Year: 1886

page_text: Date of Application, 20th Aug., 1886.
Complete Left, 18th Apr., 1887.
Complete Accepted, 20th May, 1887.
I, JAMES COURTHOPE PEACHE of Thames Ditton in the County of Surrey, Engineer
do hereby declare the nature of this invention to be as follows
My invention is applicable to quick running single acting steam and other engines
in which the valve is contained in a hollow piston rod or other portion of the recipro-
cating parts. In such engines I transmit to the valve a motion compounded of the
angular motion of the connecting rod and the reciprocating motion of the piston. In
this way any desired amount of lead in the movements of the valve can be obtained.
The end of the connecting rod which is jointed to the piston I form with an arm
extending at right angles from it, this arm I connect by a link with a lover which also
(in its central position) is at right angles with the axis of the cylinder and which at
one end turns on a fixed centre.
The lever I connect by a link with the valve stem. This link may be coupled to
the lever either nearer to or further from the axis of the lever than the first mentioned
link.
Or the point of connection of one or both links may be made adjustable, by suitable
mechanism for the purpose of varying the motion of the valves to give greater or less
expansion of steam."
In this case it might be desirable to place the fixed point of the lever at a position
either above or below the position at which, at half stroke, it would be square with
the axis of the cylinder.
To prevent leakage at the piston valve through the packing rings being forced
inwards by the pressure of steam I employ a number of small narrow.rings and when
one face only of the piston valve has to be passed beyond ports in the piston rod or
other part then at the other face I always have one or more rings which are nover
brought in front of the port.

page_text: The crank chamber of the engine I form on one side with a circular flanged face
in the plane at right angles to the crank shaft and concentric with it and I bolt this
face to a flat face at the end of the bearing which carries the crank shaft. This
admits of the engine being swivelled around the crank shaft and of its being fixed in
any desired position.
The crank shaft may be coupled by a suitable coupling to the axis of a fan or pump
or such like or it may itself form the axis of such machines.
The connecting rod I make to work on to a crank pin projecting from a disc at the
end of the shaft just inside the crank chamber. Or the crank axis might be carried
through the crank chamber and be coupled at one end to the machinery to be driven
and at the other end carry a governor.
Dated this 20th day of A nouust 1996
CARPMAEL & Co.,
Agents for the Applicant.

page_text: I JAMES COURTHOPE PRACHE of Thames Ditton in the County of Surrey Engineer,
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:-
My Invention is applicable to quick running single acting steam and other engines
in which the valve is contained in a hollow piston rod or other portion of the recipro-
cating parts. In such engines I transmit to the valve a motion compounded of the
angular motion of the connecting rod and the reciprocating motion of the piston. In
this way any desired amount of lead in the movements of the valve can be obtained.
The end of the connecting rod which is jointed to the piston I form with an arm
extending at right angles from it, this arm I connect by a link with a lever which also
(in its central position) is at right angles with the axis of the cylinder and which at
one end turns on a fixed centre.
The lever I connect by a link with the valve stem. This link may be coupled to the
lever either nearer to or further from the axis of the lever than the first mentioned
link.
Or the point of connection of one or both links may be made adjustable by suitable
mechanism, for the purpose of varying the motion of the valves to give greater or less
expansion of steam."
In this case it might be desirable to place the fixed point of the lever at a position
either above or below the position at which, at half stroke, it would be square with the
axis of the cylinder.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings horeunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figuros 1, 1ª and 1 show respectively a vertical section, an elevation and a plan of
an engine with my valve gear applied.
Figure 2 is a vertical section of another similar engine but with a valve of another
form.
Figure 2 shows separately the crank and connecting rod of the engine shown by
Figure 2.
A, is the steam branch e e, ff, gg, are rings of ports in a hollow piston rod. Bis
a stuffing box through which the piston rod passes. C. O. is the cylinder. V in
Figure 1 and Vand Q. in Figure 2 are pistons working inside the hollow piston rod,
and acting.as valves by passing above or below the ports and so allowing stoam to
enter or escape.
These valves are actuated by my arrangement of valve gear. X is the little end of
the connecting rod which pivots on a pin made fast in the crosshead. This connecting
rod has an arm projecting at right angles and which at m, is connected to a link m, n.

page_text: This link again is connected at n, to a lever n. l. y. which is pivoted at y, and to which
the valve connecting rod is attached at l.
The engine runs in the direction shown by the arrow in each case. In Figure 1 the
valve moves downward admitting steam over the piston by ports e, e, f, f. In Figure 2
the valve moves upward also admitting steam by ports e eff. The exhaust is by
ports ff, and g. g. It will be seen that any desired amount of lead may be given to
the valve.
The valve gear is shown as applied to an engine of well known type such as is made
by Messrs. Willans & Robinson of Thames Ditton but is equally applicable to any
engine of the central valve type.
Having now particularly described and ascertained the nature of my said invention
and in what manner
the same is to be performed I declare that what I claim is :-
1. Actuating the valve of a central valve engine by connecting it with a lever or
part having a stationary fulcrum and receiving motion by a link connecting it with
an arm on the connecting rod.
2. The arrangement of levers by which the valve receives its motion substantially
as described and illustrated by the annexed drawings.