IMPROVEMENTS IN THE ARRANGEMENT AND CONSTRUCTION OF GAS MOTOR ENGINES
Year: 1883

page_text: LETTERS PATENT to Samuel Griffin of Kingston Iron Works Bath in the
County of Somerset Engineer, for an Invention of "IMPROVEMENTS IN THE
ARRANGEMENT AND CONSTRUCTION OF GAS MOTOR ENGINES
"
PROVISIONAL SPECIFICATION left by the said Samuel Griffin at the
Office of the Commissioners of Patents on the 23rd August 1883.
SAMUEL GRIFFIN of Kingston Iron Works, Bath, in the County of Somerset
Engineer, "IMPROVEMENTS IN THE ARRANGEMENT AND CONSTRUCTION OF GAS
MOTOR ENGINES
"
My Invention has for its object, first-the so arranging the motor cylinder slide
valve, and parts connected and working in connection there with as to entirely
eject the products of combustion or explosion from the cylinder and compression
space or spaces, after each explosion or impulse and fill same with a uniform mixture
of air and gas or explosive compound previous to firing same. By this means I
obtain greater power with economical results.
To effect this I arrange the motor cylinder with a clearance space at one end,
into which the uniform mixture of air and gas or explosive compound is drawn and
afterwards compressed and fired. The slide valve which performs the double office
of admitting the air and gas or explosive compound to the cylinder, and afterwards
firing it is so arranged as to make one stroke to three of the piston.
The mode of igniting the explosive compound is advantageously that described in
the Specification of Letters Patent granted to me and dated 15th December 1881
No 5483 other modes of igniting the charge may be employed.
The operation is as follows:-
During the first portion of one outstroke of the piston air and gas or explosive
compound is drawn in in just sufficient quantity to fill the compression space this
is followed by air until the stroke is completed. At the next in-stroke the
exhaust valve is open, consequently the air which passed into the cylinder during
the last portion of the previous outstroke, together with any products of combustion
is expelled and the air and gas or explosive compound drawn in during the first

page_text: portion of the previous out-stroke is driven into the compression space. At the
next outstroke the exhaust valve is closed and air and gas or explosive compound
is drawn in during the whole stroke. At the next instroke this compound is
compressed, and fired at the commencement of the next outstroke. The piston has
thus one impulse at every 3 revolutions of the crank.
The exhaust port is situated at the extreme end of the clearance or compression
space farthest from the piston while the inlet port is situated close to the piston
when the mixture is fully compressed.
According to the second part of my improvements I so arrange the motor
cylinder and parts connected and working in connection therewith as to obtain an
impulse or explosion during every one and a half revolutions of the crank shaft the
impulses or explosions taking place alternately at the back and front of the motor
cylinder. I thus obtain increased power and steadiness in running.
To effect this I construct my motor cylinder with a clearance or compression
space at each end, the piston being connected with a rod passing through a stuffing
box in the usual manner:
The various ports and passages both in the motor cylinder and slide valve are
the same in construction as those described in the first part of this specification
but they are duplicated as is also the exhaust valve. The cycle of operations
described in the first part of this specification as taking placo at one end of the
motor cylinder only, thus takes place at each end alternately.
According to the third part of my improvements I arrange a cam to work in
connection with the wheel and shaft which gives motion to the slide valve in such
a manner as to open the gas valve during a portion of one stroke of the piston, and
during the whole of the next stroke of the piston for the purpose before described.
By any suitable arrangement of governors and mechanisin working in connection
therewith the eam may be disconnected from the gas valve, by this means gas is.
only admitted in direct proportion to the work performed by the engine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Samuel Griffin in the Patent Office on the 23rd February 1884.
