Improvements in or connected with the Valves and Valve-gear of Steam Engines.
Year: 1892

page_text: Date of Application, 6th Dec., 1892
Complete Specification Left, 6th Sept., 1893-Accepted, 7th Oct., 1893
PROVISIONAL DIGITIVATION.
Improvements in or connected with the Valves and Valve-gear of
Steam Engines.
We, JOHN HENRY TATTERSALL, of 3 Lauderdale View, Preston, in the County
of Lancaster, Consulting Engineer, and JOSEPH BAXTER, of 23 Christian Road,
in the same Town, Draughtsman, do hereby declare the nature of this invention to
be as follows:-
This invention has reference to improvements in or connected with the valves
and valve gear of steam engines and relates firstly to a novel arrangement of that
class of valves known as "piston valves" and secondly to an improved variable cut
off motion or apparatus applicable to piston valves and also to slide, Corliss, and
other forms of steam engine valves.
As regards the first part of our invention it has heretofore been customary so far
as we are aware to arrange the two sets of piston valves that is to say the steam
valves and the exhaust valves so as to operate together on a common spindle.
According to our invention we arrange the steam valves and the exhaust valves to
operate separately and apart from each other. We mount each of the two steam
valves on a separate valve spindle and impart a direct longitudinal movement to the
valves preferably by means of the improved arrangement of valve-gear hereinafter
described. We form behind each of the two said valves a small steam chamber
each of these small chambers being in direct communication with the interior of the
main or ordinary steam chamber or chest--by this means effecting the "balancing
of the valves by causing the steam to press equally on the back and front of the
valves. The two exhaust valves we mount on a common spindle in a separate
chamber and operate them together by a separate eccentric or valve motion. By
the above described arrangement of piston valves we are enabled to work the steam
valves in an equilibrium of pressure and to adjust the said steain valves separately
from or independently of the exhaust valves. We are moreover enabled to substitute
a direct longitudinal to and fro or reciprocatory motion for the rotary or semi-rotary
motion heretofore customary in operating piston-valves.
"
Our improved variable cut off apparatus as applied (to work automatically) to
engines having piston valves as above described is constructed and operates in the
following manner :- -We arrange upon the steam port side of the cylinder a sliding
frame or carriage to which a reciprocatory motion in a plane parallel with the axis
of the cylinder is given by an ordinary eccentric. This frame supports two wedge-
shaped pieces or inclined planes arranged to slope downwards towards each other
the said wedges being so carried or fitted on the frame as to be capable of sliding
thereon the two wedges being each separately in connection with the engine
governor. The sliding frame carries two fork-like picces which move or slide in
suitable bearings at right angles to the frame and to the two wedges against the
downward pressure of a coiled spring the bridge of each fork resting on the
sloping surface of one of the wedges and the two depending prongs of the fork
standing on each side of its wedge. The extremities of the said prongs extend
downwardly through the sliding frame so, as to project somewhat in front of the
outer extremity of one of the two valve rods or spindles which carry the steam
valves. The end of each valve rod or spindle and the adjoining extremities of the
forks are made of tempered steel in the form of square-edged lips and work at
right angles to each other the valve rods being arranged to work against an
ordinary arrangement of coiled spring to facilitate the suddenness of the cut-off
when the prongs of the fork are raised clear of the valve rod end as hereinafter
mentioned. The action of the apparatus as above described is as follows:-At

