An Electrically-operated Electric Switch.
Year: 1894

page_text: Date of Application, 4th Apr., 1894-Accepted, 25th May, 1894
COMPLETE SPECIFICATION.
An Electrically-operated Electric Switch.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,.
Westminster, in the County of Middlesex, and GEORGE SYLVESTER GRIMSTON
of Claremont, Glenluce Road, Westcombe Park in the County of Kent, Electrical
Engineers, 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 electric switch which is worked so as to open and
close a circuit by currents of electricity transmitted from a distance, as we shall
describe referring to the accompanying drawings, Figs. 1 and 2, which are vertical
sections, each partly in elevation, on planes at right angles to each other.
A is a solenoid having its coil connected to a source of electricity and switch at a
distance. The core B of the solenoid is linked to one arm of a lever the other arm
of which carries a spring pawl C and is loaded by a weight or is urged downwards
by a spring so as to overbalance the core B. On the spindle E on which the pawl
lever turns, is fixed a ratchet wheel D having four teeth with which the pawl C
engages, and on the same spindle E, within a casing G closed air tight, are fixed
insulated two arms F, in the form of staples, both limbs of each staple having their
front edges sharp as knife edges. In the lower part of the casing G are fixed
insulated two cups containing mercury M, above which in each case is a layer of
sand S. The cups are made with terminals H to which are connected the conductors
for the circuit governed by the switch. When one of the staple arms F is in the
position shewn, it electrically_connects the two mercury cups, closing the circuit
connected to the terminals H H. When an electrical current is transmitted from a
distance to the coil of the solenoid A, the core B is attracted downward; and the
pawl C causes the ratchet wheel D to turn one quarter round. The arms F are
thus brought round to a horizontal position, both out of the mercury M, so that the
circuit of H H is opened. After this movement, the pawl C descends in obedience
to the weight or spring acting on it, and engages under the next tooth of the
ratchet D, so that when another current from a distance excites the solenoid A, the
ratchet being turned another quarter round, the other of the arms F is immersed in
the mercury, again closing the circuit of H H. The sand lying over the mercury
prevents sparking when the arms leave the mercury, and protects the mercury
against oxidation. As the arms F are knife edged, they enter and pass through the
mercury and sand easily without causing much disturbance.
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. An electrically operated electric switch, constructed and operating substantially
as described with reference to the accompanying drawings.
2. For operating the switch above referred to the combination of the solenoid A
having its core B linked to the lever carrying the pawl C and the ratchet wheel D
fixed on the switch spindle E substantially as described.
3. For closing and opening the circuit of the switch above referred to, the com-
bination of the pair of staple shaped arms F, fixed insulated on the spindle E and

page_text: the two insulated cups containing mercury covered with sand, substantially as
described.
ABEL & IMRAY,
Agents for Applicants.