Improvements in Valve-gear.
Year: 1891

page_text: Date of Application, 15th Sept., 1891
Complete Specification Left, 15th July, 1892-Accepted, 20th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvements in Valve-gear.
I, MICHAEL MARY BROPHY, of the firm of James Slater and Company, of
251, High Holborn, in the County of London, Engineers, do hereby declare the
nature of this invention to be as follows:-
My invention relates to improved gear for operating the valves of steam-engines,
pumps and the like.
In carrying out my invention I provide a sliding-rod in connection with which
the valve to be operated is arranged, the said rod at one end sliding in a bush
pivotted at a suitable point upon the engine and at the other end through a second
bush or bearing carried by a crank in such a manner that, when the said crank is
moved upon its axis, an oscillatory movement will be imparted to the said rod.
Upon the sliding-rod are two springs, one of which is arranged between a collar,
upon its end having the greatest oscillatory movement, and the bearing carried by
the crank, whilst the other spring is arranged upon the opposite side of the said
crank bearing and between it and a collar also secured to the rod.
In connection with these two collars I arrange brackets having curved surfaces
against which, during a certain part of the oscillatory movement of the said rod; the
collars are adapted to bear so as to hold the rod stationary in so far as its longi-.
tudinal movement is concerned, in order that first one spring and then the other
spring shall be compressed. The said curved surfaces, however, are so arranged
that, after the collars have moved a certain distance thereon, they will be released,
thereby allowing the reaction of the springs to move the rod to operate the valve
in connection therewith. A.cushioned stop or stops is or are provided for limiting
the movement of the said rod under the action of the springs.
With this arrangement it will be readily understood that valves can be fully
opened and fully closed instantaneously, whereby, when used in conjunction with a::
steam engine, the wire-drawing of the steam may be prevented.
In some cases I arrange in conjunction with the main valve a cut-off valve.
operated by similar mechanism to that hereinbefore described, and I arrange the
brackets having the curved surfaces in conjunction with governors in such a manner..
that they can be moved to release the sliding-rod and allow the cut-off valve to be
operated more or less early in the stroke.
Dated the 15th day of Santamban 1901
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
. . '
COMPLETE SPECIFICATION.
Improvements in Valve-gear.
I, MICHAEL MARY BROPHY, of the firm of James Slater and Company, of
251, High Holborn, in the County of London, Engineers, 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 relates to improved gear for operating the valves of steam-engines, .
pumps and the like.
In carrying out my invention I provide a sliding-rod in connection with which
the valve to be operated is arranged, the said, rod being adapted to a crank in
such a manner that, when the said crank is moved upon its axis, an oscillatory
movement will be imparted to the said rod. Upon the sliding-rod are two springs
which serve to operate the rod to move the valve.

page_text: In connection with the rod is a bracket having curved surfaces against which,.
during a certain part of the oscillatory movement of the. said rod, a collar or
rubbing piece thereon is adapted to bear so as to hold the rod stationary in so far
as its longitudinal movement is concerned, in order that first one spring and then
the other spring shall be compressed. The said curved surfaces, however, are so
arranged that, after the collar has moved a certain distance thereon, it will be
released, thereby allowing the reaction of the springs to move the rod to operate
the valve in connection therewith. A cushioned stop or stops is or are provided
for limiting the movement of the said rod under the action of the springs.
With this arrangement it will be readily understood that valves can be fully
opened and fully closed instantaneously, whereby, when used in conjunction with a
steam-engine, the wire-drawing of the steam may be prevented.
In some cases I arrange in conjunction with the main valve a cut-off valve
operated by mechanism somewhat similar to that hereinbefore described.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is a rear elevation partly in section of a vertical engine, the valve of
which is arranged to be operated by my improved mechanism and in conjunction
with which there is arranged cut-off mechanism :
Figure 2 is a sectional side elevation of the engine :
Figure 3 is a section on the line, Figure 2; and,
Figures 4 and 5 are sections on the lines y y and
respectively of Figure 1:
Figure 6 is a rear view of the valve-chest with its cover removed shewing the
arrangement of the cut-off valve in connection with the main valve.
Similar letters of reference indicate corresponding parts in all the figures.
a indicates the frame of the engine, the cylinder, c the piston-rod, d the cross-
head, e the connecting-rod and the crank-shaft, all of which parts are of ordinary
construction and require no further description.
is the valve-chest and h is the slide-valve working therein, the said slide-valve
being provided with two ports ', designed to be placed alternately in communi-
cation with the cylinder ports, 6. The said valve is operated through the medium
of a lever i, one end of which engages in a slot in the said slide-valve, as shewn
most clearly in Figure 6, whilst the other end is secured to one end of a shaft j
carried in a bearing in the cover of the steam-chest and provided with a packing-
gland for preventing the escape of steam around the said shaft ;; the other end
of the shaft carries a lever is the oscillating rod, one end of which is
connected to the lever and is the crank by means of which the said rod is
oscillated, the said crank carrying a sleeve sliding upon the rod k. Motion
is imparted to the crank through the medium of cords or chains m, m', each of
which is at one end connected to a-bar m³ carried by arms m³ secured to the cross-
head d and projecting through a slot in the back of the frame of the engine, the
cord m being secured to the lower end of the bar m² and the cord m' to the upper
end thereof. In connection with the crank is a disc pivotted at and having
in its periphery two grooves in which the cords m, m¹ run and also two lugs n, n¹
to which the cords m, m³ are respectively connected, the cord m passing around the
upper side of the disc and the cord m' around the under side. With this
arrangement it will be understood that as the bar. m³ is moved up and down,
during the working of the engine, one cord will be unwound from the disc causing
the same to rotate and the other wound thereon. This will be clearly understood
by reference to Figure 1, where the cord m is represented as being around the
disc and the cord m' to be lying against the face of the bar m². It will be
obvious that as the bar m³ moves downwards the cord m will be unwound from the
disc and the cord m' wound thereon; the reverse taking place when the bar
again moves upwards. The result of this arrangement is that the disc will be
caused to partly rotate in opposite directions, the parts being proportioned so that
each partial rotation is through an arc of 180 degrees.
o, o indicate the springs surrounding the rod k and which are alternately

