IMPROVE- MENTS IN GAS-ENGINES
Year: 1882

page_text: LETTERS PATENT to Frederick William Turner, of St. Albans Iron Works,
St. Albans, in the County of Herts, Engineer, for an Invention of "IMPROVE-
MENTS IN GAS-ENGINES."
PROVISIONAL SPECIFICATION left by the said Frederick William Turner
at the Office of the Commissioners of Patents on the 24th January 1882.
FREDERICK WILLIAM TURNER of St. Albans Iron Works, St. Albans, in the
County of Herts, Engineer. " IMPROVEMENTS IN GAS-ENGINES."
My invention relates to gas engines or motors, that is to say engines for
developing the motive forco obtained from the explosive and expansive force of a
mixture of gas and atmospheric air.
Engines worked by the explosive and expansive force of a mixture of gas and
air previously compressed to a pressure considerably above that of the atmosphere,
have heretofore been constructed in such manner that the force is applied to the
crank shaft during less than one half of the revolution of the said shaft, tho
gaseous fluid being allowed to escape before its whole force is utilized and in such
engines the ignition of the gases and consequent development of the greatest
expansive force takes place when the crank is on the "dead point," or nearly so
and before the said crank reaches that part of its course or path where the pressure
acts most favorably for its propulsion. In consequence of the condensation of the
gases in the cylinder the pressure is considerably reduced. This action causes a
fluctuating motion of the crank shaft which is very disadvantageous when the
engine is required to drive machinery for electric lighting and for similar purposes
where almost perfect uniformity or regularity of speed is required and moreover it
results in a loss of power,
But by the improvements which form the subject of my present invention I
obviate these difficulties as will be understood from the following description; that
is to say, I provide my improved engine with two cylinders, the pistons of which
are coupled to separate cranks formed or fixed on the same crank shaft at right
angles, or thereabouts, to each other. At one end these cylinders communicate with
i

page_text: each other by a port or passage in which is placed a conical or other suitable valve,
I term these two cylinders the first and second cylinders. The gaseous charge is
ignited in the first cylinder, and during the outward movement of the pistons it
exerts its expansive force in both cylinders which are then in communication
through the said port or passage. The expansive force drives or propels the piston
in the first cylinder during more than one half of its outward stroke and drives or
propels the piston of the second cylinder during the whole of its outward stroke
less the requisite lead of the exhaust; therefore the driving or propelling force
is exerted upon the crank shaft during more than one half of its entire
revolution.
The parts of the engine are so arranged. that the crank of the first cylinder
moves in advance of the other crank and at the time of ignition the crank of the
first cylinder is at an angle with the axial line of the cylinder, the piston having
then performed nearly half of its outward stroke; that is to say this crank, at the
instant of ignition and development of the explosive force of the charge, is in a
position to utilize entirely such force while the crank of the second cylinder
receives the explosive force at the same instant when on its "dead point," this last
named crank being worked by the subsequent expansion of the gases from the
first cylinder through the aforesaid port which at this time has been opened by the
valve.
A single slide-valve serves for the ignition and for regulating the admission of
the charge of gas to the first cylinder. The pistons are caused to work as close as
practicable to the closed ends of the cylinders so that the whole, or nearly the whole,
of the foul gases are expelled from both cylinders previous to the admission of a
fresh charge of gas and air. Moroever by the movement of the first piston in
advance of the second piston a space is provided in the first cylinder for the
compressed charge of gas and air prior to ignition thus obviating the necessity for
_an elongation of the cylinder for this purpose as heretofore employed.
In every alternate revolution each cylinder acts as a charging and compressing
pump, to the other, that is to say, during a portion of the revolution of the crank
shaft the first cylinder piston partly compresses the charge into the second cylinder
while during another part of the revolution of the said shaft the second cylinder
piston compresses the charge into the first cylinder, where it is ignited. This
alternate compressing action of the piston thoroughly mixes the gaseous charge as
required previous to the ignition of the same.
