IMPROVE- MENTS IN GAS MOTOR ENGINES
Year: 1883

page_text: "
LETTERS PATENT to Charles Denton Abel of N° 28 Southampton Buildings
Chancery Lane in the County of Middlesex for an Invention of "IMPROVE-
MENTS IN GAS MOTOR ENGINES communicated to him from Abroad by
Nicolaus August Otto of the Gas Motoren Fabrik Deutz of Deutz on the
Rhine in the German Empire
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at
the Office of the Commissioners of Patents on the 3rd April 1883.
CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane, in the
County of Middlesex IMPROVEMENTS IN GAS-MOTOR ENGINES [Communi-
cated to him from Abroad by Nicolaus August Otto of the Gas Motoren Fabrik
Deutz of Deutz on the Rhine in the German Empire]
"
This invention has for its object to produce a very uniform or equable motion in
single acting gas motor engines, that is to say, those in which the admission and
ignition of a combustible gaseous charge takes place on one side only of the
piston.
The invention consists in causing the power produced by the combustion of a
gaseous charge to be partially expended in compressing air during the outstroke of
the piston which air is allowed to expand again on the return stroke of the piston,
thus giving out the power previously stored up.
Various arrangements may be employed for carrying out the invention. In the
arrangement employed by preference there is provided in combination with the
engine a closed receiver or chamber, in which air is in the first instance compressed
to a certain degree by a hand pump or other suitable means, so that, at the
commencement of the working outstroke of the piston, when the expansive force
of the combustion gases is greatest, there shall be opposed to it a considerable
resistance in causing it to effect the further compression of the already compressed
air in the receiver. The compression of the air may be effected either directly by
the working piston, by closing the front end of the cylinder and establishing a
communication between the front end and the compressed air receiver, so that the

page_text: air in front of the piston, being under the same pressure as that existing in the
receiver, will be forced back into the latter. Or the front end of the cylinder may
be open as usual, and a second cylinder be provided which communicates with the
air receiver, and whose piston is connected to the crank-shaft in such manner that
when the working piston is performing its outstroke the piston in the auxiliary
cylinder is caused to force the air from the latter into the receiver, while on the
return stroke of the working piston the compressed air, in expanding in the
auxiliary cylinder, moves its piston so as to transmit the power thus given off to
the crank-shaft. In employing this arrangement it is convenient to construct the
engine with two working cylinders whose pistons are connected to parallel cranks,
so as to perform their outstrokes simultaneously while the auxiliary cylinder is
situated between them and has its crank so arranged relatively to the others that
the piston performs its compressing stroke while the other pistons are performing
their instrokes. Any leakage in the air receiver may be made good from time
to time either by means of the before mentioned hand pump, or by establishing a
communication between an intermediate point in the length of the working
cylinder and the air receiver, so that when the piston passes that point, should the
pressure in the air receiver be less than that of the gases under pressure behind
the piston these will pass partly into the air receiver and raise the pressure therein
to the same degree. The said communication is provided with a check valve, so
as to prevent the air pressure from passing back again into the cylinder when the
pressure therein has becoine reduced by the further expansion of the gases. The
reservoir is provided with a cock for preventing the escape of air pressure when
the engine is not at work.
According to another modification the power of the engine instead of being
made to compress air may be caused to produce a vacuum, so that the atmospheric
pressure in acting against such vacuum on the return stroke of the piston will
give back the power previously expended. For this purpose the piston of the
before mentioned auxiliary cylinder may merely be drawn outwards during
the outstroke of the working piston, so as to produce a vacuum behind it, and
be forced inward again by the atmosphere on the return stroke of the working
piston.
The auxiliary cylinder may be provided with a small check valve through which
any air that may have leaked into it while the vacuum is being produced will be
forced out again on the return stroke of the piston..

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
27th September 1883.
CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane, in the
County of Middlesex "IMPROVEMENTS IN GAS MOTOR ENGINES"
A com-
munication to me from abroad by Nicolaus August Otto of the Gas Motoren
Fabrik Deutz of Deutz on the Rhine in the German Empire.
This invention has for its object to produce a very uniform or equable motion in
single acting gas motor engines, that is to say, those in which the admission and
ignition of a combustible gascous charge take place on one side only of the piston.
The invention consists in causing the power produced by the combustion of a
gaseous charge to be partially expended in compressing air during the outstroke
of the piston, which air is allowed to expand again on the return stroke of the
piston, thus giving out the power previously stored up.
Various arrangements may be employed for carrying out the invention. In the
arrangement employed by preference, there is provided in combination with the
engine, a closed receiver or chamber, in which air is in the first instance com-
pressed to a certain degree by a hand pump or other suitable means, so that, at
the commencement of the working outstroke of the piston, when the expansive
force of the combustion gases is greatest, there shall be opposed to it a considerable
resistance in causing it to effect the farther compression of the already compressed
air in the receiver. The compression of the air may be effected either directly
by the working piston, by closing the front end of the cylinder and establishing a
communication between the front end and the compressed air receiver, so that
the air in front of the piston being under the same pressure as that existing in
the receiver will be forced back into the latter. Or the front end of the cylinder
may be open as usual, and a second cylinder be provided which communicates
with the air receiver and whose piston is connected to the crank shaft in such
manner that when the working piston is performing its outstroke, the piston in
the auxiliary cylinder is caused to force the air from the latter into the receivor,
while on the return stroke of the working piston the compressed air in expanding
in the auxiliary cylinder moves its piston so as to transmit the power thus given
off to the crank shaft. In employing this arrangement, it is convenient to
construct the engine with two working cylinders whose pistons are connected to
parallel cranks, so as to perform their outstrokes simultaneously, while the
auxiliary cylinder is situated between them and has its crank so arranged relatively
to the others that the piston performs its compressing stroke while the other
pistons are performing their instrokes. Any leakage of the air receiver may be
made good from time to time either by means of the before mentioned hand pump
or as will be presently described. According to another modification, the power
of the engine, instead of being made to compress air, may be caused to produce a
vacuum, so that the atmospheric pressure, in acting against such vacuum on the
return stroke of the piston, will give back the power previously expended.
Fig. 1 of the accompanying drawing shews a sectional plan of one construction
of engine according to the present invention. In this arrangement, there are two
working cylinders a and b, with pistons a' and b¹ connected to parallel cranks on
the crank shaft c. Between these is a third cylinder d with a piston d connected
by a pipe with the compressed air receiver e. The crank of the piston d' is
diametrically opposito those of a¹ and b¹, so that when the latter alternately
perform their working outstroke on the combustion and expansion of a gaseous