SAMUEL GRIFFIN of Kingston Ironworks, Bath. in the County of Somerset
Engineer IMPROVEMENTS IN THE ARRANGEMENT AND CONSTRUCTION OF GAS
16
MOTOR ENGINES
"
My invention has for its object first the so arranging the motor cylinder, slide
valve and parts connected and working in connection therewith as to entirely eject
the products of combustion or explosion from the cylinder and compression space
or spaces after each explosion or impulse and fill same with a uniform mixture of
air and gas or explosive compound previous to firing same.
By this means I obtain greater power with economical results.
To effect this object I arrange the motor cylinder with a clearance space at one
end into which the uniform mixture of air and gas or explosive compound is
drawn and afterwards compressed and fired. The slide valve which performs the
double office of admitting the air and gas or explosive compound to the cylinder
and afterwards firing it, is so arranged as to make one stroke to three of the
piston.
The slide valve may be used for igniting the mixture only. The admission of
air and gas or explosive compound to the cylinder being regulated or governed by
a separate valve or valves of any suitable form or arrangement...
The mode of igniting the explosive compound is advantageously that described
in the Specification of Letters Patent granted to me and.dated 15th December 1881
No 5483 other modes of igniting the charge may be employed.
The operation is as follows:-
During the first portion of one outstroke of the piston air and gas or explosive
compound is drawn in in just sufficient quantity to fill the compression space, this
is followed by air until the stroke is completed.
At the next instroke the exhaust valve is open consequently the air which
passed into the cylinder during the last portion of the previous outstroke, together
with any products of combustion is expelled and the air and gas or explosive
compound drawn in during the first portion of the previous outstroke is driven
into the compression space.
At the next outstroke the exhaust valve is closed and air and gas or explosive
compound is drawn in during the whole stroke. At the next in-stroke this
compound is compressed and fired at about the commencement of the next
outstroke. The piston has thus one impulse at every 3 revolutions of the
crank.
The exhaust port is situated at the extreme end of the clearance or compression
space farthest from the piston while the inlet port is situated close to the piston
when the mixture is fully compressed.
. According to the second part of my improvements I so arrange the motor
cylinder and parts connected, and working in connection therewith as to obtain
an impulse or explosion during every one and a half revolutions of the crank
shaft, the impulses or explosions taking place alternately at the back and front
of the motor cylinder. I thus obtain increased power and steadiness in running.
To effect this I construct my motor cylinder with a clearance or compression
space at each end, the piston being connected with a rod passing through a stuffing.
box in the usual manner as arranged in steam engines.

page_text: The bottom of this stuffing box terminates in a long tube or sleeve which extends
through the compression space as far as the piston when at its nearest point to the
stuffing box, i.e. when its stroke in the direction of the stuffing box is completed.
The object of this long sleeve is two-fold.
Firstly, in consequence of its great length the escape of pressure round the
piston rod is almost entirely prevented so that an oxceedingly light packing in the
stuffing-box is sufficient to prevent all escape.
Secondly it protects the piston rod from the direct action of the flame during
the explosions.
A water jacket can also be advantageously fitted round this sleeve through
which the water can circulate in connection with the water round the outside
of the cylinder or otherwise. The piston rod is thus kept at a comparatively low
temperature.
The length of the sleeve may be advantageously such that no part of the piston
rod which passes into the interior of the cylinder into contact with the flame comes
in contact with the packing in the stuffing box. The satisfactory working of the
piston rod is thus secured without overheating.
The various ports and passages both in the motor cylinder, and slide valve are
the same in construction as those described in the first part of this Specification
but they are duplicated as is also the exhaust valve.
The cycle of operations, described in the first part of this specification as taking
place at one end of the motor cylinder only, thus takes place at each end
alternately.
According to the third part of my improvements I arrange a cam to work in
connection with the wheel and shaft which gives motion to the slidō valve in such
a manner as to open the gas valve during a portion of one stroke of the piston,.
and during the whole of the next stroke of the piston for the purpose before
described. By any suitable arrangement of governors and mechanism working in
connection therewith the cam may be disconnected from the gas valve by this
means gas is only admitted in direct proportion to the work performed by the
engine.
