Year: 1895

page_text: Тарготошоцию
I, WILLIAM DONALDSON, of 38 Parliament Street, Westminster, in the County
of Middlesex, Civil Engineer, do hereby declare the nature of this invention to
be as follows:-
-
My invention relates to improvements in the construction of gas motors or
engines, and has for its object to provide means in engines working with the "Otto
cycle" to vary the volume of gases produced by explosion, left in the cylinder after
the termination of the exhaust stroke, from a minimum represented by the volume
of short port-hole passages, to any desired amount; to ensure in the case of a single
cylinder engine that the ratio of expansion after explosion, shall if desired, exceed
the ratio of compression before ignition; to allow of the regulation of work done
in any of the cylinders of a compounded engine, so that the work in any cylinder
may be practically the same or otherwise as desired; to insure the thorough mixing
of the gas and air before entering the cylinder; and finally to insure the
non-occurrence of premature ignition, and the certainty of ignition.
The means I propose to employ to effect my purpose are of the following nature.
To the back of the ordinary operative cylinder provided with the usual operative
piston, connecting rod, crank, and fly-wheel shaft, I apply a regulating auxiliary
piston, entering through the rear of the operative cylinder, and receiving recipro-
cating motion from a crank, eccentric, or equivalent device fitted to a transverse
counter shaft at the rear of the engine.
This counter shaft is so connected with the main crank shaft by cog wheels, (or
so that the
such suitable form of connection or gearing, as will not allow of slip),
counter shaft revolves at half the speed of the main crank shaft.
I utilize the rotation of this counter shaft at half speed as compared with the
main crank shaft, to operate admission and exhaust valves to or from the operative
cylinder, driving the said valves, by eccentric tumblers on said counter shaft, and
connecting rods, in the usual manner.
In consequence of the operation of my regulating auxiliary piston from an
eccentric or other equivalent device, capable of adjustment upon the counter shaft,
either as to the throw or stroke of the said auxiliary piston, (in which case the
connecting rod to the said piston is also capable of adjustment as to length,) or as
to the angular lead or position of the eccentric or other equivalent device on the
said counter shaft, relatively to the angular position of the main crank upon the
crank shaft, I can, at any time, at or after construction, regulate the movement of
the auxiliary piston, relatively to the operative piston, so that they meet in actual
contact, simultaneously, at the innermost points of their respective strokes during
exhaust, thus eliminating all exhaust products, except as regards the remaining
volume contained in the clearance of short ports through the walls of the cylinder;
or I may cause the completion of the inner stroke of the auxiliary regulating
piston to be delayed in any desired degree after the completed inner stroke of the
operative piston, and thus I may retain any desired volume of exhaust products in
the cylinder, thus also reducing the volume of the fresh charge drawn in on the
rext outward stroke, and also ensuring a greater ratio of expansion after explosion
than the ratio of compression before ignition.

page_text: It will also be observed that, owing to the half speed as compared with the
crank shaft, at which the counter shaft revolves, although the stroke and timing of
the auxiliary piston may be such that all exhaust products are, removed from the
operative cylinder on the exhaust, full space is left on the next inner compression
stroke of the operative piston for the requisite volume of compressed combustible
charge. And further, although in this setting of the auxiliary piston isochronous
with the operative piston, but at half speed, the inner stroke of the auxiliary
piston must be made against the force of the explosion, the work of the resistance
so experienced is given back to the operative piston by the movement of the
auxiliary piston towards it; and I can; by throwing back, relatively to the main
crank, the angular position of the eccentric or equivalent device operating the
auxiliary piston, convert largely the motion of the auxiliary piston towards the
explosive force at the time of highest pressure into an outward receding movement
therefrom, transmitting work in aid of the main operative piston; and the
remaining movement of the auxiliary piston against the internal pressure, would
be limited to a short period, at or about its dead centre, and against the very
reduced pressure at the end of the operative stroke.
This regulation of the action of the auxiliary piston will enable me to nicely
adjust the amount of work done in any of several cylinders of a compounded engine,
to render the work in any cylinder practically the same, or otherwise, as desired.
Where the lead of the auxiliary piston is put back as above described out of
isochronism with the operative piston, I may prevent to a large extent the
accumulation of exhaust products on the discharge stroke, if desired, by adding a
false backing to the operative piston to discharge them.
To insure the thorough mixing of the gas and air before entering the cylinder,
I provide a somewhat tortuous passage with baffle plates between the inlet gas and
air valves, and the admission valve to the cylinder.
To prevent the occurrence of premature ignition, I utilize the said auxiliary
piston to cover the ignition port until the exact moment at which I desire the
ignition to take place, and after once the ignition port is so uncovered, it remains
open for some time, so as to ensure the ultimate certainty of ignition.
Dated this 4th day of April 1895.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant,
Improvements in Gas Motors.
I, WILLIAM DONALDSON, of 38 Parliament Street, Westminster in the County
of Middlesex, Civil 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 :-
:
This invention relates to motors operating by the explosion of combustible gas,
and has for its object the provision of means in such engines or motors, working on
what is known as the "Otto cycle" (that is working in the following cycle of
operations 1st suction of inflammable charge, 2nd compression of the same,
3rd explosion and operative stroke, and 4th exhaust of burnt products) by which
it shall be easy to vary at and after construction, the volume of residual burnt
gases left in the cylinder, after the termination of the exhaust stroke, from a
minimum represented by the unavoidable volume of short port-hole passages, to
any desired amount; further to insure, in the case of a single cylinder engine,
that the ratio of expansion after explosion, shall, if desired, exceed the ratio of
compression before ignition; and to vary both ratios; and to thus allow of the
regulation of the work done in any of the cylinders of a compounded engine;

