An Improvement in Gas Motor Engines.
Year: 1888

page_text: Date of Application, 3rd Oct., 1888
Complete Specification Left, 3rd July, 1889-Accepted, 3rd Aug., 1889
PROVISIONAL SPECIFICATION.
An Improvement in Gas Motor Engines.
We, FRANCIS WILLIAM CROSSLEY, HENRY PERCY HOLT, and FRANK HERBERT
ANDERSON, all of Openshaw, near Manchester, in the County of Lancaster, Engineers,
do hereby declare the nature of this invention to be as follows:
:-
In starting a gas motor engine, its shaft has usually to be turned by hand through
several revolutions. In order to facilitate this operation, a special_cam
or cam
step is made to act on the exhaust valve for a time so as to open the valve and
thereby relieve the pressure in the cylinder when the piston is making part of its
compressing stroke.
It is also necessary that the ignition gear should be timed to act a little later during
this starting operation than when the engine is in full action.
Various arrangements have been adopted to ensure that, when the action of the
exhaust valve is altered for the purpose of relieving pressure in starting the engine,
the timing of the ignition is also altered so as somewhat to delay ignition, otherwiso
premature ignition might produce a pressure in the cylinder resisting the effort of the
operator in moving the engine by hand. The present invention has for its object to
provide still further security against premature ignition during the starting of the
engine, by connecting the gear for the gas supply valve with that for the exhaust valve
and that for the igniter in such a manner that no supply of gas can be given unless
ignition is suitably delayed in the operation of starting. The nature of the con-
nections for this purpose depends in great measure on the particular arrangement of
the governor and gas valve. Taking, by way of illustration, an arrangement largely
used where the governor moves a narrow roller to the one side or the other of a
narrow cam, so that if the engine goes too fast or does not go at all, the roller is not
moved by the cam and therefore the gas valve is not opened, the connections for the
exhaust valve and ignition gear may be arranged as follows. The sleeves of the
exhaust and ignition cams or the rollers that bear against them are connected together
so that when the one is shifted laterally by a hand lever, the other is also shifted
laterally. Both these cam sleeves have duplicate steps, the one step in each case
suited for the ordinary working of the engine when the cams or rollers are in
their normal position, the other step which comes into play when the sleeves are
shifted, acts on the exhaust valve so as to relieve pressure and acts on the ignition gear
to delay ignition.
The same movement which shifts the cams or their rollers is, according to this
invention, made to shift also the roller of the gas valve so as to bring it into the range
of the gas cam, or to shift the sleeve carrying the gas cam so as to bring an additional
step on it into the range of the roller during the starting operation.
When the engine is started, the exhaust and ignition cams or their rollers are shifted
back to their normal positions, and the gas cam or its roller also resumes its normal
position subject to the action of the governor.
Dated this 3rd day of October 1888.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improvement in Gas Motor Engines.
We, FRANCIS WILLIAM CROSSLEY, HENRY PERCY HOLT, and FRANK HERBERT
ANDERSON all of Openshaw near Manchester in the County of Lancaster Engineers,
do hereby declare the nature of this Invention and in what manner the same is