page_text: compressed and released to operate in the manner hereinafter described. Each of
these springs at one end bears against the sliding sleeve and at the other end
against the bottom of a tubular casing o² secured to the rod and enclosing the
springs and also the sleeve l', a slot being formed in the said tube for the passage
of the pin connecting the said sleeve to the crank l.
p indicates the bracket having the curved surfaces p', against which a rubbing
piece upon the lower end of the bar k will alternately act, the surface being
curved to a circle having its centre at the pivot connecting the rod k and the
lever when the latter is in its upper position and the surface curved to a circle
struck froin the same centre but when the latter is in its lowest position. The said
bracket is slotted, as shewn at p, Figures 2 and 3, to afford a clearance space for
the tube o and for the nut upon the lower end of the rod k.
79 are spring-stops which limit the movements of the lever j³.
The operation of the apparatus thus far described is as follows:-Assume
the piston of the engine to be at the top of its cylinder, as shewn, and the
valve to be in such a position that the ports ', will coincide, as shewn in
Figure 2: if now steam is admitted it will force the piston downwards and at the
same time, as the bar m³ moves downwards with the cross-head, the crank will be
caused to move in the direction of the arrow, Figure 1, whereby the rod k will
be oscillated to bring the rubbing piece p³ into contact with the curved surface p'.
As the rotation continues the sleeve will be caused to move downwards upon the
rod k and as the said rod is held from moving downwardly owing to the contact
of the rubbing piece p³ with the surface p₁ it follows that the spring o¹ upon the
lower part of the said rod will be compressed, the compression continuing until
the pin of the crank has moved to its lowest position. By the time this position is
reached, however, the rubbing piece p³, which, during the first part of the
movement of the disc, moved up the surface p¹ and during the latter part of
the movement back again, passes out of contact with the said surface p' so that the
rod being unsupported will be acted upon by the reaction of the spring o' to
move the lever downwards to the position indicated by the dotted lines and
thereby shift the valve to move the port h¹ out of coincidence with the port b¹
and the port into coincidence with the port to admit steam to the lower end of
the cylinder. As now the piston commences to move upwards, the cord m³
commences to rotate the crank back to its original position; the result of which
movement of the said crank is that the rod is caused to oscillate to bring the upper
surface of the rubbing piece p³ into contact with the surface p² of the bracket
so that the said rod is held against upward movement and the spring o is compressed
by the sleeve. By the time that the crank has reached its uppermost position
the rubbing piece p³ is disengaged from the surface p³ so that the spring o is free
to move the rod to its uppermost position to again reverse the valve h and so on.
When my valve-mechanism is used in connection with a pump or water motor
the mechanism thus far described is sufficient: when, however, it is used in
connection with, say, a steam-engine it is necessary to provide for cutting off the
steam before the end of the stroke and this I may accomplish by the following
means, that is to say,-In conjunction with the valve I arrange a cut-off valve r
of ordinary construction and which is adapted to be operated through the medium
of a lever r', a shaft and a lever in substantially the same manner as the
valve h. s is a tube jointed to the outer bifurcated end of the lever and having
sliding through it a rod t connected to an arm t¹ carried by the cross-head d of the
engine. u, are two cup-shaped collars loosely mounted upon the rod t, and u², u³
are spiral springs which, at their outer ends, bear against and are connected to the
ends of the tubes and at their inner ends bear against and are connected to the
collars respectively. The collars u, u are provided with bent arms u, u
respectively, which bent arms slide through slots in the tube s, the said slots being
of such length as to limit the distance to which the collars shall be moved in the
tube under the action of their respective springs.
P
v is a centrifugal governor of ordinary construction, the movements of which are

