IMPROVEMENTS IN GAS ENGINES
Year: 1881

page_text: LETTERS PATENT to Samuel Ford, of South Lambeth, in the County of
Surrey, Engineer, for an Invention of "IMPROVEMENTS IN GAS ENGINES."
PROVISIONAL SPECIFICATION left by the said Samuel Ford at the Office of
the Commissioners of Patents on the 24th May 1881.
SAMUEL FORD, of South Lambeth, in the County of Surrey, Engineer.
"IMPROVEMENTS IN GAS ENGINES."
The Invention relates to improvements specially applicable to rotary gas
engines, but certain of the said improvements are more or less applicable to
ordinary reciprocating gas engines.
The said improvements are of the following character:-
Firstly. In some cases after the explosion of the mixture of gases, or of gas and
air, has taken place in the cylinder of a gas engine, and the piston has been moved
forward by such explosion, the pressure behind the piston falls below the pressure
of the atmosphere some short time before the piston has completed its stroke, and
on the opening of the exhaust port to allow of the escape of the products of the
explosion atmospheric air enters into the partial vacuum thus formed, and has to
be ejected at the cost of more or less of the power generated by the next
explosion.
In order to obviate this inconvenience I employ a self-acting valve in the
exhaust pipe, which remains closed by the external pressure of the atmosphere,
while the pressure of the products of the explosion remain below that pressure
after the exhaust port has been opened, but opens as soon as their pressure exceeds
that of the atmosphere, allowing the said products to be ejected from the cylinder
in the ordinary way. By this means the loss of effect arising from the aforesaid
reduction of pressure of the products of explosion before the completion of the
effort of the exposive action is compensated for by a corresponding reduction of
back pressure at the beginning of the exhaust.
Secondly. For the purpose of actuating the supply gas valve I employ a separate
piston and cylinder distinct from the working piston or pistons and cylinder, such
piston being actuated by the partial vacuum in the working cylinder of the engine

page_text: during the indraft of gas or of gas and air, whereby the said valve is opened
when the engine is running, but is shut when the engine comes to rest by the said
piston and valve falling when the aforesaid vacuum in the working cylinder
ceases.
Thirdly. In connection with rotary gas engines I employ rotating or partially
rotating valves adapted with suitable ports and passages for governing the admission
of gas and air to the working cylinder, and for communicating the flame to the
explosive mixture in the said cylinder.
Fourthly. In certain kinds of rotary gas engines I admit a small quantity of
water through the abutment into the space behind the piston, such water being
received from the cylinder jacket into a groove or channel in the cylinder liner or
abutment conveying it into the aforesaid space behind the piston, where it becomes
partly converted into steam by the explosion, and partly serves as a lubricant
during the next passage of the piston.
Fifthly. In connection with the rotating or partially rotating valve mentioned
above under the third head I employ a check valve for the purpose of preventing
the explosion from driving back the gas in the pipe or passage through which the
exploding flame is supplied.
Sixthly. I make the check valve mentioned above under the fifth head of ebonite,
as being a material specially adapted for that purpose, on account of its lightness
combined with hardness.
Seventhly. I sometimes compress the mixture or charge of gases, or of gas and
air, before exploding them by means of a cylinder separate and distinct from the
working cylinder, compressing the charge to the required degree in the said separate
cylinder, and then delivering the said compressed charge to the working cylinder,
wherein it is exploded. The two cylinders may be disposed end to end on the
same shaft, and connected together by suitable pipes or passages; or a single
cylinder may be used with a diaphragm in the middle or at any suitable part of
the length thereof, the pistons being in either case so placed on the shaft with
relation to each other as to perform their respective functions of compression and
production of motion in the best manner.
Eightly. I combine the various improvements described under the seven heads
herein before enumerated with the general arrangement and construction of gas
engine described and illustrated in the Specification of a Patent granted to me
bearing date the 6th day of February A.D. 1874, and numbered 486.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Samuel Ford in the Great Seal Patent Office on the 24th November
1881.
