Improvements in Switches for Electrical Purposes.
Year: 1889

page_text: Date of Application, 4th June, 1889
Complete Specification Left, 1st Mar., 1890-Accepted, 5th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in Switches for Electrical Purposes.
I WILLIAM BARNICOAT of 83 Upper Thrift Street Northampton in the County of
Northampton Engineer do hereby declare the nature of this invention to be as
follows:-
In carrying out my invention I arrange segmental opposite plates on the base of
the instrument which are secured thereto by a screw the said screws also clamping
the terminal wires to each plate.
By this means the number of screws used in securing contact plates is reduced.
I mount a tongued contact maker or breaker always in connection with one plate
on a spindle of irregular shape adapted to fit a key possessed only by those in charge
of the plant, so that careless mischievous or insane persons (such as in an asylum)
cannot tamper therewith.
I cover this spindle by a guard plate with a hole to insert the key and to prevent
possibility of shock I insulate the key part of the spindle from the contact breaker in
any suitable manner.
To ensure the contact maker or breaker being always "on" or "off" I mount on
it a cam or eccentric (which may carry a small friction roller if desired); this bears
against a plunger set up by a spiral spring carried in fittings on the base.
The thrust of the spring bears on the cam or eccentric so always tending to keep
the contact maker or breaker against one contact plate so leaving an open circuit.
Turning the key causes the tongue of the contact breaker to connect both plates
so completing the lighting or other circuit.
Dated this 4th day of June 1889
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Switches for Electrical Purposes.
1, WILLIAM BARNICOAT of 83 Upper Thrift Street Northampton, in the County of
Northamptonshire, 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:-
In carrying out my invention I arrange segmental opposite plates A and B on the
fireproof base of the instrument, each of which are secured thereto by a screw, the
said screws C and D also clamping the terminal wires to each plate the nuts for
said screws being placed in recesses under the base of the instrument, by this means
the number of screws used in securing contact plates is reduced to two; on the
removal of which, the contact plates can be repaired, or renewed, without removing
the switch-base when once fixed in position.
I mount a tongued contact maker or breaker E, always in connection with one
plate, on a spindle F of irregular shape adapted to fit a loose key G possessed only
by those in charge of the plant, so that careless, mischievous, or insane persons (such
as in an asylum) cannot tamper therewith.
The contact maker or breaker E can also be fitted with a fast key H.
I cover the base with a fireproof cover J, with a hole to insert the keys, and to
prevent possibility of shock. I insulate the key part of the spindle from the contact
breaker in any suitable manner.
One end of the contact maker or breaker is cam shaped, which carries a small
friction roller K, this bears against a plunger L held in position by contact plate B.

page_text: The thrust of the spiral spring M, on the plunger L bears on the roller K, thus always
tending to keep the contact maker, or breaker in, or out, of circuit, thereby ensuring
a quick make or break movement when the fast or loose keys are put in motion.
Turning the keys causes the tongue of contact maker, or breaker, E to complete,
or break the circuit.
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 arrangements of screws C and D securing all the fittings and terminal wires
to base.
2. The shape, make, and position of segmental plate B, plunger L and spiral
spring M.
3. The shape, make, and position, of contact maker and breaker E, and friction
roller K.
4. The shape and make of spindle F and loose key G.
Dated this 28th day of February 1890.
WILLIAM BARNICOAT.