IMPROVEMENTS IN STEAM ENGINES
Year: 1880

page_text: LETTERS PATENT to Samuel Wright Wilkinson, of Stockport, in the County
of Chester, Cotton Spinner, Francis Preston, of Huddersfield, in the County of
York, Consulting Engineer, and John Blomfield Hamond, of Stockport,
Mechanical Engineer, for an Invention of "IMPROVEMENTS IN STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Samuel Wright Wilkinson,
Francis Preston, and John Blomfield Hamond at the Office of the Com-
missioners of Patents on the 20th March 1880.
SAMUEL WRIGHT WILKINSON, of Stockport, in the County of Chester, Cotton
Spinner, FRANCIS PRESTON, of Huddersfield, in the County of York, Consulting
Engineer, and JOHN BLOMFIELD HAMOND, of Stockport, Mechanical Engineer.
"IMPROVEMENTS IN STEAM ENGINES."
Our Invention consists in an improved arrangement for varying the working of
the cut off valve of steam engines so as to make it selfacting and controlled
by the same governor that is used for acting upon the ordinary throttle valve.
This is effected by having two friction discs or bevel cones revolving upon the
shaft of the governor of the engine, or they may be placed in any other convenient
position and be acted upon by the same governor.
Between the discs or bevel cones is placed a friction pulley or cone, keyed on a
shaft communicating by suitable gearing to the rod of the cut off valve, which
closes or opens the ports according to the requirement of the engine.
The friction pulley and the discs are brought into connection by the raising or
lowering of the governor slide according to the speed of the engine, but when the
engine is working at its normal speed the friction pulloy does not touch either of
the discs or cones.
In order to enable us to utilize the ordinary governor of the engine, whether it
be of the quick or slow speed type, we construct the cut off gearing so as to allow
the governor to continue acting upon the throttle valve in the ordinary way with-
out interfering with its free action.
When more or less steam is required the friction pulley or cone comes in contact
with one of the revolving discs or cones and the cut off responds, and so soon as
the required speed of the engine is obtained the friction pulley again ceases to
touch either of the discs or cones.

