IMPROVEMENTS IN OPERATING THE VALVES OF STEAM ENGINES
Year: 1873

page_text: -
ETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN OPERATING THE VALVES OF STEAM ENGINES." - A:
communication from abroad by William Jay Stevens, of the City,
County, and State of New York, and Dudley Sanford Steele and
Nathan Woodhull Condict, of Jersey City, County of Hudson, State:
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 17th September 1873.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said.
Invention for "IMPROVEMENTS IN OPERATING THE VALVES OF STEAM ENGINES,"¨
a communication to me from abroad by William Jay Stevens, of the
City, County, and State of New York, and Dudley Sanford Steele and
'

page_text: Nathan Woodhull Condict, of Jersey City, County of Hudson, State of
New Jersey, all in the United States of America, to be as follows:-
The object of this Invention is to operate the slide valve of a steam
engine, such for instance as a direct action steam pump directly from
the piston rod by the aid of springs contained within the steam chest in
conjunction with other appliances.
The steam chest contains a slide valve adapted to the steam ports and
to the exhaust port in a manner common to the valves of steam pumps.
A rock shaft passes through and has its bearings on opposite sides of the
steam chest, and derives its vibrating motion from the piston rod of the
engine. Through the medium of a lever and arm, the latter being secured
to the rock shaft, and the lever which is connected to the piston rod of
the engine being arranged to operate the said shaft, and as it vibrates to
strike alternately projections on the arm, the vibration of which and
consequently of the shaft must be intermittent.
To the shaft and inside the steam chest is screwed a lever having two
horizontal arms projecting in line with each other from opposite sides of
the said shaft, and a third arm arranged at right angles to the other arms.
Between the end of each horizontal arm and a set screw passing
through the steam chest intervenes a spring, the two springs by their
joint action tending to maintain the three-armed lever in its two
opposite positions. The third arm of the lever is arranged to strike
alternately projections on the back of the valve.
.
The movement of the lever is partly effected by the piston rod and
partly by the springs, thus supposing the valve to be nearly at the
extreme end of its stroke, the said lever will be moved by the piston rod
to such an extent only as will enable the springs to complete the move-
ment of the valve; and the space between the projections on the valve
is such that the movement of the latter will be effected by the action of
the springs, the preliminary movement of the lever before it begins to
act on the valve being accomplished by the direct action of the piston
rod; the subsequent and remaining portion of the movement of the
lever by means of the springs alone being permitted by the distance
which the projections on the aforesaid arm are arranged from each
other, this distance permits a limited play of the said arm independently
of the lever which actuates it.

page_text: By this arrangement and operation of the above described parts the
movements of the valve take place at the precise points and intervals
demanded by the position and movement of the piston in the cylinder,
and the desired dwell or pause of the valve after the completion of each
movement is insured. It is necessary however that the valve should be
under such controlling influence that it cannot be projected beyond its
proper limits by the impetus which the spring imparts to the lever.
Different devices for arresting the valve at the proper points will
readily suggest themselves to engineers. The device which has however?
been found most efficient in practice consists of a three-armed lever inside
the steam chest, and hung loosely to the before-mentioned rock shaft, two
of its arms being in line with each other, and each arm being connected
to a piston adapted to a small cylinder on the under side of the steam
chest cover; the third arm being so adapted to a recess at the back of
the valve that it can have no play therein. When the valve has reached
the proper limit of its movement in either direction it is arrested by one
of the pistons coming in contact with the end of its cylinder, but as the
piston has a small hole through which steam can pass into the said
cylinder the sudden movement of the piston caused by the action of the
springs is in a measure arrested by a cushion of steam which suffices to
obviate all shocks without in any way interfering with the prompt and
determined action of the valve.
Various kinds of springs may be arranged within the steam chest for
contributing to the movement of the valve, but flat, volute, or helical
springs are preferred. These springs consist each of a double helix, into
each end of which is introduced a stud of hardened steel, one stud
having a concave recess adapted to the convex end of one of the arms of
the threc-armed valve lever, and the other stud to the similarly shaped
end of a set screw, these studs being readily replaced with new ones.
According to another modification of the Invention the loose arm on.
the rock shaft is dispensed with, and a pin inside the steam chest
projects from opposite sides of the rock shaft; this pin being arranged
as the shaft vibrates to strike alternately two shoulders on the hub of a
lever which is loose on the shaft and has but two arms, against each of
which bears a spring similar to the springs above described. A second lever
operating directly upon the valve is also hung loosely to the rock shaft
and operates within a slot in the two-armed lever, one arm of the said

