IMPROVEMENTS IN GAS-MOTOR ENGINES, PARTS OF WHICHL IMPROVEMENTS ARE APPLICABLE TO STEAM-ENGINES OR OTHER ENGINES WORKED BY FLUID PRESSURE."
Year: 1881

page_text: LETTERS PATENT to Francis William Crossley and Henry Percy Holt, both
of Great Marlborough Street, Manchester, in the County of Lancaster, for an
Invention of "IMPROVEMENTS IN GAS-MOTOR ENGINES, PARTS OF WHICHL
IMPROVEMENTS ARE APPLICABLE TO STEAM-ENGINES OR OTHER ENGINES
WORKED BY FLUID PRESSURE."
PROVISIONAL SPECIFICATION left by the said Francis William Crossley
and Henry Percy Holt at tho Office of the Commissioners of Patents on the
14th December 1881.
FRANCIS WILLIAM CROSSLEY and HENRY PERCY HOLT both of Great
Marlborough Street Manchester in the County of Lancaster. "IMPROVEMENTS
IN GAS MOTOR ENGINES, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO
STEAM-ENGINES OR OTHER ENGINES WORKED BY FLUID PRESSURE."
In gas-motor engines of the kind known as the Otto engine, the piston after
making its instroke expelling products of combustion from the cylinder, makes an
outstroke drawing in a charge of air and of combustible mixture, which is com-
pressed by the succeeding instroke of the piston and being then ignited propels the
piston during its next outstroke. Our Invention relates to a modified construction
and arrangement of such gas-motor engines whereby we are enabled to effect
during one outstroke and instroke of the piston the combustion of the charge, the
discharge of products of combustion and the introduction and compression of a
fresh charge of air and combustible mixture, and to apparatus for regulating the
supply of combustible gas to such engines, this regulating apparatus being
applicable also to gas motor engines of other kinds, and with suitable modifications
to regulate the supply and cut off of steam in steam engines or of compressed air
or other elastic fluid in engines worked by such fluid.

page_text: We modify the Otto gas motor engine in the following manner. We provide an
exhausting pump worked by the engine which maintains a partial vacuum in a
vessel. We provide an outlet from the cylinder governed by valves which are
so arranged as to put it first in communication with the outer air and then with
the vacuum vessel, their movements being timed to those of the engine so as to
operate as follows. When the piston is approaching the end of the outstroke
during which it is propelled by the expansion of the ignited charge, the discharge
passage is opened and a portion of the products of combustion escape from the
cylinder to the outer air. This discharge is then closed and the passage to the
vacuum vessel is opened and at the same time the main slide or valve at the
farther end of the cylinder is opened to admit air and thereafter a mixture of air
and gas. Thus while the piston is moving slowly at and about the extreme of its
outstroke, a farther quantity of the products of combustion are drawn from the
cylinder into the vacuum vessel, the space which they occupied in the cylinder
being supplied by air and combustible mixture entering by the port of the usual
admission valve behind the products of combustion and following them up as they
move towards the outlet passage. The charge being thus admitted to the cylinder
the passage and port being closed by their respective valves or slides, the piston
makes its instroke compressing the contents of the cylinder, which are then ignited
and propel the piston during its next outstroke.
