Year: 1887

page_text: We ARTHUR CHARLES STERRY of Heatherlea, Redhill in the County of Surrey,
Gentleman and JOHN STERRY of Redlands, Redhill in the County of Surrey,
Gentleman do hereby declare the nature of this invention to be as follows:-
Our invention relates to improvements in motive power engines which are driven
by the explosive force of mixed gases the object being to work such engines at any
desired compression and expansion after the manner of steam engines, that is,
reversing the direction of motion at pleasure and varying the expansion automatically.
Our improvements apply both to engines which have two pistons working in the
same cylinder and to engines having cylinders fitted with a single piston. In either
case, we transmit the motion through differential gearing or its equivalent to the
crank shaft and thereby cause the crank shaft in its rotation to control the movements
of the pistons. In constructing a double piston engine we provide spur gearing in the
proportion of two to one, keying the smaller wheel to the crank shaft and mounting
the larger wheel on a radius arm which has the crank axle for its fulcrum. This arm
we connect with the governor which will raise and lower it, and thereby shift the
position of the wheel which it carries with respect to the smaller wheel into which
it gears in order to vary the relative movements of the pistons and thus to vary the
compression space to suit the quantity of gas admitted.
Each wheel we connect through a crank pin with the rod of one of the two pistons,
the speed of travel of which will relatively vary greatly. The explosive gases are
admitted to the cylinder between the pistons and are by them compressed before
firing. When the explosion takes place the engine will work expansively through
the controlling power of the gearing.
The arrangement of power transmitting gear above described we adapt to single piston
engines by connecting the crank pins of the gear wheels by rods to the opposite ends
of a cross head and this cross head we pivot to the piston rod of the engine. Or the
cross head may be attached to a slotted radius arm to which the piston rod is coupled.
This arrangement admits of the coupling pin being shifted to and from the fixed
fulcrum of the radius arm by means of the governor thereby adjusting the travel of

page_text: the piston rod and its piston and controlling the speed of the engine. Slotted radius
arms may also be applied to the double piston engine.
In some cases we propose to use concentric gearing and to connect the two wheels
together by adjustable intermediate gearing mounted on a radius arm having the
crank axle for its fulcrum and connected with the governor.
-
The position of the adjustable radius arms which has the crank axle for its
fulcrum determines in which direction the engine shall work and also the limits of
the compression space. When it is desired to make the single piston engine double
acting the gearing and resulting reciprocations must be three to one.
In the two piston engine above described both pistons are working pistons that is
transmitting power either direct or through the gear to the crank shaft but with a
suitable cam motion upon, say, the slow moving shaft in place of the revolving crank
pin; one piston may be made to stand still during the expansion stroke and the power
will then be entirely transmitted direct through the other piston.
The same arrangement may also be applied to the single piston engine when the
cross head will vibrate as it were upon a fixed fulcrum and the power of the engine
will be transmitted directly from the piston to the crank shaft.
NEWTON & SON,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Explosive Gas Engines.
We ARTHUR CHARLES STERRY of Heatherlea, Redhill in the County of Surrey,
Gentleman, and JOHN STERRY of Redlands. Redhill in the County of Surrey,
Gentleman, 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:-
Our Invention relates to improvements in motive power engines which are driven
by the explosive force of mixed gases, the objects being to work such engines at any
desired compression and expansion of the mixed gases, after the manner of working
steam engines, and when desired, to provide for reversing the direction of motion at
pleasure, and also to vary the expansion automatically when the same is required to
be effected.
Our improvements apply both to engines which have two pistons working in the
same cylinder, and to engines having cylinders fitted with a single piston. In eithor
case, when we desire to expel the whole of the burnt gases from the cylinder, we
transmit motion through differential gearing or its equivalent to the crank shaft, and
thereby cause the crank shaft, in its rotation, to effect a complete control of the
movements of the piston or pistons.
In the accompanying drawings
Fig. 1, Sheet 1, shows in longitudinal vertical section a double piston engine
constructed according to our invention, and
Fig. 2 is a plan view of the same.
