Improvements in and connected with the Valves and Valve Gear of Steam Engines and similar Motors.
Year: 1895

page_text: Date of Application, 28th June, 1895
Complete Specification Left, 13th Feb., 1896-Accepted, 14th Mar., 1896
και οι πρωηνακιδη col unc του
Complete Specification Left, 13th Feb., 1896-Accepted, 14th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Valves and Valve Gear of
Steam Engines and similar Motors.
We, WILLIAM DUNDAS WIGHT, of Pentre in the County of Glamorgan,
Engineer, and MATTHEW BROWN WILD and THOMAS RYDER, both of the
Falcon Iron Works, Oldham in the County of Lancaster, Engineers, do hereby
declare the nature of this invention to be as follows:-
This invention relates to the valves and valve gear of steam engines and similar
motors actuated by expansible fluids, and its objects are to provide mechanism and
devices whereby a positive and variable cut-off of the expansible fluid may be
secured, and to dispense with the necessity for employing a separate excentric for
the cut-off valve.
In carrying out our invention, we actuate the cut-off valve from the main valve
spindle through a suitable trip motion such as the toggle joint device hereinafter
described. We will describe the construction and arrangement of the means and
devices we prefer to employ, as applied to one end only of a cylinder, it being
understood that in a double acting engine they will be duplicated at the opposite
end, where the main valve spindle will be represented by a tail spindle to that
valve.
Near the end of the main valve, we arrange the cut-off valve which is mounted
on the inner end of a comparatively large spindle, the outer part of which is
connected by a suitable trip motion with the main valve spindle in such a manner
that the cut-off valve is actuated at the required times by the main valve
spindle.
The trip motion which we prefer to employ has as its essential element, a toggle
or knuckle joint. The ends of this joint may be respectively connected to two
cross-heads or the like, one cross-head being connected to the main valve spindle
and the other to the cut-off valve spindle. With this arrangement, so long as the
joint is straight, both the spindles and valves will move exactly together, but if the
joint be folded or bent by any means, the pressure of the expansible fluid in
the valve chest, acting upon the end of the comparatively large rod of the cut-off
valve, will cause that valve and its rod to move outwards relatively to the main
valve and rod, with the result that the access of the expansible fluid is instantly cut
off. The toggle joint will become re-straightened at the end of the stroke, through
its fixed connection with the main valve spindle. To prevent too sudden action,
the cut-off valve rod may be connected with a dash pot.
The initial bending of the toggle joint at the appropriate moment may be effected
by any suitable means such, for example, as an inclined plane working opposite to a
projection from the centre of the toggle joint. The position of the inclined plane
may be adjusted, so as to cause an earlier or later cut off, either by hand or by the
governor.
The main and cut-off valves may be variously constructed and arranged to meet
special requirements. Thus, the main valve may have each end projecting beyond
its working face or faces, and the steam inlet in the projecting part on each side of
the valve, that is to say, an opening may be made through the projecting end of
the valve, through which steam is admitted to a passage leading to the valve outlet

page_text: at or near the cylinder port. The cut-off valve is arranged to open and close both
ends of the inlet. As an alternative, the main valve may have, at each end, a
straight through passage corresponding with a port in a balance plate at the back,
which port is opened and closed by the cut-off valve. If it be desired to have the
cylinder ports near the ends of the cylinder, the working part of the main valve
may be made solid and its faces be extended to form a chamber to which the steam
gains access through a port in the outer face or balance plate, which port is opened
and closed by the cut-off valve. In this case, it is preferred to extend the working
faces and to form steam inlets to the chamber above and below, or on each side of
the chamber, both of the openings being opened and closed by the cut-off valve.
⚫ Dated this 26th day of June A.D. 1895.
W. E. HEYS & SON,
Agents for the Applicants.
Improvements in and connected with the Valves and Valve Gear of
Steam Engines and similar Motors.
We, WILLIAM DUNDAS WIGHT, of Pentre in the County of Glamorgan,
Engineer, MATTHEW BROWN WILD of 52 Copester Hill, and formerly of the
Falcon Iron Works, Oldham, in the County of Lancaster Engineer, and THOMAS
RYDER of the Falcon Iron Works, Oldham in the County of Lancaster, 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 :-
This invention relates to the valves and valve gear of steam engines and similar
motors actuated by expansible fluids, and its objects are to provide mechanism and
devices or appliances whereby a positive and variable cut-off of the expansible fluid
may be secured.
In carrying out our invention, we actuate the cut-off valve from the main valve
spindle through a suitable trip or slip gear such as the toggle joint hereinafter
described, and dispense with the necessity for employing a separate excentric,
crank, cam or the like, for giving motion to the cut-off valve.
The accompanying drawings illustrate in what manner our improvements may
be carried into practical effect, and are hereinafter referred to.
In the arrangement shewn in longitudinal section by Figure 1, A is the main
valve, which is reciprocated in the usual manner by the spindle D. This valve
has also a tail spindle D' which may be dispensed with in single acting engines.
The means employed for operating the cut-off valves being similar at each end, in
double acting engines, we will hereinafter describe those at one end only, it being
understood that the gear at the back end is actuated by the tail spindle D¹ and
that at the front end, in the same manner, by the spindle D.
The cut-off valve C is mounted upon the inner end of a comparatively large
spindle F, the outer end of which is connected with the trip or slip gear and valve
spindle in such a manner that the cut-off valve is alternately actuated at the
required times, by the main valve spindle, and the pressure of steam within the
valve chest, alone or aided by a spring.
The trip or slip gear which we prefer to employ has as its essential element, a
toggle or knuckle joint O. The opposite ends of this joint are respectively con-
nected with two cross-heads J J or the like, one of which, J, is connected with
the main valve spindle, and the other, J', with the cut-off valve spindle. Each
cross head J or J' has attached to it a ferrule or collar ; or which slides upon
the other spindle. With this arrangement so long as the toggle joint is straight,
both the spindles and the valves will move exactly together, but if the joint be