In admitting the charge to the cylinder either in the manner above described or
in the manner ordinarily adopted in the Otto engine, the latter portion of the
charge should consist of a combustible mixture of gas and air, and therefore when
a governor is employed to regulate the engine, it is applied to work a separate gas
valve in such a way that the last portion of the entering charge whether it be a
greater or less fraction of the total charge shall have a proper proportion of gas to
render it thoroughly combustible, so that the mixture occupying the inlet passage
may certainly ignite. The governor is therefore arranged so as to open the gas
valve sooner or later during the entrance of the charge to the cylinder, but not to
close it before the whole charge is admitted. On the other hand in steam or other
engines worked by the pressure of an elastic fluid, when a governor is employed to
work a cut off or expansion valve, it should do it in such a manner as to have the
valve open at the beginning of each stroke but to close it sooner or later in the
course of the stroke, thus determining the quantity of fluid that is admitted to
expand in the cylinder. The governing apparatus which we will now describe is
applicable to both these cases. We employ a centrifugal governor of any known
form driven by the engine, and to the lever of this governor we joint a rod which,
as the governor lever is caused to oscillate by variations of speed, reciprocates in a
path nearly tangential to the path of a cam on the engine shaft or on a counter-
shaft driven by the engine shaft. The rod has projecting from it towards the cam
a roller or a finger, on which the protuberance of the cam acts pressing the rod
aside, and this lateral movement of the rod is communicated to the supply valve
causing it to open and holding it open until the protuberance of the cam passes the
roller or finger, whereupon the valve is closed by a spring or equivalent load. As
the speed of the governor determines within a certain range the point in the
revolution of the cam at which the roller or finger on the tangential rod is presented
to it, the period of the opening of the valve in the case of a gas motor engine or of
its closing in the case of a steam or other fluid pressure engine can thus, within
the range of the apparatus, be regulated according to the speed of the engine. As
the frictional contact of the cam on the roller or finger of the tangential rod might
by tending to move the rod in the direction of its length interfere with the proper
action of the governor, we arrange the connection from the tangential rod to the
supply valve in the following manner. On the back of the tangential rod we form
a number of triangular notches and make the valve stem with a wedge-shaped end
or tooth presented towards these notches into one or other of which it becomes
engaged when the rod is pressed back by the cam, and thus the rod while it is

page_text: pressing and holding the valve open is prevented from being moved by the cam
in the direction of its length. In the case of a gas motor it is preferred to make
the notches at each end so much deeper than the others that when the valve stein
faces either of these the movement given by the cam to the rod is not sufficient to
open the valve. Thus when the engine and governor are stopped, or when the
speed exceeds a certain limit the gas valve is not opened at all. When the
apparatus is applied to a steam or other engine the depth of the notches may bo
varied when it is desired that the governor shall affect not only the time but also
the extent of opening the supply valve. Obviously the notches may be made on a
head attached to the valve stem, the tangential rod in that case having on its back
a tooth to engage with one or other of them.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis William Crossley and Henry Percy Holt in the Great Seal
Patent Office on the 13th June 1882.
FRANCIS WILLIAM CROSSLEY and HENRY PERCY HOLT both of Great
Marlborough Street. Manchester in the County of Lancaster. "IMPROVEMENTS
IN GAS MOTOR ENGINES, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO
STEAM ENGINES OR OTHER ENGINES WORKED BY FLUID PRESSURE."
In gas motor engines of the kind known as the Otto engine, the piston after
making its instroke expelling products of combustion from the cylinder, makes an
outstroke drawing in a charge of air and of combustible mixture which is compressed
by the succeeding instroke of the piston and being then ignited propels the piston
during its next outstroke. Our Invention relates to a modified construction and
arrangement of such gas motor engines whereby we are enabled to effect during
one outstroke and instroke of the piston the combustion of the charge, the discharge
of products of combustion and the introduction and compression of a fresh charge
of air and combustible mixture, and to apparatus for regulating the supply of
combustible gas to such engines, this regulating apparatus being applicable also to
gas motor engines of other kinds, and with suitable modifications to regulate the
supply and cut off of steam in steam engines or of compressed air or other elastic
fluid in engines worked by such fluid.
We modify the Otto gas motor engine in the following manner. We provide an
exhausting pump worked by the engine which maintains a partial vacuum in a
vessel. We provide an outlet from the cylinder governed by valves which are so
arranged as to put it first in communication with the outer air and then with the
vacuum vessel, their movements being timed to those of the engine so as to operate
as follows.