A A is the main framing on which is mounted an open-ended horizontal cylinder B.
This cylinder is fitted with a pair of trunk pistons CC, which move towards and
from each other for the purpose of expelling the burnt gases, for drawing in a
fresh supply of mixed gases, and for compressing the same preparatory to the next
explosion.
That portion of the cylinder which is directly exposed to the heat of the burnt
gases is jacketted to receive a circulating stream of cooling medium, by which the
beat of the engine is kept down.
These trunk pistons transmit their motion to the crank shaft D, which turns in
pluminer blocks on the main framing A.
The rod of the piston C is directly connected to a crank of the shaft D, while the
rol of the piston C is made to communicate its motion through gearing to the crank
shaft
Keyed to the crank shaft D), is a spur pinion E, and in gear with this pinion is a
wheel F of double the number of teeth.
This wheel F is keyed to a spindle F mounted in a rocking arm F, which has
for its fulcrum the crank shaft D. The spindle F1 carries a crank pin, which is
connected to the piston C in the following manner.
Mounted in bearings on the bed plate of the engine, in rear of the cylinder B, is

page_text: a rock shaft G carrying a pair of arms. One of these armis g connects directly with
the rod of the piston C, and the other g', through a rod g², with the crank pin f of
the spindle F¹.
The arm is connected by a link F³ with a nut F4, which travels along the screw
thread of a horizontal spindle F mounted in fixed bearings on the bed plate, and
carrying a hand wheel F. By turning this hand wheel, the nut F is traversed along
the screw thread, and the link connecting the nut with the arm F is thereby caused
to raise or depress that arm, and shift the position of the wheel F which the arm
carries with respect to the smaller wheel into which it gears.-The result of this
adjustment of the nut is to vary the relative movements of the pistons, and thus to
vary the compression space to suit the quantity of gas admitted to the cylinder.
The means for controlling the supply of the mixed gases to the cylinder, as shewn
at Fig. 2, will be presently explained.
By connecting the pistons with the crank shaft by gearing or its equivalent, the
one piston will serve to control the movements of the other, and their relative speeds
of travel will consequently vary greatly.
The explosive gases are admitted to the cylinder between the pistons, and are by
them compressed before firing. When the explosion takes place, the engine will work
expansively through the controlling power of the gearing.
We have said that the trunk piston is connected directly by its rod to the crank
shaft D its stroke therefore always remains the same.
The piston C however varies the time of its stroke relatively to the piston C,
according to the necessities of the case, by reason of its connection with the travelling
crank pin f.
His a cam shaft for operating the valves.-This shaft lies parallel with the
cylinder B, and is mounted in bearings carried by the framing A.-The cam shaft H
receives rotary motion from the crank shaft D through a pair of bevil wheels. It is
fitted with a pulley for transmitting motion to the governor I (of the ordinary
construction), by which the passage of gas from the supply pipe to the admission
valve is controlled in the usual manner.
The shaft H also carries an adjustable double cam h' for actuating the admission
valve, and reversing the action of the engine.- is a fixed cam for operating the
ignition valve, and is the adjustable double cam for actuating the exhaust valve.
The cam is made to slide on a feather on the shaft, in order to adjust the cut off
of the supply of gas and air, and also to reverse the engine, and connected with it is
the double exhaust cam h³. A rock lever carrying the spindle of the admission
valve is borne up against the cam h' by a spring, and as the cam rotates, the valve
is raised from, and dropped onto its seat.
For shifting these cams, a fork lever / embracing the cam is provided. By
throwing this lever over to the right or left, the arm F2 having simultaneously been
shifted to the dotted position, the action of the engine is reversed, and by giving it a
shorter movement, the cam is caused to control the supply of mixed gases to the
engine. When the cam is shifted endwise on its shaft, it will present an inclined
.projection to the rock lever 1, by which the lifted valve is held up for a lengthened or
diminished period, and thus the supply of the gas and air will be regulated according
to the requirements of the work.
