IMPROVEMENTS IN APPLIANCES FOR ELECTRICALLY CONTROLLING AND REGULATING THE SPEED or MOTORS EMPLOYED FOR DRIVING DYNAMO- ELECTRIC MACHINES
Year: 1885

page_text: COME DEI DE DIFICATION
We, CHARLES JOHN BOSANQUET of Old Bolingbroke, Spilsby, in the county of
Lincoln, Fitter; and WILLIAM AUGUSTUS TOMLINSON of Birthorpe, Folkingham, in
the County of Lincoln, Draughtsman do hereby declare the nature of our said
Invention for "IMPROVEMENTS IN APPLIANCES FOR ELECTRICALLY CONTROLLING
AND REGULATING THE SPEED or MOTORS EMPLOYED FOR DRIVING DYNAMO-
ELECTRIC MACHINES" and in what manner the same is to be performed to bo
particularly described and ascertained in and by the following statement, reference
being had to the accompanying drawings and to the letters of reference marked
thereon that is to say :-
This our Invention is a further improvement of our invention for "Improve-
ments in appliances for electrically controlling and regulating the speed of motors
employed for driving dynamo electric Machines" and for which our application for
Letters Patent was made on the 10th day of March 1884 and numbered 4665.
This our Invention relates to a method of electrically regulating a motor used
for driving Dynamo electric machines, so as in the case of electric lighting to ensure
as far as possible the maintainence of a constant current in the lamps independent
of the number of lamps burning or of one or more lamps being stopped or renewed,
or of any other outside cause; by means of gearing rotated by the main shaft of
the motor and brought into action by the aid of solenoids or electro magnets and
solenoids. The said gearing in accordance with this our Invention increases and
decreases (as required) the rate of expansion; or opens and closes (as required) the
valve used to control the speed of the motor. According to this Invention we
construct the apparatus so that when the current of the dynamo is at its normal
electro motive force, the gearing is out of action, but immediately the electro
motive force rises above the normal, the gearing is brought into action by the
solenoids, or by the solenoids and electro magnets, and the speed of the motor is
thereby reduced.
The reverse of this takes place upon the electro motive force falling below
the normal. Provision is also made in this Invention for bringing the motor
automatically to rest should the main circuit be accidentally. or otherwise broken.

page_text: This our Invention is equally applicable to any motor whether actuated by
steam, gas, air, or other motive power and is not limited to the regulation of one
motor or dynamo, but may with suitable connections control several. In the
arrangement shewn in Fig 1 the position of the solenoid core is sensibly the same
irrespective of the variations in the strength of the current. The pull of the
solenoid core exerts a varying pressure upon a brake or disc rotated by the motor
through gearing, one of the wheels of which (in direct communication with the
throttle valve) takes up different positions, according to the tension of a spring,
caused by pressure and friction upon the disc. Thus when the strength of the current
is excessive the power required to overcome the friction alters the position of this
wheel, and extends the spring, and in so doing partially closes the throttle valve.
On the contrary when the current diminishes, the pressure on the disc decreases,
and the spring contracting opens the valve. The driving pulley and disc are in this
arrangement capable of rotation at different speeds and whenever a variation
occurs the travelling wheel takes up a new position and a similar change is made
in the position of the throttle valve.
DESCRIPTION OF DRAWINGS.
a is a horizontal shaft from which the governor is driven, and 6 the driving
pulley. The shaft a terminates in a bevel wheel c which gears with a similar
wheel d this latter wheel being loose upon its spindle serves to transmit motion
through a third wheel e which is also loose upon its spindle, to a fourth wheel ƒ
keyed to the brake disc spindle g. The axis upon which the wheel e turns is so
mounted that it is capable of angular motion, and thus can travel round between
wheels d and f through part of a circle moving the valve with it. The solenoid /
may be placed upon top of the apparatus and the core i of same acts through the
levers upon the saddle piece m which stands upon the friction disc n placed
upon a fixed steel surface o.
As the core i is drawn up by the action of the current the levers kl transmit a
highly increased pressure upon sadde piece m forcing it upon friction disc n, and
augmenting the power required to drive same. This power passes through the
four bevel wheels the axis of one of which e is capable of motion against the
spring p. When the power transmitted through the wheels is increased, the wheel.8
is carried round until the tension of the spring balances the greater strain upon
the teeth of the wheels, and will remain in that position while the current is
constant. The connection between the travelling wheel and valve is made by
fixing their spindles together which may be done, as shewn, by pin r
Fig 2 shews a solenoid and magnet for working the arrangement of our regulator
as described. The spring is here used to close the valve. Upon the current
breaking, the spring p shewn in Fig 1. instantly closes the valve and stops the
engine. The magnet a in Fig 2 takes the position of the solenoid h in Fig 1, and
produces friction through the levers kl.
The current is varied in magnet a by the solenoid b as follows.
A small portion of the current from dynamo flows through the solenoid by the
strength of which varies upon the lights being turned on or off, the core c moves
the levers d and regulates the supply of current to the magnet u. In the normal
position a given amount of current excites the magnet a through the wires e and f
and the cup of mercury (or other variable resistance) g producing friction through
the levers on the friction disc n, as described with reference to Fig. 1.
When the current falls below the normal, the solenoid b allows more current to
pass through the resistance g, producing more friction on disc n. Should the
current rise excessively, that through the magnet a is short circuited by the solenoid
lever d. touching the contact h.
No sparking is caused, as the current is not broken, but only diverted.
It is obvious that the details of this apparatus may be considerably modified
to suit different circumstances and requirements, the variations in the current

page_text: circulating in solenoids, or solenoids and magnets not directly effecting an adjust-
ment of the throttle valve or equivalent part of motor, but simply bringing about
the adjustment of govenor details requiring little force, the power communicated
from the motor to the govenor being made to effect required adjustment of the
throttle valve or equivalent part of motor. With this arrangement the govenor is
made much more sensitive than it could otherwise be.
Having now particularly described and ascertained the nature of our said
Invention, and in what manner the same is to be performed we declare that what
we claim is
First The method of electrically controlling and regulating the speed of motors
employed for driving dynamo electric machines, by means of gearing rotated by
the main shaft of the motor and brought into action by the aid of solenoids or of
electro magnets and solenoids, substantially as herein before set and described.
Second-The methods herein described of instantly cutting off the admission
of steam, gas, air, or other motive power to the Engine in case of any accidental
stoppage of the current, substantially as herein before set forth and described.
Third: The general arrangement and construction of appliances for electrically
controlling and regulating the speed of motors employed for driving dynamo
electric machines, substantially as hereinbefore set forth and described, and fully
illustrated in the drawings annexed.