IMPROVE- MENTS IN THE VALVE GEAR OF STEAM AND OTHER ENGINES
Year: 1876

page_text: LETTERS PATENT to Charles John Galloway and John Henry Beckwith, both
of Manchester, in the County of Lancaster, for the Invention of "IMPROVE-
MENTS IN THE VALVE GEAR OF STEAM AND OTHER ENGINES."
Scaled the 21st October 1876, and dated the 13th June 1876.
PROVISIONAL SPECIFICATION left by the said Charles John Galloway and
John Henry Beckwith at the Office of the Commissioners of Patents on the
13th June 1876.
CHARLES JOHN GALLOWAY and JOHN HENRY BECKWITH, both of Manchester, in
the County of Lancaster. "IMPROVEMENTS IN THE VALVE GEAR OF STEAM AND
OTHER ENGINES."
Our Invention relates to means of working the admission slides of steam or other
fluid pressure engines in such a manner that at any desired part of the stroke the
admission port shall become closed, and that such closure can be put under the
control of a governor.
We will describe the apparatus which we employ for this purpose as applied to
a steam engine, it being understood that similar apparatus is applicable to engines
worked by compressed air or other elastic fluid.
At each end of the cylinder we provide a steam admission port separate from the
exhaust port, and to each of those admission ports we fit a slide, which is connected
by a rod to an excentric or crank, so that there are two such excentrics or cranks
working opposite to one another, or instead of two such eccentrics or cranks there
may be one working a lever, to the opposite ends of which the two slides are
connected, so that they work opposite to one another. At any convenient part of
the rod connecting each slide to its eccentric, crank, or lever we provide a means of
breaking the connection so as to leave the slide free to be moved independently of
the eccentric, crank, or lever. This disconnecting apparatus is of the following
kind-The slide rod is fitted to slide within a fork of the rod connecting it to its
motor, and on the face of the slide rod is fixed a steel plate, the edge of which
engages with the edge of another steel plate attached to a tripping lever pivotted
on the motor rod. When this lever is in one position, such as to engage the edge
of the one plate with that of the other, then the motion of the motor rod is com-
municated to the slide rod, and the slide is moved so as to open the admission port
of the cylinder. When, however, the tripping lever is moved so as to disengage
[Price Gd.]

page_text: the one plate from the other then the slide is left free to be moved back, by means
which we will presently describe, so as to close the admission port of the cylinder.
There is also on the motor rod a pin working in a slot of the slide rod, the slot
giving freedom for the slide to move back, but being such that if the slide should
not move back the motor rod will pull it back. For moving back the slide in-
dependently of its motor rod we form upon the slide rod a swell constituting a
piston or plunger, which sustains on one side the pressure of the steam, and on
the other the less pressure of the atmosphere. When, therefore, the slide rod is by
the movement of the tripping lever disconnected from its motor then the steam
pressure acting on the piston part of the slide rod pushes it back. Instead of
employing the steam pressure to effect this the pressure of the atmosphere may be
used, the piston of the slide rod being fitted to work in a vacuum cylinder
connected to the condenser, or the piston may have steam pressure on the one
Bide and vacuum on the other; or instead of pressure on a piston the slide rod may
be pressed always backwards by a weight or spring. The tripping lever above
referred to is connected by an adjustable chain or a slotted or sliding rod either to
a fixed point on the framing of the engine, or to a lever worked by the governor.
In the former case when the slide has been advanced to a certain distance the
tripping lever is moved by the tightening of its chain or rod and the slide is set
free to be closed, the point of the stroke at which it is so closed being determined
by adjusting the length of the chain or rod, or the position of the point to which
it is connected. In the latter case the point at which the slide closes is determined
by the tightening of the chain or rod combined with the position of the governor
lever to which it is attached, such position being determined by the speed of the
engine.
In order to render this latter cut-off apparatus more sensitive, and to extend its
action over a greater range of the stroke, we prefer to mount on the governor lever
a secondary lever which is caused to oscillate by a rod connecting it to a crank or
eccentric on the engine shaft, and we connect this secondary lever to the chain or
sliding rod leading to the tripping lever. The secondary lever thus mounted has a
compound motion resulting partly from that of the crank or eccentric to which it
is connected, and partly from that of the governor lever on which it is mounted,
and its action in releasing the slide, and allowing it to close, depends upon the
relative movements of these parts. This arrangement of secondary lever mounted
on the governor lever and worked by a crank or eccentric is applicable to work a
tripping lever, such as is employed for valves other than slide valves, such, for
example, as the partially rotating valves of the kind known as Corliss valves.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles John Galloway and John Henry Beckwith in the Great Seal
Patent Office on the 4th December 1876.
CHARLES JOHN GALLOWAY and JOHN HENRY BECKWITH, both of Manchester, in
the County of Lancaster. "IMPROVEMENTS IN THE VALVE GEAR OF STEAM AND
OTHER ENGINES."
Our Invention relates to means of working the admission slides of steam or
other fluid pressure engines in such a manner that at any desired part of the stroke
the admission port shall become closed, and that such closure can be put under the
control of a governor.
We will describe the apparatus which we employ for this purpose as applied to a
steam engine, it being understood that similar apparatus is applicable to engines
worked by compressed air or other elastic fluid.
At each end of the cylinder we provide a steam admission port separate from the
exhaust port, and to each of those admission ports we fit a slide, which is connected
by a rod to an eccentric or crank, so that there are two such eccentrics or cranks

