Improvements in Gas Engines.
Year: 1893

page_text: Date of Application, 15th Feb., 1893
Complete Specification Left, 15th Dec., 1893-Accepted, 20th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in Gas Engines.
We, JOHN WILLIAM HARTLEY of Kay Park, Kilmarnock, Engineer, and
JOHN KERR, Engineer, of the Firm of Dick, Kerr and Company Limited, of
Britannia Engineering Works, Kilmarnock, both in the County of Ayr, do hereby
declare the nature of this invention to be as follows:-
Our invention relates to improvements in the details and in the cycle of operation
of gas engines; and with regard to the cycle of operation our object is to improve
upon the action of ordinary "Otto" cycle gas engines by so arranging the
impulses that the engine runs with greatly increased steadiness, so that it may be
more suitable for electric lighting and other purposes where greater steadiness is
desired.
Another part of our invention relates to improved details of gear suitable for
application where our improved cycle is adopted.
In constructing our improved engine we arrange a piston with piston rod passing
through a stuffing box and cover, and we operate such end of the cylinder
according to the "Otto" cycle so that we produce a double acting "Otto" cycle
gas engine. In this engine one impulse behind the piston is immediately succeeded
by an impulse in front, so that on one revolution of the engine two impulses are
given as in an ordinary steam engine. On the next revolution the cycle is devoted
to exhausting and charging operations, so that no impulse is given; but the
following revolution has two impulses. In this manner when the engine is at full
load or is governing by reducing the explosion we obtain running which is very
much steadier than that of an "Otto" cycle engine; that is, we run the engine
with a much smaller interval of time or revolutions between the impulses. In
another form of this our double acting engine we couple together two engines of
the type herein before described and so arrange the explosions that when one
cylinder has completed two explosions the other cylinder follows on with two
explosions so that with a two cylinder double acting "Otto" cycle engine we
obtain two impulses for every revolution of the engine, and are enabled to obtain a
regularity in impulses with two cylinders such as a steam engine obtains with one
cylinder.
In the construction of such engines we require to proportion the piston so that it
is long in proportion to diameter (not less in length than three fourths the diameter)
so as to prevent firing past from one explosion to the explosive mixture contained
in the cylinder on the other side of the piston ready for the next compression and
explosion. With rapidly succeeding explosions on both sides of the piston it is also
necessary to provide ample cooling surface in contact with the water jacketed cylinder.
In a piston constructed with these objects we provide a light shell stayed by means
of ribs to a central boss and to the end, and we form a junk ring similarly stayed
to a central boss; the two parts are brought together and the piston rod slipped
through them and screwed home so that a very light piston is produced having
large cooling surface and ample space for rings.
In coupling our single cylinder double acting engines together to form our double
cylinder double acting gas engine when we couple two engines together instead of
arranging two cylinders on one crank shaft, we key on the end of each shaft a
strong sleeve having at its extremity a conical collar or a flange with conical sides.
We unite these shafts by caps having conical recesses, the opposing caps are

page_text: strongly bolted together by bolts and the conical grooves or recesses clip the
conical flanges and so the shafts to be coupled are firmly united in a truly central
manner,
In governing our double acting engines where the steadiest running is required
we prefer to operate one gas valve for each cylinder by step cams so cut as to
constantly close at one point of the piston charging stroke, that is the end, and to
open later and later in the stroke as less load is required. At the same the gas
valve is given its full lift in every position of the step cam.
A step cam for the double acting single cylinder engine has its steps placed at
right angles to each other. The governor has thus to operate a single roller in
governing our double acting single cylinder engine.
Instead of the foregoing described single cam with double lift we sometimes use
two stepped cams and two gas cam rollers on separate levers each lever being
arranged to lift the one gas valve independently of the other. The rollers are
actuated by the governor, each roller being separately operated by one modification
of the device illustrated in Figure 1 of Patent No. 21496 of 1891. In another
modification we arrange a stepped cam to admit gas to the back end of the cylinder
the roller in this case being made adjustable by hand instead of being controlled
by the governor.
The impulses at the back of the cylinder are in this case always of the same
power until the roller is adjusted by the attendant. The roller for admitting gas
to the front end of the cylinder being controlled by the governor as already
described.
In governing our double cylinder double acting gas engine we prefer to use one
governor and couple to the second engine by a way shaft or lever so that the
second step cam or cams is or are controlled by one governor. In this case we
employ with each roller so controlled the device or the spring catch arrangement
illustrated in one modification at Figure 1 of our Patent No. 21496 of 1891.
Dated this 14th day of February 1893.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Gas Engines.
We, JOHN WILLIAM HARTLEY, of Kay Park, Kilmarnock, Engineer, and
JOHN KERR, Engineer, of the Firm of Dick, Kerr and Company Limited, of
Britannia Engineering Works, Kilmarnock, both in the County of Ayr, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:—
Our invention relates to gas engines, and comprises an improved cycle of
operations, the object of this part of our invention being to improve upon the
action of ordinary Otto cycle gas engines by so arranging the impulses that the
engine shall run with greatly increased steadiness as compared with engines hereto-
fore made so that it may be more suitable for electric lighting and other purposes
where great steadiness is desired.
Our invention also comprises improved details of gear suitable for application
where our improved cycle is. adopted, and other improvements of construction as
hereinafter described.
Referring to the two sheets of accompanying drawings:
Figure 1 is a plan of a coupled double-acting engine arranged in accordance with
our invention.

