An Improved Gas Engine.
Year: 1891

page_text: Date of Application, 24th Feb., 1891-Accepted, 29th Mar., 1891
COMPLETE SPECIFICATION.
An Improved Gas Engine.
I, BARTON HAXALL COFFEY, Mechanical Engineer, residing at 308, South
Tenth Street, Philadelphia, State of Pennsylvania, United States of America, do
hereby declare the nature of my invention for "AN IMPROVED GAS ENGINE,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
My invention relates to the construction of gas engines and has for its object to
simplify and improve the construction and operation of the same. The nature of
my improvements will be best understood as described in connection with the
drawings in which they are illustrated and the novel features which I desire to
protect by Letters Patent are hereinafter pointed out in the claims.
In the drawings which represent a gas engine constructed with my improve-
ments,
Figure 1 is a side elevation showing the cylinder and its valves in section."
Figure 2 is an end elevation of the cylinder end of the engine.
Figure 3 is an elevation of the other end of the engine.
Figure 4 is a view of the guiding pivot shaft and its connections taken on the
line of Figure 1.
Figure 5 is a face view of a fly-wheel showing a governor and its connection with
the guiding pivot shaft.
Figure 6 is a side view of the same parts.
Figures 7 and 8 show details.
Figure 9 is a plan of the end-plate of the cylinder showing the ports formed
in it.
Figure 10 is a section on line -y of Figure 9.
Figure 11 is a plan view of the inner face of the valve acting on the end-plate;
and
Figures 12 and 13 are diagrams illustrating the action of the engine in two
positions of the guiding pivot shaft.
A is the frame of the engine; B the cylinder; C the trunk piston; C¹ the pin
by which it is connected with the connecting-rod G D is the end-plate of the
cylinder E the valve-plate having a circular rack E' formed on its outer rim; Fa
shaft which actuates the valve E by means of the gear-wheel F engaging rack E
There are novel features in connection with the valve and valve-ports shown which
I will describe hereafter but I may here state that my principal novel feature
which I am about to describe can be employed in connection with any convenient
valve system.
Kis the main shaft of the engine; 11' crank-arms secured to said shaft, and
the crank-pin is a pivot preferably made adjustable or movable for
reasons which I will state, and H is a link of substantially triangular form and
provided with a slot H' which may be straight as shown or if desired may have
a curved outline; this link is pivoted to the crank-pin 1. as shown and to the
connecting-rod Gath, and also to the guiding pivot by means of its slot H;
the connection being made in the plan shown by means of a block J sliding in
slot H and turning on pivot J. The effect of this combination of the con-
necting-rod, crank-shaft, guiding pivot, and slotted link, upon the motion of the
piston is shown in the diagram 12 and 13, the piston making two strokes for
each revolution of the shaft and an explosion occurring for each revolution.
For instance in the diagrams X 1. 2. 3. 4. indicates the different extreme positions
of the piston during each revolution of the main shaft, Y 1. 2. 3. 4. the corre-
sponding positions of the pivot at the end of the connecting-rod G; and

page_text: Z 1. 2. 3. 4. the corresponding portions of the crank-pin I, while the position of the
guiding pivot is indicated in Figure 12 at u and in Figure 13 at u'. As the
crank-pin moves from 1 to 2 the piston moves from 1 to 2 sucking in the charge
of gas and air; as the pin moves from 2 to 3 the piston moves back to 3 com-
pressing the charge; the explosion then occurs forcing the piston to 4 and
impelling the crank-pin from 3 to 4 and the rotation of the crank-pin from the
piston back to expelling the burnt charge and completing the cycle. The
curve described by the end of the connecting-rod is indicated at Y. My device
of the slotted link and its connection with the connecting-rod, crank, and guide
pivot is, I believe, entirely new and it is a simpler and more convenient device
for accomplishing the desired movements of the piston than any with which I
am familiar besides giving a capacity for regulating and altering the operation
of the engine by making the guide pivot adjustable. For instance, referring to
Figures 12 and 13, by making the guide pivot adjustable between points u and u
the movements of the piston are changed in degree so that when the pivot is
at the outward stroke of the piston which draws in the charge is longer
than when the pivot is at and the compression stroke correspondingly
altered. This adjustability of the guide pivot is another important feature of
my invention.
