IMPROVEMENTS IN ENGINES WORKED BY GAS AND AIR, AND IN THEIR APPLICATION FOR RAISING OR FORCING LIQUIDS
Year: 1875

page_text: LETTERS PATENT to Charles Denton Abel, of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN ENGINES WORKED BY GAS AND AIR, AND
IN THEIR APPLICATION FOR RAISING OR FORCING LIQUIDS."-A com-
munication from abroad by Nicolaus August Otto, of the Gas
Motoren Fabrik-Deutz, at Deutz, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition,
on the 18th October 1875.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN ENGINES WORKED BY
GAS AND AIR, AND IN THEIR APPLICATION FOR RAISING OR FORCING LIQUIDS," to
be as follows:-
This Invention relates to engines of the kind in which a combustible
mixture of gas and air being ignited in a cylinder, a piston is propelled

page_text: by the force of the explosion without doing work, and as the products of
the combustion contract by cooling the piston is forced back by the
atmospheric pressure doing work in its return stroke. Engines of this
kind have been made to act with a single piston connected in such a
manner to a rotating shaft that during its out stroke it is disengaged
from the shaft, but during its in stroke it is engaged with it and com-
municates motive power to it, as described in the Specification of a
Patent No. 434, of 1866. Such engines have also been made to act
with two pistons, the one working piston being always connected to the
rotating shaft, and the other or loose piston being alternately released so
as to be free to be propelled by the explosion of the gaseous mixture,
and held while the working piston makes its in stroke as described in
the Specifications to Patents No. 2098, of 1863, No. 1173, of 1864,
No. 2959, of 1870, and others. In all such engines certain kinds of
mechanism have been employed for the purpose of alternately engaging
the one working piston with the rotating shaft and disengaging it
therefrom, or for alternately releasing and holding the loose piston when
two pistons are employed.
This Invention consists in substituting for such mechanism hydraulic
arrangements, whereby a liquid such as water or oil is made by
alternately stopping its flow and giving it freedom to flow, to effect
the desired alternation of action upon the moving parts of a gas motor
engine, the power of which when worked in this manner may be applied
to drive a rotating shaft or holder, or partially to pump or force
liquid.
The hydraulic arrangements applied to a gas motor engine are of the
following character:-There is a working piston connected by a con-
necting rod to a crank on the shaft of a heavy fly wheel, and a loose
piston is fitted to work in the same cylinder behind the working piston.
Both ends of the cylinder are open to the atmosphere; near the front
end is a lateral aperture governed by a slide, through which the com-
bustible gaseous mixture and the igniting flame are admitted, and near
the back end is an outlet for the products of combustion fitted with a
check valve opening outwards. Behind the main cylinder and in line
with it is another or hydraulic cylinder of smaller diameter charged
with water, oil, or other suitable liquid, and fitted with a piston which
is connected by a rod with the loose piston. The two ends of the
hydraulic cylinder communicate with each other by a pipe in which

page_text: there is a valve made to open of itself when there is excess of pressure
at the back end, and to close when there is excess of pressure at the
front end of the hydraulic cylinder; this valve however is connected by
suitable levers and rods to a cam on the fly wheel shaft, which during a
certain portion of cach revolution causes it to open and holds it open
against the pressure tending to close it.
The engine thus constructed operates in the following manner :-
Supposing the working piston to be at the extreme of its out stroke, and
the loose piston at a little distance behind it, a charge of the combustible
gascous mixture occupying the space between the pistons, then on
igniting this mixture the loose piston is rapidly propelled backwards
forcing with it the piston in the hydraulic cylinder which is free to
move as the liquid in that cylinder can flow freely from the back end
past the valve and into the front end of the cylinder. The loose piston
having effected its stroke the gascous contents of the working cylinder
contract by cooling, reducing the pressure therein below the external
atmospheric pressure which tends to force the loose piston forwards and
the working piston backwards. The loose piston cannot move forwards
because the hydraulic piston attached to it is held by the liquid in front
of it, which cannot return to the other end of the hydraulic cylinder, the
valve closing against its return. The working piston therefore makes its
in stroke, giving power to the crank and fly wheel with which it is
connected. As it approaches the loose piston which is then stationary
the gaseous products of combustion contained in the space between the
two pistons are compressed and forced out by the lateral aperture, and
the working piston comes close up to the loose piston. The cam on the
rotating shaft now opens the valve in the pipe of the hydraulic cylinder
making a free communication from the one end to the other, so that the
pressure on the two sides of the hydraulic piston is equalised. The
working piston being then by the momentum of the fly wheel caused
to make its out stroke the loose piston is caused by the atmospheric
pressure to follow it to nearly the end of its stroke. A little before the
end, however, the loose piston is stopped by the hydraulic piston attached
to it reaching the end of its cylinder, or by the cam permitting the
bydraulic valve to close, and the working piston still advancing draws
into the space between it and the loose piston a charge of inflammable
gas. This charge being ignited the action is repeated as above
described.