page_text: :-
working opposite to one another, or instead of two such eccentrics or cranks there
may be one working a lever, to the opposite ends of which the two slides are con-
nected so that they work opposite to one another. At any convenient part of the
rod connecting each slide to its eccentric, crank, or lever we provide a means of
breaking the connection so as to leave the slide free to be moved independently of the
eccentric, crank, or lever. This disconnecting apparatus is of the following kind:-
The slide rod is fitted to slide within a fork of the rod connecting it to its motor,
and on the face of the slide rod is fixed a steel plate, the edge of which engages
with the edge of another steel plate attached to a tripping lever pivotted on the
motor rod. When this lever is in one position, such as to engage the edge of the one
plate with that of the other, then the motion of the motor rod is communicated to
the slide rod, and the slide is moved so as to open the admission port of the
cylinder. When, however, the tripping lever is moved so as to disengage the one
plate from the other, then the slide is left free to be moved back, by means which
we will presently describe, so as to close the admission port of the cylinder. There
is also on the motor rod a pin working in a slot of the slide rod, the slot giving
freedom for the slide to move back, but being such that if the slide should not
move back the motor rod will pull it back. For moving back the slide indepen-
dently of its motor rod we form upon the slide rod a swell constituting a piston
or plunger, which sustains on one side the pressure of the steam, and on the other
the less pressure of the atmosphere. When, therefore, the slide rod is by the
movement of the tripping lever disconnected from its motor then the steam pressure
acting on the piston part of the slide rod pushes it back. Instead of employing
the steam pressure to effect this the pressure of the atinosphere may be used, the
piston of the slide rod being fitted to work in a vacuum cylinder connected to the
condenser, or the piston may have steam pressure on the one side and vacuum on
the other; or instead of pressure on a piston the slide rod may be pressed al..ays
backwards by a weight or spring. The tripping lever above referred to is con-
nected by an adjustable chain or slotted or sliding rod either to a fixed point on
the framing of the engine or to a lever worked by the governor. In the former
case when the slide has been advanced to a certain distance the tripping lever is
moved by the tightening of its chain or rod and the slide is set free to be closed,
the point of the stroke at which it is so closed being determined by adjusting the
length of the chain or rod, or the position of the point to which it is connected.
In the latter case the point at which the slide closed is determined by the
tightening of the chain or rod combined with the position of the governor lever to
which it is attached, such position being determined by the speed of the engine.
In order to render this latter cut-off apparatus more sensitive, and to extend its
action over a greater range of the stroke, we prefer to mount on the governor lever
a secondary lever, which is caused to oscillate by a rod connecting it to a crank or
eccentric on the engine shaft, and we connect this secondary lever to the chain or
sliding rod leading to the tripping lever. The secondary lever thus mounted has
a compound motion resulting partly from that of the crank or eccentric to which it
is connected, and partly from that of the governor lever on which it is mounted,
and its action in releasing the slide, and allowing it to close, depends upon the
relative movements of these parts. This arrangement of secondary lever mounted
on the governor lever and worked by a crank or eccentric is applicable to work a
tripping lever, such as is employed for valves other than slide valves, such, for
example, as the partially rotating valves of the kind known as Corliss valves.
Fig. 1 represents a plan partly sectional as to the cylinder, and Fig. 2 an elevation
partly sectional as to the slide coupling of a double acting horizontal steam engine
provided with valve gear according to our Invention. Fig. 3 is a sectional plan of
the slide couplings.
A is the cylinder having eduction ports B and B¹, which may be governed by
slides or valves in any known manner, and separate induction ports C and C¹

