Improvements in Gas Engines.
Year: 1896

page_text: Date of Application, 16th Dec., 1896-Accepted, 13th Feb., 1897
Improvements in Gas Engines.
I, FITZ EDWARD CULVER, Manufacturer, of 207 East Indiana Street, Chicago,
County of Cook and State of Illinois, United States of America, 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 :-
One of the difficulties encountered in gas engines is the heating of the cylinder
and piston and the consequent burning of the lubricant which becomes incrusted
upon the walls of the combustion chamber and not only increases the friction but
is apt to become ignited and cause premature explosions.
This is measurably
guarded against by the use of a water jacket for the cylinder, but this in turn gives
rise to unequal expansion of the parts, the cylinder being kept comparatively cool
while the piston becomes hot, and it fails to prevent the combustion of the oil which
accumulates upon the face of the piston.
The object of this invention is to provide improved means for cooling the piston
of such an engine by the use of water or other fluid, and to this end it consists in
forming the piston head with a chamber through which fluid is circulated by the
use of ports in one of the sliding parts of the engine, as for example, the piston or
crosshead registering with ports in fixed portions of the engine, as for example, the
cylinder wall, or the slide bars, the ports in the moving and in the fixed portious
being maintained in constant communication by the employment of longitudinal
grooves, preferably in the movable parts, which are of such length that they are
always open to the port in the other part.
As the invention has no relation whatever to the gas and air supply, or to the
exhaust of the engine, I have not shown in the drawings ports or valves for these
purposes, the invention being applicable to any form of gas engine in connection
with which a piston is used which may be chambered.
In the drawings-
Fig. 1 is a longitudinal, central section of the cylinder and piston of a single
acting gas engine, the piston being at the end of its outstroke, dotted lines
indicating its position at the end of its instroke;
Fig. 2 is a transverse section on the line 2-2 of Fig. 1 ;
Fig. 3 is a central, longitudinal section of the cylinder and piston of a double
acting gas engine;
Fig. 4 is a detail section on the line 4-4 of Fig. 3;
Fig. 5 is a detail plan section through the cylinder, piston, connecting rod and
cross-head of an engine showing the means for introducing water into the piston
through the cross-head;
Fig. 6 is a sectional view on the line 6-6 of Fig. 5;
Fig. 7 is a sectional view on the line 7-7 of Fig. 5.
I show at A the cylinder of a vertical gas engine, a portion of the base being
shown at X. Within the cylinder reciprocates a trunk piston, B, to which is
attached a pitman, C, by means of a wrist pin, c. Within the head of the piston is
formed a chamber, b. In the peripheral walls of the piston are formed longitudinal
grooves or channels, D, E, which may be oppositely disposed, as shown, or other-
wise arranged, as may be desired or may be found necessary in view of the
arrangement of gas and other ports in the particular engine to which the invention
is applied, and which may be of any desired width. These grooves or channels, D, E,