page_text: folded or bent by any means, the pressure of the expansible fluid within the valve
chest, or that pressure aided by a spring, acting upon the end of the comparatively
large rod F, will cause that rod and the cut-off valve to move outwards relatively
to the main valve and rod, with the result that the access of the fluid to the
cylinder is instantly cut off. The toggle joint will become re-straightened at the
end of the stroke, through its fixed connection with the main valve spindle D. To
prevent too sudden action, the cut-off valve rod may be connected at its outer end
with a dash-pot M, or an equivalent spring or buffer.
Suitable means for ensuring the act of bending the toggle joint may consist of a
cam or the like, or the inclined plane illustrated in plan by Figure 1 and in side
elevation by Figure 4. The inclined plane K fixed upon the block is arranged
below a bevelled projection P, from about the centre of the toggle joint. The
position of the appliance for bending the toggle joint may be varied by hand but it
is preferred to vary it by the governor, for which purpose the block k may be;
mounted in a slide along which it may be moved, in either direction, by the lever L,.
which is connected with the governor through the rod N and the lever l. In
double acting engines, the lever L at the front end may be connected with the
similar lever at the back end by the connecting rod R as shewn, so as to secure
synchronous motion.
The main and cut-off valves may be variously constructed and arranged to suit
special requirements. Thus, as shewn in sectional plan, Figure 1, and in elevation
by Figure 4, the main valve A, may have each end projecting beyond its seating
and beyond the balance plate B. The steam inlet is formed in each projecting end"
by a through passage a from which there is an L-shaped passage to the working
face of the valve, communicating with the cylinder ports p. The L-shaped passage
may communicate through the small opening shewn, with the back of the valve
and face of the balance plate, thus putting the valve in equilibrium. The cut-off
valve C is constructed to open and close both ends of the inlet a on the opposite
faces of the main valve, as indicated by Figure 1.
A modified construction and arrangement are illustrated by Figure 2 in which
the cut-off valves C work upon the back of the balance plate B, through which
suitable ports are formed for the passage of the expansible fluid to the main valve,,
which ports are alternately opened and closed by the cut-off valves. The passages
through the main valve are in this case direct.
Figure 3 represents in horizontal section and Figure 5 in elevation, a valve
similar to that shewn by Figure 2, but without the balance plate. The main valve
is consequently unbalanced.
It is at present usual, in engines with long cylinders, to construct the main
valve and balance plate, when the latter is employed, in two separate parts one of
which is located at each end of the cylinder, the two parts of the main valve being-
connected by the spindle or otherwise. Such a construction as arranged for the
purpose of the present invention, is illustrated by Figure 6 in side elevation and by
Figure 7 in sectional plan. The same letters of reference are employed to denote
similar parts as in the preceding figures. It will be seen that the two parts of the
main valve, A A', are solid and located in rectangular chambers S S' at the
opposite ends of the cylinder, to which the steam or expansible fluid has access-
through the passages TT, on opposite sides of the chamber. Each cut-off valve C
consists of a rectangular strap or the like, mounted upon the inner end of its-
comparatively large spindle F F and constructed to embrace the chamber and
alternately open and close the passages T T. The two parts of the main valve are
connected by means of the spindle D.
Having now particularly described and ascertained the nature of our said inven--
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a steam engine or like motor, a cut-off valve having a spindle of com--
paratively large diameter connected with the main valve spindle by a trip or slip.

page_text: gear and actuated in one direction by the pressure of the steam in the valve chest
alone or aided by a spring, and in the other direction from the main valve spindle
through the trip or slip gear, constructed and arranged substantially as herein before
described and as illustrated by the accompanying drawings.
2. In a steam engine or similar motor, the combination construction and
arrangement of a main valve having one or both its ends projecting beyond its
seating, steam inlets in the projecting end or ends, and an independent cut-off valve
for each operative end of the main valve, substantially as herein before described
and as illustrated by the accompanying drawings.
3. In a steam engine or like motor, the combination construction and arrange-
ment of a main valve adapted to open and close a port or ports at the end or ends
of the cylinder, a chamber for each operative end of the main valve having inlets
formed therein, and a cut-off valve or valves adapted to open and close the chamber
inlets, substantially as hereinbefore described and as illustrated by the accompanying
drawings.
4. In a steam engine or like motor, the combination construction and arrange-
ment of a main valve having ends projecting beyond its seating, steam inlets in the
projecting ends, an independent cut-off valve at each end adapted to open and close
the inlets, and a trip or slip motion actuating the cut-off valve spindle from the
main valve spindle, substantially as hereinbefore described and as illustrated by the
accompanying drawings.
5. In a steam engine or similar motor, the combination construction and
arrangement of a main valve adapted to open and close a port or ports at the end
or ends of the cylinder, a chamber or chambers in which the end or ends of the
main valve works and in which steam inlets are formed, a cut-off valve adapted to
open and close the steam inlets, and a trip or slip gear actuating the cut-off valve
spindle from the main valve spindle, substantially as herein before described and as
illustrated by the accompanying drawings.
6. In a steam engine or like motor, the combination and arrangement with the
main valve spindle, of a toggle joint, a cut-off valve spindle connected with the
main valve spindle by the toggle joint, and means for bending the toggle joint at
the proper moments, substantially as herein before, described and as illustrated by
the accompanying drawings.
Dated this 19th dow of February A D. 1896..