Improvements in and relating to the Valves of Steam Engines.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to the Valves of Steam Engines.
I, SYDNEY WILLIAM WILKINSON, of 6, Crookes Place, Hillsbro', City of Sheffield,
Engineer, do hereby declare the nature of my invention to be as follows:-
My invention has for its object to simplify the mechanism of valves for steam
engines, and is specially adapted for use in connection with three cylinder engines
for vehicles, launches and the like.
In its application to a three cylinder engine for example, steam being admitted
to the back of the pistons only, I arrange the inlet ports and the exhaust at the
upper ends of the inverted cylinders.
A steam chest covering the three sets has a shaft running through it from end
to end, and is caused to revolve at the required speed by any suitable gearing.
Through this shaft which is tubular, is another shaft with means by which it
can be moved longitudinally from the outside, and by removing the end plate of
the steam chest I can remove both these shafts with the valves for inspection or
repairs.
Secured to the inner shaft, and projecting through long slots cut through
opposite sides of the outer or tubular shaft, are metal plates or keys each pro-
jecting side forming an incline in opposite directions.
These double keys pass through a diagonal slot in a cam or eccentric, one of
which operates each valve, and by moving the inner shaft and the three keys, the
eccentrics (which are held from moving along the shaft by guides) are thrown
out of the centre more or less as desired, and thus the valves are adjusted to cut
off more or less, or they may be reversed.
The valve itself is moved to and fro by the direct action of the eccentric.
Improvements in and relating to the Valves of Steam Engines.
I, SYDNEY WILLIAM WILKINSON, of 6, Crookes Place, Hillsbro', City of Sheffield,
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:
-
The obiect of my invention is to simplify the mechanism of the slide valves of

page_text: steam engines, and especially those of three cylinder engines, such as are used for
steam launches, motor vehicles and the like.
The invention is illustrated in the annexed sheets of drawings, in which like
letters refer to like parts in any of the figures.
Fig. 1, represents part of a steam chest of a three cylinder engine, with the
slide valve for one cylinder, and the means I use for regulating and reversing the
valve.
Fig. 2, plan of same with portions removed to show the parts underneath.
Fig. 3, end view of the steam chest and valve with the end plate removed to
show the interior.
In the application of my invention to the slide valves of a three cylinder engine
for example, in which steam is admitted to the back of the pistons only, the front
or lower end being open, the steam chest A, is situated above the cylinders C, and
below the cylinders I support the crank shaft to which the piston rods are coupled
in the usual manner.
The steam ports D, and the exhaust ports E, communicate with the upper end
of the cylinders and are operated by the slide valve V, which is chambered under-
neath at J. its ends V2, being carried upwards and connected at the top by a cross
bar K, and sliding upon its base between two guide strips R.
Between the end plates V2, is fitted a slide block L, which is carried by and
encircles a cam M, being held in position by a number of screws L³, passed
through it and entering a grooved nath P, indicated by a dotted circle, and made
in the periphery of the cam, or into a ring fitting in the said path.
The cam M is preferably made in halves for convenience in putting together,
and through the centre of the cam I make an oblique slot m, to receive a corre-
spondingly shaped adjusting key or plate N. which is firmly secured upon a
sliding spindle passed through it, hy means of the screws n, or equivalent means.
Through the steam chest A, is passed a tubular revolving shaft F, supported at
each end in bearings G, and through the centre hole of this shaft is passed the
spindle H, which carries the inclined adjusting plates N.
Through the valve shaft F, and its collars F2. extending from F³, to F¹, is a
slot to permit the lateral movement of the inclined plate N, which can be traversed
to the right or left by moving the spindle H, within the tubular shaft.
The movement of the key or plate N. from the position shown in Fig. 1.
towards the position indicated by dotted lines will raise or alter the position of
the cam M, and also the travel of the valve, thus enabling the " cut-off" to br
adjusted to any desired amount, when central the action of the valve ceases, and
when moved past the centre the revolutions of the crank shaft are reversed.
The central portion of the oblique slot through the cam is enlarged to an oblong
rectangular form at Q. to permit the passage of two short rectangular portions F5,
of the shaft F. seen in Figs. 2 and 3, between the collars F2 this part of the
opening is made of sufficient length or height to permit the required adjustable
action of the cam.
The above described arrangement of the valve, slide block, cam and inclined
plate or key is repeated for each cylinder, but the three sets of valves are all
operated by one shaft F, and spindle H, which are made long enough for the
purpose.
The end plate T, of the steam chest A, is made with a chamber S, to enclose
the end of the spindle H, when it is moved in that direction.
The opposite end plate (not shown) is made with an ordinary gland or stuffing
box through which the end of the shaft F, projects, and is rotated by means of
two pairs of bevel wheels and an intermediate shaft, from the crank shaft below,
and at the same speed.
When this end plate is removed, the shaft F, the spindle H, and the cam and
slide block may be drawn out for inspection or repairs.
The spindle H, also projects from the end of the shaft F, and is arranged to be

page_text: moved to and fro longitudinally as before mentioned either by a hand lever or
the like, or it may be connected with the governors and operated by them auto-
matically in various ways, the method of accomplishing this action of the spindle
forms no part of my invention.
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 The herein before described mechanism for moving and regulating the slide
valves of steam engines, consisting of a shaft F, in combination with a spindle H,
inclined key or plate N, cam M, sliding block L, and a valve V, constructed and
arranged as set forth in the drawings annexed.
2-The mechanism for imparting a reciprocating movement to a slide valve of
a steam engine, and for starting, stopping, reversing, and regulating the "cut-
off," consisting of a slotted tubular shaft F, an inclined key or plate N, held
within the said slot, and secured to a central sliding spindle H, a cam M, through
which the plate N, can move, and a slide block L, encircling the cam, and
engaging with the valve as hereinbefore described and shown.
3 As part of an arrangement of mechanism for operating and regulating the
slide valve of a steam engine, a cam M, having a central oblique opening m, the
throw of the cam being capable of adjustment by means of an inclined plate or
key N, passing through the said oblique opening, and secured to a spindle H,
capable of being moved longitudinally from the outside, as hereinbefore described
and set forth.
ROBT. F. DRURY, C.P.A.,
Agent for Applicant, Bank Buildings, George Street, Sheffield.