page_text: lever being adapted to a recess at the back of, one valve, the other arm
passing through an elongated slot in a cylinder and projecting into a
slot in a piston contained within the said cylinder which is confined by
set screws or in other convenient manner to the interior of the steam
chest. Shoulders on the two-armed lever are arranged to bear alter-
nately against opposite edges of the valve actuating lever.
After the valve has reached its forward position its return movement
will be accomplished as follows:-The pins on the rock shaft bearing
against the shoulders will move the two-armed lever without disturbing
the valve lever, valve, or piston, until the centre of the inner end of one
spring is slightly above, and the centre of the inner end of the other
spring is slightly below the central line when the two-armed lever ceases
to be controlled by the rock shaft and is entirely under the control of
the springs which complete the movement of the two-armed lever, the
shoulder of the latter bearing against one edge of the valve lever and
moving the latter, and with it the valve to a position determined by the
small piston coming in contact with the end of its controlling cylinder;
a supply of steam admitted to the latter serving as a cushion to absorb
the shock.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Scal Patent
Office on the 17th March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sevententh day of September, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators,
and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the

page_text: "
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN OPERATING THE VALVES OF STEAM ENGINES," a communication to me from
abroad by William Jay Stevens, of the City, County, and State of New
York, and Dudley Sanford Steele, and Nathan Woodhull Condict, of
Jersey City, County of Hudson, State of New Jersey, all in the United
States of America, upon the condition (amongst others) that I, the
said John Henry Johnson, my
by an
instrument in writing, under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the accompanying
Drawings and to the letters and figures marked thereon, that is to
say:―
The object of this Invention is to operate the slide valve of a steam
engine, such for instance as a direct action steam pump directly from
the piston rod by the aid of springs contained within the steam chest
in conjunction with other appliances.
The steam chest contains a slide valve adapted to the steam ports and
to the exhaust port in a manner common to the valves of steam pumps.
A rock shaft passes through and has its bearings at opposite sides of the
steam chest, and derives its vibrating motion from the piston rod of the
engine. Through the medium of a lever and arm, the latter being
secured to the rock shaft, and the lever which is connected to the piston
rod of the engine being arranged to operate the said shaft, and as it
vibrates to strike alternately projections on the arm, the vibration of
which and consequently of the shaft must be intermittent.
To the shaft and inside the steam chest is screwed a lever having two
horizontal arms projecting in line with each other from opposite sides of
the said shaft, and a third arm arranged at right angles to the other
arms.

page_text: Between the end of each horizontal arm and a set screw passing
through the steam chest intervenes a spring, the two springs by their joint
action tending to maintain the three-armed lever in its two opposite
positions. The third arm of the lever is arranged to strike alternately
projections on the back of the slide valve.
The movement of the lever is partly effected by the piston rod and
partly by the springs, thus supposing the valve to be nearly at the
extreme end of its stroke the said lever will be moved by the piston rod
to such an extent only as will enable the springs to complete the move-
ment of the valve, and the space between the projections on the valve is
such that the movement of the latter will be effected by the action of
the springs, the preliminary movement of the lever before it begins to
act on the valve being accomplished by the direct action of the piston
rod; the subsequent and remaining portion of the movement of the
lever by means of the springs alone being permitted by the distance
which the projections on the aforesaid arm are arranged from each other,
this distance permits a limited play of the said arm independently of the
lever which actuates it.
By this arrangement and operation of the above described parts the
movements of the valve take place at the precise points and intervals
demanded by the position and movement of the piston in the cylinder,
and the desired dwell or pause of the valve after the completion of each
movement is insured. It is necessary however that the valve should be
under such controlling influence that it cannot be projected beyond its
proper limits by the impetus which the spring imparts to the lever.
Different devices for arresting the valve at the proper points will
readily suggest themselves to engineers. The device which has however
been found most efficient in practice consists of a three-armed lever
inside the steam chest and hung loosely to the before-mentioned rock
shaft, two of its arms being in line with each other, and each arm being
connected to a piston adapted to a small cylinder on the under side of
the steam chest cover; the third arm being so adapted to a recess at
the back of the valve that it can have no play therein. When the valve
has reached the proper limit of its movement in either direction it is
arrested by one of the pistons coming in contact with the end of its
cylinder, but as the piston has a small hole through which steam can
pass into the said cylinder, the sudden movement of the piston caused