page_text: charge, the piston d' will be made to perform its instroke, forcing the air under
pressure contained in the cylinder, through the pipe f back into the reservoir e.
On the return stroke of the pistons a' b the compressed air in e will force the
piston d² outward, thus giving off the power again that was previously stored up.
kis a hand pump for charging the reservoir with air of the required pressure in
the first instance. A cock is provided for preventing the escape of the air
pressure when the engine is not at work.
Fig. 2 shews a sectional plan of an arrangement in which the additional com-
pressing cylinder is dispensed with, the front end of the cylinder b being closed
and connected directly by a pipe f with the reservoir c. The reservoir is also
connected by a second pipe g provided with a check valve h with an intermediate
point in the length of the cylinder, by which arrangement any loss of pressure in
the reservoir due to leakage is made good automatically at each working out-
stroke of the piston, inasmuch as when the piston passes beyond the opening of g
the gases under pressure contained behind it will enter e and raise the air therein
to the same pressure. The check valve h prevents such pressure from passing
back again when, by the further expansion of the gases, their pressure has
decreased; by regulating the load on this valve the degree of pressure in the air
vessel will also be regulated.
Fig. 3 shows an arrangement in which the attainment of greater uniformity of
motion is effected by the production of a vacuum or partial vacuum during the
working stroke of the engine, against which the atmospheric pressure acts in aid
of the return stroke. For this purpose a third cylinder d is provided, whose
piston d' moves in the same direction as the working pistons a¹ and b¹. The
piston moves close up to the bottom of the cylinder d at its instroke and expels
any air that may leak into the cylinder through the discharge valve i, so that
when it is caused to perform its outstroke, during the working outstroke of the
pistons a b', a vacuum or partial vacuum is formed behind it, against which the
atmospheric pressure acts on the return stroke.
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. In gas inotor engines in which the admission and combustion of the
gaseous charge only takes place on one side of the piston, the method of causing a
portion of the power produced by the combustion of the charges to be expended
during the working stroke of the piston in increasing the compression of air which
has been previously compressed to a certain degree and which is afterwards
allowed to expand again so as to give off the power so stored up during the return
stroke of the piston, substantially as herein described.
Second. In combination with a gas motor engine in which the admission and
combustion of the gaseous charges only take place on one side of the piston, a
compressed air reservoir, the air in which is still further compressed during the
working outstroke of the engine piston, and expands during the instroke of the
engine piston, substantially as and for the purposes herein described with reference
to Figs. 1 and 2 of the drawings.
Third. In a gas motor engine, the combination of two single acting cylinders a b,
whose pistons a¹ b' are connected to parallel cranks on the engine shaft c with a
compressing cylinder & whose piston d' is connected to a crank opposite to those
of a b', and which is connected by a pipe f with a reservoir e for compressed air
substantially as herein described.
Fourth. In combination with a gas motor engine, a compressed air reservoir, the
air in which is still further compressed during the working outstroke of the piston
and which communicates by a pipe or passage with an intermediate point in the
length of the cylinder, so that on the piston passing such point during its working
outstroke, the combustion gases behind it will enter the reservoir and raise the
pressure therein should it have sunk through leakage.
Fifth. In combination with a gas motor engine in which the admission and

page_text: combustion of the gaseous charge is effected only on one side of the piston, a
separate cylinder, whose piston during the instroke of the working piston, moves
close up to the bottom of the cylinder, so as to expel all the air therefrom through
a discharge valve, so that when the piston is made to perform its outstroke, during
the working outstroke of the working piston or pistons, a vacuum or partial
vacuum is formed behind it, against which the pressure of the atmosphere acts on
the return stroke of the piston, thus giving out the power again that had previously
been expended in forming the vacuum, substantially as described with reference to
the accompanying drawings.
Sixth. In gas motor engines, the combination with a single acting working
cylinder of an auxiliary cylinder d with discharge valve i and piston d by whose
outstroke a vacuum or partial vacuum is formed in the cylinder, and at whose
instroke any air in the cylinder is expelled through the valve 2, 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 twenty ninth day of August in the year of our Lord One thousand
eight hundred and eighty three.
.