An Electric Switch.
Year: 1889

page_text: Date of Application, 31st Oct., 1889
Complete Specification Left, 30th July, 1890-Accepted, 13th Sept., 1830
PROVISIONAL SPECIFICATION.
[Partly communicated from abroad by FRANK JACOB, Electrical Engineer, at present
on the s.s. Faraday, on the high seas in the North Atlantic.]
An Electric Switch.
1. GEORGE SYLVESTER GRIMSTON of Claremont, Glenluce Road, Westcombe Park,
Greenwich, S.E., in the County of Kent, Electrical Engineer, do hereby declare the
nature of this invention to be as follows:-
My invention relates to a simple and inexpensive construction of electric switch so
arranged that the circuit to which it is applied is closed or opened by a very rapid
movement, and that the switch, whether it is set for closing or opening the circuit,
remains steadily in position until it is moved again by hand.
For this purpose, 1 provide a ratchet wheel having an even number of teeth, which
are alternately of conducting and of insulating material or are faced with such material,
all the conducting parts being connected to the one wire of the circuit.
A metallic
spring pawl which is connected to the other wire of the circuit bears against the ratchet
wheel, which is otherwise insulated from the pawl. On turning the wheel by hand
partly round the pawl is first strained against its spring and then jumps rapidly from
one tooth to the next, making or breaking contact as the case may be, and then holding
the wheel steadily in position and preventing it from being turned backwards.
Dated this 31st day of October 1889.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Electric Switch.
1, GEORGE SYLVESTER GRIMSTON, of Claremont, Glenluce Road, Westcombe Park,
Greenwich, S.E., in the County of Kent, 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 :-
My invention relates to a simple and inexpensive construction of electric switch so
arranged that the circuit to which it is applied is closed or opened by a very rapid
movement, and that the switch, whether it is set for closing or opening the circuit,
remains steadily in position until it is moved again by hand.
For this purpose, I provide a ratchet wheel having an even number of teeth, which
are alternately of conducting and of insulating material or are faced with such material,
all the conducting parts being connected to the one wire of the circuit. A metallic
spring pawl which is connected to the other wire of the circuit bears against the ratchet
wheel, which is otherwise insulated from the pawl. On turning the wheel by hand
partly round, the pawl is first strained against its spring and then jumps rapidly from
one tooth to the next, making or breaking contact as the case may be, and then holding
the wheel steadily in position and preventing it from being turned backwards.
Fig. 1 of the accompanying drawings is a section and Fig. 2 is a plan with cover
removed of a switch according to this invention arranged to be turned by hand.
Fig. 3 is a section and Fig. 4 is a front view shewing how the switch may be moved
from a distance by successive pulls of a cord. In Figs. 3 and 4 the contact mechanism
is not shewn, but it may be understood to be similar to that shewn in Figs. 1 and 2 to
which I now refer. The button or knob a to which the fingers are applied is of non-
conducting material made in one piece with a ratchet wheel of two teeth b and c.
tooth c is faced with a strip of metal which is metallically connected to the axis d on
---Price 6d.
The

page_text: which a turns and so to the metal base plate e to which one of the leading wires is
attached. The other wire is attached to a plate on which is mounted a pawl g which
is pressed by a spring against the ratchet wheel.
When the wheel is in the position shewn in Fig. 2 the circuit is closed, there being
complete conducting connection from e through the axis & the metal face of c and the
pawl g to f
On turning the knob a round until the pawly escapes the end of the tooth c, and
comes to bear against the non-conducting tooth b, the circuit is opened. When the
switch is in a position inaccessible to the hand for turning a, a grooved pulley may be
fixed on the axis of a with a cord connecting it to a pulley in an accessible position by
turning which the switch can be turned. Or the arrangement shewn in Figs. 3 and 4
may be adopted.
Here a lever carries a loaded pawl & which engages with teeth of a ratchet wheel
fixed on the axis of the switch. The lever can be drawn in the one direction by a
pull cord n, a spring m moving it back, and by a series of these movements of the lever
the switch a can be turned step by step till it comes to the position to close or to open the
circuit. Although I bave shewn in Figs and 2 only a pair of ratchet teeth b and c
with one pawl g to bear against the one or the other, obviously there might be several
pairs of teeth and several pawls connected to several different leads, or there might be
one conducting and several non-conducting teeth so that in the different positions to
which the switch might he turned different circuits might be closed or opened.
.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
claim is
An electric switch wherein a wheel has a non conducting ratchet tooth, and a
conducting ratchet tooth connected to one lead, or several such teeth, pressed against
by a spring pawl connected to another lead or several such pawls substantially as and
for the purpose set forth.
ባለ
T '
ABEL & IMRAY,
Agents for the Applicant.