Improvements in Variable Automatic Cut off Mechanism for Fluid Pressure Engines.
Year: 1888

page_text: Date of Application, 28th July, 1888
Specification Accepted, 26th Oct., 1888
COMPLETE SPECIFICATION.
Improvements in Variable Automatic Cut off Mechanism for Fluid
Pressure Engines.
WC, GEORGE STONES, and JOHN STONES; both of Atlas Works, Brook Green,
Smethwick, in the County of. Stafford, Manufacturer, do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement :-
This invention has reference to a simple construction of variable automatic cut off
mechanism for fluid pressure engines, in which a wedge, or a plate formed with an
inclined edge, and operated by a governor is-used in conjunction with relatively adjust-
able cams that serve to effect the opening and closing of the valve or valves to be
controlled, the adjustment being effected by the governor through the medium of the
said wedge or plate with inclined edge.
In order that the nature of this invention and the manner of carrying it into effect
may be readily understood reference is made to the accompanying sheet of illustrative
drawings in which :-
Fig. 1 is a side elevation of cut off mechanism according to my invention.
Fig. 2 is a view at right angles to Fig. 1, shewing the combination of the mechanism
with a valve rod and a valve to be controlled; the valve and valve chamber are drawn
to a larger scale than the rest of the figure.
Figs. 3 and 4 are respectively a face view and a plan or top view drawn to a larger
scale of the cams and part of the valve rod.
Upon the shaft 1 that drives the governor 2 is fixed a main cam plate 3 provided
with diametrically arranged projecting cams 4. 5 is a cut off cam plate provided with
diametrically arranged projecting cams 6; it is mounted to revolve on the shaft 1 and
is connected to the main cam plate 3 by screws 7 in such a manner that it may be
turned through part of a revolution relatively to the main cam plate. The main and
cut off cam plates 3 and 5 are formed with curved slots 8 and 9 respectively. 10 is a
curved wedge or plate formed with an inclined edge 10ª; it extends through the
slots 8 and 9 of the cam plates and is connected at its smaller end to a sleeve 11
arranged so as to be capable of sliding on the shaft 1 under the action of a lever 12
which in turn is actuated by the sliding sleeve 13 of the governor.

page_text: When the governor is in action the wedge 10 will be caused to move through the
slots 8 and 9 to a greater or lesser extent, depending upon the speed of the engine and
thereby the cut off cam plate 5 will be moved relatively to the main cam plate 3, and
thus the position of the cut off cams 6 will be automatically adjusted in relation to
the cams which effect the opening movement of the valve or valves. 14 is a valve
rod connected at one end to a piston valve 15 that is arranged to work in a cylinder 16
and control the passage of motive fluid through a port 17. The valve rod is bent at
its other end and is formed with projecting portions or shoulders 18 and 19, which
may be furnished with antifriction wheels or rollers as shewn, and so arranged as to
be operated in turn by the cams on the cam plates 3 and 5 respectively. 20 is a
steady rod for the wedge 10; it works through a guide 21.
With the construction shewn it will be readily seen that if the shaft 1 be rotating
in the direction of the arrow (Fig. 2) the valve rod will be alternately moved to the
right by the cams 4 to admit of motive fluid passing through the port 17, and to the
left by the cams 6 to cut off the supply of such fluid the latter operations being
effected sooner or later according to the position of the cams 6 relatively to the cams 4
and consequently to the speed of the engine.
The valve rod in lieu of controlling one valve only may control two or more
valves.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is -
The arrangement substantially as described of variable automatic cut off mechanism
comprising a wedge actuated by a governor and operating in conjunction with cams-for
controlling a valve or valves.
Dated this 28th day of July 1888.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.