page_text: Avets improvements in Gas and Air Engines.
For giving greater freedom of movement to the loose piston when it
is propelled by the explosion the hydraulic piston may be made with a
passage through it fitted with a valve opening when the piston makes
its back stroke and closing when it makes its forward stroke. By
attaching this valve to the piston rod and giving the latter longitudinal
play in the piston, the cam arrangement for working the hydraulic valve.
may be dispensed with. To lessen the shock on the parts when the
explosion takes place an air chamber may be provided in the hydraulic
piston or in communication with the cylinder.
The hydraulic cylinder instead of being arranged in the same line
with the working cylinder may be placed at the side parallel to it, the
hydraulic piston being connected to a lever which is moved by the loose
piston.
The hydraulic cylinder may be made open at the back end, and its
front end made to communicate with a cistern by a suction pipe and
valve operated as above described.
The hydraulic cylinder and piston may be made to act for pumping or
forcing the liquid by providing at its back end a suction and dischargo
valve besides the valve already mentioned, which in that case is situated
in the passage from the cylinder to the discharge valve. In the forward
stroke of the piston it draws liquid in by the suction valve, and in its
back stroke it forces the liquid out by the discharge valve.
According to another construction the atmospheric pressure may be
made to act through the liquid on the working piston in the following
manner: The working piston is connected by a rod to the crank on the
fly wheel shaft, and works in a hydraulic cylinder. The loose piston is
connected to a cross head, to which are also connected two pistons, one
on each side, working in a hydraulic cylinder. Both these cylinders, as
well as the hydraulic cylinder first mentioned, are connected by a pipe
with a cistern containing liquid, in which pipe is a valve opening
outwards from the cistern, but opened for a time by the action of a cam
on the fly wheel shaft, like the valve already described.
The action is as follows:-The loose piston having been partially
raised from the bottom of its cylinder, drawing a charge of the com-
bustible gaseous mixture into the space below it, this charge is ignited,
and the piston is propelled upwards, carrying with it the two hydraulic

page_text: These by their ascent draw liquid
As the products of combustion
pistons connected to its cross head.
from the cistern past the opened valve.
cool the loose piston descends, moving downwards the two hydraulic
pistons. The liquid under them, as it is prevented by the valve from
returning to the cistern, is forced into the working cylinder, raising the
working piston therein, and so giving an impulse to the fly wheel shaft.
When the working piston reaches the top of its stroke the cistern valve
is opened by the cam, and the working piston is made by the momentum
of the fly wheel to descend, forcing the liquid under it back into the
cistern. As the working piston approaches the bottom of its stroke the
cistern valve is allowed to close, and the working piston in completing
its stroke forces liquid under the two hydraulic pistons, partially raising
them and the loose piston, whereby a charge of inflammable mixture
is drawn into the cylinder, and this charge being ignited the action is
repeated.
Instead of employing a piston working in a hydraulic cylinder and
connected to a crank on the fly wheel shaft, the liquid propelled by the
hydraulic pistons during the return stroke of the loose piston may be
made to act on the rotating shaft by means of a rotary engine arrange.
ment of any known kind; also, instead of applying in this manner two
hydraulic pistons connected by a cross head to the loose piston, one
hydraulic piston may be employed attached directly to the rod of the
loose piston, and working in a cylinder set in line with that in which the
loose piston works.
A convenient form of rotary engine to be worked by the liquid is that
kind of apparatus which has been employed as a rotary pump, consisting
of two toothed wheels gearing with each other within a casing. One of
these wheels being keyed on the fly wheel shaft the liquid forced into
the casing causes it to revolve, and thus the in stroke of the loose piston
effected under the influence of the atmospheric pressure is applied
through the hydraulic piston or pistons connected to it to give impulse
to the rotating shaft.
The hydraulic cylinder or cylinders in this case, as in the form of
engine first described, may be applied for the pumping or forcing of the
liquid by providing suitable suction and discharge passages and valve,
so that at the one stroke of the hydraulic piston, when it is propelled
along with the loose piston by the force of the explosion, liquid is drawn

