IMPROVE- MENTS IN GAS MOTOR ENGINES
Year: 1879

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN GAS MOTOR ENGINES." A communication from abroad by Gottlieb
Wilhelm Daimler, of the Gas-Motoren Fabrik-Deutz, at Deutz on the Rhine, in
the German Empire.
Sealed the 21st October 1879, and dated the 12th August 1879.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 12th August 1879.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN GAS MOTOR ENGINES." [A com-
munication from abroad by Gottlieb Wilhelm Daimler, of the Gas-Motoren Fabrik-
Deutz, at Deutz on the Rhine, in the German Empire.]
This Invention relates to that class of gas motor engines wherein a charge of
combustible gaseous mixture, drawn into a cylinder during one outstroke of its
piston, is compressed by the instroke, and being then ignited propels the piston
during its next outstroke, the products of combustion being expelled by the
next instroke. The present improvements consist in combining with one or more
cylinders operating in this manner at high pressure another low pressure cylinder,
in which the products of combustion from the high pressure cylinder or cylinders
expand doing work, the actions being so timed that at every stroke a portion of the.
power is communicated to the one crank shaft with which the several pistons are
connected. In a horizontal engine constructed to operate in this manner the low
pressure cylinder, open in front, is placed between two high pressure cylinders, also
open in front, one on each side of it, and the back end of the low pressure cylinder
is connected with the back end of each of the others by a passage containing induc-,
tion and eduction valves, of which the former are worked by levers from a crank or
eccentric on a longitudinal counter shaft driven by bevil gearing from the crank.
shaft of the engine, the eduction valve of the low pressure cylinder being worked by
a cam. Each of the high pressure cylinders has at its back end suitable ports for
the admission of gas and air and of the igniting flame, governed by a slide worked
from the same countershaft.

page_text: The passage from each high pressure cylinder to the low pressure cylinder is
provided, firstly, with an admission valve, and secondly, with a stop valve for pre-
venting the gaseous products from passing to the second high pressure cylinder,
and the low pressure cylinder is provided with an escape valve leading to the
atmosphere.
In order to establish an equilibrium of pressure on each side of the admission
valves to the low pressure cylinder the piston of the latter is caused to compress
the gaseous products somewhat on its return stroke, and the stop valves are for the
same purpose caused to open somewhat before the admission valves.
For facility of starting the engine each high pressure cylinder is provided with an
escape valve, which during the commencement of the first compressing stroke is kept
open by a lever, so as to reduce the compression by allowing the gases to escape.
These levers are arranged to slide out of action when the engine is once started.
The escape valve of the low pressure cylinder is also kept open by a sliding pin
during the first outstroke, so as to allow air to enter, and thus prevent a vacuum
being formed behind the piston.
The gas is supplied to the high pressure cylinders through a valve regulated by a
governor by branch pipes leading to the two slides. Each of the three cylinders is
fitted with a piston or plunger, the two high pressure pistons being connected to
cranks on the engine shaft in line with each other, but performing their working
strokes alternately, and the low pressure piston being connected to a crank on the
same shaft opposite to the high pressure cranks, and made to perform a working
stroke at each revolution.
The operation of the engine will be understood by reference to the following
table, shewing the ralative timing of the actions in the three cylinders.
This cycle of operations is continuously repeated.
Although by the complete arrangement above described the full power of the
combustible is developed and applied with regularity to the crank shaft, yet when
it is desired to work without so much expansion the low pressure cylinder may be
dispensed with, the two high pressure cylinders then working so as to impart power
to the shaft alternately; or when regularity of action on the shaft is comparatively
unimportant one of the high pressure cylinders may be dispensed with, the low pressure
piston being then worked intermittently by expansion of the exhaust from a single
high pressure cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 11th
February 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN GAS MOTOR ENGINES." A com-
munication from abroad by Gottlieb Wilhelm Daimler, of the Gas-Motoren Fabrik-
Deutz, at Deutz on the Rhine, in the German Empire.
This Invention relates to that class of gas motor engines wherein a charge of com-
bustible gaseous mixture, drawn into a cylinder during one outstroke of its piston,
is compressed by the instroke, and being then ignited propels the piston during its
next outstroke, the products of combustion being expelled by the next instroke.
The present improvements consist in combining with one or more cylinders operating
in this manner at high pressure another low pressure cylinder, in which the products
of combustion from the high pressure cylinder or cylinders expand doing work, the
actions being so timed that at every stroke a portion of the power is communicated
to the one crank shaft with which the several pistons are connected. In a horizontal
engine constructed to operate in this manner the low pressure cylinder, open in front,
is placed between two high pressure cylinders, also open in front, one on each side
of it, and the back end of the low pressure cylinder is connected with the back end
of each of the others by a passage containing induction and eduction valves, of
which the former are worked by levers from a crank or eccentric on a longitudinal
counter shaft driven by bevil gearing from the crank shaft of the engine, the
eduction valve of the low pressure cylinder being worked by a cam. Each of
the high pressure cylinders has at its back end suitable ports for the admission of
gas and air and of the igniting flame, governed by a slide worked from the same
countershaft.
The passage from each high pressure cylinder to the low pressure cylinder is
provided, firstly, with an admission valve, and secondly, with a stop valve for pre-
venting the gaseous products from passing to the second high pressure cylinder,
and the low pressure cylinder is provided with an escape valve leading to the
atmosphere.
In order to establish an equilibrium of pressure on each side of the admission
valves to the low pressure cylinder the piston of the latter is caused to compress.the
gaseous products somewhat on its return stroke, and the stop valves are for the same
purpose caused to open somewhat before the admission valves.
For facility of starting the engine each high pressure cylinder is provided
with an escape valve, which during the commencement of the first compressing
stroke is kept open by a lever, so as to reduce the compression by allowing the
gases to escape.
These levers are arranged to slide out of action when the engine is once started.
The escape valve of the low pressure cylinder is also kept open by a sliding pin
during the first outstroke, so as to allow air to enter and thus prevent a vacuum
being formed behind the piston.
The gas is supplied to the high pressure cylinders through a valve regulated by a
governor by branch pipes leading to the two sides. Each of the three cylinders is
fitted with a piston or plunger, the two high pressure pistons being connected to
cranks on the engine shaft in line with each other, but performing their working
strokes alternately, and the low pressure piston being connected to a crank on the
same shaft opposite to the high pressure cranks and made to perform a working
stroke at each revolution.