And in order that my invention may be clearly understood and readily carried
into practice I will proceed to describe the same more fully with reference to the
Drawing horota annuent
Figures 1 and 2 show a side elevation and plan of my improved gas motor
engine as described in the first part of my specification. Figures 3 and 4 shew
vertical horizontal longitudinal sections of the cylinder. Figures 5 and 6 show
transverse sections of the cylinder through the exhaust valve and ignition port.
a is the cylinder open at the front end. b. is the connecting rod which commu-
nicates motion from the piston c...(Figures 3 and 4) to the crank d. On this crank
shaft is fitted the toothed pinione which gears with the toothed wheel driving it
at one revolution to three of the crank d. In this wheel fis fitted a crank pin g
which communicates motion through the rod to the slide valve which is kept
in position against its face by the cover; and tightening screws k. k. On the
opposite end of the spindle on which the wheel is fitted and working in
connection with it is the cam 7 which imparts motion through the small roller m.
and rod to the gas valve o. The small roller m works on a pin attached to the
rocking lever p this pin being extended to take the joint q.
The governors 7 are connected by means of a lever not shown, similar to 8, with
the rocking bar t, (which passes through the base plate under the cylinder); to
this rocking bar is fixed the lever s the free end of which is in connection with
1
. I

page_text: one end of the rod u, the other end being in connection, by means of a joint v.
with the free end of the rod n which can thus be raised or lowered by the action
of the governors, and its contact with the gas valve o. established or interrupted.
wis the exhaust valve which is actuated by the lever x. and rocking shaft y
motion being imparted to it through the lever z and roller a. by cams "b¹
back of the wheel f
the
The small gas jet c' burning in the chimney d¹ is for the purpose of igniting the
charge by any suitable arrangement. e¹ is the ignition port in slide valve fi
ventilating port g¹, air port h¹ gas port in valve cover, .port in slide valve in
which the air and gas is mixed and afterwards drawn into the cylinder through
the port the compound being afterwards ignited through the same port the
slide valve and piston are oiled by the lubricator k¹.
The action of the gas motor engine previously described arranged and constructed
in accordance with the first part of my improvements is as follows.
During the first portion of one out stroke of the piston air and gas or explosive
compound is drawn into the cylinder, this compound being next the piston, when
a sufficient quantity has been drawn into the cylinder to fill the compression
space the gas valve o is closed by the action of the cam l. and air only is drawn in
during the remaining portion of the stroke. At the following instroke of the
piston the exhaust valve w. is held open by the cam b¹ and lever x consequently
the air drawn in during the latter part of the previous out-stroke, together with
the air or vapour in the compression space will be entirely expelled and the air
and gas or explosive compound drawn in during the first portion of the previous
outstroke will be driven into the compression space. The exhaust valve wis now
closed.
At the next outstroke of the piston air and gas or explosive compound is drawn
into the cylinder during its entire travel the mixture or explosive compound both
in the cylinder and compression space (1) being thus rendered homogeneous and
uniformly combustible throughout.
At the next instroke of the piston this compound is compressed, and fired at
about the commencement of the next outstroke of the piston.
At the next instroke of the piston the exhaust valve w, is held open and the
products of combustion partially expelled. At the next outstroke of the piston
the cycle of operations above described is again commenced.
When the engine exceeds its normal velocity the governors rise and interrupt
the contact between the rod n and gas valve o and thus prevent the further
admission of gas until the speed is again reduced.
Figures 7 and 8 show a side elevation and plan of my improved gas motor
engine as described under the second part of my Specification.
Figures 9 and 10 show vertical and horizontal longitudinal sections of cylinder.
Figures 11 and 12 show transverse sections. Figures 13 and 14 show details of
governors and mechanism for actuating exhaust and gas valves.
a is the cylinder closed by covers at both ends having a stuffing box.b at the front
end, through which passes the piston rod c. in connection with the piston d, this
piston rod communicates its motion through the block e and connecting rod f
to the crank g. The block e works in a suitable guide or channel h.