When the piston is approaching the end of the outstroke during which
it is propelled by the expansion of the ignited charge, the discharge passage is
opened and a portion of the products of combustion escape from the cylinder to
the outer air. This discharge is then closed and the passage to the vacuum vessel
is opened and at the same time the main slide or valve at the farther end of the
cylinder is opened to admit air and thereafter a mixture of air and gas. Thus
while the piston is moving slowly at and about the extreme of its outstroke a
farther quantity of the products of combustion are drawn from the cylinder into
the vacuum vessel, the space which they occupied in the cylinder being supplied by
air and combustible mixture entering by the port of the usual admission valve
behind the products of combustion and following them up as they move towards
the outlet passage. The charge being thus admitted to the cylinder and the passage
and port being closed by their respective valves or slides, the piston makes its
instroke compressing the contents of the cylinder, which are then ignited and
propel the piston during its next outstroke.
In admitting the charge to the cylinder either in the manner above described or
in the manner ordinarily adopted in the Otto engine, the latter portion of the charge
should consist of a combustible mixture of gas and air, and therefore when a
governor is employed to regulate the engine, it is applied to work a separate gas
valve in such a way that the last portion of the entering charge whether it be a
greater or less fraction of the total charge shall have a proper proportion of gas to
render it thoroughly combustible, so that the mixture occupying the inlet passage
may certainly ignite. The governor is therefore arranged, so as to open the gas
valve sooner or later during the entrance of the charge to the cylinder, but not to
close it before the whole charge is admitted. On the other hand in steam or other
engines worked by the pressure of an elastic fluid, when a governor is employed to
work a cut off or expansion valve, it should do it in such a manner as to have the
valve open at the beginning of each stroke but to close it sooner or later in the
course of the stroke, thus determining the quantity of fluid that is admitted to
expand in the cylinder. The governing apparatus which we will now describe is
applicable to both these cases. We employ a centrifugal governor of any known

page_text: form driven by the engine, and to the lever of this governor we joint a rod which,
as the governor lever is caused to oscillate by variations of speed, reciprocates in a
path nearly tangential to the path of a cam on the engine shaft or on a countershaft
driven by the engine shaft. The rod has projecting from it towards the cam a
roller or a finger, on which the protuberance of the cam acts pressing the rod aside,
and this lateral movement of the rod is communicated to the supply valve causing
it to open and holding it open until the protuberance of the cam passes the roller
or finger, whereupon the valve is closed by a spring or equivalent load. As the
speed of the governor determines within a certain range the point in the revolution
of the cam at which the roller or finger on the tangential rod is presented to it, the
period of the opening of the valve in the case of a gas motor engine or of its closing
in the case of a steam or other fluid pressure engine can thus, within the range of
the apparatus, be regulated according to the speed of the engine. As the frictional
contact of the cam on the roller or finger of the tangential rod might by tending to
move the rod in the direction of its length interfere with the proper action of the
governor, we arrange the connection from the tangential rod to the supply valve in
the following manner. On the back of the tangential rod we form a number of
triangular notches and make the valve stem with a wedge shaped end or tooth
presented towards these notches into one or other of which it becomes engaged
when the rod is pressed back by the cam, and thus the rod while it is pressing and
holding the valve open is prevented from being moved by the cam in the direction
of its length. In the case of a gas motor it is preferred to make the notches at
cach end so much deeper than the others that when the valve stem faces either of
these the movement given by the cam to the rod is not sufficient to open the valve.
