A New or Improved Automatic Switch or Cut-out for Electrical Circuits.
Year: 1887

page_text: Date of Application, 24th. Feb., 1887
Complete Left, 24th Nov., 1887
Complete Accepted, 6th Jan., 1888
PROVISIONAL SPECIFICATION.
A New or Improved Automatic Switch or Cut-out for Electrical
Circuits.
I, THOMAS PARKER of Commercial Road, Wolverhampton, in the County of
Stafford, Electrical Engineer do hereby declare the nature of this invention to be
as follows:
This Invention relates to an automatic switch or "cut-out" to be employed in
combination with a dynamo and secondary battery for the purposes of bringing the
battery into circuit with the dynamo upon starting the latter, as soon as, or not
before, the E.M.F. of the dynamo current equals or exceeds the E.M.F. of the battery,
and for cutting the dynamo out of circuit when the current ceases, or when a reversal
of current occurs from any cause; and it has for its object the construction and
employment of the switch in such a manner that it shall be certain in its action, of
moderate dimensions, not liable to derangement and so that it will involve but a very
small loss of power for its operation.
These Improvements consist in the construction and use of a compound electro-
magnetic device one part of which operates to open or close a circuit as may be
desired. The compound electro-magnetic system or device consists of two opposed
electro-magnets the poles of which are so formed that the pole pieces of one pair
oppose the pole pieces of another pair; two of the contiguous pole pieces are hinged
or similarly connected together. One of the electro-magnets is secured to a base
board or suitable foundation while the other is free to move through a small angle so
that its pole piece may approach to or recede from the corresponding pole piece of
the fixed electro-magnet. The winding of one of the electro-magnets is of thick wire
and is included in the main circuit; the winding of the other is of thin wire and is
included in a shunt circuit. The movable electro-magnet carries upon its pole piece
a contact plate, bar or equivalent which is electrically connected to the main
circuit through the coils of the electro-magnet wound with thick wire. Upon
the base board or foundation of the apparatus there are secured metallic contact
brushes, plates or their equivalent so arranged and constructed that when the movable
electro-magnet approaches the fixed electro-magnet the contact piece thereon closes
DQ71

page_text: with the fixed contact pieces and thus closes the circuit. The movable electro-magnet
or its pole piece is connected to or in contact with a spring the tendency of which is
to pull or force the movable electro-magnet away from the fixed one.
When the dynamo is started current passes through the shunt circuit only and
energises the movable electro-magnet upon which a part of the shunt circuit is wound ;
the consequent action is to close the moveable magnet upon the fixed magnet but this
is so far prevented by the action of the spring that the contact pieces do not close
together and consequently_close the main circuit, until the dynamo is fully in
operation or until the E.M.F. of the current is equal to or exceeds the E.M.F. of the
battery. On the closing of the circuit the battery is included in the dynamo circuit
and the current passes through the wire on the fixed magnet and energises it; as a
result, the contacts are firmly closed. On the cessation or reversal of the current the
spring forces or pulls the contacts apart and thus opens the main circuit ; on the
reversal of the current, the action of the spring is reinforced by a reversal of polarity.
Dated, this 22nd day of February A.D. 1887.
WILLIAM E. HEYS,
Agent for Applicant.

page_text: COMPLETE SPECIFICATION.
A New or Improved Automatic Switch or Cut Out for Electrical
Circuits.
I, THOMAS PARKER of Commercial Road Wolverhampton in the County of
Stafford, Electrical Engineer, 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 an automatic switch or cut out to be employed in
combination with a dynamo and a secondary battery for the purposes of bringing the
battery into circuit with the dynamo after the dynamo has been started and as soon
as or not before the e.m.f. of the dynamo current equals or exceeds the e.m.f. of
the battery, and for cutting the dynamo out of circuit when from any external cause
the current ceases or there is a reversal of current.
In order that this Invention may be more readily understood and carried into
practical effect two sheets of drawings are appended hereto and reference is herein-
after made to them and to the letters marked thereon.
Fig. 1 is a plan. Fig. 2 is an end view of the apparatus and Fig. 3 is a diagram
showing the circuits and connections. In each of the Figures similar letters are
employed to denote similar parts. In Fig. 1 parts of the coils are shown in section.
The apparatus consists essentially of a compound electro-magnetic device one part
of which operates to open or to close an electrical circuit. Two opposed electro-
magnets A B are so constructed and arranged that the pole pieces constituting one
pair C. D. oppose the pole pieces of the other pair E. F. Two of the pole pieces C. E.
are hinged or similarly connected together at G. One of the electro-magnets A is
secured to a base board or suitable foundation H, while the other, B, is free to move
through a small angle so that its pole piece D may be caused to approach to or recede
from the corresponding pole piece F of the fixed electro magnet A. The winding of
one of the electro-magnets, the fixed one as represented by the drawings, is of thick
wire and is included in the main circuit; the winding of the opposed magnet is of
thin wire and is included in a shunt circuit S from the main to the dynamo. The
movable electro-magnet B carries a contact plate I or an equivalent metallic extension.
Upon the base board or foundation H there is or are secured a contact piece or
contact pieces. As shown by the drawings this contact consists of a pair of metallic
brushes K. L. The fixed contact is electrically connected to the main circuit which
may be completed by taking the circuit from the dynamo through the coils on the
magnet wound with thick wire to the metallic part or coil of the electro-magnet and
the hinge G to the contact piece I ; but I prefer to complete the circuit as represented
by the drawings where V is the dynamo terminal from which the circuit passes
through the thick wire coils on A to the lower contact plate or brush L which is
insulated from the upper contact plate or brush K. The contact brush or plate K
may be connected to the main by the terminal M. By this arrangement when the

page_text: contact piece I is brought between the brushes or plates K. L. the main circuit is
closed and when removed therefrom the circuit is opened. In any case the respective
fixed and moving contacts are so constructed and arranged that when the electro-
magnet B approaches the fixed magnet A, the moving contact closes with the fixed
contact and closes the circuit, and the reverse.
The movable electro-magnet B or its pole piece D is connected to or in contact
with a spring as at N, the tendency of the spring being to pull or force the movable
electro-magnet and its pole piece away from the fixed magnet.
When the dynamo is started, the current passes through the fine wire coils on the
electro-magnet in the shunt circuit and thus energises that magnet. The consequent
action is to close the movable magnet upon the fixed magnet, but this is so far
prevented by the action of the spring that the contacts do not close together and
consequently close the main circuit until the dynamo is fully in operation or until the
e.m.f. of the current equals or exceeds the e.m.f. of the battery. On the closing of
the switch the battery is included in the dynamo circuit and the current passes
through the coils of the magnet wound with thick wire and energises it; as a result,
the contacts are still more firmly closed and held together. On the cessation or
reversal of the current, the spring forces or pulls the contacts apart and opens the
main circuit.
The tension of the spring may be regulated and adjusted by means of a screw
such as that shown at O on the drawings."
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed, I declare that what I claim is :
(1) The construction and arrangement of an automatic switch or cut out for
electrical circuits; substantially as hereinbefore described and as illustrated by the
accompanying drawings.
(2) In an automatic switch or cut out for electric circuits, the combination and
arrangement of movable and fixed electro-magnets with contact pieces, constructed
arranged and operated substantially as herein before described and as'illustrated by the
appended drawings.
Dated this 23rd day of November A.D. 1887.
WILLIAM E. HEYS,
Agent for the Applicant.