In order to explain the action of the engine just described, we will now refer to
a series of five diagrams, by following which, the movements of the pistons will be
clearly understood.
Diagram 1, Sheet II, shews the engine cylinder in section, and the pistons C. C'
in the position they assume at the completion of the discharge of the burnt gases.
In this, and in all the following diagrams, the connections of the pistons with the
gearing and crank shaft are sufficiently illustrated.
Diagram 2 shews the pistons to have receded to a given extent for drawing in a
sufficient supply of mixed gases, the drawn position of the arm F and the lotted
position of the same arm indicating the two adjustments for working the engine in
opposite directions.

page_text: Diagram 3 shews the pistons advanced towards each other for the purpose of
compressing the mixed gases received into the cylinder; and
Diagram 4 shews the position the pistons have taken under the effect of the explosion
of the gases. The impulse imparted to the crank shaft by the explosion causes the
return of the pistons to the position of the Diagram 1, and the complete expulsion of
the burnt gases from the cylinder.
Diagram 5 illustrates the position of affairs within the cylinder at the time of
compression, when the admission valve has been caused to contract the supply of
mixed gases to the cylinder.
Under such circumstances, it is necessary that the piston shall have moved
further inwards, in order to ensure a proper compression of the smaller charge.
This is effected by altering the position of the arm F from the dotted position to
the drawn position by means of the travelling nut F on the screw spindle F of
Fig. 1.
The Diagrams 1. 2. 3. 4 and 5, Sheet III, show practically the same results as the
Diagrams in Sheet II, the arm F which carries the spur wheel F approaching, in
this instance, a vertical instead of a horizontal position.
In this case, when the crank pin f. is placed on the pitch line, the burnt gases
are completely expelled at all powers of the engine, whereas, in the arrangement
shewn in Sheet II, the burnt gases are only completely expelled when the engine is
at full power. This arrangement of engine is, however, not reversing.
In Sheet IV we have shewn in Diagram a modification of our above described
double piston engine, the pistons in the several Diagrams corresponding in position
with the Diagrams of like numbers in the preceding Sheets.
In this arrangement of engine the pinion E is, as before, keyed to the crank shaft D,
but the wheel Fis carried by a stationary spindle. A crank on the end of the
spindle connects by a rod with a longitudinally slotted radius arm 2 situate in
rear of the cylinder B.-Fitted into the slot of this radius arm is a block f³, and to
it is connected the rod c¹ of the piston C¹.
This radius arm is mounted on an adjustable fulcrum, which is capable of being
raised and lowered either by hand or automatically, for the purpose to be presently
explained. Or the fulcrum may be fixed, and the block made adjustable in the
slotted radius arm.
In either case, in proportion as the distance between the fulcrum of the arm and
the block is varied, so will the oscillations of the arm increase or diminish the traverse
of the piston C in the cylinder.
By this arrangement, therefore, the contraction and enlargement of the compression
space will be effected in a similar manner to that described with respect to the
preceding Diagrams.
When the charge, and consequently the compression space, is to be increased, the
fulcrum of the radius arm will be lowered, and when they are required to be decreased,
the fulcrum will be raised upon the dotted line **; which is in a position to give
complete expulsion of the burnt gases, as well as varied compression space.
An equal compression, therefore, of the gases may be readily ensured, whatever
may be the rate of supply to the cylinder; or at lower powers, weaker mixtures of
explosive gases may be used at higher compressions.
The arrangement of power transmitting gear above described we adapt to single
piston engines, by combining in one piston the fast and slow motions before
described.
One mode of carrying out this connection is shown at Sheet V, where Fig. 3 is a
longitudinal section of the single piston engine, and Fig. 4 is a plan view of the
same.
A is the framing, B the cylinder having one end closed, C is the trunk piston
working in the cylinder, D is the crank shaft, to which is keyed the spur pinion E.
