Improvements in Corliss Valve Gear for Steam Engines.
Year: 1895

page_text: Date of Application, 19th Sept., 1895-Accepted, 26th Oct., 1895
COMPLETE SPECIFICATION.
Improvements in Corliss Valve Gear for Steam Engines.
We, GALLOWAYS LIMITED, and JOHN HENRY BECKWITH, all of Knott Mill
Iron Works, Manchester, in the County of Lancaster, Engineers, 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 relates to the gear for working and releasing the Corliss valves
of steam engines, as will be described referring to the accompanying drawings,
Fig. 1 of which shows in elevation the trip-gear for the valves at both ends of the
cylinder and in section the dashpot used in connection with the one trip-gear
Fig. 2 is a sectional plan on Z Z of Fig. 1. A is the valve spindle on which is
keyed the boss B presenting an edge at to the edge c of the trigger lever C
which is pivotted on one arm d of a lever D, and has an arm c¹ connected to the
governor. The lever D has another arm d' connected to an eccentric or cam on
the engine shaft, and the boss B has an arm to which is linked the rod E of the
dashpot piston. This rod is made with a head e entering a recess in the bottom of
ths piston F, which works in the cylinder G, being urged downwards by the
spring H.
At one side of the cylinder G is formed a seating for a segmental slide
valve K which can be adjusted to a higher or lower position by a screw and nut k.
As the lever D oscillates in the one direction the edge c of the trigger-lever C
meeting the edge b causes the boss B to move, partly turning the valve spindle A.
When, by the action of the governor, the arm c¹ is moved aside, the edge c
escapes and thereupon the spring H causes the piston F to retreat into the
cylinder G until the air compressed between it and the cylinder bottom causes it
to stop, the valve spindle A being thus turned back.
By raising or lowering the slide valve K the amount of air compressed under
the piston can be varied, so as to allow for more or less rapid working or more
or less leakage past the piston.
In case the piston F should be stopped too far from the cylinder bottom
the head e of the rod E can be moved onwards by the lever D acting on the eye e¹
of the rod, thus bringing the edge into suitable position to be engaged again
by c.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. For moving and releasing the spindle A of a Corliss valve, the combination
of the boss B having edge b, the trip-lever C having edge c, and the working
lever D on which C is pivotted, substantially as described.
2. In combination with the dashpot cylinder of Corliss valve gear the adjustable
segmental slide valve K arranged and operating substantially as and for the
purpose set forth.
3. In combination with the dashpot piston F, its rod E having its head e free in
the piston bottom, and having its eye e¹ in a recess of the working lever D, as and
for the purpose set forth.
Dated this 19th day of September 1895.