An improved. Electric Switcn.
Year: 1894

page_text: ** Date of Application, 6th Sept., 1894
Complete Specification Left, 31st May, 1895-Accepted; 24th Aug., 1895
„An improved. Electric Switcn.
We SHERARD OSBORN COWPER-COLES of 16 Adam Street Manchester Square
London in the County of Middlesex; Engineer, and JAMES BINGHAM ALLIOTT of
The Park, Nottingham in the County of Nottingham, Esquire, do hereby declare
the nature of this invention, to be as follows:-
Our invention relates to an improved contact breaker, or switch and has for, its
object to construct a quick break switch which is more. especially adapted for use
with large currents of low tension.
According to our invention we provide a suitable base having secured thereto
suitable terminals for the leads between which the switch is to be placed.
Attached to the terminals are contact pieces or poles of, the switch,, said
contact piece preferably consisting of a number of strips, of copper or the, like
separated by slips of metal, asbestos or other suitable material.. The ends of the
contact pieces are cut off obliquely and are placed opposite to each other so,as.to
leave a triangular or wedge, shaped space between. We provide a wedge, shaped
piece of copper, or brass or the like which is adapted to be forced by means of a
suitable handle or lever into the space between the ends, of, the aforesaid contact
pieces and make a good, sliding contact with the bevelled ends of said pieces thereby
closing the, circuit between the terminals of the switch. The said. wedge shaped
piece of copper or the like we term, the bridge piece. We also provide according
to our invention means whereby when the handle is operated to, withdraw, the bridge
piece from contact, a spring or springs. come into action and withdraw the bridge
piece and break the circuit very quickly.
In one method of carrying out our invention the mechanism for.obtaining a quick
break is constructed as follows:-The handle is voted, loosely, on a spindle which
is secured to the base of the switch. On this handle a, cam is also loosely pivoted,
said cam, having a projection with which a projection on the,boss of the handle can
engage. The bridge piece of the switch is guided on suitable guides and is provided
with springs which tend to draw or force it away from the contact pieces and break the
circuit. When the handle is turned the cam is ultimately rotated and acts to press the
bridge piece against the contacts and close the switch at the same time putting a stress
on the springs. If the haudle is turned further, as soon as a definite positions of
the cam is reached the springs act to pull or force the bridge. piece away, a quick
break is thereby, effected.
We have, described our improved, switch, as being especially suitable for use
with circuits carrying large currents, as, there is a large area of contact between
the bridge pieces and the contact pieces, but can of course, be constructed of a size
suitable for any purpose.
Our improved switch is made of; any suitable materials; and we do not limit
ourselves to the exact construction herein above described, but we vary the details
of said construction without departing from the nature of our invention.
Dated this Fifth day of September 1894.

page_text: An Improved Electric Switch.
We, SHERARD OSBORN COWPER-COLES of 16 Adam Street, Manchester
Square, London, in the County of Middlesex Engineer, and JAMES BINGHAM
ALLIOTT of The Park, Nottingham in the County of Nottingham, Esquire, 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 :-
Our invention relates to an improved contact breaker or switch and has for its
object to construct a quick break switch which is more especially adapted for use
with large currents of low tension.
According to our invention we provide a suitable base having secured thereto
suitable terininals for the leads between which the switch is to be placed.
Attached to the terminals are contact pieces or poles of the switch, the said
contact pieces preferably each consisting of a number of strips of copper or the
like separated by slips of metal, asbestos or other suitable material. The ends of
the contact pieces are cut off obliquely and are placed opposite to each other so as
to leave a triangular or wedge-shaped space between. We provide a wedge-shaped
piece of copper or brass or the like which is adapted to be forced by means of a
suitable handle or lever into the space between the ends of the aforesaid contact
pieces and make a good sliding contact with the bevelled ends of said pieces, thereby
closing the circuit between the terminals of the switch. The said wedge-shaped
piece of copper or the like we term the bridge piece.
We also provide according to our invention means whereby when the handle
is operated to withdraw the bridge-piece from contact, a spring or springs come into
action and withdraw the bridge piece and break the circuit very quickly.
In one method of carrying out our invention the mechanism for obtaining a
quick break is constructed as follows:-The handle is pivotted loosely on a spindle
which is secured to the base of the switch. On this handle a cam is also loosely
pivotted this cam having a projection with which a projection on the boss of the
handle can engage.
In applying the invention to currents of low tension the handle can be rigidly
fixed to the cam, so that the handle itself turns on the contact being broken.
The bridge piece of the switch is guided in suitable guides and is provided with
springs which tend to draw or force it away from the contact pieces and break the
circuit. When the handle is turned the cam is ultimately rotated and acts to press
the bridge piece against the contacts and close the switch, at the same time putting
a stress on the springs. If the handle is turned further as soon as a definite position
of the cam is reached the springs act to pull or force the bridge picce away;
a quick break is thereby effected.
We have described the improved switch as being especially suitable for use with
circuits carrying large currents, as a large area of contact with a minimum of metal
is obtained between the bridge pieces and the contact pieces, but it can of course
be constructed of a size suitable for any purpose.
We will describe by way of example and with the aid of the accompanying
drawings the invention as it may be used in connection with a current of say
100 amperes at an E.M.F. of 100 volts. Figure 1 illustrates the switch with the
contact broken; Figure 2 with the bridge piece in the position it occupies when the
contact is made.
The switch in this case is mounted on a base A of slate or other suitable material.
The wires B B are connected through the terminals with contact pieces CC
composed in this case of four strips of copper which may be separated by asbestos
or other material in the usual manner. These contact pieces C C are cut off

page_text: obliquely so as to leave a wedge shaped space between into which the bridge piece D
fits. The handle E revolves on a spindle secured to the base A. Attached to the
spindle is the cam F.
The bridge piece D works in suitable guides G and is furnished with rollers H
(or inclines may be used) against which the cam F works. A strong spring J is
inserted between the bridge D and the handle E.
In Figure 1 contact is broken, and if contact is desired to be made, the handle E
and cam F are turned in the direction of the arrow thereby forcing the bridge
piece D to slide into the position shown in Figure 2. On a further turn of the
handle the spring forces the bridge piece D away from the contact pieces C C¹ as
shown in Figure 1.
Our improved switch is made of any suitable material and we do not limit
ourselves to the exact construction herein above described, but we vary the details
of such construction without departing from the nature of our invention.
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 :-
1. In an electric switch, the combination of two contact pieces cut obliquely
so as to leave a triangular or wedge shaped space between then and a sliding wedge
shaped bridge piece for making contact with the said contact pieces, substantially
as hereinbefore described.
2. The improved electric switch consisting of the contact pieces C C¹, the bridge
piece D, the cam F and the spring J, substantially as described and as illustrated
in the accompanying drawings.
Dated this 30th day of May 1895.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.