Improvements in or relating to the Governing of Steam Engines, particularly Marine Engines.
Year: 1892

page_text: Date of Application, 2nd Feb., 1892
Complete Specification Left, 6th Apr., 1892-Accepted, 2nd Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Governing of Steam Engines,
particularly Marine Engines.
GEORGE POLLOCK VASEY care of National Safe Deposit Coy. Ld. Queen
Victoria Street London E.C. Gentleman do hereby declare the nature of this
invention to be as follows:-
The engine or screw shaft to be controlled revolves a cog wheel which acts upon
a spiral thread placed horizontally and connected by suitable means to a cut off
valve to the engine so as to control the admission of steam thereto. The spiral
runs longitudinally on a shaft and shaft and spiral are revolved by a subsiduary
steam engine. The action of the cog wheel moves the spiral longitudinally on its
shaft and operates to shut the cut off valve of the main engine. This movement
is counteracted by the revolving of the spiral. While the main and subsiduary
engines maintain equal relative speeds, the spiral remains in one position longi-
tudinally relative to its shaft and the cut off valve of main engine is kept
stationary.
If the main engine increase its speed, the spiral is moved along its shaft and the
cut off valve of main engine proceeds to close. This closing of the valve reducing
the speed of the main engine and consequently also of the cog wheel and the rotary
movement of the spiral being maintained at its regular speed, the spiral is drawn
back towards its original position on its shaft and consequently the cut off valve
of main engine proceeds to reopen.
18th January 1899
GEORGE POLLOCK VASEY.
COMPLETE SPECIFICATION.
Improvements in or relating to the Governing of Steam Engines,
particularly Marine Engines.
I, GEORGE POLLOCK VASEY formerly of the "National Safe Deposit
Company," Queen Victoria Street, but now of 112 Cambridge Gardens, Notting
Hill, in the County of Middlesex, Gentleman 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 :-
The engine or screw shaft to be controlled revolves a worm-wheel which acts
upon a worm connected by suitable means to a cut-off valve of the engine so as to
control the admission of steam thereto. The worm runs longitudinally on a shaft
and both shaft and worm are revolved by a subsidiary steam-engine. The action
of the worm-wheel tends to move the worm longitudinally on its shaft and shut the
cut-off valve of the main engine; but this movement is counteracted by the
revolving of the worm. While the main and subsidiary engines maintain equal
relative speeds, the worm remains in one position longitudinally, relative to its
shaft, and the cut-off valve of the main engine is kept stationary. If the main
engine increase its speed the worm is moved along its shaft and the cut-off valve
of the main engine closes. This closing of the valve reducing the speed of the
main engine and consequently also of the worm-wheel and the rotary movement of
the worm being maintained at its regular speed, the worm winds itself back towards
its original position on its shaft and consequently the cut-off valve of the main
engine re-opens.
The worm may also be suitably connected to a valve that may regulate the

page_text: admission of steam to the subsidiary engine so that the speed of the subsidiary
engine may be automatically regulated. The result of the actions of the worm-
wheel and the worm is to automatically limit the main engine to nearly a set
speed however much the load on the main engine may vary.
The accompanying drawing represents diagrammatically one way in which this
invention may be carried into effect, although the precise arrangement may be
varied without departing from the spirit of the invention.
In this drawing, A represents the worm-wheel which may be carried upon the
main shaft of the engine or upon any other suitable shaft, or in some other suitable
manner is caused to rotate at a speed increasing or decreasing with that of the
engine to be governed. This speed need not necessarily be the same speed as that
of the engine and in some cases might with advantage be faster or slower; for
instance if the speed of the main engine was intended to be very high it might be
advantageous to make the speed of the worm-wheel A less, and vice versa.
The shaft B is driven in any convenient manner by the subsidiary engine which
may be governed in any desired manner so as to obtain as much regularity as
possible in the speed at which this shaft revolves. The subsidiary engine may be
any suitable engine by which the shaft B may be directly or indirectly revolved;
for instance, for governing a marine engine probably a special small subsidiary engine
would be employed to drive this shaft, but for governing a fixed engine some other
convenient source of power may be utilized for the purpose of driving the
shaft B.
The shaft B is preferably provided with a feather B and the worm C fits
freely upon the shaft B and has a feather-way in it which engaging with the
feather B causes the worm always to revolve with, although it may slide longi-
tudinally upon, the shaft B. The shaft B does not participate in the longitudinal
movement. In the diagram the worm is shown of considerable length but this may
be varied to any extent required, the worm being made longer or shorter according
to circumstances. The movement of the worm is to be imparted to the device or
devices controlling the valves of the main engine and perhaps also of the subsidiary
engine and a convenient way of doing this is to prolong the body or core of the
worm C at each end beyond the worm and in these prolongations to form peripheral
grooves C with each of which engages a fork or other suitable connection D for
the main engine and E for the subsidiary engine. These forks may be connected
in any convenient manner with the throttle valve or other valve or device which
controls the supply of steam to or the movement of the engine in question.
As previously explained the particular object for which this invention has been
designed is the prevention of racing in marine engines at sea, which is due to the
screw propeller being raised out of the water or to the water falling away from the
screw propeller; in either case the load is taken off the engines and they
consequently run away or race. The object in controlling the movement of the
subsidiary engine is to stop it or make it go slower when the worm C has been
moved beyond its normal position in one direction and thus cause it to be more
quickly returned by the action of the worm-wheel to its normal position than would
be the case if the shaft B continued to revolve at its regular rate of speed. The
mechanism will however work satisfactorily without altering the speed of the
subsidiary engine.
The operation of this invention is as follows,
The proportions of the gearing A and C with their speeds of rotation are so
arranged that in normal circumstances, that is with the two engines running at
their proper speeds, the movements of A and C will synchronize or keep pace with
each other (the rotary movement of C neutralizing the tendency of A to impart
longitudinal movement to C) and A will remain at about the longitudinal centre
of C and the two parts A and C will continue to occupy the respective positions
shown in the drawing. Or the normal position of A might be at or near one end
of C.
Should however the main engine increase its speed A will be revolved beyond

