IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1875

page_text: LETTERS PATENT to Francis William Crossley, and William John
Crossley, both of Great Marlborough Street, Manchester, in the
County of Lancaster, for the Invention of "IMPROVEMENTS IN GAS
MOTOR ENGINES."
PROVISIONAL SPECIFICATION left by the said Francis William
Crossley and William John Crossley at the Office of the Com-
missioners of Patents, with their Petition, on the 15th September
1875.
We, FRANCIS WILLIAM CROSSLEY and WILLIAM JOHN CROSSLEY,
both of Great Marlborough Street, Manchester, in the County of
Lancaster, do hereby declare the nature of the said Invention for
“IMPROVEMENTS IN GAS MOTOR ENGINES," to be as follows :—
Our Invention relates to improvements in gas motor engines of the
kind described in the Specifications of Patents granted to C. D. Abel on

page_text: No. 2245, being communications to him from E. Langen, and N. A.
Otto; also in the Specification of a Patent granted to C. D. Abel, on
the 18th February, 1874, No. 605, being a communication from G. W.
Daimler, and in the Specification of a Patent granted to me, the said
F. W. Crossley, on the 19th September, 1874, No. 3205.
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
propelled 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 products of combustion to escape therefrom.
"
***The object of our present improvements is to provide an efficient-air
spring or cushion for checking the piston and forcing it back again at.
the-end-of-its-stroke when-it has been impelled by a large charge of the
combustible gases, to simplify the means of raising the piston for the
introduction of the combustible. charge, and to render the action of the
-governor-more_direct_and_effective; for this purpose we provide the
cylinder with a cover, having through it a hole larger than the piston
rack rod which passes through it; but fitting a boss projecting upwards
'from the piston. During part of the upward stroke of the piston the
air above the piston escapes freely by this hole, but as the piston.

page_text: approaches the end of its stroke, the boss upon it entering and filling
the hole prevents the farther escape of air from the cylinder, and the
air thus confined therein acts as an elastic buffer or cushion to check
the piston before it can quite reach the cylinder cover and to force it
back, thus adding to the effective pressure of the down stroke.
According to a modified form of this arrangement the piston instead
of having a boss projecting from its centre may have an annular rib
projecting upwards from its circumference or from some part of its
upper face, the cylinder cover being made with a corresponding annular
hollow, into which the said rib enters as the piston approaches the end
of its stroke. By the use of such a cushion as we have described, con-
siderable variations may be made in the charge of combustible matter.
so as both to allow for differences of temperature in the cylinder without
subjecting the engine to shocks when the charge is large, and also tọ
render it possible to obtain with safety much more work from a given
engine than before.
In order to raise the piston for drawing in the charge of combustible
gas we mount a roller on the strap of the eccentric, which works the
valve, and provide a stop on the side of the toothed wheel friction box
which gears with the rack piston rod, this stop being so placed that
when the piston is at the bottom of the cylinder the roller by the
movement of the eccentric is brought to bear upon the stop, and
thereby to partly turn the toothed wheel and so to raise the piston
the required distance for drawing in the charge. The wheel being made
of such size that the full stroke of the piston causes it to make less than
a whole revolution, the stop upon it does not at the up stroke of the
piston come so far round as to bear against the roller on the eccentric
strap.
We apply the governor to these engines by mounting the balls
directly on the working shaft, with a spring urging them to collapse.
When they are caused to expand by excess of velocity, a sleeve slid by
them along the shaft in opposition to the spring moves a bell-crank
lover so as to prevent the pawl on the eccentric which works the valve
from engaging with its driver, and as the eccentric is thus made to
remain at rest the valve is not moved to admit a charge into the
cylinder, nor is the piston raised as above described to draw in the
charge, until the speed having become moderated the governer balls

page_text: collapsing withdraw the bell crank and permit the eccentric to become
engaged, and the valve and piston to be moved for the supply of a
charge to the cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent;
filed by the said Francis William Crossley and William John
Crossley in the Great Seal Patent Office on the 13th March 1876.
--
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, FRANCIS
WILLIAM CROSSLEY and WILLIAM JOHN CROSSLEY, both of Great
Marlborough Street, Manchester, in the County of Lancaster, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of September, in the
year of our Lord One thousand oight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Francis William Crossley
and William John Crossley, Her special license that wc, the said
Francis William Crossley and William John Crossley, our executors,
administrators, and assigns, or such others as we, the said Francis
William Crossley and William John Crossley, our executors, admini-
strators, 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 lawfully might make, use, exercise, and vend,
within the United Kingdom 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 we, the said
Francis-William-Crossley-and-William John Crossley, our executors.
or administrators, by an instrument in writing under our or their
hands and seals, or under the hand and seal of one of us or them,
_should—particularly describe-and-ascertain the nature of the¨said
Invention, and in what manner the same was to be performed, änd
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
-

page_text: NOW KNOW YE, that I, the said Francis William Crossley, on
behalf of myself and the said William John 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 accom-
panying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :-
Our 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 C. D. Abel, on
the 18th February, 1874, No. 605, being a communication from G. W.
Daimler, and in the Specification of a Patent granted to me the said
F. W. Crossley on the 19th September, 1874, No. 3205.
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 propelled 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 products of combustion to escape therefrom.