1
I
By connecting a governor with the movable guide pivot by mechanism which
will cause the said pivot to change its position as the load on the engine varies.
am enabled to regulate and govern the engine in the most effective way; that is,
to shorten the suction stroke as the load falls and lengthen it as it increases and
this also is an important feature of my invention.
Referring again to the drawings I will describe the mechanism there shown for
adjusting the guiding pivot and for actuating it by the governor, the construction
shown being, I believe, well adapted for its purpose but being capable of almost
indefinite change and modification in its details of construction. The guide pivot J
is formed as a shaft on which the sliding block J can turn freely and to said shaft
are secured bearing rings or wheels 13 and spur gears JJ; a worm-wheel.J
being secured to one end. M* M² are blocks in which are formed guide
bearings M M to secure the wheels or rings J³ and racks M M in which the gear-
wheels J engage.
It is obvious that by this construction the rotation of shaft
will cause it to travel back or forward in the guiding bearings M M. N is a worm
which engages worm-wheel J; it is secured to a shaft N' by means of a slot n
which engages a feather on said shaft the worm being thus free to move along
the shaft while it turns with it on the lower end of worm N is secured by means
of bolts n an extension which is free to move to and from the worm for a short
distance being held normally at the greater distance from it by gravity or if
desired, a light spring, a shoulder with gradual inclined slope is formed on its
face. As the shaft N revolves in the direction indicated by the arrow in Figure 7,
the worm revolving with it rotates shaft by engaging with worm-wheel and as
the shaft moves up on racks M' the worm moves up along the shaft N' until the
end of feather comes beneath the extension ³ of the worm when the worm ceases
to turn and the further revolution of the shaft simply causes the extension
move to and fro on its supporting bolts, but as soon as the rotation of shaft N¹
changes in direction the feather n² engages shoulder n and rotates the worm which
immediately begins its backward movement along the shaft. The purpose of this
construction is to provide a limit to the upward movement of the guiding pivot
when it is coupled with a governor in the way shown and which am about to
describe.
to
On the upper end of shaft N' is fixed a friction cone N fitting between beveled
collars oo on a ring O which ring is internally threaded and screwed upon a screw
threaded ring or collar Kon shaft K. Extending from ring O are arms 01 01 to
which are pivoted at one end links P P, which, at their ends, are pivoted to
links PP, the other ends of which are pivoted, as at p, to the fly-wheel L.
On links Pare secured weights P2 and springs P³ are provided to hold the

page_text: weighted links normally in their desired position and to act against the centrifugal
force of the weights as the fly-wheel revolves. The operation of the device shown
is easily followed, as the fly-wheel revolves with increasing speed the centrifugal
force of the weighted levers overcome the springs and as they move outward they
act upon the arms O¹ of ring O causing it to turn on shaft K and by reason of its
engagement with threaded ring K¹ to move along it this brings the ring o' in
contact with cone N2 causing shaft N to revolve as shown by arrow in Figure 7
and by the connection described causing the pivot shaft J' to move up and shorten
the suction stroke of the piston. On the other hand the slowing down of the fly-
wheel causes the springs to overcome the centrifugal force of the governor weights
and the ring O is rotated in the opposite direction on shaft K, the ring o being
brought in contact with the cone N2 and the guide pivot J caused to move down-
ward with the result of lengthening the suction stroke of the piston.
