Improvements in Gas Motor Engines.
Year: 1890

page_text: Date of Application, 30th June, 1890
Complete Specification Left. 28th Mar., 1891-Accepted, 2nd May, 1.91
PROVISIONAL SPECIFICATION.
Improvements in Gas Motor Engines.
I, CHARLES GRANTLEY BEECHEY of 17 York Street, Liverpool, Engineer,
do hereby declare the nature of this invention to be as follows:-
In gas motor engines (such for example as that described in my Specification
No. 8818 of 1887) which comprise a compression cylinder or pump to force the
charge of the air and gas into the working or power cylinder and a slide valve for
controlling the admission of the air and gas to the compression cylinder and its
passage from this cylinder to the working cylinder and for effecting communication
with the firing or igniting tube, difficulty is experienced in properly setting up the
valve after cleaning, if it is not sufficiently tight leakage occurs, while if it is too
tight it is liable to excessive friction and to cut its facings. Further as the slide
valve covers the port leading to the working cylinder at the time that the explosion
takes place the force of the explosion drives the valve hard against the opposite
face; again when the charge is being forced through the D-port of the valve from
the compression cylinder to the working cylinder the valve is similarly forced against
the opposite face.
The chief object of my invention is to overcome these drawbacks and the invention
mainly consists in the employment of a piston valve which will open and close
communication at the proper times respectively between the air and gas inlets and
the compression cylinder, between the compression cylinder and the working
cylinder, and with the firing or igniting tube, and will also be in such a position at
the time of the compression and at the time of the explosion of the charge that the
effect upon the valve will in each case be equilibrated.
For the purpose of my invention I employ two suitably packed valve pistons
connected together by a short rod or stem. These two pistons and their connecting
stem constitute the valve; it is actuated from an excentric on the engine shaft or
otherwise. The valve moves in a box or casing preferably water jacketted which
has openings or ports at or near one end communicating with the air and gas supply
pipes, a port or ports at a suitable distance from that end communicating with the
compression cylinder or pump, a port or ports at a further distance from that end
communicating with the working or power cylinder, and a port at a still further
distance communicating with the firing or igniting tube. The air inlet is preferably
in the form of a pipe in line with the end of the valve box to which it forms a
continuation except that an annular space is left between them for the inlet of
the gas.
In the movement of the valve in the one direction one of its pistons which for
distinction I will call No. 1 uncovers the port communicating with the compression
cylinder and thereby puts this cylinder in communication with the air and gas supply
a charge of which the piston of that cylinder then draws in, while valve piston No. 2
has uncovered the port leading to the firing tube and put this port in communication
through the space between the two valve pistons with the port leading to the power
cylinder so that the charge previously admitted to this cylinder is ignited. In the
return movement of the valve its piston No. 2 closes the port to the firing tube and
piston No. 1 passes beyond the port leading to the compression cylinder so that this
cylinder is first shut off from the air and gas inlets and then put into communication
through the space between the valve pistons with the port leading to the power
cylinder; this cylinder then becomes charged from the compression cylinder ready
for the next explosion which will take place during the next movement of the valve
after communication between the two cylinders has been closed and before the
compression cylinder begins to draw in the next charge. As each compression and

page_text: each explosion occur when the power cylinder is in communication with the space
between the two valve pistons the valve is acted upon equally in both directions by
the compression or by the explosion (as the case may be) the effects of which on
the valve are therefore equilibrated.
The movements of the valve relatively to those of the pistons of the working
and compression cylinders must of course be so timed as to open and close the
various ports at the proper times to enable the compression cylinder to draw in its
charge and then force it into the working cylinder and the working cylinder to be
shut off from the compression cylinder and put into communication with the
firing tube.
The equilibrating of the force of the compression and explosion respectively by
arranging for the power cylinder to be in communication with the space between the
two valve pistons when the compression and the explosion respectively occur is a
characteristic feature of my invention, and is applicable to gas motor engines other
than those which have a separate compression cylinder as hereinbefore referred to
such for instance as those in which the piston of the working cylinder serves the
several purposes of drawing in and compressing the charge and transmitting the
power. The ports will obviously have to be arranged accordingly as well be well
understood.
Dated this 30th day of June 1890.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Gas Motor Engines.
I CHARLES GRANTLEY BEECHEY of 17 York Street, Liverpool, Engineer
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 :—
In gas motor engines (such for example as that described in my Specification
No. 8818 of 1887) which comprise a compression cylinder or pump to force the
charge of the air and gas into the working or power cylinder and a slide valve for
controlling the admission of the air and gas to the compression cylinder and its
passage from this cylinder to the working cylinder and for effecting communication
with the firing or igniting tube, difficulty is experienced in properly setting up the
valve after cleaning; if it is not sufficiently tight leakage occurs, while if it is too
tight it is liable to excessive friction and to cut its facings. Further as the slide
valve covers the port leading to the working cylinder at the time that the explosion
takes place the force of the explosion drives the valve hard against the opposite
face; again when the charge is being forced through the D port of the valve from
the compression cylinder to the working cylinder the valve is similarly forced against
the opposite face.
The chief object of my invention is to overcome these drawbacks and the
invention mainly consists in the employment of a piston valve which will open and
close communication at the proper times respectively between the air and gas inlets
and the compression cylinder, between the compression cylinder and the working
cylinder and with the firing or igniting tube and will also be in such a position at
the time of the compression and at the time of the explosion of the charge that the
effect upon the valve will in each case be equilibrated.
Figure 1 of the annexed drawings is a longitudinal section of so much of a gas
motor engine as is necessary to illustrate this invention and shows the adaptation of
a piston valve such as above explained to an engine of the kind described in my
Specification No. 8818 of 1887.
Figure 2 is a section on the line A B of Figure 1.
For the purpose of my invention I employ two suitably packed valve pistons a