page_text: Figure 2 is a front elevation and Figure 3 is a side elevation of an improved
double gas cam with steps.
Figure 4 is a longitudinal section and Figure 5 is a corresponding transverse
section of a coupling for coupling gas engine shafts together.
Figure 6 is a longitudinal section and Figure 7 is an end elevation of a gas
engine piston.
Figure 8 is a plan and Figure 9 is an end view of the gas valve operating gear.
In constructing our improved engine we pass the piston rod through a stuffing
box and cover, and we operate each end of the cylinder according to the Otto
cycle so that we produce a double-acting Otto cycle gas engine. In this engine
one impulse behind the piston is immediately succeeded by an impulse in front so
that during one revolution of the shaft two impulses are given as in an ordinary
steam engine. The next revolution is devoted to exhausting and charging
operations so that in it no impulse is given, but the following revolution has two
impulses and so on. In this manner when the engine is working with full load or
is governing by reducing the explosion we obtain running which is very much
steadier than that of an Otto cycle engine. That is to say, we run the engine with
a much smaller interval of time or number of revolutions between the impulses.
In another form (see Figure 1) of this our double acting engine we couple together
two engines as A and B of the type herein before described and we so arrange the
explosions that when one cylinder as A has completed two explosions, the other
cylinder as B follows on with two explosions, so that with a two cylinder double
acting Otto cycle engine we obtain two impulses for every revolution, and are
cuabled to obtain the same regularity in impulses with two cylinders as a steam
engine obtains with one cylinder.
In such engines we require to construct the piston so that it is long in proportion
to its diameter (not less in length than three fourths the diameter) so as to prevent
the communication of the firing of one explosion to the explosive mixture contained
in the cylinder on the other side of the piston which is ready for the next com-
pression and explosion. With rapidly succeeding explosions on both sides of the
piston it is only necessary to provide ample cooling surface in contact with the
water jacketed cylinder.
In a piston constructed with these objects (see Figures 6 and 7) we provide a
light shell F stayed by means of ribs F to a central boss F2 and to one end, and
we provide for the open end a junk ring G similarly stayed by ribs G¹ to a central
boss G. The two said parts are brought together and the end H' of the piston
rod H is slipped through them and screwed home by a nut as H2 so that a very
light piston is produced having large cooling surface and ample space for rings.
In coupling together two single cylinder double-acting engines to form one
double cylinder, double-acting gas engine as shown at Figure 1 (when we couple
two engines together instead of arranging two cylinders on one crank shaft), we
key on the end of each shaft A and B', Figures 4 and 5, a strong sleeve as A³
or B2 each of which has at its extremity a conical collar as A or B³ or a flange
with conical sides. We unite these shafts A¹ B' by caps as D D' having recesses
to fit the collars A³ B³. The opening caps D D' are firmly bolted together by
bolts as E E E and the conical grooves or recesses in the cups clip the conical
flanges and thus firmly unite the shafts in a truly central manner.
For governing our double-acting engines where very steady running is required,
we prefer to operate one gas valve for cach cylinder by step cams so cut as to
constantly close at one point of the piston charging stroke, that is the end, and to
open later and later in the stroke as less load is required. At the same time the
gas valve is given its full lift in every position of the step cam. Such a cam is shown
at Figures 2 and 3 and its peculiarity is that one set of steps follow at right angles
to the leading set so as to operate the same gas valve first for charging one end of
the double-acting cylinder and then the other.
A step cam as Figure 3 for the double-acting single cylinder engine has its
steps C C¹ placed approximately at right angles to each other as described. The

