COMPOUND GAS MOTOR ENGINE
Year: 1884

page_text: We HENRY PEROY HOLT and FRANCIS WILLIAM CROSSLEY both of Manchester,
in the county of Lancaster Engineers, do hereby declare the nature of our
invention for "COMPOUND GAS MOTOR ENGINE" to be as follows:-
This invention relates to a construction of compound gas motor engine in which
the passages for charging, igniting and exhausting are governed by the movements
of the high pressure piston without requiring a separate slide. There are two
cylinders, preferably side by side, the one, which may be called the high pressuro
cylinder, and the other, larger, the low pressure or expansion cylinder. The
cylinders are fitted with pistons connected in the usual way to cranks on the
engine shaft, the high pressure crank being about 90° in advance of the low
pressure crank. Each piston gives an impulse beginning with its outstroke.
There are ports through the sides of the cylinders and ports and passages in the
high pressure piston arranged to operate in the following manner. The low
pressure cylinder being at the beginning of its outstroke, the high pressure piston,
in approaching the end of its outstroke, uncovers a passage to the low pressure
cylinder and the gaseous contents of the high pressure cylinder expand, propelling
the low pressure piston.
At about the end of the outstroke of the high pressure piston, a port in it comes
opposite a port in the side of the cylinder communicating with the air and gas
supply, and then owing to the reduction of internal pressure caused by the con-
tinued movement of the low pressure piston, a charge of gas and air is drawn into
an open mouthed cavity in the high pressure piston. By means of a trough-like
projection from the back of the high pressure piston, enclosing at both sides but
not at its farther end the passage to the low pressure cylinder, while the gaseous
products of combustion continue to pass into the low pressure cylinder through the
hollow of this projection, the fresh charge of gas and air is prevented from taking
the same course.
The high pressure piston, during its return or instroke closes first the charging
port and then the passage to the low pressure cylinder, after which it goes on
compressing the charge in the chamber of the piston and the residuary products of
combustion in the space at the end of the cylinder. At the end of the instroke of
the high pressure piston, a port leading into its charge chamber comes opposite an
igniting port in the side of the cylinder, and the compressed charge is ignited by
S011

page_text: contact with any known igniter. The increase of pressure and volume caused by
the combustion of the charge now propels the high pressure piston. The exhaust
of the low pressure cylinder is effected in the following manner.
In the front part
of the high pressure piston there is a D cavity which, at the time when this
piston is approaching the end of its instroke and performing the first part of its
outstroke, faces two ports, one opening to the low pressure cylinder and the other
to a discharge passage. At this time, when the low pressure piston is making the
principal part of its instroke, the contents of the low pressure cylinder are dis-
charged through the D-cavity as exhaust. It is of advantage to provide in the
passage from the high pressure to the low pressure cylinder a valve worked by a
cam or otherwise so that it can close the passage before it is covered by the high
pressure piston. By this means the quantity of gaseous fluid retained as charge in
the high pressure cylinder can be varied. The gas supply is determined by a valve
regulated by a governor in a manner such as is adopted in the "Otto" gas motor
engines.
1
ABEL & IMRAY,
Agents for the Applicants,
28, Southampton Buildings,
London, W.C.