page_text: to be performed to be particularly described and ascertained in and by the following
statement:
In starting a gas motor engine, its shaft has usually to be turned by hand through
several revolutions. In order to facilitate this operation, a special cam or cam step is
made to act on the exhaust valve for a time, so as to open the valve and thereby
relieve the pressure in the cylinder when the piston is making part of its compressing
stroke.
It is also necessary that the ignition gear should be timed to act a little later during
this starting operation than when the engine is in full action.
Various arrangements have been adopted to ensure that, when the action of the
exhaust valve is altered for the purpose of relieving pressure in starting the engine,
the timing of the ignition is also altered so as somewhat to delay ignition, otherwise
premature ignition might produce a pressure in the cylinder resisting the effort of
the operator in moving the engine by hand. The present Invention has for its
object to provide still further security against premature ignition during the starting
of the engine by connecting the gear for the gas supply valve with that for the
exhaust valve and that for the ignitor in such a manner that no supply of gas can
be given unless ignition is suitably delayed in the operation of starting. The nature
of the connections for this purpose depends in great measure on the particular
arrangement of the governor and gas valve. Taking, by way of illustration, an
arrangemont largely used where the governor moves a narrow roller to the one
side or the other of a narrow cam, so that if the engine goes too fast or does not
go at all, the roller is not moved the cam and therefore the gas valve is not
opened, the connections for the exhaust valve and ignition gear may be arranged as
follows: The sleeves of the exhaust and ignition cams or the rollers that bear against
them are connected together so that when the one is shifted laterally by a hand lever,
the other is also shifted laterally. Both these cam sleeves have duplicate steps, the one
step in each case suited for the ordinary working of the engine when the cams or rollers
are in their normal position, the other step which comes into play when the sleeves are
shifted, acts on the exhaust valve so as to relieve pressure and acts on the ignition
gear to delay ignition.
The same movement which shifts the cams or their rollers is, according to this
Invention, made to shift also the roller of the gas valve so as to bring it into the range
of the gas cam, or to shift the sleeve carrying the gas cam so as to bring an addi-
tional step on it into the range of the roller during the starting operation.
When the engine is started, the exhaust and ignition cams or their rollers are
shifted back to their normal positions, and the gas can or its roller also resumes its
normal position subject to the action of the governor.
Figure 1 of the accompanying drawings is a part end view. Figure 2 is a part side
view and Figure 3 is a part plan showing the valve gear of a gas motor engine to
which our Invention is applied. In this case the governor moves a narrow roller J
to the one side or the other of a narrow cam D, so that when the engine goes too
fast or does not go at all, the roller J is not moved by the cam D, and therefore
the gas valve P is not opened. We fix the exhaust cam F, the cam G for relieving
pressure in starting the engine the gas cam D, and the additional gas cam E for
opening the gas valve at starting the engine all on one sleeve which can be slid along
the lateral counter shaft T by the handle O. This handle O is connected to the weigh-
shaft M on which is fixed the lever carrying the ignition roller H so that the roller H
partakes of the same sliding motion as the exhaust cams F G and gas cams D E. In
the ordinary working of the.engine, the ignition roller H bears against the cam A, the
exhaust valve roller K bears against the cam F and the gas roller J bears against
the narrow cam piece D, but the roller J is moved out of the range of the cam
piece D when the governor sleeve S is either raised or lowered by the governor,
this raising or lowering being effected when the engine moves too quickly or too
slowly. At starting the engine, the governor sleeve S is down and the roller J con-
sequently is out of the plane of the gas cam D; the handle O being then moved in
the direction of the arrow brings the ignition roller H opposite to the cam B which is

page_text: arranged to give a little later opening to the ignition valve Q; at the same time the
exhaust cams F G and the gas cams D E are moved so as to bring the cam G for
relieving pressure at the starting the engine into the plane of the exhaust roller K. and
thus
the additional gas cam E into the plane of the gas roller J. The gas roller J
in position to be worked by the additional gas cam E and can only be moved out of
the range of cam E when the governor sleeve S is raised or when the cams are moved
back by the handle O to their normal position, when the gas cam D comes into
action.
Obviously the weigh shaft M, instead of moving the roller H, might be arranged to
move the cams A and B.
Figs. 4, 5 and 6 are respectively part end view, side view and plan showing an
alternative arrangement in which the exhaust roller and the roller are moved instead
gas
of their respective cams. The exhaust cam F and the cam G for relieving the pressure
at starting are in this case fixed on the lateral counter shaft T on which the gas cam
piece D is also fixed. The handle O is connected to the weigh shaft M on which are
fixed, first the lever N which holds the exhaust valve roller laterally, secondly the
finger E which is to hold the governor lever C so as to keep the gas valve roller J
opposite the gas cam piece D at starting, and thirdly the lever which carries the
ignition roller H. In ordinary working, the ignition roller H is moved by the cam A,
the exhaust valve roller K is worked by the cam F and the gas valve roller J is
worked by the narrow cam piece D out of the range of which the roller J is moved
when the governor sleeve S is either raised or lowered when the engine moves either
too quickly or too slowly.. At the starting of the engine, the handle O is moved in
the direction of the arrow and thus the roller H. is brought opposite the cam B which is
arranged to give a littlo later opening to the ignition valve Q. Also the arin N moves
the exhaust roller into the plane of the cam G to relieve the pressure and the finger E
holds the governor arm C so as to keep the gas valve roller Jon the gas cam piece D
until such speed is attained as causes the governor to hold it normally in that
position.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim :-
In a gas motor engine, connecting together the sliding cams which work the exhaust
valve, the gas valve and the ignition valve, or the sliding rollers which bear against
these cains, so that, in starting the engine, when the exhaust valve is opened to relieve
pressure in the cylinder, the gas valve is opened independently of the governor, and
the opening of the ignition valve is somewhat delayed substantially as and for the
purpose herein set forth.
T 1 1000
ABEL & IMRAY,
Agents for the Applicants.