IMPROVEMENTS IN GAS MOTOR ENGINES."
Year: 1874

page_text: LETTERS PATENT to Francis William Crossley, of Great Marlborough
Street, Manchester, in the County of Lancaster, for the Invention
of "IMPROVEMENTS IN GAS MOTOR ENGINES."
of "IMPROVEMENTS IN GAS MOTOR ENGINES."
Sealed the 23rd February 1875, and dated the 19th September 1874.
PROVISIONAL SPECIFICATION left by the said Francis William
Crossley at the Office of the Commissioners of Patents, with his
Petition, on the 19th September 1874.
I, FRANCIS WILLIAM CROSSLEY, of Great Marlborough Street, Man-
chester, in the County of Lancaster, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN GAS MOTOR ENGINES," to be as
follows:-
This Invention relates to improvements in gas motor engines of the
kind described in the Specifications of Patents granted to C. D. Abel
on the 12th February 1866, No. 434, and on the 3rd August 1867;
No. 2245, being communications to him from E. Langen and N. A.
Otto; also in the Specification of a Patent granted to the said C. D.

page_text: G. W. Daimler.
The engine described in the said Specifications operated in the
following manner :-A piston was raised in a cylinder a little distance,
drawing in through the ports of a slide a charge of combustible gas and
air at atmospheric pressure in suitable mixture for ignition. A flame being
then drawn in ignited the gaseous mixture, which by its expansion pro-
pelled the piston along the cylinder. The cylinder being kept cool by a
water jacket the pressure of the products of combustion within the
cylinder was rapidly reduced, and the cylinder being open at top the
piston was propelled backwards by the superior pressure of the external
atmosphere, the products of combustion being finally expelled by the
piston as it approached the extreme of its in stroke. The piston rod
was toothed as a rack, and geared with a wheel mounted on the engine
shaft, which was provided with a heavy fly wheel. The wheel geared to
the piston rod was mounted on the engine shaft with a clutch in such
manner that it could turn freely on the shaft in the one direction when
the piston was making its out stroke, but that when the piston was
making its in stroke the wheel caused the shaft to revolve with it.
This shaft, or a shaft connected with it, had on it cams or eccentrics
for moving the piston through a portion of its out stroke to draw in the
gaseous charge, and also for moving the slide so as to admit the gaseous
mixture and the igniting flame to the cylinder, and to permit the pro-
ducts of combustion to escape therefrom.
The object of my present improvements is to reduce the weight and
cost of certain of the moving parts, particularly those which have an
intermittent motion, and also to apply a governor to the regulation of
the speed of such engines by causing it to act directly upon the piston,
so as to retard or arrest it in case of excessive speed.
I mount by the side of the main shaft of the engine a countershaft,
on which I fit a loose wheel gearing with a wheel on the main shaft of
the engine, and I prefer to proportion the gearing so that the wheel on
the countershaft shall revolve more slowly than the main shaft. On the
loose wheel I fix a ratchet wheel, and on cach end of the countershaft I
fix a light crank. The crank at the outer end has mounted on it a
spring pawl, which can engage with the teeth of the ratchet wheel. It
has also on it a pin, which is connected to the slide valve of the engine.
.

page_text: The crank on the inner end of the countershaft has mounted on it a
roller, and a projection is formed on the side of the piston rack near
the upper end thereof, on which projection the roller comes to bear
when the piston reaches the lower end of its stroke. A spring lever of
the kind described in the Specification of the Patent, No. 2245 of 1867,
is mounted under the countershaft, such lever having on it a catch
which engages with the tail of the pawl above mentioned, and also with
the crank on which the pawl is mounted, and having also a projecting
end within range of a stud on the piston rack. As the piston approaches
the lower end of its stroke this stud meeting the spring lever disengages
its catch from the pawl, which thereupon engages with one of the teeth
of the ratchet wheel. The countershaft is thus caused to revolve, the
crank on its inner end acting on the projection of the piston rack, so as
to raise the same, and thereby draw the charge into the cylinder, at the
same time the second crank pin on the outer end of the countershaft
moves the slide valve so as to admit and ignite the charge of the
cylinder, the said pin being set in relation to the other crank, so as to
time the movement of the slide suitably to that of the piston. The
piston ascending the stud on its rack is taken off the spring lever, which
returns to its former position, and catches the tail of the pawl, disen-
gaging the same when the countershaft has made a complete revolution,
and arresting the countershaft. For engines of small size, where the
working parts are light, this arrangement may be modified by dispensing
with the countershaft and its two cranks, and substituting for them a
pair of eccentrics coupled together, but mounted loosely on the main
shaft of the engine, the ratchet wheel being fixed on the same shaft, and
the pawl being mounted on the eccentrics. The one of these eccentrics
serves as the inner crank previously described to raise. the piston for
drawing in the charge by acting on a lever, which bears against a pro-
jection on the side of the piston rack. The other eccentric serves as the
pin previously described on the outer end of the countershaft to work
the slide valve, and the pawl being thrown into gear with the ratchet
so as to make the eccentrics revolve, and being thrown out of gear so as
to arrest them by means of a lever acted on by a stud on the piston rack
in a manner similar to that already described.
In applying a governor to regulate the speed of engines of this kind
I provide on the upper part of the piston rack a projection, which may
be elastic, and may be sloped off at its lower end. To the governor