page_text: governor has thus to operate a single roller in governing such double-acting single
cylinder engine.
Instead of the foregoing described single cam with double lift we sometimes use
two stepped cams as I I¹ (Figures 8 and 9) and two gas cam rollers as QQ' on
separate levers K K' each lever being arranged to lift the one gas valve indepen-
dently of the other. The rollers are controlled by the governor, each roller being
separately operated by one of the devices illustrated at Figure 1 of the Specification
of Patent No. 21496 of 1891 granted to us.
A convenient arrangement is shown at Figures 8 and 9 where L L are two
independent frames pivoted on the fixed spindle M. The said frames L L'operate
on the single gas valve O (Figure 9) by its spindle O¹ so that when either frame is
raised the valve O is opened. Two levers K and K' slide on the outer part of the
frames L L' and by bosses k¹ on the spindle M. These levers carry rollers QQ'
which engage respectively the cams I I on the rotating cam shaft D, the governor
rod N carries collars N₁ N2 arranged with spring connections to the rod N as.
described in the herein before mentioned Patent. The collars N' N' engage
projections k³ from the levers K K¹ as shown and so are controlled by the
governor; the levers K K' slide along and cause the cam rollers QQ to engage
in different steps of the cams I l' and so vary the gas supply. Sometimes we
control one of the levers as K by a screw as P shown in dotted lines operated by
hand independently of the governor.
In this modification we arrange a stepped cam to admit gas to the back end of
the cylinder, and adjust the roller by hand as described instead of controlling it by
the governor. The impulses at the back of the cylinder are in this case always
of the same power until the roller is adjusted by the attendant. The roller for
admitting gas to the front end of the cylinder is controlled by the governor as
already described.
In governing our double cylinder double-acting gas engine we prefer to use one
governor as R Figure 1 and couple to the second engine by a way shaft S or lever
so that the second step cam or cams is or are controlled by one governor. In this
case we employ with each roller so controlled the device or the spring catch
arrangement illustrated in one modification at Figure of our Patent No. 21496
of 1891.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. A double-acting gas engine in which power impulses are given on both sides
of the piston, having a single gas valve which operates to admit gas alternately to
each end of the cylinder.
2. A double-acting gas engine in which power impulses are given on both sides
of the piston and one gas valve is operated to admit gas alternately to each end of
the cylinder by a double cam with steps actuating one roller controlled by the
governor, substantially as and for the purposes hereinbefore described.
3. Coupling together two double-acting gas engines or arranging an engine with
two double-acting cylinders on one crank shaft in such manner as to produce a
combined engine capable of giving two impulses for each revolution of the crank
shaft, the said impulses being arranged in sequence from cylinder to cylinder
substantially as, and for the purpose, hereinbefore described.
4. A gas engine piston for double-acting gas engines constructed in such manner
as to comprise a light shell as F with ribs as F' connecting to a boss as F2; a junk
ring as G also having ribs G' and a boss G', the said shell and junk ring being held
together by a portion of the piston rod passed through and a suitable screw or nut
substantially as hereinbefore described with reference to Figures 6 and 7 of the
accompanying drawings.
5. A crank shaft coupling for gas and like engines comprising keyed on sleeves
as A B with conical or other collars as A³ B³; recessed caps as D D' to fit the

page_text: said collars; and strong bolts to pull the caps together all substantially as
herein before described and illustrated at Figures 4 and 5 of the accompanying
drawings.
6. A double-acting gas engine in which one gas valve supplies both ends of the
cylinder and the said valve is operated alternately by pivoted frames as L L'
carrying levers controlled by governor or hand screw adjustment as K K' having
rollers to be operated on by two cams as I I¹ substantially as and for the purposes
herein before described with reference to Figures 8 and 9 of the accompanying
drawings.
Dated this 14th day of December 1893.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicants.