Improvements in or connected with "Corliss and other Engines, such as are Fitted with Variable Automatic Tripping Gear on their Steam Valves.
Year: 1889

page_text: Date of Application, 8th Mar., 1889
Complete Specification Left, 9th Dec., 1889-Accepted, 1st Feb.,
1890
PROVISIONAL SPECIFICATION.
"
Improvements in or connected with "Corliss and other Engines,
such as are Fitted with Variable Automatic Tripping Gear on
their Steam Valves.
I, ROBERT MIDDLETON, of Sheepscar Foundry, Leeds, in the County of York,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to a mode of showing, say, on a dial, or on, or by,
any like equivalent, the exact proportion of the stroke at which the steam is
being cut off from the cylinder of an engine then in motion.
The object of the invention is to so add to, or arrange, the mechanism of the
valve motion that the proportion (resulting from the last action of the tripping
gear) of the length of the stroke of the piston during which steam is admitted into
the cylinders shall be clearly seen at a glance, say, in percentage of the stroke, hotli
for the guidance of the attendant and also for the information of anyone else interested
in the engine's economy.
On the valve spindles, or on any suitable rocking shafts connected with them,
1 arrange a pointer which travels along the face of a plate on which is exhibited
the per-centage-points of the stroke of the piston carefully laid out in relation to
the movement of the said valve spindle or rocking shaft. Of course either the
pointer may move along the dial, or the dial may move in relation to the pointer or
there may be a compound movement if such be suitable.
In some cases I move an additional registering pointer which is pushed along
by the vibrating pointer and stands at the maximum "cut off."
This non-vibrating pointer may be moved back towards zero by hand at any
time by the attendant, or it may be fitted with a slowly-acting return motion so that
the variations of the "cut off," at any such times as they occur, may be followed and
more clearly shown by this additional pointer.
Dated this 7th day of March 1889.
WM.
SNOWDON,
9, Beckett's Bank Chambers, Leeds, Yorks, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or connected with "Corliss " and other Engines;
such as are Fitted with Variable Automatic Tripping Gear on
their Steam Valves.
I, ROBERT MIDDLETON, of Sheepscar Foundry, Leeds, in the County of York,
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 :-
This invention has reference to a mode of showing, say, on a dial,-
,-or on, or by, any
like equivalent the exact proportion of the stroke at which the steam is being cut
off from the cylinder of an engine then in motion.
The object of the invention is to so add to, or arrange, the mechanism of the
valve motion that the proportion (resulting from the last action of the tripping gear)
of the length of the stroke of the piston during which steam is admitted into the
cylinder shall be clearly seen at a glance (say, in per-centage of, the stroke) both for
the guidance of the attendant and also for the information of anyone else interested
in the engine's economy.
On the valve spindles, or on any suitable rocking shafts connected with them,

page_text: I arrange a pointer which travels along the face of a plate on which is exhibited
the per-centage-points of the stroke of the piston carefully laid out in relation to the
movement of the said valve spindle or rocking shaft. Of course either the pointer
may move along the dial, or the dial may move in relation to the pointer, or there
may be a compound movement if such be suitable.
In some cases I move an additional registering pointer which is pushed along
by the vibrating pointer and stands at the maximum cut off."
This non-vibrating pointer may be moved back towards zero by hand at any time
by the attendant, or it may be fitted with a slowly acting return motion so that the
variations of the "cut off," at any such times as they occur, may be gradually followed
up and more clearly shown by this additional pointer.
Referring to the drawing-fig. 1 is a front elevation of an apparatus arranged
and fixed after my system-on the valve gear of a Corliss engine, and fig. 2 is a
corresponding side elevation-partly in section-of the same. The same letters refer
to the same parts in each figure. Each steam admitting valve may with advantage
have its own dial. A is a rocking shaft of a Corliss valve spindle which works in the
well known manner. B, B, is a valve spindle guide upon which may be mounted the
dial C whose zero point is supposed to be at C¹. A rocking pointer D may be
arranged, say at the apex of a triangular-shaped frame D¹, DI, fixed on the valve
spindle A, which frame thus spans the valve spindle guide B. When the pointer D
advances a stud D² (at the apex of the frame) pushes before it a lever E, arranged
(for the sake of appearance) at the back of the dial. This lever E has its axis at F
and is there joined to the pointer G which stands in front of the dial ready to register
the "cut off" of the steam.
No further part of the apparatus shown on the drawing need be fitted up; but
in such a case the last mentioned non-vibrating pointer G would require to be pushed
back by hand so as to be brought within the range of the vibrating one, whenever an
observation was to be taken.
So long as the pointer D is advancing, from zero, steam is being admitted, but as
soon as the valve is closed (by being tripped off) then this pointer falls back again
leaving however the non-vibrating pointer G to record the limit of the advance.
The best way of marking off the dial is from the engine itself, by moving the
piston through the series of points required.
A mode of supplying a slowly acting return motion to the non-vibrating pointer D
is further shown on the drawing. Here an endless cord H, H, which obtains its
motion from the engine in any convenient way, moveing, say in the direction of
the arrow, causes the pointer G to be moved slowly back to zero. In the arrangement
here shown the pinion H₁ of the cord pulley is mounted on a stud H2 and gears
into the wheel J mounted on the axis F. This wheel would be loose on the axis were
it not that a nut K can be used to give the requisite friction to cause all to move
together. The eye of the lever G would require to be fitted with a sliding key to
permit this nip to be given. Hence the pointers E & G could always be advanced
to the limit required and the cord would at once begin to move them back (E & G
advance without moving J).
If the movement of the cord were derived from a rocking shaft, say from an
adjacent valve spindle, a ratchet arrangement could be devised to suit it, the lever G
being moved backwards intermittently.
In some cases the front pointer G could be arranged to move other independent
In this
pointers not shown-representing the maximum and minimum "cut off."
case after the engine was fully started the attendant would have to move the
:: minimum ። pointer into range.
A com-
The actuating cord could be slipped off and on as required.
A modification of this method of moving the pointers could easily be made to
suit a valve spindle whose motion was in the direction of its length.
bination with clockwork could be arranged to register the ".
cut off" say, on a
revolving cylinder, as the hours ran by, after the manner of a self registering
barometer or pressure recording instrument.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The application to an engine fitted with tripping gear on its steam valves of
Recording Dials with Indicating Pointers-worked directly or indirectly off the
Steam-valve-spindles-for the purpose of showing the point of the "Cut off."
2. The Apparatus, in whole, or in part, substantially as and for the purpose set
forth.
1
L 1
11000
WM. SNOWDON,
9, Beckett's Bank Chambers, Leeds, Yorks, Agent for the Applicant.