-Gearing into the pinion E, is the spur wheel F, having double the number of
teeth of that pinion. It is keyed to a short shaft F which has its bearings in the
framing A.

page_text: A crank pin f. of this wheel, and a crank of the shaft D, connect respectively
with the rod of the piston C in the manner to be presently described, for the purpose
of controlling the reciprocating movements of the piston."
d. is a link connected at one end to the crank of the crank shaft D, and at its other
end to the rod c. of the piston C.
The pin which connects the link and the rod together forms also a fulcrum for a
link d which connects at its other end with the arm g. of a rock shaft G having its
bearings on the bed plate of the engine. A second arm gl of this rock shaft connects
with a pin g fitting the slot of a longitudinally slotted link or bar K, which is
capable of being slidden end wise, like the link of a steam engine, for the purpose of
adjustment.
One end of this link or slotted bar is pivotted to a radius arm k, which is free to
rock on a fixed fulcrum, and the other end of the slotted link K is pivotted to a rod k¹,
which connects it with the crank pin f'of the spur wheel F.
The slotted link or bar K is adjusted end wise, and held in position by means of a
link attached to a screwed rod 3 fitted with an adjusting sleeve nut . This nut
works in a bracket projecting from the bed plate, and is actuated by a hand wheel k³
made fast to the nut.
I is the governor for cutting off the supply of gas when the speed of the engine is
in excess.
It is actuated in precisely the same manner as the governor in Sheet I.
Before referring to the diagrams which illustrate the working of the single piston
engine, it may be well to explain how the adjustment automatically of the moveinents
of the piston is effected.
In place of the hand wheel 45, we fit the nut k*, with a bevil pinion, as shewn in
Sheet VI., which represents the governor employed for automatically adjusting the
link connection between the crank pins of the gear wheels E and F.
Fig. 5 is a front elevation of the governor shewn as connected with the engine; and
Fig. 6 is a plan view of the same.
.L is a vertical spindle mounted in bracket bearings of the framing, and fitted at its
lower end with a bevil pinion l. gearing into a bevil wheel 7', on the nut k*.
L' is a sleeve fitting loosely over the spindle L, and carrying at its upper end a
bevil wheel and a spur wheel 13.
Projecting laterally from the spindle L is a pair of studs carrying a pair of bevil
wheels in gear with the bevil wheel 12.
Set above these wheels on the spindle L, is a sleeve L², carrying a bevil wheel 7
that gears into the intermediate wheels 1.
Keyed to this sleeve is a coned pulley for receiving a band from a similar coned
pulley m, keyed to a governor spindle M.
This spindle
driven from a bevil wheel on the crank D gearing into a bevil
pinion m on the lower end of the spindle M.
This spindle carries also a spur wheel m² in gear with the spur wheel 13 on the
sleeve L¹.
The sleeve m³ of the governor serves, in its rise and fall, to operate a belt shifter m
which controls the position of the coned pulley band which drives the sleeve L².
From the foregoing explanation, it will now be understood that so long as an equal
speed of rotation is imparted by the governor spindle M to the sleeves L' L', there
will be no tendency for the spindle L to rotate in its bearings, and thereby to drive
the wheel . on the adjusting nut k*.
So soon, however, as, by the rise or fall of the speed of the engine, the governor,
by shifting the belt on the coned pulleys, varies the speed of rotation of the
sleeves LL², their bevil wheels, by reason of their gearing into the intermediate
wheels carried by the studs of the spindle L, will impart an axial motion to that
spindle, and cause it to shift the position of the slotted link or bar K in which the
pin g² works.
The result of this movement is to rock the shaft G, and through its connection
with the piston rod, to control the stroke of the piston when advancing to compress
the charge.

page_text: This arrangement of mechanism is equally applicable for automatically adjusting
the position of the arm F2 which carries the wheel F of the first described engine,
which adjustment is required to vary the compression of the mixed gases.
The mechanism shewn in Sheet VI also applies to the shifting of the fulcrum of
the radius arm, forming part of the arrangement described with reference to
Sheet IV. It also has a wider application, as will be hereafter more particularly
referred to.
