Improvements in Automatically Variable Expansion or Cut-off Apparatus for Steam Engines.
Year: 1890

page_text: Date of Application, 3rd July, 1890
Complete Specification Left, 3rd Apr., 1891-Accepted, 9th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Automatically Variable Expansion or Cut-off
Apparatus for Steam Engines.
I, JAMES LUMB, of Perseverance Engine Works Elland, in the County of
Yorkshire, Engineer, do hereby declare the nature of this invention to be as
follows:-
From a single steady reciprocating motion obtained from any suitable eccentric
or other moving part of a steam engine, I obtain two reciprocating motions timed
alternately and having a quick and free return for cutting off the steam by the
following arrangement of mechanism.
Two sliding bars having the valve rods or spindles attached to them are mounted
in juxtaposition and are free to move longitudinally. There is a suitable space
between them and on the adjacent faces of each a notch or notches are formed each
having an inclined edge and a toothed or undercut edge, the toothed edge on one of
the bars being at one end of the notch and on the other bar at the other end. In
the space between the bars two spring members of a hinged trigger piece are
caused to reciprocate longitudinally by the steady motion obtained from the engine
as aforesaid. At their fixed ends these spring members are rigidly attached
together and at their outer ends they carry or are formed with enlargements having
teeth and inclined planes corresponding with and formed so as to engage with the
inclined and toothed edges of the notches hereinbefore described as being formed
in the sliding bars.
open
"
Thus at or about the end of an outward stroke of the trigger piece the toothed
edge of one of its spring members will engage with one of the bars, and draw it
back upon its next inward stroke thus opening the valve. Just before the com-
pletion of this stroke one of two oscillating catches provided for the purpose and
pivoted to the framework will fall into position to retain the bar in this "
position till the desired moment of cut-off arrives by gearing with a second tooth
formed or fixed upon the bar and which I called the retaining tooth. This
retention of the bar occurring just after the commencement of the second outward
stroke of the trigger piece causes the tooth of the trigger piece spring member to
disengage with the tooth on the bar. and the continued movement of the trigger-
piece on this outward stroke brings the inclined plane of this same member to come
in contact with the inclined plane on the retained bar and thus the whole of the
hinged trigger piece is pushed or "kicked" over so that the tooth of its other
member will engage with the tooth of the other bar, pushing it forward and so
opening the other valve. By the same action the tooth of the first member is
brought into a position in which it is out of the line of movement of the tooth of
the first bar so that when the same is released to close the valve it shall pass it by
without engaging.
A second oscillating catch pivoted to the frame-work is provided to fall into
gear with the retaining tooth of this bar and retain it also in the "open" position
till the desired moment of cut-off. Upon the reversal of the movement of the
trigger piece for the second instroke the inclined planes of the second spring member
and of the second bar cause the trigger to be "kicked" over so that the tooth of
the first or drawing member of the trigger shall engage with the tooth of the first
bar, which, having in the meantime been released has rapidly returned into its first
"closed" position by the action of a suitable spring or by steam pressure, its
sudden action being preferably cushioned by any suitable device.
or
The oscillation of the retaining and releasing catches is obtained by connecting
them by links to an oscillating "T" piece or double bell-crank lever which is

page_text: operated by a motion obtained from any suitable moving part of the engine but
which I prefer to obtain by a simple link connection with the reciprocating part to
which the beforementioned trigger piece is pivoted. Suitable are slots are provided
in this "T"lever to allow the retaining catches to remain at rest till their teeth
can fall into gear but of such length as to lift them out of gear at the desired
moment of cut-off. The fulcrum or pivot of the said "T" lever is not pivoted to
the framework but is carried by a short lever or other moving piece whose move-
ment in either direction is caused by the variations of the engine governors.
variations in the speed of the engine cause the "T" lever to lift the retaining or
oscillating catches out of gear with the retaining teeth of the bars at an earlier or
later moment as desired.
Thus
The closing movement is imparted to the sliding bars by means of suitable
springs which may act upon them through the medium of levers or bell-cranks or
which may be mounted direct upon the valve spindles at any suitable point or at
their external ends. Any suitable air or other cushion may be employed.
My invention as hitherto described is specially applicable to cut-off valves of the
"Rider" class that is plate-valves working upon the back of a main slide-valve
of a steam engine, and closing "through" ports therein, but by means of a modi-
fication it is also applicable to single valves of any class, working both the
admission and cut-off of steam, such as "Corliss,'
9966 Stamper," «Grid,' Crown,'
Plug," or other valves.
66
In this case I dispense with the second or "retaining" pair of oscillating catches
and I arrange to release the hold of the first or pulling and pushing spring members
of the trigger at any point determined by the engine governors. This is done by a
suitable cam, eccentric, wedge, or "T"lever whose relative position or fulcrum is
variable by the governors and which derives its motion from any suitable moving
part of the engine. The connection with the spring members to be released may
be direct or through the medium of suitable swing links.
Dated this 2nd day of July 1890.
EDGAR CONISTON MILLS,
Agent to the Applicant.
COMPLETE SPECIFICATION.
Improvements in Automatically Variable Expansion or Cut-off
Apparatus for Steam Engines.
I JAMES LUMB of Perseverance Engine Works, Elland in the County of
Yorkshire, Engineer, 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 :-
From a single steady reciprocating motion obtained from any suitable eccentric
or other moving part of a steam engine, I obtain two reciprocating motions timed
alternately and having a quick and free return for cutting off the steam by the
following arrangement of mechanism.
DESCRIPTION OF DRAWINGS.
Fig. 1. is a front elevation of my invention applied to a tandem engine.
Fig. 2. is a plan of Fig. 1.
A. A. are the two sliding bars having the valve rods or spindles B B. attached
to them; the said sliding bars A A. are mounted in juxtaposition and are free to
move longitudinally. There is a suitable space between them, and on the adjacent
faces of each a notch or notches C. C. are formed having an inclined edge and a
toothed or undercut edge. In the space between the bars, two spring members C¹
of a hinged trigger piece D. are caused to reciprocate longitudinally by the steady
motion obtained from the engine as aforesaid.