page_text: by the action of the springs is in a measure arrested by a cushion of
steam which suffices to obviate all shocks without in any way interfering
with the prompt and determined action of the valve.
And in order that the said Invention may be fully understood I shall
_now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the Figures.
· Figure 1 on the Drawing represents a vertical section of a steam chest
and slide valve adapted to my Invention; Figure 2, a transverse section
on the line 1, 2, in Figure 1; and Figures 3 and 4 detailed views of
some of the working parts in Figures 1 and 2..
I
A represents the steam chest containing a slide valve B adapted to
the steam ports a, a², of the cylinder and to the exhaust port 6 in a
manner common to the slide valves of steam pumps. D is a rocking
shaft passing transversely across the centre of the steam chest A, and
mounted in suitable bearings 1,2, at the sides of the same, the bearing 2
being furnished with a stuffing box and gland through which the
rocking shaft D passes to the outside of the steam chest A. Placed
loosely on the outer end of the rocking shaft D is a lever E, and close
against the lever E fixed to the same shaft is a lever F having two pro-
jections or lugs i, i, on its face, as shewn. The lever E receives a vibrating
motion from the piston rod of the engine with which it is connected and
strikes alternately against the projections or lugs i, i, for the purpose
hereafter described.
To the rocking shaft D and inside the steam chest A is attached a
lever H. having two arms p, p, projecting in line with each other from
opposite sides of the rocking shaft D, and a third arm m at right angles
to the arms p, p, as shewn. Between the end of each arm p and a set
screw e passing through the end of the steam chest A intervenes a
spring G, the two springs G, G, by their joint action tending to
maintain the three-armed lever H in the position shewn in Figure 1, or
in the reverse position indicated by dotted lines in the same Figure.
The arm m of the lever H is arranged to strike alternately pro-
jections n, n, on the back of the slide valve B. Various kinds of
springs may be arranged within the steam chest A, but those seen in
Figure 1 are preferred. Each spring G consists of a double helix into.

page_text: each end of which is introduced a stud t of hardened steel, one stud
having a concave recess adapted to the convex end of one of the arms p
of the lever H, and the other stud to the similarly shaped end of the set
screw e, these studs being readily replaced with new ones.
The mode of operating the slide valve B by this arrangement is thus
described :—Supposing the slide valve B to be in the position shewn in
Figure 1, steam is entering the cylinder through the port a, and the
piston rod is consequently moving in the direction indicated by the
arrow, this causes the vibrating arm E to press hard against the pro-
jection i of the lever F (as seen in Figuire 3), and thereby to turn the
rocking shaft D and with it the lever H, until the arm m of the latter
comes in contact with, but no further than the projection n¹ at the other
end of the recess on the slide valve B, at the same time the arms p, p,
of the lever H are brought into such a position respectively above and
below their horizontal centre line as will enable the compressed
springs G, G, by their tension to complete the movement of lever H by
forcing the arms p, p, into the position indicated by dotted lines, and so
causing the arm m to shift or throw over the slide valve B to the
opposite end of the steam chest A so as to admit steam to the cylinder
port a', when the piston rod will begin to return and the operation will
be repeated by bringing the slide valve B to its original position, and so
on, alternately shifting the slide valve B so as to admit and exhausting
the steam at each end of the cylinder as required. The distance
between the projections i, i, on the lever F gives sufficient play for
allowing the latter to make a certain alternate vibration (produced by
the action of the springs G, G, before described) beyond that given to it
by the lever E, and independently of the latter. The distance between
the projections n, n³, on the slide valve B allows the arm m of the
lever H to perform a certain part of its vibration without moving the
slide valve B so as to give the dwell or pause, during which the piston is :
allowed to travel in the cylinder before the slide valve B is shifted and
the steam cut off.
By this arrangement and operation of the above described parts the
movements of the slide valve B take place at the precise points and
intervals demanded by the position and movement of the niston in the