page_text: We, HENRY PERCY HOLT and FRANCIS WILLIAM CROSSLEY both of Manchester
in the County of Lancaster, Engineers do hereby declare the nature of ou
invention for "COMPOUND GAS MOTOR ENGINE" 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 a construction of compound gas motor engine in which
the passages for charging, igniting, and exhausting are governed by the movements
of the high pressure piston without requiring a separate slide, as we will describe
referring to the accompanying drawings which shew so much of the engine as is
necessary to explain the action. Fig. 1 is a longitudinal section of the smaller or
high pressure cylinder, Fig. 2 is a sectional plan and Fig. 3 a transverse section of
both cylinders, that is to say the smaller or high pressure cylinder A and the
larger or low pressure cylinder B. Fig. 4 is a sectional plan shewing a modification
in which the check valve C shewn in Figs. 1, 2 and 3 is dispensed with.
Referring first to Figs. 1, 2 and 3, the two cylinders A and B, which are
preferably arranged side by side as shewn, are fitted with pistons connected in the
usual way to cranks on the engine shaft, the bigh pressure crank being from 70°
to 90° in advance of the low pressure crank. Both cylinders are kept cool by
circulation of water through casings W. From the end of the cylinder B there is
a passage containing the check valve C, communicating through a grid opening D
with the interior of the cylinder A, and from A there is an exhaust passage E.
Through the side of the cylinder A there is a passage F for admitting the com-
bustible charge of gas and air. The piston of A has in it a cavity G with a
lateral charging passage H and an igniting passage I opening from the cavity.
Also from the piston of A thero extends backwards a trough like piece K. which is
open at the end and the circumference but closed at the sides.
The operation is as follows: The piston of B being at the beginning of its
outstroke, the piston of A in approaching the end of its outstroke uncovers the
passage D, and the valve C being then held open by a cam, the gaseous contents
of A expand, passing partly into B and propelling the piston of B. At about the
end of the outstroke of the piston of A, its port H faces F and thereupon, owing
to the reduction of internal pressure caused by the continued movement of the
piston of B a charge of gas and air is drawn into the cavity G. The trough like
projection K continues to allow passage of products of previous combustion from A
to B while it prevents the fresh charge admitted by F and H from taking the same
course. The piston of A. during its return or instroke first closes the port F and
then the passage D leading to B, and afterwards goes on compressing the charge
in A, including the fresh supply of gas and air and the residue of the products of
previous combustion left in the cylinder.
At the end of the instroke of the piston of A, the passage I communicates with
an igniter of any suitable kind, whereby the compressed mixture in G is ignited.
The increase of pressure and volume of the contents of A now effects propulsion of
the piston of A. For escape of exhaust from the cylinder B there is a D cavity L

page_text: formed in the piston of A which, while this piston is approaching the end of its
instroke and performing the first part of its outstroke, makes communication
between D and E thus allowing exhaust to pass from B to E while the piston of B
is making the principal part of its instroke.
In the modified arrangement shewn in Fig. 4 a chamber J is formed within the
piston of A, this chamber having a lateral passage I to communicate with the
charging port F and the igniting port M, and a central opening j at the rear end
of the piston. Around ; there are passages d (as shewn in Fig. 5 which is an end
view of the piston) which makes communication through I) with the cylinder B,
when D is not covered by G and when the piston of A is approaching the end of
its outstroke. As the piston of A makes the latter part of its instroke, a cavity L
in it makes communication between D and the exhaust passage E allowing the
contents of B to escape the piston of B then moving inwards. Figs. 6, 7 and 8 shew
respectively a longitudinal section, a part elevation and a cross section of a similar
arrangement but without the chamber J in the piston of A. In both Fig. 4 and
Fig. 6 the check valve C shewn in Figs. 1, 2 and 3 is dispensed with, the passage g
in the piston of B being so arranged as to uncover D only during suitable portions
of the stroke. The gas supply ƒ may communicate with F as shewn in Fig. 4 or
there may be a channel in the piston leading to I as shewn in Fig. 6. In both
cases as well as in the form of engine shewn in Figs. 1, 2 and 3 the supply of gas
is determined in the manner usually adopted in the Otto gas motor engines. In
Fig. 4 the mouth j of the cavity J and in Fig. 6 the channel I, is so directed
relatively to the inlet to the passage D that the charge of combustible mixture
which enters by I displaces, without materially mingling with that portion of the
products of previous combustion which passes through D into the cylinder B.
.
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 is.
The construction of compound gas motor engine having passages for charging,
igniting and exhausting governed by the movements of the high pressure piston,
substantially as herein described.