"
SAMUEL FORD, of South Lambeth, in the County of Surrey, Engineer.
IMPROVEMENTS IN GAS ENGINES."
The Invention relates to improvements specially applicable to rotary gas engines,
but certain of the said improvements are more or less applicable to ordinary
reciprocating gas engines.
The Drawings hereto annexed represent a rotary gas engine with the said
improvements applied thereto. Figure 1 is a side elevation, Figure 2 a front
elevation, Figure 3 a transverse section on line 1-1 of Figure 2; Figure 4, a
horizontal section through the centre of the working cylinder taken at line 2-2,
Figures 1 and 2; Figure 5, a vertical section through the working cylinder, taken
on line 3-3 of Figure 1; Figure 6, a vertical section through valve of engine
on line 4 of Figure 3; Figures 7 and are horizontal sections of same on
lines 5-5 and 6-6 of Figure 6; and Figure 9 shows detail of parts for operating
the valve.
In these Drawings similar letters refer to like parts in all the Figures.
A represents the working cylinder of the engine; B, the water jacket sur-
rounding the said cylinder; C, the piston block revolving therein; D, D, the
" leaves " or slides constituting the working pistons; E, the abutment; F, the
valve for admitting gas and air to the cylinder, and for introducing the exploding
flame to the mixture; G, the exhaust pipe; H, the fly wheel; and I, the main
shaft.
The said improvements are of the following character:-
Firstly. In some cases, after the explosion of the mixture of gases, or of gas and
air, has taken place in the cylinder of a gas engine, and the piston has been moved
forward by such explosion, the pressure behind the piston falls below the pressure
of the atmosphere some short time before the piston has completed its stroke, and
on the opening of the exhaust port to allow of the escape of the products of the
explosion atmospheric air enters into the partial vacuum thus formed, and has to
be ejected at the cost of more or less of the power generated by the next
explosion.
In order to obviate this inconvenience I employ a self-acting valve J in the
exhaust pipe G, which valve remains closed by the external pressure of the
atmosphere, while the pressure of the products of the explosion remain below that
pressure after the exhaust port has opened, but opens as soon as their pressure
exceeds that of the atmosphere, allowing the said products to be ejected from the
cylinder in the ordinary way. By this means the loss of effect arrising from the
aforesaid reduction of pressure of the products of explosion before the completion
of the effort of the explosive action is compensated for by a corresponding reduction
of back pressure at the beginning of the exhaust.
Secondly. For the purpose of actuating the supply gas valve K, I employ a
separate piston L and cylinder M, distinct from the working piston or pistons and
cylinder, such piston L being actuated by the partial vacuum in the working
cylinder A of the engine during the indraft of gas, or of gas and air, whereby the
said valve is opened when the engine is working, but is shut when the engine
comes to rest by the said piston L and valve K falling by their own weight, or by
the action of a spring or springs, when the aforesaid vacuum in the working
cylinder ceases.

page_text: The upper end of the cylinder M above the piston L is connected by a pipe N
with a check valve-box O fixed on one of the cylinder covers, and communicating
with the part of the space in the working cylinder A, which is behind the piston D,
while the latter is drawing in a charge of gas and air. This valve-box O is fitted
with a check valve opening inwards, so as to be closed by the pressure generated
at the explosion. The piston L is by preference made heavy enough to fall by its
own weight when not drawn up by the partial vacuum in the working cylinder,
and is prolonged upwards into a stem P, which acts upon and lifts the main gas
valve K as far as the screwed spindle Qwill allow. This latter may be adjusted
so as to admit of any required lift of the said valve K, or to close it down, and to
hold it closed when it is desired to shut off the supply of gas, and to stop the
engine entirely.
Thirdly. In connection with rotary gas engines I employ rotating or partially
rotating valves of special construction adapted with suitable ports and passages for
governing the admission of gas and air to the working cylinder, and for
communicating the flame to the explosive mixture in the said cylinder.
