Improvements in Electric Switches.
Year: 1889

page_text: Date of Application, 28th May, 1889-Accepted, 6th July, 1889
COMPLETE SPECIFICATION.
[Communicated from abroad by WALTER THOMPSON, of New York, in the United
States of America.]
Improvements in Electric Switches.
I, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane in the
County of London, Fellow of the Institute of Patent Agents, 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 :-
The object of this invention is to simplify and cheapen electric switches, to secure
good contact of terminals, to reduce liability to sparking, to facilitate the operation
of switching or closing or opening a circuit; and to render the switch more durable as
I shall describe referring to the accompanying drawings in which like letters of reference
indicate corresponding parts Fig. I is an elevation of a glow lamp, provided with a
switch according to this invention Fig. 1ª is a section of the same on the line < ;
Fig. 2 is a plan of a double switch suitable for wall or table purposes, the cap being
removed to show the interior working parts, Fig. 3 is a section of the same on the
line Y, and Figs. 4 and 5 are sections on the line z, the former shewing the parts in
position for opening the circuit and the latter shewing the parts in position for closing
the circuit Fig. 6 is an enlarged section of the sliding bar and spring arms. a is a
suitable bed plate or base preferably being in the form of a disc as shewn in Fig. 2,
b, are binding posts secured to the base in pairs and arranged to receive the
conducting wires.
Each stud as shown at 6 in Figs. 4 and 5 has attached to it a spring arm c bent
the one over the other under a sliding bar d which is guided and stopped preferably
by pins working in slots of d.
Where the spring arms c engage the bar dit is oppositely beveled as shewn in
Fig. 6 so that when the bar is moved to one extreme the springs engage one of the
inclines 9 and when it is moved to the other extreme the springs pass over the crown
or crest g¹, and engage the opposite inclines g².
The crest or angle formed by the opposite inclines is such that the springs cannot
rest thereon but make a complete passage over the crest thus insuring a perfect make
or break of contact.
:
The sliding bar d is made of non-conducting material but on the one set of
inclines are fixed metallic plates h h, which are connected by a pin h¹ passing
through bar.
When the springs c rest on the inclines 9 they are insulated from one another, but
when they are on the inclines 92, the circuit is completed through h.
The electric current can then pass from the wire i through 6, upper spring c, and
plate through connection h¹, lower plate h lower spring c, post 6 to wire i¹³, or vice
versa.
«
The ends of the sliding bar d extend through openings in the cap jor beyond
the limits of the bed plate, as at j, in Fig. 2, and are adapted to be pushed by the
finger, the projecting ends being preferably marked with words such as on and
"off" indicating that the circuit of the wires is closed or opened. Obviously the
form of the switch may be varied without departing from the spirit or scope of this
invention. As shewn in Figs. 1 and 1ª the sliding bar d is applied directly to a
lamp being fitted in the lamp socket and arranged to effect a single make
or break.
As the metallic plates h on the sliding. bar d present broad contact surfaces to the
spring arms c good contact is secured and danger of sparking and burning the
terminals is avoided. Also as the arms c, c have a sliding and scraping action on
the plates h, the contact surfaces are kept bright and in good conductive condition.

page_text: 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 I
claim is :-
:-
1. The improved switch combining with a sliding bar having opposite inclines
providing a ridge or crown gl, a spring arm serving as a conductor, substantially as
and for the purposes set forth.
2. The improved switch herein described combining with a suitable bar and
conductors for electricity, a sliding bar having opposite inclines one of which is pro-
vided with a plate serving as a terminal, and spring arms serving as the co-operating
terminal substantially as and for the purpose set forth.
3. The improved switch herein described combining therein a bed, a sliding bar
having opposite inclines g, g², on opposite sides thereof and spring arms c e extending
from suitable bearings in opposite directions into engagement with the opposite sides
of said bar substantially as and for the purposes set forth.
4. The combination with the disc or bed plate a, having screws or pins ff and a
cap j, a slotted bar d of non-conducting material extending at its opposite extremities
through said cap, the said bar being provided with opposite inclines g g², the latter
being provided with a contact plate serving as a terminal of a circuit and a spring
arm c serving as a co-operating terminal, substantially as and for the purposes
set forth.
5. The combination with the disc or bed plate a, having screws or pins ff, and
a cap of a slotted bar d of non-conducting material extending at its opposite
extremities beyond the limits of said cap, the said bar being provided with opposite
inclines g g on opposite sides thereof and spring arms c, c, extending into engagement
with the opposite sides of said bar substantially as set forth.
6. In an electric switch the combination of a sliding bar having opposite inclines
respectively conducting and non conducting meeting in a crest with contact springs
bearing against opposite sides of the bar, so that as the bar is pushed in the one
direction or the other, the springs make a sudden leap over the crest to make or break
contact, substantially as described.
Dated this 28th day of May 1889
ABEL & IMRAY,
Agents for the Applicant.