page_text: lever I connect by a screw or toggle joint a moveable piece, which
when the governor balls expand is brought within range of this pro-
jection, so that as the piston approaches the lower end of its stroke it
becomes retarded or arrested, and is thereby prevented from completing
its down stroke until by the collapse of the governor balls it is released.
Thus when the engine shaft tends to revolve at too great speed the
number of strokes of the piston become reduced until the speed of the
shaft is again moderated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Francis William Crossley in the Great Seal 1
Patent Office on the 18th March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
WILLIAM CROSSLEY, of Great Marlborough Street, Manchester, in the
County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 1
Patent, bearing date the Nineteenth day of September, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Francis William Crossley, Her
special license that I, the said Francis William Crossley, my exe- 2
cutors, administrators, and assigns, or such others as I, the said Francis
William Crossley, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and law-
fully might make, use, exercise, and vend, within the United Kingdom a
of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN GAS MOTOR ENGINES," upon the
condition (amongst others) that I, the said Francis William
Crossley, my executors or administrators, by an instrument in writing,
under my, or their, or one of their hands and seals, should particularly $
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent,

page_text: . NOW KNOW YE, that I, the said Francis William Crossley, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Sheets of Drawings, and to the figures and letters
marked thereon, that is to say:―
This Invention relates to improvements in gas motor engines of the
kind described in the Specifications of Patents granted to C. D. Abel
on the 12th February 1866, No. 434, and on the 3rd August 1867,
No. 2245, being communications to him from E. Langen and N. A.
Otto; also in the Specification of a Patent granted to the said C. D.
Abel on the 18th February 1874, No. 605, being a communication from
G. W. Daimler.
In order that the nature of my improvements may be better under-
stood I will explain the operation of the engine described in the said
Specifications with my present improvements thereon, referring to the
accompanying Drawings, of which Fig. 1 represents a front view;
Fig. 2, a vertical section partly in side view; and Fig. 3, a plan of the
upper portion chiefly in section; Figs. 4, 5, and 6 representing to an
enlarged scale respectively a front view, vertical section, and plan of the
parts to which my Invention principally applies.
The engine described in the said Specifications operates in the
following manner :-A piston A is raised in a cylinder C a little distance,
drawing in through the port B governed by a slide B' a charge of com-
bustible gas and air at atmospheric pressure in suitable mixture for
ignition. A flame being thereupon drawn in ignites the gaseous charge,
which by its expansion propels the piston upwards. The cylinder C,
being kept cool by a water jacket D, the pressure of the products of.
combustion within the cylinder under the piston is rapidly reduced, and
the cylinder being open at top the piston is propelled downwards by the
superior pressure of the external atmosphere, the products of combustion
being finally expelled through the port B by the piston, as it approaches
the end of its down stroke. The piston rod is toothed as a rack, and
gears with a wheel A¹ mounted loosely on the engine shaft E, which is
provided with a heavy fly wheel, or with two fly wheels, as shewn in
Fig. 2. The wheel A' is connected with another wheel E¹ (fixed on the
shaft E) by a friction clutch in such manner that A' can turn freely in