page_text: in through the suction valve, and at the return stroke the liquid is
forced out; also by means of a suitable valve or cock situated in the
pipe communicating with the rotary portion of the apparatus the liquid
may be partly applied to give the rotary impulse to the fly wheel, and
partly may be forced or pumped out.
According to another modification the hydraulic cylinder instead of
being fixed is capable of longitudinal reciprocating motion, and is
connected by a connecting rod to the crank on the engine shaft. The
engine cylinder is closed at the back end, and its piston is connected by
a piston rod to the piston of the hydraulic cylinder. The explosion of
the charge propels the working piston forwards, the hydraulic piston
being at the same time made to travel to the front end of its cylinder,
causing the liquid therein to pass from the one end to the other, as
before described. On the return stroke of the working piston due to the
atmospheric pressure the hydraulic cylinder is caused to travel with it,
the hydraulic piston being prevented from moving backward in its
cylinder by the check valve. At the end of the back stroke the
momentum of the fly wheel causes the hydraulic cylinder and with it
the working piston to commence the next forward stroke, so as to draw
in the explosive charge, after which the check valve being opened by a
cam the hydraulic cylinder is free to complete its forward stroke, leaving
the working piston stationary.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Denton Abel in the Great Scal Patent
Office on the 15th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Charles Denton Abel,
Her special license that I, the said Charles Denton Abel, my exe-

page_text: cutors, administrators, and assigns, or such others as I, the said
Charles Denton Abel, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time, and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN ENGINES WORKED BY GAS AND
AIR, AND IN THEIR APPLICATION FOR RAISING OR FORCING LIQUIDS," a communi-
cation to me from abroad by Nicolaus August Otto, of the Gas
Motoren Fabrik-Deutz, at Deutz, in the German Empire, upon the con-
dition (amongst others) that I, the said Charles Denton Abel, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE that I, the said Charles Denton Abel, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Drawings, and to the figures and letters marked thereon,
that is to say :—
This Invention relates to engines of the kind in which a combustible
mixture of gas and air being ignited in a cylinder, a piston is propelled
by the force of the explosion without doing work, and as the products
of combustion contract by cooling the piston is forced back by the
atmospheric pressure doing work in its return stroke. Engines of this
kind have been made to act with a single piston connected in such
a manner to a rotating shaft that during its out stroke it is disengaged
from the shaft, but during its in stroke it is engaged with it, and com-
municates motive power to it, as described in the Specification of a
Patent, No. 434, of 1866. Such engines have also been made to act with
two pistons, the one working piston being always connected to the
rotating shaft, and the other or loose piston being alternately released so
as to be free to be propelled by the explosion of the gaseous mixture,
and held while the working piston makes its in stroke, as described in
the Specifications to Patents No. 2098 of 1863, No. 1173 of 1864,

