declare that I make no general
claim to apparatus for imposing on the slide of a gas motor engine a temporary,
strain pressing it against the facing on which it works so as to counteract the
temporary pressure which tends to force it away from the facing, nor to effecting
variation of strain for this purpose by means of an elastic diaphragm subject to the 3
pressure in the working cylinder, but what I claim is
In a gas motor engine, in combination with the slide cover H, the moveable piece G
with its foot or feet B bearing against the elastic diaphragm A covering a cavity
which is in fluid communication with the working cylinder, so that the diaphragm'
acts both as a spring and also as a communicator of the cylinder pressure, 4
substantially as herein described and illustrated by the Drawings.
Dated this 23rd day of May 1885.