The governor M, besides controlling the movements of the piston, may indirectly
serve to adjust the cam which operates the admission valve.
This is also illustrated in Sheet Vl.-Connected to the rod k. of the link K by
means of a rod h, is a bell crank lever . forked at one end to embrace the shifting
cam h¹.
This bell crank lever works on a fulcrum pin carried by a bracket of the framing,
and as the slotted link L is adjusted by the action of the governor, the rod k. will
be moved on its fulcrum, and caused to impart a rocking motion to the bell crank
lever h³.
By reason of the connection of the can with the bell crank lever, the cam will
be shifted so as to increase or diminish the supply of mixed gases admitted to the
cylinder by the rise of the admission valve.
Having described, with reference to Sheet VI, the various parts employed in
adapting our invention to a single-piston gas engine, we will proceed to show, with
the aid of the diagrams in Sheet VII, how the single piston is controlled, so as to
draw in the supply of mixed gases and compress the same preparatory to their
ignition, premising that the Diagrams in this Sheet shew that the rod k¹, instead of
linking onto the crank pin f, is fitted with a bowle for working in a grooved cam F*
carried by the spur wheel F.
Diagram 1 shews the piston brought up to the head of the cylinder for the
expulsion of the burnt gases.
Diagram 2 shows the piston drawn back to its full, for the admission of the
mixed gases.
Diagram 3 shows the piston as having compressed the gases; and
Diagram 4 shews the piston at the end of its working stroke, the expansion of the
gases having driven it into that position.
A cam action may also be employed in connection with the arrangement shewn in
Figures 1 and 2.
In such case, we use a duplex or a triplex peripherical cam, in lieu of the crank on
the spindle F.
This cam we fit to the spindle, so that it may rotate with the spur wheel F, but
we provide for its being shifted laterally to bring one or other of its cam surfaces
opposite a bowle mounted on the end of the rod 92, and held in contact therewith by
a suitable spring.
Provision must be made for shifting this cam so as to bring one or other of the
cam surfaces into action, to suit the supply of mixed gases required for the engine.
The diagrams in Sheet VIII illustrate the action of the double-piston. engine when
a cam action is substituted for the crank pin f.
Diagram 1. shews the pistons advanced to their utmost for expelling the burnt
gases, the cam being set so that the cam face 1 is in position for action.
Diagram 2 shews their recession from each other to draw in a fresh supply.
Diagram 3 shews the pistons again advanced, at this time to compress the gases; and
Diagram 4 shews the pistons apart by the explosive force of the mixed gases.
Diagram 5 shews the cam face 2 set for action, and illustrates the change effected
thereby in the movement of the pistons to complete the compression of the gases.
The Diagrams in Sheet IX illustrate a modified arrangement of single-piston
engine, and explain also the movements of the piston in its cylinder.
These Diagrams shew the crank pins of the gear wheels E and F connected by
rods to the opposite ends of a cross head K, which cross head is pivotted to the
piston rod of the engine.

page_text: Diagram shews the piston thrust up to the head of the cylinder ¦
Diagram 2 its extreme intake position ;
Diagram 3 its extreme compression position; and
Diagram 4 the extreme position of its effective stroke.
In Diagram 5, a variation is shewn in the extreme compression position of the
piston produced by adjusting the position of the arm F2 which carries the gear
wheel F, as described with reference to Sheet I.
It will be obvious that instead of varying the controlling action upon the piston of
the gear wheels, by shifting the position of the wheel F relatively to a given line
passing through the axis of the wheel E, the same result may be obtained by
mounting the wheel E, as a fixture, on an adjustable arm F³, and mounting the
wheel F on the crank pin of the crank axle, and thus obtaining a sun-and-planet
motion.
This modification is illustrated in sheet X, the diagrams of which sheet shew the
piston controlled in a precisely similar manner to the last described arrangement, the
Diagrams 1, 2, 3, 4, and 5 corresponding with these of like number in Sheet IX.