page_text: No. 2959 of 1870, and others. In all such engines certain kinds of
mechanism have been employed for the purpose of alternately engaging
the one working piston with the rotating shaft and disengaging it there-
from, or for alternately releasing and holding the loose piston when two
pistons are employed.
This Invention consists in substituting for such mechanism hydraulic
arrangements whereby a liquid such as water or oil is made by alter-
nately stopping its flow and giving it freedom to flow to effect the desired
alternation of action upon the moving parts of a gas motor engine, the
power of which when worked in this manner may be applied to drive a
rotating shaft or wholly or partially to pump or force liquid.
On the accompanying Drawings are shewn various modified con-
structions of such hydraulic arrangements as applied to gas motor
engines.
Fig. 1 shows a longitudinal section and Fig. 2 a plan of one arrange-
ment. A is the gas engine cylinder and B its working piston, the piston
rod B of which is connected by connecting rods C, C, to crank pins D
on the fly wheel D fixed on the engine shaft E. Both ends of the
cylinder are open to the atmosphere, and near the front end is a port F
governed by a slide F¹, through which the combustible gascous mixture
and the igniting flame are admitted, while near the back end is an
outlet G for the products of combustion fitted with a check valve
opening outwards. Behind the main cylinder and in line with it is
another or hydraulic cylinder H of smaller diameter charged with water,
oil, or other suitable liquid, and fitted with a piston I, which is con-
nected by a rod I' with a loose piston K situated in the cylinder A.
The two ends of the hydraulic cylinder communicate with each other
by a pipe H³, in which there is a valve L made to open of itself when
there is excess of pressure at the back end, and to close when there is
excess of pressure at the front end of the hydraulic cylinder. This
valve, however, is connected by suitable levers and rods M, M³, to a
cam N on the fly wheel shaft, which during a certain portion of each
revolution causes it to open and holds it open against the pressure
tending to close it.
The engine thus constructed operates in the following manner :—
Supposing the working piston B to be at the extreme of its out stroke,
and the loose piston K at a little distance behind it, as shewn at Fig. 1,

page_text: a charge of the combustible gaseous mixture occupying the space
between the pistons, then on igniting this mixture the loose piston is
rapidly propelled backwards, forcing with it the piston I in the hydraulic
cylinder, which is free to move, as the liquid in that cylinder can flow
freely from the back end through the passage H₁ past the valve Land
into the front end of the cylinder. The loose piston K having effected
its stroke the gaseous contents of the working cylinder A contract by
cooling, reducing the pressure therein below the external atmospheric
pressure, which tends to force the loose piston forwards and the working
piston backwards. The loose piston cannot move forwards because the
hydraulic piston I attached to it is held by the liquid in front of it,
which cannot return to the other end of the hydraulic cylinder, the
valve L closing against its return. The working piston therefore makes
its in stroke, giving power to the crank, fly wheel, and shaft with which
it is connected. As it approaches the loose piston K, which is then
stationary, the gaseous products of combustion contained in the space
between the two pistons are compressed and forced out by the lateral
aperture G, and the working piston comes close up to the loose piston.
The cam N on the shaft E now opens the valve L in the pipe H' of the
hydraulic cylinder, making a free communication from the one end to
the other, so that the pressure on the two sides of the hydraulic piston
is equalised. The working piston being then by the momentum of the
fly wheel caused to make its out stroke, the loose piston is caused by the
atmospheric pressure to follow it to nearly the end of its stroke. A little
before the end, however, the loose piston is stopped by the hydraulic
piston attached to it reaching the end of its cylinder, or by the cam N
permitting the hydraulic valve L to close, and the working piston still
advancing draws into the space between it and the loose piston a charge
of inflammable gas. This charge being ignited the action is repeated as
above described.
For giving greater freedom of movement to the loose piston when it is
propelled by the explosion the hydraulic piston may be made with a
passage through it fitted with a valve opening when the piston makes its
back stroke, and closing when it makes its forward stroke. By attaching
this valve to the piston rod and giving the latter longitudinal play in
the piston the cam arrangement for working the hydraulic valve may be
dispensed with. This arrangement is shewn at Figs. 3 and 4, where A
is the engine cylinder; K, the loose piston; H, the hydraulic cylinder;