Another part of my invention refers to improvements in the mode of attaching
the slide valve back plate to the cylinder. To the sides of the valve-box in which
the slide valves work I fix, by screws, two flexible plates of. steel or other metal ;
these extend to the outsides of the back plate to which they are attached also by
screws, but the holes in the said plates through which these screws pass are
elongated sufficiently to allow an outward movement of the back plato equal to the
extent of expansion of the valves where they become heated. The friction of the
flexible plates upon the sides of the back plate caused by the pressure at the
aforesaid screws is intended partially to provide the resistance necessary for
holding the back plate in position against the explosive and expansive force of the
gases in the cylinders thereby rendering unnecessary the very heavy pressure
exerted by strong springs on the back plate so that comparatively weak springs
can be used for the regulation of the pressure. Moreover the pressure on the valves
and liability to abrasion will be materially reduced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick William Turner in the Great Seal Patent Office on the
24th July 1882.
FREDERICK WILLIAM TURNER, of St. Alban's Iron Works, St. Albans, in the
County of Herts, Engineer. "IMPROVEMENTS IN GAS-ENGINES."
My Invention relates to gas engines or motors, that is to say, engines for
developing the motive force obtained from the explosive and expansive force of a
mixture of gas and atmospheric air.
Engines worked by the explosive and expansive force of a mixture of gas aud
air previously compressed to a pressure considerably above that of the atmosphere,
have heretofore been constructed in such manner that the force is applied to the
crank-shaft during less than one half of the revolution of the said shaft, the gaseous
fluid boing allowed to escape before its whole force is utilized; and in such engines
the ignition of the gases and consequent development of the greatest expansivo
force takes place when the crank is on the "dead point" or nearly so, and before
the said crank reaches that part of its course or path where the pressure acts most
favorably for its propulsion. In consequence of the condensation due to the
expansion of the gases in the cylinder, the pressure is considerably reduced. This
action causes a fluctuating or irregular motion of the crank shaft which is very
disadvantageous when the engine is required to drive machinery for electric
lighting and similar purposes where almost perfect uniformity or regularity of
speed is required, and it also results in a loss of power. Moreover, in these engines,
as heretofore constructed, the cylinder is elongated to provide space for the com-
pressed gaseous charge, and consequently the foul gases or products of combustion
are not wholly expelled from the cylinder, a portion of thein remaining within the
said space and mixing with the succeeding charge of gas and air. But by the
improvements which form the subject of my present Invention I obviate theso
difficulties in the manner hereinafter set forth.
My Invention is illustrated in the accompanying Drawings, in which
Figure 1 represents a side elevation, partly in section, of my improved gas engine,
with some of the parts removed.
Figure 2 represents a front elevation thereof partly in section.
Figure 3 represents the gearing for operating the admission and exhaust valves.
Figure 4 is a section of the slide valve and slide face on the line x, x Figure 5,
and,
Figure 5 is an elevation of the slide face.
Like letters indicate the same parts throughout the Drawings.
A, A', represent the cylinders, B, B¹ the pistons which may be connected in any
suitable manner to the cranks C, C' formed or fixed on the crank shaft D nearly
at right angles to each other. At the upper end these cylinders communicate with
one another by the port or passage E in which is placed a conical valve F. Gis
the slide-valve which is operated by means of the connecting rod G' and the
crank H fixed on the shaft I. This shaft is rotated in bearings in the frame of the
engine and in the bracket J, by means of the pinion K, fixed on the crank-shaft D
and gearing with the toothed wheel L fixed on the shaft I. The cams M, N are
also fixed on this shaft.
The cam M operates the valve F by means of the lever a fixed on the shaft b
carried in the bearing c which is secured to the frame; on the other end of this
shuft is fixed the lever a¹ to the end of which is coupled the connecting rod d; this
connecting rod is also coupled to the lever e pivotted at e', the other end of which

page_text: enters a slot in the stem of the valve F. The cam N operates the exhaust valve O,
against the pressure of the spring O¹, by means of the lover pivotted at g and
having a short arm connected by the rod h to the said valve. P is a valve for
the admission of air, held to its seat by the spring PL.