Referring now to the engine, valves and ports, the construction of the end-
plate D is shown in Figures 1-9 and 10; it is secured to the cylinder by a number
of bolts as d and has a water space d¹ formed in it. d² d² are exhaust ports
connected together by a passage d³, and d is a passage leading from one of them to
the open air or exhaust pipe; d' d' are air inlet ports, and d a gas inlet port; as
shown it is separated from an adjoining air port d by a partition and the gas
pipe leads through the air port and the partition; ds d³, &c., are ports
leading through plate D to the interior of the cylinder; do is the ignition port
into which leads a passage d" into which is fastened a closed tube R" situated in a
flue R in which a Bunsen burner is situated in the usual way. The valve E is
chambered out as shown at ele, said chambers connecting with the annular
opening and being open on the face of the valve through slots e e. The valve is
held in position by a bolt E2 screwing into plate E and having a threaded end e³
upon which screws a hand-wheel E. E³ is a plate which rests against the end of
valve E, balls et being preferably used to convert sliding into rolling friction. A
spring E situated between plate E³ and wheel E keeps the valve pressed against
the end-plate D with a force regulated by the compression of the spring. The
valve E is given a constant movement of rotation by means of the gear-wheel F
meshing with its circular rack E' and driven by shaft F which has at its end a
spirally-toothed wheel F engaging a spiral gear Q, the gearing being such as will
cause the valve E to make a half revolution for each complete revolution of the
shaft K. The action of the valve is very simple; when its ports e e register with
the air and gas ports d' d' d³ the charge is drawn in, passing through openings el e
to the ports and thence to the cylinder, the valve continuing to revolve; its
openings e are closed by the plain face of plate D during the compression of the
charge and one of said openings, e, registers with the firing port 10 at the end of
the compression stroke allowing the mixture in the cylinder to enter the heated
tube R and become ignited, the ignition being freely communicated through
passage d", port do, opening e, chamber el, opening e², and ports a³, to the cylinder.
At the end of the explosion stroke of the piston the openings e of the valve
register with the exhaust ports and the gases are freely expelled during the
return stroke of the piston.
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 :-
First: In a gas engine the combination of the connecting-rod, the crank of the
main shaft and a guiding pivot with a link H pivoted to the connecting-rod and
crank at fixed points and to the pivot J' by means of a slot H' formed in said link,
all substantially as and for the purpose specified.
.Second: In a gas engine the combination of the connecting-rod, the crank of the
main shaft and a movable guiding pivot J with a link H pivoted to the connecting-
rod and crank at fixed points and to the pivot J' by means of a slot H' formed in
said link, all substantially as and for the purpose specified.

page_text: Third: In a gas engine the combination of the connecting-rod, the crank.of the
main shaft and a movable guiding pivot with a link H pivoted to the connecting-
rod and crank at fixed points and to the pivot J¹ by means of a slot H formed in
said link, a governor and mechanism connecting said governor and the moveable
guide pivot arranged to change its position as the load of the engine varies..
:
Fourth In a gas engine the combination of the connecting-rod, the crank on the
main shaft, a guiding pivot shaft having gear-wheels.. attached to it, racks.M'
engaging gear-wheels J, mechanism for rotating shaft J and its gears Jº to
change its position on the racks, and a slotted link H pivoted to the connecting-rod
and crank at fixed points-and to the shaft by means of its slot, all substantially
as and for the purpose specified:
Fifth In a gas engine the combination of the connecting-rod the crank on. the
main shaft, a guiding pivot shaft J having gear-wheels attached to it, racks M¹
engaging gear-wheels J, mechanism for rotating shaft. J and its gears J to
change its position on the racks, a governor connected. witli. and controlling the
movement of said mechanism, and a slotted link H pivoted to the connecting-rod
and crank at fixed points and to the shaft . by means of its slot, all substantially
as and for the purpose specified.
:
Sixth In a gas engine having the slotted: link H and moveable pivot Jas
described, and a shaft N actuated by the governor, the combination of the worm N
mounted on shaft N' and connected with it by feather a², the moveable extension'n³
of said worm having shoulder and the worm-wheel on shaft J, all substantially
as-and for the purpose specified.
Seventh: In a gas engine the combination of the cylinder end-plate D having
induction ports d³, exhaust ports de d², air ports dd, and gas port d³, arranged
substantially as specified; and a rotating valve E having openings ee, chambers e e¹,
and passage e².
:
Eighth In a gas engine the combination of the cylinder end-plate Dihaving
induction ports de, exhaust ports d³ d², air ports dd, gas port d³, and ignition
port do with passage d", arranged substantially as specified, and a rotating valve E
having openings e e, chambers e¹ e', and passage e².
Dated him th don of Wolmary 1901
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.