page_text: the gas and air before entering the cylinder.
The means I employ to effect my purpose are as follows
Figure 1 is a vertical section through the cylinder of my gas motor.
Figure 2 is a sectional plan of the same.
Figure 3 is a diagrammatic view of the said motor with compounded cylinders.
Figure 4 is a detached elevation and section of the adjustable eccentric, driving
the regulating piston.
Figure 5 is a detached detail of the adjustable connecting rods of same
eccentric.
Figure 6 is a sectional elevation and plan of the mixing chamber for the
explosive charge.
A is the usual open cylinder of a gas engine, in which the "Otto cycle" of
operations takes place. B is the usual operative trunk piston, connected in known
manner by connecting rod and crank to a crank shaft C carrying a fly wheel.
The back of the operative cylinder A is also made open, aud is closed by an
auxiliary regulating piston D, receiving & reciprocating motion (& making half
the number of strokes in a given time as compared with that of the operative
piston), from an eccentric tumbler E, or equivalent crank, on a counter shaft F at
the rear of the motor cylinder.
The said counter shalt is driven from the main crank shaft C conveniently
by a train of cogged wheels O, 01, 0%, or by any equivalent connection or gearing,
as will not allow of slip, so that the counter shaft revolves at half the speed of
the main crank shaft C.
This relative arrangement of the operative piston B, making two strokes to one
of the regulating piston D, is all important, as it enables me to regulate the
residual burnt gas products left in the cylinder at the termination of the exhaust
stroke, without sensibly altering the volume of the fresh charge of air and gas
admitted in the following return stroke of the piston B; and also to cause the
ratio of compression to be less than the ratio of expansion, which could not have
been effected had the reciprocations of the regulating piston D been equal in
number, in a given time, to those of the piston B.
The length of the stroke of the regulating piston D, is so adjusted, as compared
with that of the operative piston B, that when the angular position of the throw
of the eccentric E on the counter shaft F coincides with, or is opposite to, the
crauk on the main crank-shaft C, and the two pistons B, D, are meeting one
another on the exhaust stroke of the piston B, the said pistons shall reach
simultaneously a coincident line between them, and the exhaust products are
entirely discharged from the cylinder; whilst owing to the half speed of revolu-
tion of the shaft F, as compared with the crank shaft C, the regulating piston D
does not again meet the re-entering piston B on its next compression stroke, and in
this way by receding, provides the space required for the compressed charges.
By giving the eccentric tumbler E angular advance on the shaft F, as compared.
with the position of the crank on the crank shaft C, I can vary, at any time,
during the lifetime of the engine, the ratio of compression and of expansion, and
at the same time leave any desired volume of exhaust products behind in .the
cylinder, at the termination of the exhaust stroke.
To conveniently effect this, the eccentric tumbler E is not keyed to its shaft,
but is secured by a carrying pin or bolt e Fig. 4 to a disc E' keyed to the shaft,
such disc being provided with a series of holes e' by which the angular position
of the eccentric tumbler E may be adjusted on the shaft F as desired at any
time.
If also it is desired to alter the ratios of compression and of expansion, as above,
by altering the angular position of the eccentric E on the shaft F, I can still effect
the entire discharge of the exhaust products from the cylinder, by throwing
forward the piston P by lengthening the eccentric connecting rod, or by adding a
false inner end to the pistons D'or B.