Thus when the engine and governor are stopped, or when the speed exceeds a
certain limit the gas valve is not opened at all. When the apparatus is applied to
a steam or other engine the depth of the notches may be varied when it is desired
that the governor shall affect not only the time but also the extent of opening the
supply valve. Obviously the notches may be made on a head attached to the
valve stem, the tangential rod in that case having on its back a tooth to engage
with one or other of them.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a longitudinal section, Fig. 2 a plan partly in section and Fig. 3 a
transverse section on X X shewing so much of a gas motor engine as is necessary
to illustrate the application thereto of that part of our Invention which relates to
means of discharging the exhaust and introducing a fresh charge of combustible
mixture; Fig. 4 is a diagram illustrating the manner in which the movements of
the parts are timed to one another. A is the working cylinder surrounded by its
water casing A' and fitted with its piston A which is linked by the connecting
rod A³ to the crank C, the whole being mounted on the foundation frame or base B,
which may constitute a water casing as shewn. It is to be understood that the
cylinder A is provided with the usual ports and slide for admission and ignition
of the gaseous mixturo once in every revolution of the crank, but these, forming
no part of our present Invention, are omitted in the Drawings. It is also to be
understood that the usual outlet and discharge valve at the rear end of the cylinder
and apparatus for working the valve are dispensed with, as the arrangement which
we are about to describe is substituted for these. D is the chamber in which at
the required part of the stroke of the engine a partial vacuum is produced by the
outstroke of the piston D2 in the cylinder D', this cylinder being placed at an
angle so that its piston D2, which is linked by the connecting rod D³ to the crank C,
is moving rapidly outwards when the working piston A2 is approaching the end of
its outstroke. The chamber D communicates by a passage D' with the casing of
a slide E fitted at the side of the cylinder, and also through a check valve D* with
the exhaust pipe F to which also there is another communication by a branch
pipe F from the casing of the slide E. The slide E is pressed towards the left by
a spring E' and moved towards the right by a cam E' acting on a roller on a

page_text: lever E' which is pivotted to the framing at E3 and is linked to the slide E by the
connecting rod E³. Through the slide E there are two curved passages c¹ and e².
In one position of the slide as shewn in Figs. 2 and 4 the passage e¹ forms a
communication between the branch F¹ and a port A leading from the cylinder A
in such a position as to be uncovered by the piston A° as it approaches the end of
its outstroke. In another position of the slide E, its passage e' puts the port A' in
communication with the passage D'. The operation of these parts is as follows:-
The piston A is propelled outwards by the pressure of the gaseous mixture ignited
in the cylinder A. When the piston A³ approaches the end of its outstroke it
uncovers the port A and thereupon a portion of the products of combustion
escape from the cylinder A through A4 c¹ F' to the exhaust pipe F. At this time
as the crauk moves from C to C₁ Fig. 4 the piston D³ moves rapidly outwards
creating a partial vacuum in the chamber D. When the crank is at C¹ (Fig. 4)
the cam E permits the slide E to make its stroke to the left, thereby putting the
port A in communication through e² and D with the chamber D, and thereupon
the contents of the cylinder A tend to flow rapidly into the partially vacuous
chamber D. At this period the supply slide of the cylinder A is open to admit to
the cylinder the charge of air and gas, and this charge flowing into the cylinder
at its rear end takes the place of the products of combustion exhausted near the
front end of the cylinder into the chamber D. The piston A² now returning
covers the port A when-the-crank.is_about_the point C³ Fig. 4 and by its con-
tinued instroke compresses the charge that had been drawn into the-cylinder,-and-
this charge being ignited, the piston A² is again propelled outwards. Meanwhile
the pump piston D2 has made its instroke expelling a portion of the contents of
the chamber D past the check valve D5, and has made a portion of its outstroke
again creating a partial vacuum in D, and the cycle of operation is repeated.
In some gas motor engines a pump is employed for forcing the charge into the
cylinder generally under considerable pressure. In such cases the regulation of the
engine presents great difficulty because a governor when it is applied to proportion
the charge must do so when the charge is being admitted to the pump, and as the
charge so proportioned does not act in the cylinder until the piston makes its next
working stroke, a whole revolution of the engine shaft necessarily intervenes
between the action of the governor in altering the charge and the result of this
alteration in varying the engine power. Moreover as a pump when it is used for
forcing in the charge contains combustible mixture, there is always a risk of back
explosion into the pump involving not only the waste of a charge but also a serious
check to the engine and danger to its working parts. By adopting the method
of operating which we have described these difficulties attending the use of a
pump in gas motor engines are entirely avoided. The first portion of the exhaust
being allowed to escape, the duty of the pump is confined to removing only the
residue of the products of combustion and replacing them by the fresh charge at
atmospheric pressure. The charge being proportioned by the governor as it is
drawn into the working cylinder, the regulating action of the governor immediately
affects the engine, and as the pump receives no combustible mixture there is no
risk of explosion in it.
