Fluid-pressure Engines.
Year: 1894

page_text: Fluid-pressure Engines..
I, WILLIAM HAMPDEN JENKS, Machinist, a citizen of the United States,
residing at Brookville, in the County of Jefferson, and State of Pennsylvania, U.S.A.,
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:
The object of my invention is to provide improved means for relieving the
pressure in the cylinder of an engine, where steam or other fluid is admitted to the
cylinder through piston valves or valves of that class.
According to my present invention, I provide a sleeve which is loosely mounted
in the valve chest in such manner that it will form a tight joint with the cylinder
when in place against its seat, and will yet be free to move away from its seat in a
direction parallel to the direction in which the valve moves, to relieve excessive
pressure. The piston valve reciprocates through the sleeve.
In the accompanying drawings,-
Fig. 1 is a view in longitudinal section, of so much of an engine, such as a steam
engine, as is necessary to illustrate my improvements;
Fig. 2 is a transverse section, on the line 2-2 of Fig. 1;
Fig. 3 is a transverse section, on the line 3-3 of Fig. 1;
Figs. 4, 5 and 6 are detail views in section, of modifications of my invention,
showing the valves in different positions ;
Figs. 7, 8 and 9 are similar views, showing a further modification, in which
balanced valves are employed.
I will describe my improvements as embodied in a steam-engine, and will describe
them as operating when steam is employed, but I wish it understood that I do not
limit my invention to steam-engines, although it is especially designed for them.
Referring first to Figs. 1, 2 and 3, the cylinder A, has ports a a', at opposite
ends, communicating with exhaust ports B B', and with the steam-chest C. The
steam chest is provided with a case or support D, for the sleeve or relief valves E,
through which the reciprocating valve F extends. The ports a a¹ communicate
with openings ff, leading into the steam chest, and with openings bb, leading to
the exhaust passages B B. The ends of the cylinder A, and the openings c c¹ may
be closed in any suitable way.
The sleeves E E' are each shown as formed with an annular head e, adapted to
rest against a seat e', at the opening for f'. Each sleeve is also provided with a
socketed head e², and with openings e, through which the steam passes from the
steam chest into the bore of the sleeve.
The sleeves form a part of the valve cylinder, and lie loosely in the supports D,
which are bored to receive them, and hold them concentric with the openings b b'.
At their outer ends, the sleeves are faced to form steam-tight joints with the
seate ele, surrounding the openings ff. They are held against these seats by
the springs, and by the pressure of the steam in the steam chest. The central
portion G, of the valve acts merely as a support to help carry the weight of the
valves, and it is preferably made hollow to reduce its weight, as well as to give a
freer passage to the steam.
In the position of the valve, shown in Fig. 1, the port a is closed to the admission
of live steam, while the port a' is open. The exhaust at 6' is closed, while the
exhaust at bis open. Steam passing through the openings e will enter the cylinder
through the port a', as shown by arrow No. 1, while steam is exhausted through
the port a and opening b, into exhaust passage B, as indicated by arrow No. 2.

page_text: As the piston nears the end of its stroke, the valve F, moving in the same
direction, will first close the exhaust opening b, and then, continuing its motion
will, a little later, admit steam to the port a, from the steam chest C. If, during
the period of compression, viz., the period during which both band fare closed,
the pressure in this end of the cylinder rises too high, this pressure, acting on the
exposed end of the sleeve E, will force it back from its seat, and thus relieve the
pressure in the cylinder.
The tension of the springs e³, and the thickness of the sleeve or the width of its
exposed face may be so proportioned that the sleeve will open only when a pre-
determined pressure is reached. It will be observed that the sleeves really act as
supplemental valves or relief valves to relieve the abnormal pressure in the cylinder.
Figs. 4, 5 and 6 show my improvements embodied in unbalanced valves.
Similar letters of reference indicate similar parts to those shown in Fig. 1.
As indicated in Figs. 4, 5 and 6, the weight of the sleeve is sufficient to normally
hold it on its seat, and the steam will take the direction indicated by arrows. If,
however, an abnormal pressure occurs in the cylinder, as above mentioned, the
sleeve will be raised from its seat, as indicated in Fig. 6, while the valve is closed,
and thus the pressure will be relieved.
The valves and the sleeve will act in a similar manner when balanced valves are
employed, as shown in Figs. 7, 8 and 9.
In each instance, the sleeve or relief valve is normally stationary, and the
reciprocating valve, which governs the admission and exhaust, moves independently
of or without moving the relief valve.
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:
I." A fluid pressure engine provided with a cylinder, a valve chest, one or more
relief valves, and one or more reciprocating valves which pass through the relief
valve or valves, and govern the admission of steam or other fluid.
2. A fluid pressure engine provided with a cylinder, a valve chest, and a
reciprocating valve or valves governing the admission of steam and provided also
with a sleeve or relief valve through which the reciprocating. valve passes, and
means for normally holding the relief valve on its seat.
3. The combination of the cylinder, the fluid chest, ports leading from the fluid
chest to both ends of the cylinder, passages connecting the exhaust passages with
the ports at the ends of the cylinder, a valve chest, relief valves within the valve
chest provided with springs for holding them on their seats, and a reciprocating
valve extending through the relief valves.
Dated this 1st day of March 1894.