page_text: each stroke of the engine as the sliding frame is moved in one direction the lower
extremities of one of the forks will push that fork's valve rod and continue to push
the steam valve open until the said fork has moved or travelled up the inclined
face of its wedge sufficiently to lift the said fork clear of the valve rod whereupon
the latter will be free to spring back and so close its valve. On the return move-
ment of the sliding frame the like operation will take place between the wedge and
the fork at the opposite end of the frame. Thus the varying position-caused by
the action of the engine governor-of each of the wedges relatively to its fork
determines the point of the cut-off by lifting the fork clear of and releasing its
valve rod sooner or later during the stroke as will be well understood.
Although we have described our improved cut off apparatus as applied to a
steam engine having piston valves it will be obvious that with slight modifications
it is equally applicable to engines having, slide, Corliss, or other types of valves.
Moreover the wedge pieces of the said apparatus need not necessarily be arranged
to be worked variably or automatically by the action of the engine governor.
They may be so arranged-as for instance by being coupled to a screw-threaded
spindle to have their positions and therefore the point of cut-off varied as
required by hand.
Dated this 6th day of December 1892.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or connected with the Valves and Valve-gear of
Steam Engines.
We, JOHN HENRY TATTERSALL, of 3 Lauderdale View, Preston, in the County
of Lancaster, Consulting Engineer, and JOSEPH BAXTER, of 26 Christian Road,
in the same Town, Draughtsman, do hereby declare the nature of this invention and
in what manner the saine is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention has reference to improvements in or connected with the valves
and valve gear of steam engines and relates firstly to a novel arrangement of that
class of valves known as "piston valves" and secondly to an improved variable cut
off motion or apparatus applicable to piston valves and also to slide, Corliss, and
other forms of steam engine valves.
As regards the first part of our invention it has heretofore been customary 80 far
as we are aware to arrange the two sets of piston valves that is to say the steam
valves and the exhaust valves so as to operate together on a common spindle.
According to our invention we arrange the steam valves and the exhaust valves to
operate separately and apart from each other. We mount each of the two steam
valves on a separate valve spindle and impart a direct longitudinal movement to the
valves preferably by means of the improved arrangement of valve-gear hereinafter
described. We form behind each of the two said valves a small steam chamber
each of these small chambers being in direct communication with the interior of the
main or ordinary steam chamber or chest-by this means effecting the "balancing"
of the valves by causing the steam to press equally on the back and front of the
valves. The two exhaust valves we mount on a common spindle in a separate
chamber and operate them together by a separate eccentric or valve motion. By
the above described arrangement of piston valves we are enabled to work the steam
valves in an equilibrium of pressure and to adjust the said steam valves separately
from or independently of the exhaust valves. We are moreover enabled to
substitute a direct longitudinal to and fro or reciprocatory motion for the rotary
or semi-rotary motion heretofore customary in operating piston-valves.

page_text: Our improved variable cut off apparatus as applied (to work automatically) to
engines having piston valves as above described is constructed and operates in the
following manner :-We arrange upon the steam port side of the cylinder a sliding
frame or carriage to which a reciprocatory motion in a plane parallel with the axis
of the cylinder is given by an ordinary eccentric. This frame supports two wedge-
shaped pieces or inclined planes arranged to slope downwards towards each other
the said wedges being so carried or fitted on the frame as to be capable of sliding
thereon the two wedges being each separately in connection with the engine
governor. The sliding frame carries two fork-like pieces which move or slide in
suitable bearings at right angles to the frame and to the two wedges against the
downward pressure of a coiled spring the bridge of each fork resting on the sloping
surface of one of the wedges and the two depending prongs of the fork standing on
each side of its wedge. The extremities of the said prongs extend downwardly
through the sliding frame so as to project somewhat in front of the outer extremity
of one of the two valve rods or spindles which carry the steam valves. The end of
each valve rod or spindle and the adjoining extremities of the forks are made of
tempered steel in the form of square-edged lips and work at right angles to each
other the valve rods being arranged to work against an ordinary arrangement of
coiled spring to facilitate the suddenness of the cut-off when the prongs of the fork
are raised clear of the valve rod end as hereinafter mentioned. The action of the
apparatus as above described is as follows:-At each stroke of the engine as the
sliding frame is moved in one direction the lower extremities of one of the forks
will push that fork's valve rod and continue to push the steam valve open until the
said fork has moved or travelled up the inclined face of its wedge sufficiently to lift
the said fork clear of the valve rod whereupon the latter will be free to spring back
and so close its valve. On the return movement of the sliding frame the like
operation will take place between the wedge and the fork at the opposite end of the
frame. Thus the varying position-caused by the action of the engine governor-
of each of the wedges relatively to its fork determines the point of the cut off by
lifting the fork clear of and releasing its valve rod sooner or later during the stroke
as will be well understood.
Although we have described our improved cut off apparatus as applied to a
steam engine having piston valves it will be obvious that with slight modifications
it is equally applicable to engines having slide, Corliss, or other types of valves.
Moreover the wedge pieces of the said apparatus need not necessarily be arranged
to be worked variably or automatically by the action of the engine governor. They
may be so arranged as for instance by being coupled to a screw-threaded spindle
to have their positions and therefore the point of cut off varied as required
by hand.
In the accompanying drawings.