page_text: At their fixed end these spring members are pivoted and attached together and
at their outer ends they carry or are formed with enlargements having teeth and
inclined planes D' corresponding with and formed so as to engage with the inclines
and toothed edges of the notches C. C. hereinbefore described as being formed in
the sliding bars A. A.
Thus at about the end of an outward stroke of the trigger piece D. the toothed
edge of one of its spring members C' will engage with one of the bars and draw it
back upon its next inward stroke thus opening the valve.
Just before the completion of this stroke one of two oscillating catches E E.
provided for the purpose and pivotted to the framework will fall into position to
retain the bar in this "open" position (until the desired moment of cut-off arrives)
by gearing with a second tooth F. formed or fixed upon the bar, and which I call
the retaining tooth. This retention of the bar occurring just after the commence-
ment of the second outward stroke of the trigger piece, causes the tooth D¹ of the
trigger piece spring member C¹ to disengage with the notch C on the bar A and
the continued movement of the trigger piece on the outward stroke brings- the
inclined plane of the same member to come in contact with the inclined plane on
the retained bar, and thus the whole of the hinged trigger piece is pushed or
"kicked" up by means of a quick incline plane so that the tooth of its other member
will engage with the tooth of the other bar, pushing it forward and so opening the
other valve. By the same action the tooth of the first member is brought into a
position in which it is out of the line of movement of the tooth of the first bar, so
that when the same is released to close the valve it shall pass it bye without
engaging.
A second oscillating catch E pivotted to the framework is provided to fall into
gear with the retaining tooth of the other bar and retain it also in the "open" position
till the desired moment of cut-off. Upon the reversal of the movement of the
trigger piece for the second instroke, the inclined planes of the second spring
member and of the second bar cause the trigger to be "kicked" over so that the
tooth of the first or drawing member of the trigger shall engage with the tooth of
the first bar, which having in the meantime been released has rapidly returned into
its first or "closed" position by the action of a suitable spring, or by steam
pressure, or suitable motor or agent, its sudden action being preferably cushioned
by any suitable device.
The oscillation of the retaining and releasing catches E. E. is obtained by
connecting them by links H H. to an oscillating "T" piece or double bell crank
lever J, which is operated by a motion obtained from any suitable moving part of
the engine, but which I prefer to obtain by a single link connection K with the
reciprocating part L, to which the before mentioned trigger piece is pivotted.
Suitable arc or T slots J' are provided in this "T" lever to allow the retaining
catches to remain at rest till their teeth can fall into gear but of such length as to
lift them out of gear at the desired moment of cut-off.
The fulcrum or pivot M of the said T lever is not pivotted to the framework but
is carried by a short lever N or other moving piece whose movement in either
direction is caused by the variations of the engine governors. Thus variations in
the speed of the engine cause the "T"lever to lift the retaining or oscillating catches
out of gear with the retaining teeth of the bars at an earlier or later moment
as desired.
The short lever N is carried by a suitable bracket P. R. is the engine bed, S. the
main eccentric rod, T is the cut-off eccentric rod.
The closing movement is imparted to the sliding bars by means of suitable
springs which may act upon them through the medium of levers or bell cranks
on which may be mounted direct upon the valve spindles at any suitable point or at
their external ends.
Any suitable air or other cushion may be employed.
My invention as hitherto described is specially applicable to cut-off valves of the
"Rider" class, that is, plate valves working upon the back of a main slide-valve of

page_text: any class of steam engine, and closing "through" ports therein, but by means of a
modification it is also applicable to single valves of any class, working both the
admission and cut-off steam, such as ક્રૂડ
3366
Corliss," "Stamper,' Grid," "Crown,"
"Plug," or other valves.
In this case I dispense with the second or "retaining " pair of oscillating catches,
and I arrange to release the hold of the first or pulling and pushing spring members
of the trigger at any point determined by the engine governors. This is done by a
suitable cam, eccentric, wedge or "T"lever whose relative position or fulcrum is
variable by the governors and which derives its motion from any suitable moving
part of the engine. The connection with the spring members to be released may
be direct or through the medium of suitable swing links.
.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. Connecting to the valve rods sliding bars A. A. having notches C. C. spring
members C¹ and trigger piece D, operating as and for the purposes shown and
described.
2. The combination of the sliding bars A. A. spring members C¹, trigger piece D.
oscillating catches E, retaining tooth F, links H H. double bell crank lever J,
operating in the manner and for the purposes substantially such as shown and
described.
3. The general arrangement and construction of apparatus as and for the purposes
substantially as shown and described.
Dated this Second day of Annil 1001
JOHN E. WALSH,
Waterhouse Chambers, Crossley Street, Halifax, Agent for the Applicant.