When the engine is in operation and the parts are in the position shewn in the
drawings, that is to say, the piston B having performed nearly half of its downward
stroke and the piston B being at the top of its stroke, the cylinder A above the
piston B contains gas and air which have been admitted by the opening of the
valves G and P; the valve G is about to rise for the further admission of gas
from the supply aperture through the port ; the valve F is also about to be
opened by means of the cam M. When the piston B has reached the end of its
downward stroke, the cylinder A is filled and the cylinder A¹ is half filled with
the charge of gas and air and the supply is cut off. During the up stroke of the
piston B the whole of the charge is compressed into the cylinder A¹; by the further
movement of the engine in the same direction the charge is compressed from the
cylinder A' into the cylinder A, and the piston B again arrives at the position
shewn in the drawings, one revolution of the crank-shaft having been completed.
By this time the valve G has moved downward to allow the charge to be
ignited, and the valve F being open, the explosive force of the charge is exerted
simultaneously upon the two pistons. The expansive force acts upon both pistons
until the piston B₁ has terminated its downward stroke, when the valve O is
opened by means of the cam N and the foul gases or products of combustion are
exhausted or expelled from both cylinders until the piston B terminates its
upward stroke when the valve F is closed to prevent the foul gases in the
cylinder A' from entering the cylinder A while the piston B is performing the first
half of its downward stroke and drawing in the fresh charge. During this
movement the piston B¹ expels the foul gases from the cylinder A' and when the
--said-piston arrives at the top of its stroke the valve O is closed and the valve F is
again opened to admit the gas and air into the cylinder 'A'.
It will thus be seen that the explosive force of the gaseous charge is exerted on
both pistons, and during the downward movement of the pistons its expansive
force is exerted simultaneously in both cylinders, which are in communication
through the port or passage E. The expansive force drives or propels the piston B
in the cylinder A during more than one-half of its downward stroke, and drives or
propels the piston B' of the cylinder A' during the whole of its downward stroke,
less the requisito lead of the exhaust; therefore, the driving or propelling force is
exerted upon the crank shaft D during practically one-half of its entire revolution.
The parts of the engine are arranged to operate so that the crank C moves in
advance of the crank C, and, at the time of igniton, the crank C is at an angle
with the axial line of the cylinder A as shewn in Figure 1, the piston B having
then performed nearly half of its outward stroke, that is to say, the crank C at the
instant of ignition and development of the explosive force of the charge, is in a
position to utilize entirely such force, while the crank C¹ receives the explosive
force at the same instant when on its "dead point." The arrangement of the
cranks as above described ensures the explosive force of the charge being utilized
for driving the engine instead of retarding it, as is sometimes the case, in engines
heretofore constructed, when the ignition takes place prematurely.
The single slide-valve G serves for the ignition of the charge of gas and for
regulating the admission of gas to the cylinder A. The pistons B, B are caused
to work as close as practicable to the closed ends of the cylinders, so that the foul
gases or products of combustion are, as far as possible, expelled from both cylinders
previous to the admission of a fresh charge of gas and air. Moreover, by the
movement of the piston B in advance of the piston B₁ a space is afforded in the
cylinder A, for the compressed charge of gas and air prior to ignition, thus
obviating the necessity for an elongation of the cylinder for this purpose as
heretofore employed.
In every alternate revolution, each cylinder acts as a charging and compressing

page_text: pump to the other, that is to say, during a portion of the revolution of the crank
shaft, the piston B partly compresses the charge into the cylinder A', while, during
another part of the revolution of the said shaft, the piston B' compresses the charge
into the cylinder A, where it is ignited. This alternate compressing action of the
pistons thoroughly mixes the gaseous charge as required previous to the ignition of
the same.
Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that I claim-
First. A gas engine or motor constructed with two cylinders, pistons, and cranks,
so arranged that the explosive and expansive force of the charge is exerted
simultaneously on both pistons and that by the movement of one piston in advance
of the other, space is afforded for the compressed, gascous charge in such a manner
that elongation of the cylinder beyond the stroke of the piston, and the consequent
difficulty of expelling the foul gases are avoided.
Second. In the said engine, the valve arranged to open or close the passage or
communication between the two cylinders, for the purpose specified.
In witness whereof I tho said Frederick William Turner, have hereunto set
my hand and seal this Twenty fourth day of July in the year of our Lord
One thousand eight hundred and eighty two.
Witness
HENRY H. LAKE
8 Southampton Buildings
London.
FREDERICK WILLIAM TURNER. (L.S.)