page_text: The operation of the engine will be understood by reference to the following
table shewing the relative timing of the actions in the three cylinders :-
This cycle of operations is continuously repeated.
Although by the complete arrangement above described the full power of the
combustible is developed and applied with regularity to the crank shaft, yet when
it is desired to work without so much expansion the low pressure cylinder may be
dispensed with, the two high pressure cylinders then working so as to impart power
to the shaft alternately; or when regularity of action on the shaft is comparatively
unimportant one of the high pressure cylinders may be dispensed with, the low
pressure piston being then worked intermittently by expansion of the exhaust from
a single high pressure cylinder.
DESCRIPTION OF THE DRAWINGS.
The construction of a compound engine operating according to this Invention is
shewn on the accompanying, Drawings, in which Fig. 1 shews a side elevation of
the engine partly in section, and with one of the high pressure cylinders removed;
Fig. 2 shews a sectional plan; Fig. 3. shews a back end elevation; and Fig. 4 shews
,a cross, section on line X, X, Fig. 2. The two. high pressure cylinders A',.A³, are
open to the atmosphere at the front end, and contain pistons B1, B2, which by one
outstroke draw in a charge of combustible.gas and air, which is compressed by the
following: instroke, the charge being then fired, causing the piston to perform its
working outstroke, and, by the. next instroke the gaseous products of combustion
are expelled, the, mode of operating being so far. the same as described in the
Specification to Abel's Patent, No. 2081 of 1866. The two pistons B1, B2, are so
, connected by their piston rods to cranks C1, C2, on the engine shaft C as to perform
their outstrokes. simultaneously or nearly so, but these strokes are so timed that
while the one, piston is performing its working outstroke the other is performing
the stroke by which the combustible charge is drawn into the cylinder, so that the
engine shaft is propelled by a working stroke at every revolution, instead of only at
every other revolution, as would be the case with 'a single working cylinder. In
like manner, while the one piston is performing its compressing instroke, the other
performs its expelling instroke. Instead of allowing the expelled gases to escape
into the atmosphere, as was the case in the engine described in the above mentioned
Patent, they are caused to enter a third cylinder A³, whose piston B³ they conse-
quently propel outwards by their expansive force, and such piston being connected
by its rod to a crank C on the engine shaft opposite those C³, C³, of the high
↓