page_text: This permissive mechanical arrangement is obtained by having a balanced lever
resting on a fixed centre in connection with the revolving discs or cones, and acted
upon by means of two weights hung on the throttle valve lever, one on each side
of the fixed centre of the throttle valve lever, immediately above the cut off lever,
so that one of the weights will rest or bear upon the cut off lever when the throttle
valve lever is raised or lowered.
The fixed centres of the throttle valve lever and the revolving disc lever are in a
direct vertical position to each other.
The hooks or slotted links by which the two weights are suspended from the
throttle valvo lever are arranged so that when either of the weights comes into
contact with the cut off lever the discs or cones will be either elevated or depressed,
and immediately cause the friction pulley or cone to revolve, and thus open or close
the cut off valve as required. At the same time the slot in the hook or link allows
the throttle valve lever to continue its course freely and independently, and to
continue acting upon the throttle valve lover during the time the weight rests upon
the cut off lever.
At the opposite end of the friction pulley or cone shaft is attached suitable
gearing acting upon the right and left hand screw or other well known application
in connection with the cut off valve rod, which either opens or closes the ports
according to the direction in which the friction pulley or cone revolves.
This arrangement can be modified in various ways, viz., by having the cut of
lever to act upon the friction pulley shaft so as to raise or lower the shaft instead
of raising or lowering the discs or cones.
Or the discs may be lowered or raised by the governor without the aid of the
slotted hooks or links, but retained in their position by the means of two balanced
levers, one acting upon the top disc and the other on the bottom disc, both discs or
cones being suspended, working on keys, and kept at proper distance when not
required to act on the cut off by a boss on the governor or other shaft whereon
these discs or cones are placed. Or the discs may be made to remain in their
normal position, when required, by means of springs, one spring being placed on
the top side of the top disc or cone, and the other spring on the under side of the
bottom disc or cone. Another plan is to have the two dises or cones acted upon
without the aid of the loose weights, but depressed or raised by the action of the
governor slide, lowering or raising the discs or cones as required, assisted by the
action of a balanced lever, the lever being also used in keeping the discs in their
normal position, and the governor slide may be arranged to pass through a portion
of the upper disc.
Or the friction pulley or cone may be brought into contact with either the upper
or lower disc or cone by means of an electro-magnet, which can be brought into
action by a current of electro-magnetism, the connection being made by the contact
of a pin, spring, or collar on the governor slide as it rises or falls by the change of
speed, causing the electro-magnet to draw a lever carrying the friction pulley or
disc, so causing either the discs or cones to give motion to the friction disc or conc
in connection with the cut off rod so as to open or close the cut off as required,
the electro-magnetism being produced by any of the known machines, the same
being placed in any convenient position.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Wright Wilkinson, Francis Preston, and John Blomfield
Hamond in the Great Seal Patent Office on the 18th September 1880.
SAMUEL WRIGHT WILKINSON, of Stockport, in the County of Chester, Cotton
Spinner, FRANCIS PRESTON, of Huddersfield, in the County of York, Consulting
Engineer, and JOHN BLOMFIELD HAMOND, of Stockport, Mechanical Engineer.
"IMPROVEMENTS IN STEAM ENGINES."
Our Invention consists in an improved arrangement for varying the working
of the cut off valve of steam engines so as to make it self acting, and controlled
by the same governor that is used for acting upon the ordinary throttle valve.
And in order that our Invention may be fully understood and readily carried
into effect, we will describo the accompanying two Sheets of Drawings, reference
being had to the figures and letters marked thereon. Similar letters of reference
indicate corresponding parts on the different views.
On Sheet 1 Fig. 1 shows one method of performing our Invention. is the
governor; the sleeve is made in two pieces; and a¹ is the upper portion of tho
sleeve; b is the lever communicating with the throttle valve. This lever works on
a stud b', on either side of which are suspended the weights 62 and 6s by slotted
links. The lever bhas a forked end resting between two collars on the upper
portion of the sleeve a'; c is the cut off lever working on a stud in the same
bracket as b', and it has a forked end resting between two collars on the lower
portion of the sleeve a; a² and a are friction driving plates fixed on the lower
portion of the sleeve a revolving with the governor shaft. These friction plates are
balanced by a weight on the lever g, the forked end of which rests between
collars on a; d' is a friction pulley keyed on the shaft & communicating by suitable
gearing with the rod of the cut off valve. When the increased speed of the engine
causes the governor to raise one end of the throttle valve lever, the weight
lowered on to one end of the lever c, thus raising the other end of c and with it the
sleeve a, which brings the friction disc a into contact with the friction pulley (l',
which communicates motion to the rod of the cut off valve, and partially closes the
valve. When the engine commences to run too slowly the motion of the friction
pulley is reversed and the cut off valve is opened. The slots in the links by which
the weights are suspended allow the lever b to continue rising or falling after tho
disc a³ or a² is in contact with d'.
is
Fig. 2 shews another method of performing our Invention.
a is the governor ;
al is the upper portion of the sleeve; b is the lever communicating with the throttle
valve; a is a friction conc loose on the lower portion of the sleeve a³; and a³ is a
friction conc cast with a; hand are springs; d¹ is a friction cone fixed on the
shaft & communicating by suitable gearing (as shewn) with the rod of the cut off
valve. When the speed of the engine is too high the governor lifts one end of b,
and the spring' forces the cone a up into contact with d, and partially closes the
cut off. When the engine runs too slowly the sleeves a' and a' are pressed down-
wards, and the cone a² causes the cone d¹ to revolve in the opposite direction and
open the cut off. As a² can slide on a the sleeve a¹ can continue its descent, and
its action on the throttle valve until the speed of the engine is increased. The
springh keeps a² in contact with d' until the engine attains its normal speed.
;
On Sheet 2 Fig. 3 is a side clevation, and Fig. 4 is a plan shewing the arrange-
ment we prefer to use for varying the working of the cut off valve. a is the
governor a' is the upper portion of the sleeve; b is a bell crank lever pivotted
at b, and communicating by the levers e, e¹, e², and e with the throttle valve f;
a² and a³ are two friction discs fixed on the lower portion of the sleeve at, and
revolving with the governor shaft. These discs are overbalanced by the weight g¹

page_text: on the lever g; d¹ is a friction pulley fixed on the shaft & communicating by
suitable gearing with the rod d of the cut off valve; his a spring placed on the
governor shaft between the upper and lower portions of the sleeve.
Fig. 5 is an end elevation shewing the shaft and gearing which communicates the
motion froin the friction pulley d to the rod of the cut off valve.
The mode of operation is as follows:-When the engine is working at its normal
speed the friction pulley d' on the shaft d does not touch either of the friction
discs a and a; but a slight increase in the speed of the engine causes the friction
disc a³ to rise into contact with and drive the friction pulley d, which by the shafts
and gearing shewn communicates motion to the cut off rod, thus partially closing
the cut off valve, the governor at the same time acting upon the throttle valve.
This action continues until the engine resumes its normal speed. A slight decrease
in the speed of the engine causes the sleeve a¹ to descend, and it brings the friction
disc-a into contact with the friction pulley d,.and makes it revolve in the opposite
direction, and so opens the cut off valve. The spring allows the sleeve a¹ to
continue its descent after d has been caused to revolve, and the governor thus
continues to act upon the throttle valve until the engine resumes its normal speed,
and the friction cone or disc a is raised out of contact with <².
Having thus stated the nature of our Invention, and described the manner of
performing the same, we wish it to be understood that we do not limit ourselves to
the details given, as they may be varied or modified, but what we claim is, acting
upon the cut off valve and the throttle valve by one governor, and the manner of
effecting the same, substantially as shown and described.
In witness whereof, I, the said John Blomfield Hamond, for myself and on
behalf of the said Samuel Wright Wilkinson and Francis Preston, have
hereunto set my hand and scal, this Fifteenth day of September, One
thousand eight hundred and eighty.