page_text: and I its piston. This is formed with passages i, i, through it, and it is
free to slide upon the piston rod I' between the collar ¹ and the valve
fixed on I', and serving to close the passages i when in the position
shewn in Fig. 3. A spring tends to force the piston away from the
valve so as to keep the passages i open. When the piston K receives
its impulse on the occurrence of an explosion in the working cylinder
the rod I will in commencing its motion push open the valve ³, so as to
open the passages i, as shewn at Fig. 4, thus allowing the free passage
of the liquid from the one end of the cylinder to the other through these
passages, while at the same time liquid will also pass through the
valve L and passage H¹, as in the first-described arrangement. When
the piston I has arrived at the end of its out stroke, as shewn at
Fig. 3, the propelling force being then overbalanced by the atmospheric
pressure against the piston K, the pull on the rod I will cause the
valve to close the passages i, thus preventing the liquid from passing
through the latter, and as the valve L will then also close, the piston I,
and consequently the piston K, will be held stationary while the working
piston B, Fig. 1, performs its in stroke, as before described. The
piston B in arriving at the end of its in stroke will push against the
piston K, thereby pushing the valve open, whereupon the liquid will
be free to pass from the one end of the cylinder H to the other through
the passages
i and the pistons I, K and B will consequently be free to
perform their return stroke under the pressure of the atmosphere, the
spring serving to keep the piston I away from the valve 2 during the
stroke. An elastic buffer Z may be provided in the cylinder H, as
shewn, to check the outward motion of the piston I should the explosion
be too violent. To lessen the shock on the parts when the explosion
takes place an air chamber may be provided in the hydraulic piston or
in communication with the cylinder.
The hydraulic cylinder, instead of being arranged in the same line.
with the working cylinder, may be placed at the side parallel to it, the
hydraulic piston being connected to a lever which is moved by the loose
piston.
The hydraulic cylinder may be made open at the back end, and its
front end made to communicate with a cistern by a suction pipe and
valve operated as above described; Fig. 5 shews a longitudinal section
of such an arrangement. The hydraulic cylinder H is arranged below.
the engine cylinder A, and as its piston I is connected to the rocking

page_text: lever O, which is actuated by the loose piston K, at a point o con-
siderably nearer its fulcrum than the point of attachment o¹ of K, the
cylinder H can be made of a correspondingly less length than A. As
the piston K performs its out stroke consequent upon an explosion the
lever O draws forward the piston I in its cylinder, causing liquid in the
reservoir to rise in the suction pipe H' and through the valve L into the
back end of the cylinder H, the front end of which is open. When the
piston K has reached the end of its out stroke it is prevented from
returning, owing to the closing of the valve L preventing the liquid
from flowing out of the cylinder H again. When the piston B has
performed its in stroke, the cam N operating on the lever M connected
to the valve L will cause this to open, thus allowing the liquid to flow
out of H, and permitting the return stroke of the pistons. The motion
of the piston B is communicated to the engine shaft E through levers Q,
connected to the cranks at the point q by connecting rods.
The bydraulic cylinder and piston may be made to act for pumping or
forcing the liquid by providing at its back end a suction and discharge
valve, besides the valve already mentioned, which in that case is situated
in the passage from the cylinder to the discharge valve. In the forward
stroke of the piston it draws liquid in by the suction valve, at the same
time forcing liquid out by the discharge valve. Fig. 6 shows this arrange-
ment, R, R', being the suction pipe and valve, and S, S', the delivery
pipe and valve, on the hydraulic cylinder H, which is otherwise similar
in construction to that shewn at Fig. 1. On the piston I performing its
stroke to the right it raises liquid through the suction pipe R into the
cylinder H, at the same time forcing liquid through the passage H¹
and valve S¹ up the pipe S, and it will be seen that by regulating the
lift of the valve S₁ relative to that of the valve R' by means of the
screw spindle T, the quantity of liquid forced through S can be so pro-
portioned that the working piston shall retain sufficient power to
overcome the frictional resistance of the machine. If the valve S' be
entirely closed down by the screw T, it will be seen that the apparatus
will act in precisely the same manner as that shewn at Fig. 1.
According to another construction the atmospheric pressure may be
made to act through the liquid on the working piston, as shewn
diagrammatically at Figs. 7 and S. The working piston B is connected
by a rod to the crank D' on the fly wheel shaft E, and works in a
hydraulic cylinder U. The loose piston K in cylinder A is connected to