page_text: cach governed by its slide D and D. Each of the slide rods E and E¹ has
its end fitted to work in guides F, and within the fork of a crank or eccentric rod
G and G¹ which is also guided in F. On each slide rod head is fixed a plate of steel
e and e¹, and on each of the rods G and G¹ is mounted a bell-crank trigger lever H
and H¹, one arm of which has a steel plate h and fixed upon it, so that when the
edge of the plate engages with that of e the movement of the crank or eccentric
rod towards the left causes the slide rod to move also towards the left along with it.
The slide rods are made with swells at K, K¹, fitted to work as plungers through
packing at the end of the slide jacket, so that the pressure of the steam within the
jacket tends to push the slides towards the right, and thus if either of the trigger
levers H or H¹ be moved so as to disengage its plate h or h¹ from the plate e or e¹
on the slide rod, the slide rod so disengaged will be forced by the steam pressure
towards the right, and the slide D or D' attached to it will close the port C or C¹.
Also when the crank or eccentric rod G or G¹ retreats towards the right, the steam
pressure acting on the plunger swell K or K¹ causes the slide rod to follow it,
the plates h and e or ¹ and e¹ still remaining engaged with each other. Pins g and
g¹ working in slotted holes in the slide rod heads limit their movements relatively
to those of the rods G, G¹. The trigger levers H and H¹are connected by adjustablo
ods L and L¹ passing through sliding sockets and having exterior collars with
other bell-crank levers and which are worked by the cranks or eccentrics on
the main shaft M that move the rods G and G. The bell-crank levers l, l', are
pivotted on a stud R on the vertical arm of a counterbalanced lever N, which is
worked by a governor O, the movements thereof being steadied by a clash pot or
cataract cylinder P. From this construction it follows, that supposing the lever N
to be stationary at a certain part of each stroke of the engine, as determined by the
position of the fulcrum R, the bell-crank levers 1, 11, are moved, so that by acting on
the collars of the rods L, L', they move the triggers so as to disengage the edges
of the plates h and e and h¹ and e¹, and thereby to leave the slides D and D¹ free to
be moved back by the steam pressure acting on the plungers K and K² and to close
the admission ports C and C¹, thus effecting a rapid cut off of the steam supply to
the cylinder. When owing to increase or decrease of the engine speed the lever N
is moved by the governor 0 so as to remove the fulcrum R of the levers 7, 1¹,
towards the right or left, as the case may be, then the triggers H and H¹ are caused
at an earlier or later period of the stroke to release the slides, whereby the steam is
cut off sooner or later, according as the speed of the engine has increased or de-
creased. It is obvious that without the use of a governor the fulcrum R instead of
being on the arm of a lever N worked by the governor might be adjustable in
position on some fixed part of the engine framing so as to determine the cut off at
any desired period of the stroke irrespective of the engine speed. Although we
have described the movement of the slides D and D¹ in the cut off direction as
being effected by the excess of the pressure of the steam within the slide jacket
over that of the atmosphere acting on the plunger swells K, K', of the slide rods,
it is obvious that the same effect could be obtained by connecting the slide rods to
plungers or pistons working in cylinders or barrels in which a partial vacuum is
maintained either by a pump worked by the engine, or in the case of a condensing
engine by a communication with the condenser, also that the back or cut-off move-
ment of the slides could be effected by means of weights or springs acting on the
slide rods.
We have above described our improvements as applied to a steam engine, it is
to be understood, however, that they could be applied in a similar manner to engines 5
worked by elastic fluids generally, as, for example, to engines worked by compressed
air.
Having thus described the nature of our Invention, and in what manner the
same is to be performed, we claim-
First. Constructing a steam or other motor engine worked by elastic fluid with 5
induction ports and valves distinct from those for eduction, each of the said induction
valves being connected to a crank, eccentric, or other reciprocating motor by means

page_text: of a trigger or its equivalent, so that the connection can be readily disengaged, and
being pressed in the direction of its closing movement by a weight or spring, or by
fluid pressure, and the trigger itself being connected to a point that can be adjusted
so that at any desired period of the stroke the trigger connection is disengaged, and
the valve immediately closes and cuts off the supply of working fluid, substantially
as herein described.
Second. Connecting the triggers or their equivalents referred to in the preceding
claim to a governor lever in such a manner that they are disengaged, allowing the
induction valves to close at an earlier or later period of the engine stroke, according
as the speed of the engine is increased or diminished, substantially as herein
described.
Third. Arranging triggers or their equivalents employed for releasing from their
motors slide or other engine valves with the connections for working them, so that
the action of the triggers results from a compound or differential motion derived
partly from a governor lever, and partly from cranks or eccentrics on the engine
shaft, substantially as and for the purpose herein set forth.
In witness whereof, I, the said John Henry Beckwith, have hereunto set my
hand and seal, this Eighteenth day of November, in the year of our Lord
One thousand eight hundred and seventy-six.
JOHN HENRY BECKWITH. (L.S.)