page_text: designed to operate a bar having at its ends pins v2, v3, the free ends of which
slide in guides in a plate rigidly attached to the engine, as shewn in Figure 4,
the said pins being surrounded by springs, respectively, which normally tend
to draw the pins 3, 3 into their guides away from the governor. w, w¹ are two
plates secured to the upper and lower ends of the tubes and working in guides
on the plate. The said plates w, w' are provided with holes w³, w³ respectively
into which the ends of the pins 2, 8 are designed to engage, a space being left
between the plates w, we and the plate ', as shewn most clearly in Figure 4, to
allow the passage of the bent arms u, u of the collars u, u respectively and also
of a slight lateral movement of the said arms u, u to allow of their disengagement
with the pins 6, respectively, as shewn in Figures 4 and 5; the springs u², u³
being connected to the collars u, u and to the ends of the tubes as hereinbefore
described, the torsion of the said springs will tend to maintain notches in the
arms u, u in engagement with the pins vs, respectively.
10 is a piston or pusher fixed to the rod t and sliding within the tubes.
Stops similar to the stops q, q are provided for limiting the movements of the
lever.
The operation of this part of my apparatus is as follows:-Assume the ports of
the engine to be in the position herein before described, that is to say, the ports b¹, hi
in coincidence and assume also that the cut-off valve r is in the position shewn in
Figures 2 and 6 so that the port is uncovered and that the pin v³ is in
engagement with the hole wo² in the plate w and with the arm u: when,' now, the
piston has moved through a certain part of the stroke, the governor, if properly
adjusted, will act upon the bar and draw the pin 2 out of engagement with the
hole so that the spring u³, which was compressed by the contact of the piston *
with the collar u' during the previous stroke, will expand and lift the tube s to
operate the lever and the valve r to close the port h', the upward movement
of the said tube being such that, when in its highest position, the pin v3 at the
lower end of the bar engages with the hole 3 of the plate to again fix
the said tube. As the downward movement of the piston continues under the
expansion of the steam, the piston or pusher w* comes into contact with the
collar น and forces the same downwards to compress the spring u2 until the hook
on the arm of the said collar u engages with the pin in a similar manner to
that indicated in Figure 5, the said arm yielding laterally by reason of its
connection with the spring until its hook comes opposite to the said pin when
the torsion of the spring causes the engagement. When the piston is at the
bottom of the stroke the ports 12, 62 are in coincidence and the port is uncovered
by the cut-off valve r, the steam now enters the lower end of the cylinder and
moves the piston upwards until the speed of the governor causes the movement
of the bar to draw the pin ' out of engagement with the hole w³ in the plate 10¹
when the tubes is again free to descend to the position shewn in Figure 1 to close
the port 2. As the upward movement of the piston continues under the expansion,
the spring is compressed and the arm u caused to again engage with the pin ²
ready for the next operation and so on.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In valve-mechanism for steam-engines, pumps and the like, the combination
with the slide-valve of a rod, two springs carried upon the said rod, a sleeve
connected to a crank adapted to compress the said springs alternately and to cause
the oscillation of the rod, and curved surfaces against which the rod, during its
oscillation, is adapted to bear in order to hold it against longitudinal movement,
substantially as described.
2. The improved valve operating mechanism hereinbefore described and illus-
trated in the accompanying drawing for operating the main slide valve of a
steam-engine, pump or the like.

page_text: 3. The combination with the valve-mechanism referred to in the preceding
claiming clauses of cut-off mechanism constructed and arranged to operate sub-
stantially in the manner hereinbefore described and illustrated in the accompanying
drawing.
Dated the 15th day of July 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.