page_text: its normal speed and its teeth will consequently act upon the worm C and force it
along the shaft B thus moving the fork D and closing the throttle valve and
shutting off the supply of steam or otherwise controlling the movement of the main
engine. Cutting off the steam from the main engine necessarily reduces its speed
so that the worm wheel A will go slower than the worm C and the worm C will
consequently wind itself along the shaft B in the reverse direction to that of the
previous movement and this return movement will continue until the relative speeds
again synchronize when the longitudinal movement of C will terminate and the
fork D having returned to its former position the full supply of steam will have
been restored to the main engine. As at first explained the point when A and C
will be in equilibrium will preferably though not necessarily be when the longi-
tudinal centre of C about coincides with the centre of A.
Should for any reason the main engine go slower than its usual speed the worm C
will be moved in the appropriate direction and the throttle valve further opened so
as to supply more steam to the main engine (unless the throttle valve was fully
open when A and C were in their normal positions in which case the apparatus
need only operate in the one direction); this movement however is of slight
importance for a marine engine, as it is of much more importance to prevent the
running away or racing of the main engine than to accurately maintain it at a
precise speed of revolution.
Should the main engine be stopped, the subsidiary engine will continue to turn
the shaft B and will thus wind the worm C (obtaining its purchase upon the worm-
wheel A) along it to the end of its longitudinal travel, when the apparatus must
be arranged so that the worm can work itself entirely clear of the worm-
wheel A, unless the apparatus has been thrown out of connection with the main
engine.
It will be understood that the control by this apparatus of the subsidiary engine
is not necessary to its efficient working but it may be useful for the reasons indicated
above.
Beyond the disengagement of A and C no provision need be made for the opera-
tion of this apparatus in the case of the reversal of the main engine as the class of
engines to which this apparatus would be applied, say for instance electric light
and other stationary engines, and more particularly marine engines, either do not
require to be reversed at all, or at all events do not require to be controlled while
they are reversed. From this Specification it will be apparent that while this
invention is applicable to various kinds of engines and may be employed more or
less in the manner of an ordinary governor to control either the increase or decrease
of speed of the governed engine it is particularly designed and intended for use
with marine engines to prevent their running away or racing when at sea.
One subsidiary or governing engine may be used to control more than one
"main
or governed engine.
"
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that
what I claim is,-
1. Controlling an engine substantially as described by means of another engine
or power.
2. Connecting a marine engine with an independent controlling engine for the
purpose of preventing the former from running away or racing.
3. As a means of controlling one engine by another the employment of gearing
whereby the variation in speed of a part of the engine to be controlled acting
upon a part of the controlling engine or apparatus revolving at an approximately
constant speed causes the supply of steam to the main engine to be automatically
reduced or cut off.
4. In an apparatus for controlling one engine by another the combination with
a worm-wheel such as A whose speed of revolution conforms to the variations
of speed of the engine to be controlled of a worm such as C revolving with but

page_text: longitudinally movable upon a shaft such as B driven at an approximately constant
speed the said worm communicating with the controlling apparatus of the engine
to be controlled substantially as described and iliustrated in the accompanying
drawings.
T
1
וי
A
1 1000
G. P. VASEY.
W. P. Thompson & Boult,
Agents for the Applicant.