page_text: pressure cylinders or nearly so, it will be seen that the piston Bs will perform its
outstrokes, each of which is a working stroke, simultaneously with the instrokes of
the pistons B1, B³.
From the above it follows that with this arrangement there will occur during
each revolution of the shaft two impulses, the one being from one of the high
pressure cylinders, and the other from the low pressure cylinder. The passage of
the gaseous products from the high pressure cylinders to the low pressure cylinders
can commence before the pistons of the former arrive at the extreme end of out-
stroke, but the low pressure piston must at that time have just arrived at the
extreme end of its instroke.
The communications between the high and low pressure cylinders for effecting
the above described operations are governed by means of valves D', D³, in commu-
nicating passages E, E³, and the escape of the products from the low pressure
cylinder is regulated by the valve F closing an escape passage F¹. In order to
prevent the gases under pressure that are passing from the one high pressure
cylinder to the low pressure cylinder from passing also to the other high pressure
cylinder (which at that time will just be commencing its compressing stroke, and
will consequently contain gases at lower pressure) check valves G, G², are provided:
In order to equalize the pressure on each side of the valves D1, D2, so as both to
prevent loss of useful effect and wear and noise in working, the pressure in the
communicating passages E', E2, is maintained approximately equal to that of the
gases passing from the bigh to the low pressure cylinders by causing the escape
valve F to the latter to close before its piston arrives at end instroke, so as to
produce back pressure and to enable such back pressure to pass to the underside of
the valves D¹ or D2 before this is opened. The check valve G₁or G² is opened
slightly in advance thereof, and simultaneously with the closing of the escape
valve F. The opening of the valves D1, D2, and C, G, is effected from a counter-
shaft H by means of a crank I and connecting rod 1' working a lever I² on a
rocking shaft J carrying the rocking arms J¹, J2, with tappets which act on the
lower ends of the valve stems so as to press these upwards against the action of.
springs as shewn. The crank I also imparts the requisite reciprocating motion to
the usual admission and ignition slides K1, K2, of the high pressure cylinders by
means of the connecting rod K³. The escape valve F of the lowpressure cylinder
is actuated by two cams or tappets L³, L2, on the countershaft H through the
bell crank lever M. In order to reduce the work of compression during the first
compressing strokes of the high pressure cylinders on first starting the. engine,
these are provided with escape valves N1, N2, that are kept open during the first
part of such strokes, by means of tappet levers 01, 0%, actuated from the levers
J, J, so as to allow a portion of the first charge of the cylinders to escape. The
levers 01, 02, are capable of being slid upon their pins so as to be thrown out
of gear with the levers J¹, J, after the engine is started, as indicated by the
dotted positions 0³, 0%, at Fig. 2. In like manner the escape valve F of cylinder
A³ is kept open during the first outstroke of the piston in order to prevent a
vacuum being formed behind it, this being effected by means of a sliding pin T, as
shewn at Fig. 1, such pin being drawn backwards, as indicated by the dotted lines
when the engine is started. The supply of combustible gas to the slide K', K³,
of the high pressure cylinders is regulated by means of the gas valve P, actuated
by a bell crank lever P¹ from a sliding cam P' on the countershaft H .controlled
by a governor Q, in a similar manner to that described in the before mentioned
Patent of Abel, the valve being opened twice in one revolution of the shaft.
The gas passes from the valve P through the pipes R, R', to the engine slides,
which are also constructed and operate in a similar manner to that described in
Abel's Patent; they are so timed in their working that while the gas is passing
into slide of the one cylinder, it is cut off from the slide of the other cylinder.
The countershaft H receives its motion from the engine shaft C through gearing
S, S', so as to make one revolution for every two revolutions of the engine shaft.
The cylinders and passages are enclosed by jackets cooled by water circulation.

page_text: The above described engine may also be constructed without the low pressure
cylinder, in which case the two high pressure cylinders discharge their products of
combustion into the atmosphere, working otherwise, the same as above described.
Also a single high pressure cylinder may be combined with the low pressure
cylinder, operating in the same manner as above described.
Having thus described the nature of the said Invention and in what manner the
same is to be performed, as communicated to me by my foreign correspondent, I
claim,―
First. Constructing gas motor engines with two single acting high pressure
cylinders, each of which consecutively draws in a combustible charge, compresses it,
fires it, and performs the working stroke, and expels the products of combustion,
the pistons of the two cylinders being connected to one and the same engine shaft
so as to perform their strokes together, but the admission slides being so arranged
that the working stroke of the one cylinder is made to take place while the other
cylinder is drawing in its combustible charge, substantially as herein described.
Second. In a gas motor engine, the combination of two high pressure cylinders,
each of which consecutively draws in a combustible charge, compresses it, fires it,
and performs the working stroke, with a low pressure cylinder into which the
gaseous products are caused to pass alternately from each of the high pressure
cylinders, so as to perform further work by expansion, substantially as herein
described.
Third. In a gas motor engine, the combination of two high pressure cylinders
whose alternate outstrokes are working strokes, with a low pressure cylinder into
which the products of combustion pass from the bigh pressure cylinders, the one
high pressure piston being made to perform its working outstrokes simultaneously
with the charging outstroke of the other, while the low pressure piston performs a
working outstroke during each instroke of the high pressure cylinders, substantially
as herein set forth.
Fourth. In a gas motor engine wherein two high pressure cylinders operate in
combination with one low pressure cylinder, in which the products of combustion
from the high pressure cylinders are caused to act expansively, operating the two
admission slides of the high pressure cylinders, and the admission and check valves
from the high pressure cylinders to the low pressure cylinder by one and the same
crank or eccentric, on a shaft revolving at half the speed of the engine shaft,
substantially as herein described.
Fifth. In a gas motor engine, the combination of the high pressure cylinders
A1, A2, with low pressure cylinder A³ communicating passages E¹, E, admission
and check valves D¹, D2, G1, G2, actuated by crank I and tappet levers J¹, J2, and
escape valve F actuated by cams L and lever M, operating substantially as herein
set forth.
Sixth. In gas motor engines, the combination with the high pressure cylinders
A', A, of escape valves N¹, N³, operated by tappet levers 01, 02%, capable of being
slid out of action, substantially as and for the purposes herein set forth.
Seventh. In combination with the escape valve F of the low pressure cylinder,
the pin T capable of being slid so as to keep the valve F open, substantially as and
for the purposes set forth
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Eleventh day of February, in the year of our Lord One
thousand eight hundred and eighty.