Sheet XI shews a modification of the sun-and-planet arrangement, in which the
wheels E and F are of equal diameter, the result being, however, a two-to-one motion
as before. The wheel F is now, as before, mounted upon the main crank, but it
carries its crank pin f. beyond its periphery, and thereby ensures the requisite length
of stroke for the piston.
Diagrams 1, 2, and 3 in this Sheet illustrate the extreme movements of the piston
to expel the burnt gases, draw in a fresh charge, and compress it. Diagram 4 shows
the piston at its extreme acting stroke, and Diagram 5 shews the adjusted stroke of
the piston at the extreme of compression. As the wheel F makes two rotations to
one of the crank shaft D, the whole cycle of the piston's movements is completed in
one rotation of the crank shaft.
In all the above described arrangements, it will be noted that the control of the
piston or pistons is due mainly to the action of the gear wheels E and F, the one
having half the number of teeth of the other, and the adjustment of this controlling
power is in most of the examples due to the shifting of one or other of these wheels
to or from a given line drawn through the axis of the crank shaft.
It is not, however, absolutely necessary that the wheels E and F should gear together
in order to obtain the results which are reached by the application of our Invention.
The Diagrams in Sheet XII shew a modification of gearing which allows of the
relative adjustment of the crank shafts D and F¹ required to control the movements
of the piston.
Fulcrummed on the crank shaft D, is the adjustable arm F2, which instead of
carrying, as before, the spur wheel F, carries now two intermediate wheels E* and F*,
cast in one piece, the wheel E* gearing into and having double the number of
teeth of the wheel E, and the wheel F* having the same number of teeth as the
wheel F.
The wheel E is keyed to the crank shaft D, and the shaft F of the wheel E
passes through the crank shaft D (which is made tubular for the purpose (see the
longitudinal sectional view Fig. 7), and carries a crank pin f. This crank pin is con-
nected through a link with the piston rod of the engine, and the pivot pin forming this
connection serves also to connect a link from the crank shaft D with the piston rod.
By shifting the arm F2, it will be seen that the crank pins of the shafts D and F¹
will take a relatively different position, precisely as in the arrangements shewn in
Sheets I and V.
Diagram I, Sheet XII, shews the piston carried up to the head of the cylinder.
Diagram 2 shews the in-take extreine position of the piston.
Diagram 3 shews the extreme position for compression.
Diagram 4 shews the extreme acting stroke; and
Diagram 5 the adjusted position of the piston on completion of the compression of
the gases.
As an equivalent for the gearing above described for obtaining a two-to-one motion,

page_text: we propose to employ in some cases an endless grooved cylinder, and to fit the same
to the crank shaft.
In the groove of this cylinder will work a bowle or guide carried by a radius arm,
which arm we connect with the piston through a rod and bell crank.
By the rotation of the crank shaft, the radius arm will be vibrated, and the piston,
by reason of its connections therewith, controlled in its movements.
The adjustment of the pin which connects the radius arm and roll together, will
give the requisite adjustment for the proper action of the piston.
Or in place of the grooved cylinder, the crank shaft may be fitted with a scroll
plate for acting upon the bowle of the radius arm.
We may remark that by simply adjusting the crank pin nearer to the axis of
the wheel F, say in Sheet III, we may increase the space for the intake of the mixed
gases, thereby increasing the power of the engine. This result is however obtained
with the incomplete expulsion of the burnt gases from the cylinder.
If the crank pin is made adjustable up to the axis of the crank shaft, the maximum
intake space will be obtained, but burnt gases sufficient to fill the compression space
will be retained in the cylinder. If this retention of the burnt gases is not objected
to, the gearing which we employ solely for the purpose of expelling the burnt gases
may be dispensed with.
Sheet XIII. shows the adaptation to certain existing gas engines, of a principal
feature of our Invention, namely, our mode of controlling the movement of the
piston or pistons, so as to adjust the compression space to suit the amount of gas to
be supplied to the cylinder.