In the Drawings, F represents an example of such a valve arranged to operate
by partial rotation or oscillation round its centre, being so moved at the proper
times by cams, levers, and toothed sectors, as will be hereafter described. The
valve F is by preference made as a tapered plug, fitting into and rotating in the
box or shell R, which communicates with the interior of the working cylinder A
by the inlet passage or port S. T is a recess or channel formed in the plug F, and
extending round its circumference as far as the inlet passage U leading from the
main gas valve K; V is a passage leading from the air inlet pipe V¹. This passage V
is also in communication with the recess or channel T. It will now be understood
that when the plug F is in the position shewn in Figures 3 and 7; the air inlet V
and the gas inlet U are both in communication with the passage S, so as to allow
the pistons D to draw in a charge of air and gas, which are mixed together as they
pass through the recess or channel T.
W is a passage for conducting the gas for supplying the igniting burner into the
plug F. X is a recess or channel in the said plug, which communicates by the
passage Y with the central chamber Z connected in its turn with the passage a.
The chamber Z and the passage a constitute the igniting burner. b is the
permanent gas burner for lighting the igniting gas flame as the passage a passes
the said permanent burner b. It will now be understood that the gas for the
igniting flame enters by the passage W, passes by the channel or groove X and
passage Y to the central chamber Z, thence to the passage a, where it is ignited as
the latter passes the permanent gas flame b, being conducted by the further
movement of the latter to the inlet passage S, where it ignites the explosive charge
in the cylinder.
The weight of the plug F is supported by the screwed pivot c, which is adjustable
vertically in the cross bar d by the lock nuts e. It is operated from the main shaft
of the engine in the following way :- (see Figure 9) is a frame adapted to slide
to and fro on guides g cast on the cylinder cover, and carrying two friction rollers h
and i. Two cams j, k, fixed on the shaft I are adapted to act on these friction
rollers in such manner that one cam pushes the frame fin one direction, and the
other cam in the opposite direction, the two cams being so shaped in relation to
each other that each cam maintains the friction roller of the other against its
corresponding cam, whereby undue play between the rollers and the cams is
avoided. The cams are shaped so as to impart two to and fro movements to the
frame for each revolution of the main shaft. The frame fis connected by the
link with the arm or lever m keyed on the vertical axis n, which is free to turn
in the bearing o secured to the jacket B of the cylinder A. On the upper end of
the axis n is keyed a toothed sector p, which gears with another toothed sector q
fixed on the upper end of the valve plug F. By this means the said plug F is
caused to partially rotate or oscillate each time the frame f is moved to and fro, so
as to bring the various passages or ports in the plug to coincide with the ports or

page_text: passages in the shell R at the proper times, for effecting the admission of the
charge of gas and air to the cylinder, and the subsequent ignition or explosion of
the same.
Fourthly. In certain kinds of rotary gas engines, such as, for example, that
illustrated in the Drawings hereto annexed, for which Letters Patent were granted
to me bearing date the Sixth day of February A.D. 1874, and numbered 486, I
admit a small quantity of water through the abutment E into the space behind the
piston D, such water being received from the cylinder jacket B into a groove or
channel r in the cylinder liner or abutment E through the hole 8, and is conveyed
into the aforesaid space behind the piston D by the piston drum C as the latter
revolves. This water becomes partly converted into steam by the explosion, and
partly serves as a lubricant during the next passage of the piston. t is a screw
valve for regulating the supply of water from the jacket to the said hole 8 and
groove or channel r; the case or body of this valve may be screwed into the
water jacket B, and the seating for the screwed spindle t into the cylinder A, as
shewn in the Drawing, Figure 3.
By screwing the spindle valve t nearer to or further from its seat the supply of
water to the groover may be regulated at pleasure. Any other suitable arrange-
ment for regulating the supply of water may be employed if preferred.