page_text: A is the steam cylinder, B the steam inlet pipe, a a¹ the steam valves (of the
piston type), and the steam chambers. ppare the small steam chambers
behind the steam valves a a¹ and q q¹are pipes leading from the steam inlet pipe B
into the chambers p p so as to establish an equilibrium of steam pressure in front
and behind the steam valves.
cc' are the exhaust valves (also of the piston type), dd' the exhaust chambers,
and e the exhaust valve spindle or rod which is moved to and fro longitudinally by
its own or a separate eccentric or by any other convenient method.
The eccentric rod (not shown in the drawings) for operating the steam valves is
coupled up to the pin or arm the said arm projecting from the side of the sliding
frame or carriage g. The carriage g is preferably mounted in V slides h
(as shewn at Fig. 8) on a stationary horizontal table i fastened to the steam port
side of the cylinder A and supports (preferably also in V slides) the elongated
blocks forming the end pieces of the valve spindles respectively. jjare the
two wedge-shaped pieces which move within V slides on the upper side of the valve
rod end pieces kk and m is the bridge part and n n' the two depending prongs of
the forks the feet or lower extremities of which engage with or are moved clear of
the rectangular notches oo (see Figs. 5, 6, and 9) on the valve rod end pieces k k¹
as the case may be the two adjoining edges of the fork ends and the notches o o being
faced with tempered steel as hereinbefore mentioned. At Fig. 9, y y indicate
hardened steel bits introduced into the valve rod end pieces k k¹ in such a manner
as to be readily withdrawable or removable when required to be re-ground
when worn.
rare rods connected at their upper ends (either directly or indirectly as may
be found convenient) to the engine governor and at their lower ends to the
horizontal arms of two bell-crank levers s s pivoted upon stands a
rising from the
stationary table the vertical depending arms of the said levers being jointed into
sliding blocks tt working within slotted heads on the outer extremities of the
wedge-shaped pieces jj (see Figs. 5 and 9). Thus the simultaneous upward
movement of the governor rods simultaneously closes in or moves towards each
other the two wedge-shaped pieces jj' and thereby raises the two forks m m' causing
them as the carriage g is moved to and fro-to be lifted clear of the notches oo in
the valve rod end pieces kk so as to release the valves a a' and effect the cut-off
sooner whilst the lowering or opposite movement of the said governor rods causes the
opposite effect or in other words the cut-off is effected later.
vvare coiled springs the downward pressure of which holds the bridge part m m³
of the forks hard down upon the inclined surfaces of the wedge picces jj and w w¹
represent an ordinary arrangement of coiled springs for keeping the vertical faces
of the notches oo on the valve rod end pieces kk hard against the lower ends of
the fork prongs n n' and also for facilitating the suddenness of the cut off when the
prongs of the fork are lifted by the wedge pieces clear of the notches o o as
hereinbefore stated.
The cut off apparatus herein before described and shewn in the drawings is arranged
to be worked automatically that is to say under the variable influence of the engine
governor. If it be desired to arrange it to be worked non-automatically the two
rods may be coupled together by means of a cross bar having a central nut
through which a screw-threaded spindle mounted vertically in a suitable stand or
bracket rising from the table i may be rotated in either one direction or the other
so as to raise or lower the rods rr and the levers ss and thus close in or open out
the wedge pieces jj and retain them in any required position thereby determining
the point at which the cut-off is to take place.
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 :-
1. Causing the steam to press equally on the back and front of piston valves of
steam engines in maunor substantially as decorihed and shown in the drawings

page_text: 2. The improved cut-off apparatus consisting essentially of a sliding carriage or
frame having a reciprocating movement and carrying two vertically arranged forks
or their equivalents which operate in conjunction with two wedge shaped pieces
and two steam valve rod ends the said combination of parts being constructed
arranged and operating substantially as hereinabove described and shewn in the
drawings.
Dated this 6th day of Santambor 1902
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.