IMPROVEMENTS IN EXPANSION GEAR OF STEAM ENGINES
Year: 1886

page_text: Date of Application, 4th Sept., 1886.
Complete Left, 15th Dec:, 1886.
Complete Accepted, 18th Jan., 1887.
We CHARLES SCOTT and HENRY HODGSON of The Guide Bridge Ironworks,
Guide Bridge Nr. Manchester in the County of Lancaster, Engineers, do hereby
declare the nature of our Invention for "IMPROVEMENTS IN EXPANSION GEAR OF
STEAM ENGINES" to be as follows:-
The object of our Invention is the construction of an Improved Automatic Expansion
Valve Gear and applys to the type known as the Corliss Valve, which gears hitherto
even in their simplest form have generally been complicated in design costly to
manufacture, and not attended with that degree of efficiency in working which should
result from the application of a properly designed automatic expansion gear to
stationary steam engines.
Our invention we propose to carry out in the following manner.
The ordinary Corliss Valve is made use of, four to each cylinder, the two valves
above the cylinder being for supply, whilst the two valves placed below the cylinder
are the exhaust valves, the automatic cut-off gear being applied to the two valves for
supply only.
The automatic expansion gear operated upon by a fast running and an efficient
governor is constructed as follows:-
The eccentric rod for working the supply valves is attached to levers which have
a swinging motion, using the valve spindle as their centre of movement.
These levers have each a slot formed in them in which slides a die, which when in
a vertical position falls into a catch dovetailed or otherwise inserted in the boss of a
second lever, this lever being keyed upon the valve spindle, motion is communicated
to the valve spindle from the eccentric rod through this arrangement and which is the
means used for opening the steam valves.
The die already referred to and operated upon by the governor is lifted out of the
catch by means of another lever keyed to a shaft turning on its own centre, this said
shaft oscillating round the centre on which the valve itself turns, and is connected by

page_text: means of another lever at the lower end of this latter to the governor rod, this lever
just mentioned turning on the same centre as that upon which the valve itself moves.
If therefore the rod connecting this cut-off gear as just shortly described with the
governor be moved in either direction, through the rise or fall of the governor owing
to fluctuation of the speed of the engine, the die already referred to would then be
lifted automatically clear out of the catch, and simultaneously the supply valves by the
same means would be disengaged from the eccentric working them, and would be
instantly closed by heavy weights or pistons working in a cylinder or dashpot placed
under each of the two supply valves.
JOHN HAYES,
Agent for Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Expansion Gear of Steam Engines.
We, CHARLES SCOTT and HENRY HODGSON of The Guide Bridge Iron Works, Guide
Bridge near Manchester, in the County of Lancaster, Engineers, do hereby declare
the nature of our invention for "IMPROVEMENTS IN EXPANSION GEAR OF STEAM
ENGINES," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The object of our Invention is the construction of an Improved Automatic Expansion
Valve Gear, and applys to the type known as the Corliss Valve, which gears hitherto
even in their simplest form have generally been complicated in design, costly to
manufacture, and not attended with that degree of efficiency in working which should.
result from the application of a properly designed automatic expansion gear to
stationary steam engines.
.
Our invention we propose to carry out in the following manner.
The ordinary corliss valve is made use of, four to each cylinder, the two valves above.
the cylinder being for supply, whilst the two valves placed below the cylinder are the
exhaust valves, the automatic cut-off gear being applied to the two valves for supply
only.
The automatic expansion gear operated upon by a fast running and an efficient
governor is constructed as follows.—
The eccentric rod for working the supply valves is attached to levers which have a
swinging motion, using the valve spindle as their centre of movement.
These levers have each a slot formed in them in which slides a die, which when in
a vertical position falls into a catch dove-tailed or otherwise inserted in the boss of a
second lever, this lever being keyed upon the valve spindle, motion is communicated
to the valve spindle from the eccentric rod through this arrangement and which is the
means used for opening the steam valves.
The die already referred to and operated upon by the governor is lifted out of the
catch by means of another lever keyed to a shaft turning on its own centre, this said
shaft oscillating round the centre on which the valve itself turns, and is connected by
means of another lever at the lower end of this latter to the governor rod, this lever
just mentioned turning on the same centre as that upon which the valve itself moves.
If therefore the rod connecting this cut-off gear as just shortly described with the
governor be moved in either direction through the rise or fall of the governor owing to
fluctuation of the speed of the engine, the die already referred to would then be lifted
automatically clear out of the catch and simultaneously the supply valves by the same
means would be disengaged from the eccentric working them and would be instantly
closed by heavy weights or pistons working in a cylinder or dashpot placed under each
of the two supply valves.
In order that the said invention may be more fully understood we shall now proceed
to refer to the Drawings upon the Sheet hereunto annexed.

page_text: Fig. 1 is an elevation of the Apparatus as applied to the inlet or steam valves of
Corliss Gear.
Fig. 2 is a plan of the same arrangement and in which A is the valve spindle having
a semi rotative motion, B a lever keyed fast upon the valve spindle to which is attached
a weight or spring for closing the valves by the rod B₁; C'a hardened steel catch let
into the boss of the lever B, a lever D is shewn working loose on the spindle A
actuated by the eccentric (or other) rod D¹, E a hardened steel die working in slot in
lever D, F, lever working in a slot in the die E, a shaft G forged with the lever F, H
lever secured to the shaft & and to which is attached the rod I from the governor.
The eccentric rod D₁ is attached to the levers D which have a swinging motion,
using the valve spindle A as its centre of movement. The levers D have a slot formed
in them in which slides the die E, which when in a vertical position, falls into the
catch C in the boss of the lever B, and this lever being keyed upon the valve spindle,
motion is communicated to the valve spindle from the eccentric rod through this
arrangement, and which is the means used for opening the steam valves: the die E
is lifted out of the catch C by the lever F by the oscillation of the shaft G round the
centre A, the lower end of the lever H being held by the rod I; if therefore the rod
I be moved in either direction through the rise or fall of the governor, the die E will
be lifted out of the catch C sooner or later, and by means of the weight or spring on
the rod B¹ the valve will be closed.
Having now described the nature of the said Invention and in what manner the
same is to be performed we would have it to be understood that what we claim is,―
1st. The application of a loose key or die to Corliss valve gears, the same as above
described being raised automatically by the governor, and falling when in a vertical
position into a catch provided for that purpose, this loose key, die or its substitute in
all other corliss valve gears having not a straight vertical drop as in our present
invention, but a radial or circular one which is objectionable and not nearly so reliable
or efficient.
2nd. We also claim as novel the manner in which our improved valve gear is
designed as a whole or as a combination, and its application to stationary steam
engines in the manner above described.
JOHN HAYES,
Agent for Applicants.