Fig. 5 is a side view, Fig. 6 a front view of apparatus according to our Invention
for regulating the supply of gas to gas motor engines, Fig. 7 is a plan of the valve
rod and Fig. 8 a plan of the governor lever. The governor G may be of the kind
shewn or it may be any other known form of centrifugal governor, having a collar
G¹ which rises as the balls are expanded by centrifugal force. It may be driven
by bevil gear as shewn from the shaft which carries the cam H or it may be other-
wise driven. The lever L working on fulcrum L' and counterbalanced by an
adjustable weight L² has a pin L³ projecting under the collar G¹ of the governor
and has jointed to its end the rod K which descends as the governor balls expand
raising the collar G' and allowing the pin L³ to rise. The lower end of the rod K.
is at K' curved so as to present a rubbing face to the cam H, or it might have a
roller mounted on it to bear against the cam. At an intermediate part of the rod K

page_text: is fixed a piece K³ which may be termed a die, having in its face a number of
notches. Mis the rod of the gas supply valve which terminates in a plate M¹
presenting an edge towards the die K. The gas valve is kept closed by a spring
pressing its rod M towards K, and it is opened only when the projection of the
cain H pushing K' towards the left causes the die K³ to push the plate Al' and the
valve rod M towards the left thereby opening the gas valve until the projection of
H passes K'. The cam revolving in the direction of the arrow, its projecting part
acts on K¹ at an earlier or later part of its revolution according as K' is raised or
lowered by the action of the governor. Thus when the engine is moving too
slowly the governor balls falling inwards lower the collar G₁ and the pin L³, the
rod K being thus raised its end K'is sooner acted upon by the projection of the
cam, and the gas valve is sooner opened admitting gas at an earlier part of the
revolution of the cam shaft. When on the other hand the engine is moving too
rapidly, the governor balls expand, the collar G₁ and pin L³ rise, the rod K
descends and its end K¹ is acted on later by the projection of the cam, so that
the gas is admitted at a later period of the revolution. It is obvious that if the
rod M were connected to a shut off valve in a steam engine or other engine worked
by fluid pressure and if the cam H revolved in the opposite direction, the valve
would be closed cutting off the steam supply at an earlier or later part of the
revolution as determined by the governor lowering or raising the rod K. For a
double acting engine the cam H would necessarily have two projecting parts unless
it revolved at twice the speed of the engine shaft. The notches in the die Kº
when the edge of M' is engaged in any one of them prevent the rod K from being
moved vertically by the friction of the cam on K'. The pin L³ may have freedom
under the collar G as shewn and may be kept up by a catch N when the governor
balls collapse.
Having thus described the nature of our Invention and in what manner the
same is to be performed, we hereby declare that we make no general claim to the
charging of the cylinder of a gas motor engine by the suction of a pump, but we
claim
First. In a gas motor engine, the herein described method of discharging products
of combustion from the cylinder and drawing in compressing and firing a fresh
combustible charge during one revolution of the crank shaft.
Second. In combination with the cylinder of a gas motor engine, the slide E
with its casing, passages and working can and connections, and the chamber D and
pump cylinder D with its valve D5, piston D² and working connections, the whole
arranged and operating substantially as and for the purpose herein described with
reference to Figs. 1, 2, 3 and 4.
Third. The herein described method of varying by means of a centrifugal
governor the period of opening or closing the supply valve of a gas motor, steam or
other fluid pressure engine, the governor being for this purpose arranged to move
tangentially to the path of a cam a projection or roller on a rod which acts on the
valve, so that the projecting part of the cam actuates the rod and valve at an
earlier or later period of its revolution.
Fourth. In a gas motor, steam or other fluid pressure engine the combination of
a governor lever L a rod K with its projecting end K' or roller and its notched die
K2, cam H, valve rod M and its edged plate M¹ substantially as and for the
purposes herein set forth with reference to Figs. 5, 6, 7 and 8.
In witness whereof I the said Francis William Crossley have hereunto set
my hand and seal this Tenth day of June in year of our Lord One
thousand eight hundred and eighty two.
TO YOU
T
An Add 51
TTTI
CROSSLEY. (1.S.)