IMPROVEMENTS IN THROTTLE VALVES
Year: 1885

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake and Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS IN THROTTLE VALVES" to be as follows:-
This invention relates to steam throttle-valves, and consists in utilizing the
differences of pressure which occur in the steam supply-pipe and the steam chest
of a steam-engine, when the velocity of the piston increases or diminishes, for
regulating the admission of steam.
These fluctuations of pressure are due to the fact that when the velocity of the
engine piston diminishes the steam passing to the engine does not at once change
its velocity, so that the quantity of steam in the steam supply pipe increases and
the pressure rises. When the steam-piston is at rest the pressure in the said
supply pipe reaches its maximum, that is to say it becomes equal to the pressure
in the boiler. Inversely the pressure in the supply pipe is lowered when the
velocity of the piston increases.
According to this invention these phenomena are utilized for regulating the
admission of the steam, and consequently also for governing the steam engine.
The case of the throttle-valve is provided with three openings having flanges,
the lower one of which is bolted to the steam chest of the engine whilst the side
flange is connected with the steam supply pipe. The upper opening is closed by
a cap.
Within the casing is arranged a hollow cylinder having apertures communicating
with a chamber connected with the supply pipe. These apertures are opened or
closed more or less by a regulating piston working within the said cylinder
according as the said piston ascends or descends. The rod of the regulating piston
is connected by means of a link with a lever which has its fulcrum on a standard
upon the cap.
The said lever is, through the medium of a spiral spring, connected with a second
lever which turns upon a pivot near the lower end of the casing. This second
lever is connected by a link with the rod of a second regulating piston moving in
a small cylinder upon the side of the main casing.

page_text: This small cylinder communicates through an upper opening, into which a steam
supply pipe is screwed, directly with the boiler.
When the two regulating pistons are under pressure, the spiral spring between
the levers is expanded so far that it equilibrates the steam pressure: When the
motion of the steam-engine is accelerated in consequence of a decreased resistance,
the pressure upon the lower surface of the main piston diminishes for the reason
hereinbefore explained so that the spiral spring contracts, and the first regulating
piston descends and partially closes the openings in the hollow cylinder, con-
sequently the steam is throttled and the engine moves more slowly.
In order that the openings in the said hollow cylinder may never be entirely
closed, an adjusting screw is arranged in the first lever, which screw is so adjusted
that it rests upon the said cap as soon as the engine, when performing no work,
runs at its normal velocity.
When, on the velocity of the steam-piston being decreased, the pressure below
the first regulating piston is augmented, the latter ascends whereby the quantity
of steam admitted increases.
In order that the varying steam-pressures in the boiler shall not exert any
influence upon the operation of the improved apparatus, the second regulating
piston is employed.. When the pressure upon the upper surface of the latter piston
increases, it is pressed downward and the spiral spring is expanded more or less;
consequently it will now, as before, balance the augmented pressure upon the
lower surface of the first regulating piston and the operation of the apparatus will
continue unchanged.
It is therefore only necessary to properly adjust the tension of the spiral spring,
when the apparatus is set in operation, by regulating the nuts and screws provided
for the purpose upon the levers and to which the spring is attached.
1102 011
CTI 100
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: Improvements in Throttle-valves.
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent
Agents, Southampton Buildings, in the County of Middlesex, 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 steam throttle-valves, and consists in the provision of
means for utilizing the differences of pressure which occur in the steam supply-pipe
and the steam-chest of a steam-engine, when the velocity of the piston increases or
diminishes, for regulating the admission of steam.
These fluctuations of pressure are due to the fact that when the velocity of the
engine piston diminishes, the steam passing to the engine does not at once change
its velocity, so that the quantity of steam in the steam supply conduit pipe increases
and the pressure rises. When the steam piston is quite at rest the pressure in the
said supply pipe is at its maximum, that is to say, it becomes equal to the pressure
in the boiler. Inversely the pressure in the supply pipe is lowered when the
velocity of the piston increases.
According to this invention these phenomena are now utilized for regulating the
admission of the steam, and consequently also for governing the steam-engine.
In the accompanying drawing-
Figure 1 is a vertical central section of the improved apparatus, and
Figure 2 is a section on the line x, y Figure 1.
The case of the throttle-valve is provided with three openings having flanges,
the lower one of which is designed to be bolted to the steam-cbest of the steam-
engine, whilst the side flange is connected with the steam supply pipe. The upper
opening is closed by a cap.
Within the casing is arranged a hollow cylinder having apertures a, a communi-
cating with a chamber connected with the supply pipe. These apertures are
opened or closed more or less by a regulating piston b according as the said piston
ascends or descends. The rod of the piston b is connected by means of a link with
a lever c which has its fulcrum at d.
The lever c is, through the medium of a spiral spring, connected with a lever f
which turns upon a pivot g near the lower end of the casing. This lever fis
connected by a link with the rod of the piston h of the cylinder . The cylinder h¹
communicates directly with the boiler through an opening in the upper end into
which a steam supply pipe is screwed.
It will be seen that when the pistons 6 and are under pressure, the spiral
spring between the levers and connected to the eyes i, ¹ is expanded so far that it
equilibrates the steam pressure. When the motion of the steam engine is accelerated
in consequence of a decreased resistance, the pressure upon the lower surface of the
inain piston b diminishes for the reason herein before explained, so that the spiral
spring contracts, and the piston b descends and partially closes the openings a,
consequently the steam is throttled and the engine moves slower.
In order that the openings a are never entirely closed an adjusting screw e is
arranged in the lever c which screw is so adjusted that it rests at e¹ upon the said
cap as soon as the engine when performing no work runs at its normal velocity,

page_text: When, on the velocity of the steam piston being decreased the pressure below
the piston bis augmented, the latter ascends whereby the quantity of steam
admitted increases.
In order that the varying steam-pressures in the boiler shall not exert any
influence upon the operation of the improved apparatus, the piston his employed.
When the pressure upon the upper surface of the latter piston increases it is pressed
downwards and the spiral spring is expanded more or less. Consequently it will
now as before balance the augmented pressure upon the lower surface of the
piston b, and the operation of the apparatus will continue unchanged.
It is therefore only necessary to properly adjust the tension of the spiral spring
by the eyes and and nuts when the apparatus is set in operation.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to me
by my foreign correspondent I declare that what I claim is
A steam throttle-valve which is automatically operated, when the velocity of a
steam engine changes, by means of a piston 6 which is acted upon by a spring,
through the medium of the levers c and f, and is caused to ascend or descend by
reason of the variation of pressure in the steam admission-pipe, thereby increasing
or diminishing the area of the openings a: whilst when the steam-pressure in
the boiler changes, a piston h correspondingly increases or diminishes the spring
pressure.