page_text: the one direction when the piston is making its up stroke, but that
when it revolves in the other direction, as the piston is descending, the
wheel A¹ drives E₁ and the shaft E, the shaft thus receiving an impulse
at every descent of the piston, and the momentum of the fly wheel con-
tinuing its motion during the succeeding ascent of the piston. The
shaft E, or a shaft connected with it, is provided with cams or eccentrics
for moving the piston A through the portion of its up stroke to draw in
the gaseous charge, and also for moving the slide B¹, so as to admit the
gaseous mixture and the igniting flame to the cylinder, and to permit the
products of combustion to escape therefrom on the descent of the piston.
The general construction and arrangement of parts, and the operation
of the engine, as I have above set forth, are described in the Specifi-
cations above referred to; and it is to be understood that I make no
claim in respect thereof, the object of my present Invention being to
reduce the weight and cost of certain of the moving parts, particularly
those which have an intermittent motion, and also to apply a governor
to regulate the speed of such engines by arranging it so as to act
directly on the piston for the purpose of retarding or arresting its descent
in case of excessive speed, and thus by prolonging the interval between
one stroke and the next to diminish the amount of impulse given in
a certain time to the engine shaft.
For this purpose I mount by the side of the engine shaft E a counter-
shaft F, on which I fit a loose wheel G, gearing with a toothed wheel H
fixed on the shaft E, and I prefer to proportion the gearing of those
wheels so that G shall revolve more slowly than H. On the side of the
wheel G I fix a ratchet wheel J, and I make the countershaft F with
three light cranks K, L, and M. The pin O of the outer crank K is
connected by a rod to the slide B¹. A spring pawl N is mounted on the
crank L in such a position that it can engage with the teeth of the
ratchet wheel J. The crank M. has mounted on its pin a roller P, which
comes under a bracket Q projecting from the side of the piston rod. A
spring lever R, of the kind described in the Specification to the Patent
No. 2245 of 1867 above referred to, is mounted under the countershaft F.
The upright arm of R, when it is moved in obedience to the spring
engages with the tail of the pawl N, and also with the crank L; but
when a stud S on the piston rod on the descent of the piston bears
down the horizontal arm of R then the upright arm is disengaged from
Land N, as shewn in Fig. 5. This disengagement occurring when the

page_text: piston is close to the end of its down stroke, the pawl N being liberated
engages with one of the teeth of the ratchet wheel J, as the latter.
revolves. The countershaft F being thus caused to revolve also, its
crank K moves the slide B' for the admission of the gaseous charge to
the cylinder, and the roller P on the crank M pressing upwards the
bracket Q raises the piston so as to draw the charge into the cylinder.
As the piston ascends, the stud S rising with it permits the upright arm
of the lever R to move in obedience to the spring until it again catches
the tail of the pawl N, throwing the pawl out of gear with J after it has
made a complete revolution, and catches also the crank L stopping the
countershaft F until a succeeding descent of the piston effects a repetition
of the movement, as above described.
In applying a governor to regulate the speed of engines of the kind
described I employ apparatus of the following description :-I fix on
the side of the piston rod an elastic or spring bar K' sloping outwards
towards its upper end;. I provide the governor X, X, with a lever W,
which works a screw U in a bracket nut projecting from the piston rod
guide. When owing to excessive speed of the engine the governor
balls X, X, expand, the screw U is advanced towards the piston rod, so
as to bear against the bar K¹ as the piston is approaching the end of its
down stroke. The complete descent of the piston is thus retarded or
arrested until the speed of the engine becoming reduced the balls X, X,
collapsing unscrew U and relieve the bar K₁ of the pressure, thereby
permitting the piston to complete the down stroke.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I hereby declare that I make no
general claim to the construction of or mode of operating with gas motor
engines, such as are described in the Specifications above referred to;
but I claim as improvements in such engines,-
First. The method, substantially as herein described, of partially
raising the piston for drawing the gaseous charge into the cylinder with
a gradually increasing movement imparted by means of a revolving
crank acting directly on the piston rod without the intervention of levers
or other moving parts.
Second. The method of regulating the speed by arranging the

page_text: as herein described.
In witness whereof, I, he said Francis William Crossley, have
hereunto set my hand and seal, this Fourth day of March, in the
year of our Lord One thousand eight hundred and seventy-
five.
FRANCIS WILLIAM CROSSLEY. (L.S.)