page_text: are of as great or greater length than the stroke of the piston and at one end each
communicates with the chamber b. Induction and e.luction ports, F, G, are for ned
in the cylinder walls and lead to the chaunels D, E, respectively. These ports are
so located that the channels are in communication with them throughout the entire
stroke of the piston. A water pipe, f, leads to the port F and the port G
discharges, as may be desired; as shown into the ordinary water chamber, a, in the
walls of the cylinder. Of course the port F may, if desired, be served from the
water chamber a, though I prefer to introduce the water first into the piston.
At H is shown an eduction pipe for the water chamber a.
Packing rings, K, L, are placed around the piston B beyond the ends of the
channels D, E, to prevent leakage of water.
It will be seen that the construction described provides for a continuous
circulation of water through the piston chamber, the service anl discharge ports
being at all times open through the channels D, E, to this chamber.
In adapting the invention to a double-acting engine, it is necessary to use a trunk
piston, M, so as to provide for the channels D, E, between the packing rings K, L.
Both ends of the piston are chambered as in licated at m, m, and the channels D, E,
communicate with both chambers.
The piston rod P is screwed into the piston head, and in order to provide ample
strength while leaving comparatively little metal between the chamber m and the
exploding chamber of the cylinder, the piston rod is prolonged and enters the
opposite wall of the chamber m.
In order to keep the piston rod P cool, I form it with a longitudinal duct, p
opening to the chamber m through the transverse aperture, pl.
In order to avoid excessive weight of the piston I core the center of it, as
shown at Q, and for the same reason do not open the chamber thus formed to the
water chambers, though it is obvious that the entire material of the piston night
be a single chamber.
Instead of communicating with the chamber of the piston through its peripheral
wall, and through the walls of the cylinder, water may be led to and discharged
from it by means of ducts leading through the piston rod and communicating with
ports in the sliding faces of the cross-head which in turn register with ports in the
guide bars.
This construction is shown in Figs. 5, 6 and 7 of the drawings, and makes it
possible to use a shorter piston, D', the piston being shown of sufficient length to
provide for the formation therein of the chamber Q' of such capacity that it will
contain a body of water adequate to the cooling of the piston, and to carry a
suitable packing ring L'.
The piston rod Pi has two longitudinal ducts, p³, p3, both of which open at one
end to the chamber Q', and also open laterally through the faces of the connecting
rod near its outer end so as to communicate with ducts r, 2, formed in the body
of the cross-head R, and which at one of their ends open laterally to the
grooves T, T', respectively, formed in the sliding faces of the cross-head, which
grooves enclose ports, t, t, respectively, in the faces of the guide-bars, S, S', upon
which the grooved faces of the cross-head slide. Service and discharge pipes, U, U',
communicate respectively with the ports, t, t¹.
The length of the grooves T, T', is equal to the length of the stroke of the
piston, and the ports t, t', are so disposed that they are always open to these
grooves. It will be seen therefore that fluid served under pressure through the
pipe U, will circulate through the several ducts and through the chamber of the
piston and be discharged through the pipe U.
It is obvious that the arrangement of the ducts and ports may be varied without
departing from the scope of the invention. For example, the induction and
eduction ports might be upon the same side of the cross-head and water might be
served and discharged through the upper guide-bars, s, s', instead of through the
lower guide-bars S, S¹. I desire therefore to be granted protection for any
construction in which a fluid transmitting joint is formed between a moving and

page_text: nxen part, one element of the joint being a groove in one of the parts which is in
constant communication with the port in the other, and from which leads a port or
duct so that an uninterrupted flow of liquid is provided for.
The cross-head R shown in the drawings differs from cross-heads of ordinary
construction only in that it is provided with ports, channels and ducts, as already
described, and is of greater length than usual in order to provide for the longi-.
tudinal grooves which must be of as great length as the stroke of the piston, in
order that the flow of liquid may be continuous. The wrist pin of the cross-head
is shown at r.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a gas engine, or the like, the combination with a cylinder, of a trunk piston
having a chambered head and longitudinal grooves in its peripheral surfaces, such
grooves being of as great length as the stroke of the piston and having both
terminals intermediate of the ends of the piston and being open to the chamber
in its head, and eduction and discharge ports in the cylinder walls, each registering
with one of the grooves throughout the entire stroke of the piston.
2. In a gas engine, or the like, the combination with a cylinder, of a piston
having a chamber within its head and induction and eduction ports in its walls
communicating with the chamber, and cylinder ports registering with the said
piston ports whereby fluid may be circulated through the piston.
3. In a gas engine, or the like, the combination with a cylinder, of a trunk piston,
packing rings encircling the piston, a chamber in the head of the piston, longitudinal
grooves in the peripheral surface of the piston wholly between the packing rings,
and of a length as great as the stroke of the piston, ports leading from such grooves
to the piston chamber, and cylinder ports registering continuously with such
grooves.
4. In a double-acting gas engine, or the like, the combination with a cylinder, of
a chambered piston, a piston rod apertured longitudinally from its inner end, its
aperture being open to the chamber of the pistou, ports in the walls of the cylinder
and opening to its chamber, and ports in the cylinder registering with such piston
ports.
5. In a gas engine, or the like, the combination with a cylinder, of a trunk piston
having a chambered head and longitudinal grooves in its peripheral surfaces, such
grooves having both of their terminals intermediate of the ends of the piston and
being open to the chamber in its head, and eduction and discharge ports in the
cylinder walls, each registering with one of the grooves.
6. The combination with a fixed part having a port, of a moving part in sliding
contact with the fixed part and having a port, and a groove in its contacting
surface leading from its port in the direction of movement, and so disposed as to
register with the port of the fixed part.
7. In an engine the combination with a chambered piston having ducts leading
to and from the piston chamber and opening through sliding faces which are
grooved from the mouths of such ducts in the direction of movement, of fixed
parts over which such sliding faces move, and having ports so disposed as to be
at all times in register with the grooves of such faces.
Dated this 3rd day of December A.D. 1896.
FITZ EDWARD CULVER.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.