page_text: and b connected together by a short rod or stem c. These two pistons and their
connecting stem constitute the valve; it is actuated from an excentric on the engine
shaft or otherwise. The valve moves in a box or casing d preferably water jacketted
as at e, e which has openings or ports ƒ and g at or near one end communicating
respectively with the air and gas supply pipes, a port or ports h, h at a suitable
distance from that end and communicating with the compression cylinder or pump,
a port (or ports) i at a further distance from that end and communicating with the
working or power cylinder and a port at a still further distance and com-
municating with the firing or igniting tube. The air inlet or port f is preferably
(as shown) in the form of a pipe in line with the end of the valve box to which it
forms a continuation except that an annular space is left between them for the inlet
of the gas.
In the movement of the valve in the direction of the arrow its piston a uncovers
the port or ports hh communicating with the compression cylinder and thereby
puts this cylinder in communication with the air and gas supply, a charge of which
the piston of that cylinder then draws in, while the piston has uncovered the
port leading to the firing tube and put this port in communication thro' the space
between the two valve pistons with the port i leading to the power cylinder so that
the charge previously admitted to this cylinder is ignited. In the return movement
of the valve its piston closes the port to the firing tube and piston a passes
beyond the ports hh communicating with the compression cylinder so that this
cylinder is first shut off from the air and gas inlets and 9 and then put into
communication through the space between the valve pistons a, b with the port i
leading to the power cylinder; this cylinder then becomes charged from the com-
pression cylinder ready for the next. explosion which will take place during the
next movement of the valve after communication between the two cylinders has
been closed and before the compression cylinder begins to draw in the next charge
As each compression in the power cylinder and each explosion occur when the power
cylinder is in communication with the space between the two valve pistons a, b the
valve is acted upon equally in both directions by the compression or by the
explosion (as the case may be) the effects of which on the valve are therefore
equilibrated.
The movements of the valve relatively to those of the pistons of the working and
compression cylinders must of course be so timed as to open and close the various
ports at the proper times to enable the compression cylinder to draw in its charge
and then force it into the working cylinder and the working cylinder to be
shut off from the compression cylinder and put into communication with the
firing tube.
The piston is shown formed hollow in front and with ports or openings m, m
through which the air and gas from and y pass to the ports h, h; the ports m, m
are however not essential as the air and gas from ƒ and g may (with a suitable
disposition of the ports relatively to the piston as will be well understood) be
arranged to pass to the port h, h when the end of the piston a begins to uncover
those ports.
The equilibrating of the force of the compression and explosion respectively by
arranging for the power cylinder to be in communication with the space between
the two valve pistons when the compression and the explosion respectively occur is
a characteristic feature of my invention and is applicable to gas motor engines other
than those which have a separate compression cylinder as herein before referred to
such for instance as those in which the piston of the working cylinder serves the
several purposes of drawing in and compressing the charge and transmitting the
power. The ports will obviously have to be arranged accordingly as will be well
understood. Figures 3 and 4 show for example the adaptation of this feature to a
gas motor engine having what is called a two to one or Otto cycle. In this case
the air and gas are drawn into the working cylinder k through the ports h, during
the outstroke of the piston of cylinder k. On the return stroke of this piston the
valve piston a closes these ports h, and the gases are compressed in the combustion

page_text: 22
chamber and between the two pistons a and b of the valve. When the piston of
cylinder khas completed its inward or compression stroke the valve piston b opens
the firing tube port 1, and the charge is exploded while the space between the valve
pistons a and b is in communication with the combustion chamber. The piston of
cylinder makes its outstroke and on its next return the waste gases are expelled
through the exhaust port p which can be either in the position shown or in any
other suitable position and be actuated either by the excentric that works the
valve or otherwise. The cycle is then repeated. The piston valve is of course
so geared that the piston of cylinder k makes two strokes to one stroke of the
valve.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In a gas motor engine, a valve having two pistons in combination with ports
or passages so arranged that the working or power cylinder is in communication
with the space between the two pistons when the compression and explosion of the
charge respectively take place whereby the force or effect of the compression and
of the explosion upon the valve is in each case equilibrated, substantially as herein-
before described.
2. Constructing gas motor engines with valves arranged and acting substantially
as herein before described and represented in the accompanying drawings.
Dated this 26th day of March 1891.
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.