page_text: The object of our present improvements is to provide an efficient air
spring or cushion for checking the piston and forcing it back again at
the end of its stroke when it has been impelled by a large charge of the
combustible gases, to simplify the means of raising the piston for the
introduction of the combustible charge, and to render the action of the
governor more direct and effective.
The accompanying Drawings represent.so much of a gas motor engine
as is necessary to explain the manner in which we apply our improve-
ments, Fig. 1, -being-a-front-view; Fig. 2, a side view partly in section;
Fig. 3, a plan; and Fig. 4, a part section, shewing a modified form of
the piston and cylinder cover.
In order to provide an air spring for the piston we fit the cylinder
with a cover A, having through it a hole larger than the piston rack
rod G which passes through it, but fitting a boss B projecting upwards
from the piston., During a part of the upward stroke of the piston the
air above the piston escapes freely by the hole in A, but as the piston
approaches the end of its stroke, the boss B entering and filling the
hole in A prevents the farther escape of air from the cylinder, and the
air thus confined therein acts as an elastic buffer or cushion to check
the piston before it can quite reach the cylinder cover and to force it
back, thus adding to the effective pressure of the down stroke.
According to a modified form of this arrangement, shewn in Fig. 4,
the piston instead of having a boss projecting from its centre may have
an annular rib P projecting upwards from its circumference or from
somo part of its upper face, the cylinder cover being made with a
corresponding annular hollow Q, into which the said rib enters as tho
piston approaches the end of its stroke. By the use of such a cushion
as we have described, considerable variations may be made in the charge
of.combustible matter,-so-as-both to allow for differences of temperature.
-in-the-cylinder without subjecting the engine to shocks when the charge
is large, and also to render it possible to obtain with safety an increased
amount of work-from-an_engine-of-given size.
In order to raise the piston for drawing in the charge of combustible
gas, we mount a roller C on the strap of the eccentric D, which works
the valve, and provide a stop E on the side of the toothed wheel

page_text: I
so placed that when the piston is at the bottom of the cylinder the
roller by the movement of the eccentric is brought to bear upon the
stop, and thereby to partly turn the toothed wheel F, and so to raise
the piston the required distance for drawing in the charge. The wheel
being made of such size that the full stroke of the piston causes it to
make less than a whole revolution, the stop upon it does not at the up
stroke of the piston come so far round as to bear against the roller on
the eccentric strap.
•
.
We apply the governor to these engines by mounting the balls H, H,
directly on the working shaft J, with a spring K urging them to
collapse. When they are caused to expand by excess of velocity a
sleeve Ļ slid by them along the shaft in opposition to the spring K
moves a bell-crank lever M, M, so as to prevent the pawl N on the
eccentric which works the valve from engaging with its driver O, O,
and as the eccentric is thus made to remain at rest, the valve is not
moved to admit a charge into the cylinder, nor is the piston raised as
above described to draw in the charge until the speed having become
moderated, the governor balls collapsing withdraw the arm of the bell
crank M, and permit the eccentric to become engaged and the valve
and piston to be moved for the supply of a charge to the cylinder. The
stop R is actuated by a pin S upon the rack G, as described in the
Specification to the Patent No. 3205, dated the 19th September, 1874,
above referred to.
Having thus described the nature of our Invention and in what
manner the same is to be performed, we claim,—
First. In gas motor engines, wherein the piston rod does not work
through a stuffing box, providing an air spring for the piston at the end
of its up stroke by means of a projecting boss or rib on the piston fitting
a hole or cavity in the cylinder cover, substantially as herein described.
Second. In gas motor engines of the kind herein referred to, in which
the valve eccentric is mounted on the main shaft, effecting the partial
up stroke of the piston to draw in the combustible charge by means of a
roller or projection on the valve eccentric acting on a stop on the
toothed wheel which gears with the piston rod, substantially as herein
described.
Third. In gas motor engines of the kind herein referred to, mounting
the governor directly on the main shaft with a spring sleeve arranged to

page_text: act by a lever on the pawl that engages the valve eccentric, substantially
in the manner and for the purposes herein set forth.
In witness whereof, I, the said Francis William Crossley have
hereunto set my hand and seal, this Eleventh day of March, in
the year of our Lord One thousand eight hundred and seventy-
six.
FRANCIS WILLIAM CROSSLEY, (L.S.)