Improved Valve Gear for Automatically Controlling the Supply of Steam or the like to the Cylinders of Steam or similar Motor Engines.
Year: 1891

page_text: Date of Application, 3rd Apr., 1891
Complete Specification Left, 4th Jan., 1892-Accepted, 6th Feb., 1892 -
PROVISIONAL SPECIFICATION.
Improved Valve Gear for Automatically Controlling the Supply of
Steam or the like to the Cylinders of Steam or similar Motor
Engines.
We JAMES JUDSON, FRANCIS TITUS LONGBOTTOM and JOHN HUDSON all of
Keighley in the County of York, Engineers and Millwrights, do hereby declare
the nature of this invention to be as follows, that is to say :—
It relates to improved expansion or cut-off valve gear for automatically con-
trolling the supply of steain or the like to the cylinders of steam or similar
motor engines (wherein the usual and well known kind of reciprocating or slide
valve is employed) whereby the quantity of steam admitted into or allowed
to enter said cylinder is regulated through the medium of the rotary governor,
at or for each stroke of the piston.
As is above stated the mechanism made in accordance with this invention is
applicable for use in connection with the common slide valve mechanism and
consists of an arrangement of supplementary valves (which are or may be styled
trip valves) that operate on the face of said common slide valve or on the face of a
loosely fitting intervening plate.
These trip valves (one being used for each port as is well understood) are
operated in one direction by an eccentric mounted upon the engines crank shaft
through the medium of any of the well known connecting rod devices at present
in use or they may be operated in this said direction by any other means from any
suitable motor part of the engine, while their return movement is effected by
atmospheric pressure obtained by what are known as dash-pots" or instead of
these "dash-pots" springs may be employed.
66
The trip valves when moved by the motor parts of the engine, are withdrawn
from covering the ports or openings in the slide valve and when this movement is
to be increased or decreased for allowing greater or less space for the passage
of the steam, suitable catch mechanism controlled by the engine's governor
continues or discontinues its hold of said motor until or when the desired position
is reached on which by the actions of the "dash pots or like retracting power, the
said trip valves are immediately moved in the opposite directions in order to cover,
and so cut off the steam from entering said ports.
By the return movements of the trip-valves being effected when free indepen-
dently of the motion of the engine and their liberty being directly under the
control of the governor the best and most desirable results are obtained, any
variation in the speed of the engine being immediately counteracted.
Any method of arrangement may be followed for effecting the movements of
the trip-valves as above described among which we have found the following to
answer very well.
The trip-valve has a projection formed on it to operate within a slot formed in a
lever mounted upon a shaft passing through and rotating within a neck formed on
the lid of the steam chest. On the outer end of this shaft is mounted a bell-crank
lever one arm of which carries a projecting catch-piece while the other is coupled
to the "dash-pot."
On the same shaft is mounted a cam operated by the governor, and in proximity
therewith is arranged a reciprocating catch operated by an eccentric on the engine's
shaft so that as it slides over or upon this cam, in order to lay hold of and to
operate the catch-piece above described when and as permitted by the said cam,
when the speed of the engine is increased said cam is rotated to raise its catch out
of gear with the catch-piece thus effecting the closing of the port by the trip-valve,

page_text: while when the speed is decreased the governor moves the cam to allow the catch
to maintain its hold of the catch piece so as to keep the port longer open by which
means the speed of the engine is. increased.
11
1001
J. JUDSON,
F. T. LONGBOTTOM,
J. HUDSON,
Per Samuel Hey,
Agent.
COMPLETE SPECIFICATION.
Improved Valve Gear for Automatically Controlling the Supply of
Steam or the like to the Cylinders of Steam or similar Motor
Engines.
We JAMES JUDSON, FRANCIS TITUS LONGBOTTOM and JoHN HUDSON all
of Keighley in the County of York Engineers and Millwrights 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, that is to say :-
It relates to improved expansion or cut-off valve gear for automatically
controlling the supply of steam or the like to the cylinders of steam or
similar motor engines (wherein the usual and well known kind of reciprocating or
slide valve is employed) whereby the quantity of steam admitted into or allowed
to enter said cylinder is regulated through the medium of the rotary governor at
or for each stroke of the piston.
In the accompanying sheets of drawings,
Fig. 1 is part sectional side elevation shewing the slide valve within its casing
or chest.
Fig. 2 is front elevation of parts shewn by Fig. 1 and as seen in the direction
indicated by arrow A one half of the lid or cover being shewn in position while
the other half of the chest is shewn as having said lid removed so that parts
beneath same may be seen.
Fig. 3 is front elevation reduced scale, shewing the operating mechanism on the
outside of the valve casing or chest of a horizontal engine.
Fig. 4 is side elevation illustrative of parts shewn by Fig. 3.
Figs. 5 and 6 are drawings in detail same scale as Figs. 1 and 2 of parts herein-
after referred to.
Fig. 7 is a similar view to Fig. 3 with certain parts cut away to shew the parts
behind.
Fig. 8 is also a similar view to Fig. 3 but shews the mechanism same scale as
Figs. 1 and 2 as applied to a vertical cylinder and arranged in such a manner that
a most desirable position for certain of the parts may be maintained.
Similar letters and figures refer to similar parts throughout the several views.
As is hereinbefore stated the mechanism made in accordance with this inven-
tion is applicable for use in connection with the common slide valve mechanism
and consists of an arrangement of supplementary valves a and a¹ (which are or
may be styled trip valves) that operate on the face of said common slide valve b
or on the face of a loosely fitting intervening plate c, the latter arrangement, being
the one. preferably employed, is therefore alone illustrated from the description of
which the former will readily be understood.
Each of these trip-valves a and a' (the former being used opposite the port d
while the latter is opposite the port d') is operated in one direction, as that
indicated by the arrow B or B respectively by an eccentric mounted upon the
engine's crank shaft through the medium of the connecting rod e, the rod for f'
with its catch g or g¹ the lever h or h¹, rigidly mounted upon its respective