Fifthly. In connection with the rotating or partially rotating valve described
above under the third head I employ a check valve, similar to that described in the
Specification of the aforesaid Patent No. 486, for the purpose of preventing the
explosion in the cylinder from driving back the gas in the pipe or passage x through
which the igniting or exploding flame is supplied.
This check valve w is contained in a valve box y secured to the shell R of the
valve F (see Figure 6), and communicating by the passage z with the passage W
leading to the igniting burner. The lift of the valve w is regulated by the
adjusting screw 1, which passes through the plug 2, forming the top of the valve
box y.
3 is the spiral spring which keeps the valve w raised from its seat when
the explosive force is not acting in the cylinder. 4 is a perforated screw plug,
which may be screwed up or down in the lower part of the valve box y so as to
increase or decrease the tension of the spring 3 as may be required. The hole
through the screw plug 4 is to allow of the passage of the gas from the pipe x.
When the explosion of a charge is not taking place in the cylinder A. the valve w
is kept open by the spring 3, and gas passes to the igniting burner; but when an
explosion takes place in the cylinder, the pressure acts on the upper side of the
valve w and closes it, preventing the transmission of the said pressure into the gas
pipex. As soon as the pressure is removed from the valve w, the spring 3 again
opens it to allow of the passage of the gas as before.
Figure 10 shows another arrangement which may be employed instead of the
valve w.
In this case, instead of a valve being closed over the gas inlet by the
explosion, the recess or channel X in the plug valve F is arranged, as shown in
dotted lines in Figure 8, in such manner that the communication between the
igniting burner a Z and the gas supply pipe x is cut off by the edges of the recess
or channel X and of the passage W just before the igniting burner a comes opposite
to the passage S, when the partial vacuum produced by the motion of the piston D
draws the flame from the igniting burner a and ignites the charge.
When the piston D moves past the gas and air inlet passage S preparatory to
drawing in another charge of gas and air, it produces a partial vacuum behind it,
which extends to the igniting burner a Z and the recess or channel X in the plug F,
The consequence of this is that as soon as the said recess or channel X begins to
open to the passage W, and while the igniting burner a is passing the interval
between the passage S and the opening opposite the permanent burner b, the said
partial vacuum in the burner a Z causes the valve 5 to open for an instant,
admitting air through the openings 6, 6, which air mixes with the gas entering the
igniting burner, and assists in supporting its combustion therein while the said
burner is being moved round to coincide with the passage S.

page_text: Sixthly. I make the check valve w, mentioned above under the fifth head, of
ebonite, as being a material specially adapted for that purpose on account of its
lightness combined with hardness.
Seventhly. I sometimes compress the mixture or charge of gases or of gas and air
before exploding them by means of a cylinder and piston or pistons separate and
distinct from the working cylinder and piston or pistons, compressing the charge to
the required degree in the said separate cylinder, and then delivering the said
compressed charge to the working cylinder, wherein it is exploded, as is well
understood in connection with several known arrangements of gas engines. When
employing rotary gas engines the said compression may be effected in a separate
cylinder containing a reciprocating piston set in motion by a crank, an eccentric, a
or other suitable device, driven by the main shaft of the engine, but I prefer
to employ for the said compression a rotary pump, the cylinder of which is placed
in line with the cylinder of the engine and on the same driving shaft, the two
cylinders being connected together by suitable pipes or passages; or, if preferred, a
single cylinder may be used, with a diaphragm in the middle or at any suitable
part of the length thereof, the pistons being in either case so placed on the shaft
with relation to each other as to perform their respective functions of compression
and production of motion in the best manner.
cam,
This latter arrangement is illustrated in sectional plan in Figure 11, in which
the left-hand part of the Figure shows the engine arranged similarly to that shown
in Figure 4, but with the working cylinder and jacket extended towards the right
hand to form the cylinder A' of a compression pump, fitted with a jacket B',
piston block C¹, pistons D¹, D¹, and an abutment E', similar to those employed in
the engine. Between the engine and pump is placed a diaphragm 7 in which
revolve the inner ends 8, 9, of the engine and pump main shafts; 10 is the inlet to
the pump
for the gas and air, which may be previously mixed in any suitable
mixing chamber of known construction; 11 is the outlet for compressed gas and
air, which is conducted by the pipe or passage 12 to an inlet passage of the shell R
of the valve F, corresponding to the air inlet V in Figure 6. The relative positions
of the pistons D, D, to the pistons D', D', may be varied according to circumstances.
