Improvements in Switches for Electric Installations.
Year: 1891

page_text: Date of Application, 23rd July, 1891
Complete Specification Left, 23rd May, 1892-Accepted, 25th June, 1892
[Communicated from abroad by ALFRED SWAN, of Orange, in the State of New
Jersey, United States of America, Engineer.]
Improvements in Switches for Electric Installations.
I ALFRED VINCENT NEWTON of the Office for Patents, 6 Breams Buildings,
Chancery Lane in the County of Middlesex, Patent Agent, do hereby declare the
nature of this invention to be as follows:—
The object of this invention is to produce a simple and efficient switch, or circuit
closer, by means of which an instantaneous making and breaking of the electric
circuit may be effected.
The base of the switch is moulded in vulcanite or other suitable insulating
material, and embedded in it, while in a soft state, is a central face cam. Through
the centre of this face cam stands up a spindle which carries a contact piece, and
terminates in a handle of non-conducting material. The spindle is secured in
place by the application to its inner end, at the back of the base (which is made
hollow for the purpose), of a bow spring held to the spindle by means of a
central screw.
The cam is formed with a ring of inclined projections, over which the contact
piece works, it being held down in contact therewith by means of the bow spring.
The cam projections, of which there are two pairs, serve to raise the contact
piece above the face of a pair of contact springs, to which the electric wires are
connected. The contact piece, when turned by the switch handle, will rise up the
cam faces until it is well over the contact springs; the continued movement of the
handle will clear it of the cam surfaces, when it will suddenly drop, by the action
of the bow spring before mentioned, onto the contact springs with which the
conducting wires are connected, and thus the circuit will be completed.
A further movement of the handle in the same direction, will pass the contact
piece over, and clear of the contact springs, when it will suddenly fall, & the circuit
will be broken.
The movement of the handle will be in one direction only, so that the further
movement of the handle will effect the closing of the circuit. The contact
piece it is proposed to make of iron with a copper wire inserted, to increase its
conductibility, and the contact springs are made by preference of phosphor bronze.
If desired, the switch may be made with two or more pairs of contact springs, to
suit the various requirements of the electrical engineer.
Dated this 23rd day of July 1891.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Switches for Electric Installations.
1 ALFRED VINCENT NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Patent Agent, 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 produce a simple and efficient switch or circuit
closer, by means of which an instantaneous making or breaking of the electric
circuit may be effected.

page_text: This switch may be made with one pair, or two or more pairs of contacts, to suit
the requirements of the case.
In the accompanying drawings, I have shown two forms of the improved instru-
ment, the first of which has one pair of elastic, contacts, while the second shews two
pairs of elastic contacts.
Fig. 1 is a side elevation, and
Fig. 2 a plan view, of an arrangement of switch in which a rotating contact bar
is employed for making and breaking the circuit.
In these figures, a is the base of the switch, made of any suitable non-conducting
material, preferably that which permits of being moulded to shape.
Embedded in the base a, or moulded therewith, is a face cam b, through the
centre of which stands up a spindle c, which carries a contact bar d, and terminates
in a handle of non-conducting material. The spindle c is secured in place by the
application to its inner end, at the back of the base, which is made hollow for
the purpose, of a bow spring e, held to the spindle by a central screw f.
The face cam 6 is formed with a ring of inclined projections, over which the
contact bar d works, it being held down in contact therewith by means of the bow
spring e. The cam projections, of which there are four, serve to raise the contact
piece above the face of a pair of clastic contact springs 9, attached to plates h,
carried by the base a, and connected to the electric wires by means of binding
screws. The contact bar, when turned by the switch handle, will rise up the
cam faces until it is well over the contact springs; the continued movement of the
handle will clear the bar d of the cam surfaces, when it will suddenly drop, by
the action of the bow spring e, onto the contact springs g, with which the
conducting wires are connected, and thus the circuit will be completed.
A further movement of the handle in the same direction will pass the contact bar
over, and clear of the contact springs, when it will suddenly fall, and the circuit
will be broken.
The movement of the handle will be in one direction only, so that the further
movement of the handle will effect the closing of the circuit.
The contact piece it is proposed to make of iron, with a copper wire inserted, to
increase its conductivity. By making the contact springs 9 elastic, and forming them
of phosphor bronze, durable contact surfaces are secured, the elasticity of the springs
compensating for the wear, and thus maintaining good contact with the rotary
contact piece d. Another advantage of this arrangement is, that the rapidity of
the breaking of the circuit, due to the action of the spring e, is doubled, by
making the contact surfaces 9 resilient, the springs rising as the contact bar falls,
thereby diminishing the effect of sparking.
g
i is a cover, made, say, of thin brass, for enclosing the switch; it is sprung
into place on the base a, before the handle is applied to the spindle c.
Figs. 3, 4, and 5 shew a modification of the switch, by which two circuits are
made or broken. Fig. 3 is a cross section, and Figs. 4 and 5 are partial plan views
of the switch.
The
The cam plateb is, in this instance, rotary, and made double faced, for the
purpose of bringing two pairs of contact springs into action, the springs 9 9 being
carried by the rotating cam b, and formed from one piece of metal.
springs g g are fixed to the base a, and bear upon the inner face of the cam
which carries a metal bridge, for connecting the two springs g¹ g¹ electrically
together.
These springs g' g¹ are permanently connected to the contact pieces *, to which
are attached the wires of a second circuit, by binding screws h². The other
springs 9 9 act on the contact pieces when a rotary motion is imparted to the
face cam.
It will be obvious that, by increasing the number of pairs of springs and contact
plates, the number of circuits commanded by the switch may be proportionately
increased.

page_text: Having now particularly described and ascertained the nature of the said
invention and what manner the same is to be performed (as communicated to
me from abroad), I declare that what I claim is :-
1. The means above described with reference to Figs. 1 and 2, for ensuring an
efficient elastic and durable rubbing contact in electric switches, with a sudden drop
out of contact, for the purpose above set forth.
2. The means shewn and described with reference to Figs. 3, 4 and 5, for making
or breaking two or more circuits simultaneously.
Dated this 23rd day of May 1892.
NEWTON & SON,
Agents for the Applicant.