The cylinder has compression or clearance spaces i. i, at each end see Figures 9
and 10 into which the charge is drawn through the bent ports or passages j. ji
these ports or passages terminate at one end in the compression spaces at the end
furthermost from the covers and at the other end in the valve face k against which
the slide valve works. This valve is actuated by the rod m working in connection
with the wheel n, by means of a crank pin o, which revolves at one third the
speed of the crank shaft in connection with the pinion p, the valve thus makes
one stroke to three of the piston. This valve has in it two ports or passages q. Q.
which open communication at the proper times between the ports or passages 1. 1.
in the cover 8 and the ports or passages j. j. The ports or passages r. r. are in
communication with the atmosphere and also with the gas valve t. figures 13.

page_text: •
and 14 which is shown in position in Figures 7 and 8 the small ports u. u. in the
slide valve are for the purpose of igniting the charge alternately in the compression
spaces through the ports or passages j. j. these igniting flames are lit from the
small jet v burning in the chimney w. is they pass before it.
through
In connection with the cylinder cover there is a long tube or sleeve
which the piston rod c passes, this tube or sleeve is shown surrounded by a water
jacket in Figure 10 for the purpose of keeping the piston rod cool. Figure 0
shows this sleeve without the water jackot.
2.5. are exhaust ports or passages which communicate at one end with the
compression spaces i. i. at a point nearest the cylinder covers, and at the other end
with the exhaust valves a' a spiral springs bhold the exhaust valves close. The
exhaust valves are actuated by the levers co' which are connected with the
levers dd by micans of a hollow shaft e and sinaller shaft passing through it,
(these details are shown more clearly in Figures 13 and 14.)
The levers d' d, have on their ends pins on, which revolve small rollers g'g'
these rollers come into contact alternately with two projections or cams h¹h on
the back of the wheel n. as it revolves and thus a rocking motion is imparted to
them, which motion being communicated to the exhaust valves, opens them at the
proper time, the closing movement being effected by the springs when the cams
are out of contact with the rollers.
The gas valve t receives motion from the double cam which is fixed upon the
same spindle as the wheel n and revolves with it. In connection with this double
cam a small rocking lever j carrying a roller le works a small rod jointed to the
lever at m and communicates a reciprocating motion direct to the gas valve t.
The free end of the small rod is connected by a small link n, and lever o¹.
with a light bar or rocking shaft p which passes through the bed, under the
cylinder, and is connected at the other end by a lever q' with the governors ?.
The free end of the rod is thus raised or lowered by the action of the
governors.
In describing the action of the gas motor engine arranged and constructed
according to the second part of my improvements it will be convenient to speak of
the front and back of the piston and cylinder, in order that the description may be
better understood.
During the first portion of one stroke of the piston forward at starting air and
gas or explosive compound is drawn into the cylinder at the back, this compound
being next the piston. When a sufficient quantity has been drawn in to fill the
compression space i, the gas valve t. is closed by the action of the cam and nir
only is drawn in during the remaining portion of the stroke. During this stroke
the air in front of the piston is compressed.
At the next stroke backward the air drawn in behind the explosive compound
nt the back of the piston during the previous stroke will be expelled; together
with any air or vapour in the compression space, through the back exhaust
valve a which is held open and the explosive compound next the piston will be.
driven into the compression space, while the air or vapour which was compressed
at the front of the piston will expand again to its original volume.
•
During the next forward stroke air and gas or explosive compound will be drawn.
in at the back of the piston during its entire travel while the air or vapour in
front of the piston will be partly expelled through the front exhaust valve a¹
that in the compression space only remaining.