page_text: shaft or pink or k¹ and having at its outer end the catch-piece or 1, and
the lever m or m' also mounted upon its respective shaft k or k, or in place
of these parts other means may be employed for effecting the operations of
these valves a and a¹ in the said directions, the said parts receiving their
motions from any suitable motor part of the engine, while the return movements
of these valves a and a¹ is effected by atmospheric pressure obtained by what are
known as "dash-pots" shewn at n and n¹ (these "dash-pots" consist of a cylinder 1
and a piston 2 made to fit within it, a small tap or valve 3 being fitted near the
lower end of the said cylinder 1 in order to regulate the ingress and egress of air
so that the piston 2 may be made to operate the lever or with a greater or
less force) or instead of these dash-pots and n³, springs either of spiral or flat
form may be employed.
The trip-valves a and a¹ when moved (by the motor parts of the engine) are
withdrawn from covering their respective ports d and d in the slide valve or
plate c and when this movement is to be increased or decreased for allowing greater
or less space for the passage of the steam suitable catch mechanism (as the parts g g'
and hereinafter more fully described) controlled by the engine's governor con-
tinues or discontinues its hold of said motor until or when the desired position is
reached on which by the actions of the "dash-pots" n and n¹ or other retracting
device, the said trip-valves a and a' are immediately moved in the opposite directions
in order to cover, and so cut off the steam from passing therethrough or entering
the cylinder.
By the return movements of these trip-valves a and a being effected, when free
independently of the motion of the engine and their liberty, or liberation from
attachment to the motor parts of said engine, being directly under the control of
the governor the best and most desirable results are obtained, any variation in the
speed of the engine being immediately counteracted.
Any method of arrangement may be followed for effecting the movements of the
trip-valves a and a' as above described, among which we have found the following
to operate and answer the purposes efficiently.
P
The trip-valve a or a has a projection or a³ respectively formed on it to
operate within a slot m² or m³ formed in the lever m or m³ mounted upon the shaft k
or passing through and rotating within a neck o or o' formed on the lid of the
steam chest. On the outer end of this shaft or is mounted a bell-crank lever h
or one arm of which carries a catch-piece or while the other is coupled to
the dash-pot n or n¹ by means of the rod or ¹.
On the shaft or ki is also mounted a cam s or s', operated by the engine's
governor to which it is coupled by the rod t or t, and in proximity with the said
cam s or s¹ is arranged a reciprocating catch or g' operated by the rod for f'
being coupled to the reciprocating rode which receives its motion from an eccentric
mounted upon the engine's crank or other shaft, so that as it, said catch g or g¹,
slides over or upon this cam s or s¹, in order to lay hold of and to operate the
catch-piece or when and as permitted by the said cams s or 81, when the
speed of the engine is increased said cam s or s (or both of them) is rotated
or slightly moved to raise its catch g or g' by its tail-piece g² or so that
its part g or g is out of gear with the catch-piece or thus liberating same so
that the valve a or a' may be operated by its dash-pot n or n' to effect the closing
of the port d or d¹ by said trip-valve a or a', while when the speed is decreased
then same moves the cams s and s to allow their respective catches y and y' to
maintain their hold of their respective catch-pieces and so as to keep said
ports d and d¹ longer open by which means the speed of the engine is increased.
When the parts herein before described are used in connection with the slide
valve of a vertical cylinder the operating levers, cams, catches catch-pieces and
other parts mounted on the outside of the lid p are arranged as shewn by Figure 8,
this arrangement and formation of parts being such as to enable the dash pots
and n to maintain their vertical positions, whereas if the levers and other parts as

page_text: shewn by Figs. 3, 4 and 7 were employed in connection with said vertical cylinder,
said dash-pots would have to be placed horizontally.
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. The combination of trip valves such as those marked a and al with the
reciprocating or slide valve of a steam or other motive power engine, said valves a
and a being operated in one direction by the motor parts of the engine and in the
other direction by means other than by the parts of said motor engine substantially
as herein specified.
2. The combination of the valves a a and b, the plate e and mechanism for
operating said valves a and a substantially as herein specified.
3. The combination of the catch, catch-piece lever and valve mechanisms with
the cam s arranged to be operated by the governor of an engine substantially as
herein specified to attain the object set forth.
1000
JAMES JUDSON,
FRANCIS T. LONGBOTTOM,
JOHN HUDSON,
TTOM,
Per Samuel Hey,
Agent.