Fig. S shews a modification of Atkinson's double piston engine, for which Letters
Patent were obtained 28 February 1885 No. 2712.
In this engine, a pair of beams N N', working on fixed fulcrums connected with
the pistons C. C¹ at one end, and at the other end with the crank shaft D through
links PP.
In order to vary the stroke of the piston (³, we make the fulcrum of the beam N¹
adjustable, either by means of a screw operated by hand, as described with reference
to Sheet V, or automatically through the governor, Sheet V.I.
By this provision of a shifting fulcrum, we vary the compression space of the
cylinder, as illustrated in the preceding diagrams.
Fig. 9 shows our improvements applied to Atkinson's single-piston engine forming
the subject of a Patent dated March 12th 1886, No. 3522.
In this engine, a T-headed link Qis pivotted to the crank of the crank shaft D.
Pivotted to one extremity of the head of the T-piece is a link which connects with
the piston C, and pivotted to the other end of the T-piece is a rod R, working on a
fixed fulcrum.
This fulcrum we now fit to a radius arm S, which is free to rock on a fixed
fulcrum, and the position of this radius arm we adjust either by hand or by a
governor.
Pivotted to the radius arm S is an rod S', which carries a pin that is free to slide
in the segment slot of a radius arm S. The position of this rod S' with respect to
the radius arm S2, we adjust either by hand or by a governor.
The free end of the radius arm Swe attach to a crank on the crank shaft D,
and we thus cause the radius arm S to vibrate at every rotation of the crank shaft.
Thus, whatever change is effected in the relative positions of the rod S₁ and arm S³,
with the object of contracting or enlarging the compression space, the efficient stroke
of the piston to drive out the burnt gases will remain unchanged.
This arrangement controls the movements of the piston so as to obtain the results
illustrated by the preceding diagrams.
Fig. 10 shews a modification of Nixon's double piston gas engine, for which a
Patent was obtained June 8th 1886 No. 7658.
In this engine, the crank shaft D is connected by links to the two pistons C. C.
The rod of the piston C connects through a link T with the crank shaft, and the

page_text: pin which couples this link to the crank shaft couples it also with a link T¹ pivotted
to a radius arm T2 working on a fixed fulcrum.
The pin which connects the link and the radius rod together connects also with
the piston rod of the piston C, and the pin which connects the rod of the piston (
with its link T, serves also to connect that rod and its link with a radius arm T³
working on a fixed fulcrum.
In adapting our Invention to this arrangement of engine, we fit the fulcrum pin
of the radius arm T3 in a sliding block, or on an arm T4, as shown, and the position
of this fulcrum pin we regulate by hand or by a governor to adjust the compression
space for the explosive gases.
Sheet XIV shews a further modification of the single-piston engine of Atkinson,
the object being to obtain a more perfect control over the movements of the piston.
In this case we have removed the radius arm S of Fig. 9, and fitted the fulcrum
pin of the rod R in a sliding block, which may be adjusted in its guides either by
hand or by a governor.
Figures 11. 12. 13 and 14 shew four different positions of the piston corresponding
to the series of diagrams before referred to, and sufficiently illustrate, without
further explanation, the effect upon the piston which our invention is calculated to
produce.
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
wo claim is :
1st. The use in a gas engine, of gearing or cams as described for controlling the
effective stroke of the piston or pistons, and thereby drawing in and compressing a
charge of mixed gases, regulating the expansion and effecting the expulsion of the burnt
gases, as set forth.
2nd. Adapting to compression gas engines a movable fulcrum capable of being
adjusted by hand or automatically, as described, for the purpose of auntrolling the
action of a piston, so as to impart a regulated compression to varied supplies of mixed
gases.
3rd. The use in a gas engine, of a slotted radius arm for the purpose of varying
the length of travel of a piston, as shown on Sheet IV of the drawings.
Dated this 4th day of October 1887.
NEWTON & SON,
Agents for the Applicants.