At the next backward stroke, the uniformly explosive compound with which the
cylinder and compression space at the back of the piston, is now filled will be
compressed while a charge of air and gas followed by air alone, similar to that
described as being drawn in at the back of the piston during the first forward.
stroke will be drawn in at the front of the cylinder.
•
A
At about the commencement of the next forward stroke the explosive compound 5
at the back of the piston will be fired impelling the piston forward, while the air
next the charge of explosive compound, together with the air or vapour in the

page_text: compression space in the front of the cylinder will be expelled through the front
exhaust valve which is now. open and the combustible compound next the piston
will be driven into the compression space.
At the next backward stroke the resultant gases or vapour from the previous
explosion will be expelled through the back exhaust valve which is now open,
while a full charge of air and gas or explosive compound is drawn in in front of
the piston during its entire travel.
At the next forward stroke the operation first described is repeated at the back,
while the uniformly explosive compound in front of the piston is compressed, and
fired at about the commencement of the next backward stroke.
An impulse or explosion is thus obtained at the front and back of the piston
alternately.
The explosions or impulses follow each other in uninterrupted succession as
above described only when the engine is fully loaded. When the load is reduced
and the normal velocity of the engine consequently exceeded, the governors,
interrupt the motion of the gas valve, thus cutting off, the supply of gas until the
speed is again reduced.
Having thus described the nature of my invention and the manner of performing
or carrying the same into practice I would remark that I make no claim to any
of the parts separately which are well known and in common use But what
I claim is
First. The improved arrangement and construction of gas motor engines by
which the cylinder and parts connected therewith cause a charge of uniformly
combustible mixture of gas and air to be introduced into the cylinder and the
products of combustion entirely ejected therefrom substantially in the manner
hereinbefore described and illustrated by the drawings annexed.
Second. I claim the novel arrangement of camn (working in connection with the
wheel and shaft which imparts motion to the slide valve) for the purpose of
admitting gas during a portion of one stroke of the piston and during the whole of
the next stroke substantially in the manner hereinbefore described and represented
in the drawings annexed.
Third. I claim the improved arrangement of the governor and parts combined
therewith by which a rod working in connection with a cam as described is caused
to actuate the gas valve in proportion to the load on the engine substantially in
the manner and for the purpose herein-before described and represented in the
Drawings annexed.
Fourth. I claim the admission of the explosive compound into the cylinder in gas
engines which compress the charge through a port at a point close to or near the
piston when at the end of its travel towards the port and also the ignition of
the charge at about the same position advantageously through the same port
substantially as herein-before described and illustrated by the drawings hereto
annexed.
Fifth. I claim the improved arrangement of mechanism by which the exhaust
valves connected with each end of the cylinder are opened by means of levers
fitted on the end of a tube or hollow shaft through which a second shaft passes
having levers on each end, these levers at one end of both tube and shaft being
actuated by one set of cams working in connection with the wheel which actuates
the slide valve the levers at the opposite ends actuating the exhaust valves
substantially in the manner hereinbefore described with reference to Figures 7. 8,
13 and 14 of the Drawings annexed.
Sixth. I claim the improved arrangements of cylinder and parts combined and
working in connection therewith by which a uniform charge of air and gas or
combustible compound is introduced into the cylinder compressed and fired
alternately at each end at every one and a half revolution of the crank shaft
substantially as herein before described with reference to Figures 7. 8. 9. 10,11,
12. 13 and 14 of the Drawings hereto annexed.

page_text: Lastly. I claim the improved general arrangement of gas motor engines the
parts being arranged constructed and combined so as to act substantially in the
manner and for the purposes herein-before described' and represented in the
Drawings hereto annexed.
In witness whereof I the said Samuel Griffin have hereunto set my hand and
seal this Twenty first day of February in the year of our Lord One thousand
eight hundred and eighty four.
1
Witness.
J G TONGUE
Patent Agent
34 Southampton Buildings
Chancery Lane
London WC
SAMUEL GRIFFIN (L.S.)