page_text: proper limits by the impetus which the springs G, G, impart to the
lever H.
Different devices for effecting this will readily suggest themselves to
engineers, but that shewn in Figure 1 has been found most efficient in
practice. Inside the steam chest A a threc-armed lever K is placed
loosely on the rocking shaft D, two of its arms u, u, being in line with
each other, as shewn, and each arm being connected to a piston /
adapted to a small cylinder y on the under side of the cover of the
steam chest A, the third arm V being adapted to a recess at the back of
the slide valve B that it can have no play therein. When the slide
valve B has reached the proper limit of its movement in either direction
it is arrested by one of the pistons a coming in contact with the end of
its cylinder, but as the piston has a small hole through which steam can
pass into the said cylinder the sudden movement of the piston caused by
the action of the springs G, G, is in a measure arrested by a cushion of
steam which suffices to obviate all shocks without in any way interfering
with the prompt and determined action of the slide valve B.
In this case
Figure 5 represents a vertical section of another form of my Inven-
tion; Figure 6, a transverse section of the same; and Figure 7 a
detached view of some of the working parts in Figure 5.
the lever F is dispensed with, and a pin h inside the steam chest A¹
projects from opposite sides of the rocking shaft D; this pin / being
secured to the latter vibrates to strike alternately the shoulders q, q¹, on
the hub of the lever H¹ which is loose on the rocking shaft D, and has
but two arms p¹, p¹, against each of which bears a spring G¹ similar to
the springs G, G, above described. A lever M is also placed loosely on
the rocking shaft D and operates within a slot in the lever H³, one arm s
of the lever M being adapted to a recess at the back of the slide valve B,
the other arm & passing through an elongated slot in the cylinder N,
and projecting into a slot formed in the piston P within the cylinder N
which is confined by set screws g, g, or in any other convenient manner
to the interior of the steam chest A. Shoulders k, k, are formed on the
lever H to bear alternately against opposite edges of the lever M.
After the slide valve B, the position shewn in Figure 5, its return
movement will be accomplished as follows:-The pins i, i, on the
rocking shaft D bearing against the shoulders q, q', will move the
lever H¹ in the direction indicated by the arrows without disturbing the
lever M, slide valve B, or piston P, until the centre of the inner end of
4

page_text: the spring G is slightly above, and the centre of the inner end of the
other spring G is slightly below the centre line 2, 2, when the lever H¹
ceases to be controlled by the rocking shaft D, and is entirely under the
control of the springs G, G, which complete the movement of the lever H³,
the shoulder K of the latter bearing against one edge of the lever M and
moving the latter, and with it the slide valve B to a position determined
by the piston P coming in contact with the end of the cylinder N, a
supply of steam admitted to the latter serving as a cushion to absorb the
shock.
Having now described and particularly ascertained the nature of the ]
said Invention, and the manner in which the same is, or may be used, or
carried into effect, I would observe in conclusion that what I consider to
be novel and original and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. A slide valve B actuated by springs which derive their effective ]
operation from some moving part of the engine, substantially as and for
the purpose herein-before described.
Second. The combination with a slide valve B, of a rocking shaft,
springs G, G, and devices, whereby the movement of the shaft in either
direction is first imparted from some moving part of the engine, and is
continued and completed by the action of the springs, substantially as
and for the purpose herein-before described.
Third. The combination with the slide valve B, of the lever H, helical
springs G, G, and set screws e, e, substantially as and for the purpose
herein-before set forth.
Fourth. The combination of the rocking shaft D, its arm F having
projections i, i, and the loose lever E connected to a reciprocating part
of the engine with an arm m for acting on the slide valve B, and with
springs G, G, for aiding the rocking shaft B to actuate the slide valve B,
substantially as herein-before described.
Fifth. A slide valve B operated from some moving part of the engine
and limited in its movement by a piston acting against a cushion of
steam in a chamber, substantially as and for the purpose herein-before
described.
Sixth. A rocking shaft D to which an intermittent vibrating motion
is imparted, an arm & loose on the shaft and added to the slide valve B.

page_text: and lever H controlled by springs G, G, or their equivalents, sub-
stantially as and for the purpose herein-before described.
Seventh. The rocking shaft D having pins h, h, arranged within the
steam chest and adapted to shoulders q, q', on the lever H', substantially
as and for the purpose herein-before described.
Eighth. The combination of the lever M, piston P, and cylinders N,
all arranged within the steam chest A, substantially as and for the
purpose herein-before described.
Ninth. The combination with the helical springs G, G, of detachable
studs of steel, substantially as and for the purpose herein-before
described.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Seventeenth day of
March, One thousand eight hundred and seventy-four.