page_text: a cross head K', to which are also connected two pistons I, I, one on
cach side, working in a hydraulic cylinder H. Both these cylinders, as
well as the hydraulic cylinder U, are connected by a pipe V1 with a
cistern V containing liquid, in which pipe is a valve V opening outwards
from the cistern, but opened for a time by the action of a cam on the
fly wheel shaft, like the valve already described.
The action is as follows:-The loose piston K having been partially
raised from the bottom of its cylinder, drawing a charge of the com-
bustible gaseous mixture into the space below it, this charge is
ignited and the piston is propelled upwards, carrying with it the two
hydraulic pistons I connected to its cross head; these by their ascent
draw liquid from the cistern V past the opened valve V². As the
products of combustion cool the loose piston descends, moving down-
wards the two hydraulic pistons. The liquid under them, as it is
prevented by the valve from returning to the cistern, is forced into the
working cylinder U, raising the working piston B therein, and so giving
an impulse to the fly wheel shaft E. When the working piston reaches
the top of its stroke the cistern valvo V2 is opened by the cam, and the
working piston B is made by the momentum of the fly wheel to descend,
forcing the liquid under it back into the cistern. As the working piston
approaches the bottom of its stroke the cistern valve is allowed to close,
and the working piston in completing its stroke forces liquid under the
two hydraulic pistons I, partially raising them and the loose piston K,
whereby a charge of inflammable mixture is drawn into the cylinder,
and this charge being ignited the action is repeated.
Instead of employing a piston working in a hydraulic cylinder and
connected to a crank on the fly wheel shaft, the liquid propelled by the
hydraulic pistons during the return stroke of the loose piston may be
made to act on the rotating shaft by means of a rotary engine arrange-
ment of any known kind; also, instead of applying in this manner
two hydraulic pistons connected by a cross head to the loose piston,
one hydraulic piston may be employed attached directly to the rod of the
loose piston, and working in a cylinder set in line with that in which the
loose piston works.

page_text: One of these wheels being keyed on the fly wheel shaft, the liquid forced
into the casing causes it to revolve, and thus the in stroke of the loosc
piston, effected under the influence of the atmospheric pressure, is applied
through the hydraulic piston or pistons connected to it to give impulse
to the rotating shaft.
Fig. 9 shews diagrammatically the last described arrangement, and
Figs. 10 to 13 shew the arrangement as applied to a portable pumping
engine. In Fig. 9 the piston B which is propelled upwards in the
cylinder A by the explosive charge is connected directly to the piston I
of the hydraulic cylinder H, as this piston is propelled upwards by B it
causes the liquid above it to pass down the passage H', and through the
spring valve L into the lower end of the cylinder H. On the return
stroke of the pistons the liquid is forced through the passage H³ (the
valve L being closed) into the rotary engine W, one wheel of which is
fixed on and imparts rotary motion to the fly wheel shaft, the liquid
passing from the engine W through the pipe H³ back into the upper
part of the cylinder H. To apply this arrangement as a pump a suction
pipe would be connected to the pipe H¹ just above the valve L and a
delivery pipe to the pipe H³, which would also have a cock or valve for
cutting off the communication with the top of the cylinder H'; the
machine would then operate in a similar manner to the arrangement at
Fig. 6.
Fig. 10 shews a vertical section; Fig. 11, a sectional plan on line
X, X; Fig. 12, a side elevation, and Fig. 13, a section on line Y, Y, of
a portable pumping engine constructed according to the above described
modification, and arranged so as to act as a pumping engine or as an
ordinary engine for propelling itself or for other purposes; B is as before,
the working piston connected to the hydraulic piston I in the cylinder
H, this piston having passages through it closed by a self-acting valve ³.
The delivery passage H³ communicates with the cylinder H at bottom,
and with the rotary pump W and extends up beyond the latter to the
delivery pipe a, as shewn at Fig. 13. By means of the cock b, the
passage H can also be made to communicate with the suction passage
H', while the communication with a is cut off. The suction passage H¹
extends from this point of communication to the upper end of the
cylinder H with which it communicates, as shewn at Fig. 12. If the
cock is turned so as to establish the communication as last described,
the liquid flows from the bottom of the cylinder II through the rotary

