Improvements in Governors, applicable for Marine Engines and other purposes.
Year: 1895

page_text: Date of Application 24th Oct., 1895-Accepted, 7th Dec., 1895
COMPLETE SPECIFICATION.
Improvements in Governors, applicable for Marine Engines and
other purposes.
1, CHARLES EDWARD THOMPSON of 24 Dee View, Sealand Road, Chester in
the County of Chester, Clock Manufacturer, 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 has for its object a governing apparatus designed more
particularly for marine or propeller engines to prevent racing in a rough sea, when
the propeller is partly or altogether raised out of the water.
The invention is however applicable generally to governing the speed of rotating
shafts.
It will be understood from the following description, reference being had to the
accompanying drawings, in which,
Figure 1 is a side elevation showing my invention applied to a four cylinder
marine engine:
Figure 2 an end elevation ;
Figure 3 a detail view showing the arrangement for admitting steam to apply
the brake.
In these figures,
A, represents a four cylinder marine engine, and B, the propeller shaft, C is a
countershaft driven from the propeller shaft by means of a strap D. E is a worm
wheel keyed on the shaft C, which worm wheel gears with a worm F keyed on a
third shaft G. This latter is driven by a separate or subsidiary engine set to work
at a prescribed rate of speed such, for instance, as the electric light engine on
board ship or from any other convenient source independent of the engines driving
the main shaft. The shaft G is so mounted that it will revolve and also under
certain conditions move longitudinally in the direction of its axis. H is a rocking
lever or rod connecting the shaft G with a cock I governing the passage of steam
from the main engine to a separate brake cylinder J. K is a brake lever adapted
to bear down on the propeller shaft B when the piston rod L of the cylinder J is
raised by the steam entering the same.
The shaft G carrying the worm and the shaft C carrying the worm wheel are
driven by their respective engines at such a speed relatively to each other that
when the main shaft is running at its normal speed, the worm and worm wheel will
simply revolve without imparting any longitudinal motion to the worm shaft G,
but if the load be suddenly taken off the engine as is the case when the propeller
is raised out of the water and the engines begin to race, the speed of rotation of
the shaft C will also increase and as it cannot increase the speed of rotation of the
worm shaft G in corresponding proportion, that being controlled solely, as before
mentioned, by a separate engine, the consequence is that the worm shaft will move
longitudinally in the direction of the arrow. This longitudinal movement is made
use of by the interposition of the lever H to open a cock such as I, thereby
admitting steam from the valve chest of the low pressure cylinder of the main
engines along the pipe M to the cylinder J, raising the piston rod L and applying
the brake lever K to the propeller shaft. Per contra the submerging of the
propeller and the consequent decrease in speed of the main shaft will move the
worm shaft in the opposite direction, thereby closing the valve I and taking of
the brake, the subsidiary engine remaining all the time the unit of motion and

page_text: maintaining one uniform speed. In other words any discrepancy in the respective
speeds of rotation of the shafts C and G will cause the latter to move longitudinally
and apply the brake. It is obvious however that this longitudinal movement of
the shaft G may be utilised also for closing a throttle valve, for regulating the
period of steam induction into the cylinder, or otherwise regulating the speed.
It is obvious also that the invention can be applied to control the working of a
hoist, elevator, steam or hydraulic crane, tram car, or any revolving machinery
requiring immediate controlling power.
It must also be understood that the invention is not limited to the exact details
herein set forth, as these may be varied to suit the purpose for which it may be
used, for instance, the apparatus as applied to a marine engine, might have to be
slightly altered in detail when applied to a hoist. The auxiliary shaft C may
even be dispensed with if desired in which case the worm wheel is keyed on the
main shaft direct.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. The improvement in maintaining a uniform velocity in marine engine and
other revolving shafts, which consists in providing in combination with the main
shaft an auxiliary shaft, rotated at one uniform speed by an auxiliary motor, and
so arranged as to be capable of sliding longitudinally under certain conditions,
connecting this auxiliary shaft with a throttle valve, brake or other retarding
device, and gearing or connecting the auxiliary shaft with the main shaft or with
a countershaft driven by the main shaft, by means of a worm and worm wheel in
such a manner that whenever the speed of the main shaft abnormally increases, the
said auxiliary shaft will be caused to slide longitudinally and apply a brake, or
otherwise check the speed of the main shaft, substantially as described.
2. My improved apparatus for governing or maintaining a uniform velocity in
marine engine and other revolving shafts substantially as set forth.
Dated this 23rd day of October 1895.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Birmingham, and London, Patent Agents.