In Figure 3 the latter pistons D¹, D¹, are shown in dotted lines placed at an angle
of about 60° in advance of the pistons D, D, of the engine. In the same Figure
E represents in dotted lines the abutment corresponding to the pistons D¹, D₁, of
the pump. It will now be understood that when the engine pistons D, D, rotate
they cause the pump pistons D', D¹, to rotate also. These latter draw in the
charge of gas and air through the inlet 10, compress the same in the cylinder A¹,
and force it through the outlet 11 into the pipe 12, whence it is admitted
at the proper times by the valve F into the engine cylinder, where its explosion
produces motion of the pistons D, D, the products of combustion escaping at G, as
before explained.
Eighthly. I combine one or more of the various improvements described under
the seven heads hereiubefore enumerated, with the general arrangement and con-
struction of rotary gas engine described and illustrated in the Specification of the
aforesaid Patent granted to me, bearing date the 6th day of February A.D. 1874,
and numbered 486.
Having now described the nature of the said Invention, and in what manner
the same is to or may be carried into effect, I would have it understood that
what I claim is,―
First. The employment in gas engines of a self-acting valve, arranged and
operating in connection with the exhaust outlet, substantially as hereinbefore
described and illustrated in the Drawings, and for the purpose set forth.
Second. The employment in gas engines of a piston and cylinder for actuating
the gas supply valve, the said piston being operated in one direction by the partial
vacuum in the working cylinder, and in the other direction by its own weight, or
by a spring as hereinbefore described and illustrated in the Drawings.
Third. The employment in rotary gas engines of rotating or partially rotating

page_text: tapered plug valves adapted with recesses, channels, and passages for governing the
admission of gas and air to the working cylinder, and for communicating the
igniting flame to the explosive mixture in the said cylinder, substantially as
herein before described and illustrated in the Drawings.
Fourth. In rotary gas engines of the kind described in the Specification of the
hereinbefore mentioned Patent, No. 486, A.D. 1874, the introduction of a small
quantity of water from the water jacket into the working cylinder by means of a
hole and groove in the abutment, and the action of the piston block or drum, as
hereinbefore described and illustrated, and for the purposes set forth.
Fifth. The employment in combination with the rotating or partially rotating
valve, forming the subject of the third head of the Invention, a check valve for
preventing the explosion from driving back the gas in the pipe or passage through
which the igniting flame is supplied, such check valve being by preference fitted
with a perforated plug for adjusting the tension of the spring for holding the said
valve open, as herein before described and illustrated in the Drawings.
Sixth. The employment of the material known as ebonite for the construction
of the check valve, described under the fifth head of the Invention, as hereinbefore
described.
Seventh. The combination with a rotary gas engine of a separate cylinder and
piston or pistons for the purpose of compressing the mixture of gas and air before
the same enters the working cylinder, as herein before described and illustrated in
the Drawings.
Eighth. The combination of one or more of the improvements comprised under
the first seven heads of the Invention with the parts A, B, C, D, and E, shown in
the Drawings hereto annexed, which comprise the general arrangement and con-
struction of rotary gas engine, described and illustrated in the Specification of the
beforementioned Patent, No. 486, A.D. 1874.
In witness whereof, I, the said Samuel Ford, have hereunto set my hand
and seal, this Twenty-third day of November, in the year of our Lord
One thousand eight hundred and eighty-one.
SAM. FORD, (L.S.)
Patentee.