page_text: engine W, and into the top of H again, as described with reference to
Fig. 9, and the engine acts as an ordinary motor engine, the liquid
passing through the piston I on its upward flight, while on the down-
ward motion of the piston the valve closes, and the liquid is forced
through W, as above described, imparting motion to the fly wheel D. If
on the other hand the cock b be turned into the position shown at
Fig. 13, then on the descent of the piston I liquid will be drawn in
from the tank d through the suction pipe c, and suction passage H¹ into
the upper end of the cylinder H, while the liquid below the piston I
will be forced through the delivery passage H² and pipe a. As the
liquid on its passage passes through and actuates the rotary engine W,
part of the power of the engine may be taken off the fly wheel shaft for
any desired purpose, should the delivery column be small or should the
cock a be partially closed for this purpose. The other details of this
engine form no part of the present Invention, and need therefore not be
further described.
According to another modification the hydraulic cylinder instead of
being fixed is capable of longitudinal reciprocating motion, and is
connected by a connecting rod to the crank on the engine shaft. The
engine cylinder is closed at the back end, and its piston is connected by
a piston rod to the piston of the hydraulic cylinder. The explosion of
the charge propels the working piston forwards, the hydraulic piston
being at the same time made to travel to the front end of its cylinder
causing the liquid therein to pass from the one end to the other as before
described. On the return stroke of the working piston due to the
atmospheric pressure the hydraulic cylinder is caused to travel with it,
the hydraulic piston being prevented from moving backward in its
cylinder by the check valve. At the end of the back stroke the
momentum of the fly wheel causes the hydraulic cylinder, and with it
the working piston to commence the next forward stroke so as to draw
in the explosive charge, after which the check valve being opened by a
cam, the hydraulic cylinder is free to complete its forward stroke leaving
the working piston stationary.
Having thus described the nature of this Invention, and in what
manner the same is to be performed as communicated to me by my
foreign correspondent, I claim in respect of engines worked by gas and
air of the kind therein referred to,―
First. The method of effecting the desired alternation of action of the

page_text: piston or pistons upon the moving parts, by alternately stopping the
flow of a liquid in communication with the said piston or pistons and
giving it freedom to flow, substantially as herein described.
Second. The use for effecting the alternation referred to in the
preceding claim of a piston in a cylinder containing liquid and fitted
with a valve, so arranged that the piston is free to travel in one
direction, but has its return stroke controlled, substantially as herein
described
piston or pistons upon the moving parts, by alternately stopping the
flow of a liquid in communication with the said piston or pistons and
giving it freedom to flow, substantially as herein described.
Second. The use for effecting the alternation referred to in the
preceding claim of a piston in a cylinder containing liquid and fitted
with a valve, so arranged that the piston is free to travel in one
direction, but has its return stroke controlled, substantially as herein
described
Third. The arrangement and mode of action of such hydraulic
cylinders, as herein-before described with referenco to Figs. 1 to 5 of
the Drawings.
Fourth. Utilising such hydraulic cylinders for raising or forcing
liquids, substantially as herein described with reference to Figs. 6, 9,
and 10 to 13 of the Drawings.
Fifth. Communicating the motion of the piston to the engine shaft
through the medium of a liquid, substantially as herein described with
reference to Figs. 7 to 13 of the Drawings.
In witness whereof, I, the said Charles Denton Abel, have here
unto set my hand and scal, this Thirteenth day of April, in
the year of our Lord One thousand eight hundred and seventy-
six.