page_text: The eccentric rod P is provided with an adjustable sliding Joint F Fig. ɔ
which the length of said rod may be adjusted at any time for this purpose.
The explosive charge admission valve G and exhaust valve H, may be of any
known or convenient type, but are shown as piston valves operated by eccentric
tumblers G'H' from the shaft F, and the gas admission valve K may be opérated
conveniently by a cam K' on the shaft F.
In order to effect the thorough mixture of the gas and air for the explosive
charge before ignition, they pass through a mixing chamber L, the gas entering by
the orifice Z from the gas valve K operated mechanically at the required time by
the cam K, and the air through the valves or orifices M M before entering the
cylinder. The gas and air mix in the lower compartment X and proceed by an
orifice Y to an upper compartment. The upper compartment is provided with a
diaphragm or baffle plate L, Fig. 6, around which the gases travel, to ensure
thorough mixing of the gas and air, before issue by the port y¹ to the cylinder
as it passes through the chamber L, which is conveniently kept cool by a
water jacket N, in communication with the usual water jacket of the operative
cylinders A.
For the greatest economy in working expansively, I combine two high pressure
explosive cylinders, (exploding, as in the "Otto cycle," alternately in every other
outward stroke) with a single acting low-pressure cylinder, receiving the exhaust
in each outward stroke of the low pressure piston from either high-pressure cylinder
alternately, thus making a working stroke in the low-pressure cylinder on each
outward stroke, and exhausting on each inward stroke of the piston. This is
shown diagrammatically in Fig. 3, where QQ are the two single acting high-
pressure exploding cylinders, of the construction hereinabove described, each
exploding in every other stroke and alternately to one another. Their exhaust
exits are connected by a breeches pipe R to the supply port of the low pressure
cylinder S. The expanded gases are finally discharged from the cylinder S by the
exhaust port u, controlled by a valve operated in the usual way from the rotating
crank shaft T.
The pistons of the three cylinders Q Q and S, are connected in the usual manner
by connecting rods to a single three-throw-shaft T, in which the cranks of the high
pressure cylinders QQ,'are at the same angular position on the shaft and the crank
of the low-pressure cylinders S, is opposite to these.
The exhaust valve of cylinder S is operated in the usual way from the main
crank shaft T.
In this arrangement one gas admission valve, air & gas mixing chamber, and
supply, will suffice for both the high pressure cylinders QQ, the admission gas
valve being operated to lift every revolution of the main crank shaft, as in the
case of a single cylinder engine as hereinabove described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
:-
1st. In an explosive gas motor the combination with the known single-acting,
cylinder, trunk piston connecting rod and crank shaft and necessary admission and
exhaust valves common to such motors of a regulating piston adapted to the rear
of the operative cylinder, means to reciprocate the said regulating piston with half
the number of reciprocations in a given time as those of the main trunk piston, to
effect the regulation of volume of burnt products, undischarged on exhaust and the
ratios of compression and expansion.
2nd. In an explosive gas motor the combination with the main crank shaft of
gearing, adapted to drive a counter shaft at half speed to that of crank shafts
eccentrics or cranks on said counter shaft; gas and explosive charge admission
valves; exhaust valve, and regulating piston in rear of explosive cylinders;
connected to, and operated by, said eccentrics or cranks on said counter shaft.
3rd. In an explosive gas motor a regulating piston in main cylinder at rear of

page_text: operative piston and an adjustable lengthening piece adapted thereto, and means for
reciprocation of said regulating piston from counter shaft, revolving at half speed
of main crank shaft.
4th. In an explosive gas motor, a regulating piston in main cylinder at rear of
operative piston, a connecting rod adjustable as to length, connecting same to
eccentric on counter shaft revolving at half speed of main crank shaft.
5th. In an explosive gas motor an intermediate chamber and baffle plate therein,
between gas & air admission valves, and operative cylinder, to effect thorough
mixing of explosive gases before ignition.
6th. In an explosive gas motor, a regulating piston in main cylinder at rear of
operative piston, and adjustable means for reciprocating same at various
angular positions to main crank piston, consisting of a loose eccentric tumbler
on counter shaft, a keyed disc on said counter shaft; and a steady bolt fitting a
series of holes in said disc to effect adjustment of eccentric to fixed disc.
7th. In an explosive gas motor the combination with two single acting high-
pressure explosive cylinders, provided with operative & auxiliary pistons exploding
alternately once in every second double stroke, of a single-acting low pressure
cylinder of larger diameter; connections from supply port of larger low pressure
cylinder to exhaust ports of each of the high pressure cylinders; means of exhaust
issue from larger low pressure cylinder; a valve controlling exhaust ports of low
pressure cylinders; and a three throw main crank shaft connected by connecting
rods to pistons of all three of said cylinders, substantially as described.
Dated this 31st day of January 1896.
FELL & WILDING,
1 Queen Victoria Street, London, E.C., Agents for the Applicant.