A Door Lock Switch for Electric Lights.
Year: 1892

page_text: Date of Application, 5th Oct., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
A Door Lock Switch for Electric Lights.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by Charles Green, of the City of Toronto, in the County of York, in the
Province of Ontario, Canada, Commercial Traveller,) 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 the invention is to design a switch for electric lights to be actuated
by the shooting of the bolt of a lock so as to break the current. and extinguish the
light when the door is locked and it consists essentially of preferably locating.
within the keeper opposite the lock of the door a switch which is actuated by a bolt
when it is shot into the keeper so as to extinguish the light when the door is locked
by breaking the circuit passing through the wires which lead through the divided
plates at the inner end of the keeper to the electric light, the said switch forming
when the door is unlocked a means of connection between the divided plates in
order to complete the circuit to the light as hereinafter more particularly
explained.
Figure 1 represents a perspective view of portion of a door and wall of a room
shewing an electric fixture and wires leading thereto from the keeper, portion of
the door-frame, lock and keeper being broken away to shew the operation of my
combined switch and lock.
Figure 2 represents enlarged details of the switch and contact plates.
A is the lock, B the bolt, C the switch, and D are the wires leading from the
main circuit wires to the incandescent electric light E. and G are contact plates
located at the inner end of the keeper. The contact plate F is formed of an
insulating plate and two plates ƒ separated by the central insulating ridge f.
The contact plate G is formed of an insulating plate G₁ and two plates 9 separated
by the central insulating ridge g'. The wires D lead first to each of the plates f
which are separated from the plates by a space, and the wires D continue from
each plate g to the incandescent light E. The major portion of the switch C is
made of insulating material and has two contact angular strips c secured to the top
of it and insulated from each other and designed to readily fit into the spaces
between the contact plates, f, g, g. The upper part of the lever of the pivotted
switch C is weighted or if preferable held normally against the contact plates f
and g by a spiral spring a. When the door is locked as shewn in the drawing, the
switch is tilted on its pivot so as to hold the wedged or V-shaped portions from the
contact plates, f and g, y. When the door is unlocked the metal wedged
portions c, of the switch C are held against both of the contact plates f, f and
fitting into the space between them. In this position it will be seen that the wedged
or V-shaped portions of the switch C completes the circuit over the wires D to the
incandescent electric light E.
9, 9
It will of course be understood, however, that although this circuit is complete
from the main circuit yet there is a main switch for the main circuit so that during
the day no electric current passes, over the wires to the electric light, E,
consequently no light will be emitted therefrom. When, however, the current is
turned over the main circuit it will flow over the branch wires, D, but if the door
of the room should be locked it will of course be understood that no light will be
thrown out in the room.
My invention is generally applicable but is more particularly adapted for hotels
and offices in which the occupant of the room or office when leaving it locks the

page_text: door thereby extinguishing the light. In hotels particularly it will be found
invaluable. When the occupant of the room is in the room instead of locking the
door he of course can have a supplemental bolt which is suggested in the drawing
and thereby bolt the door from the inside when he wishes to have the light
turned on.
When, however, the occupant leaves the room it frequently happens that he
leaves the switch at the lamp turned on and it remains so for hours at a time and a
great waste of current is thereby caused and considerable expense is consequently
incurred as this is done very frequently, but by providing a switch in connection
with the lock it will be seen upon the occupant leaving it in the evening the light
will be extinguished immediately upon him locking the door so no waste of current
and consequent expense to the host of the hotel will be incurred. When the
occupant, however, returns and unlocks the door he will find the room lighted and
will not have to grope about in the dark in order to locate the position of the
fixture.
I wish it to be understood that the ordinary lamp switch would also be provided
so that the occupant upon retiring could by turning it extinguish the light. As,
however, it would be necessary that this switch should be turned on in order to
have my door lock switch work it will be readily understood that it might be made
the duty of the caretaker or chambermaid to turn on this switch every day when
doing up the office or room, it being understood that the current would always be
turned off at the main switch so that there would be no current flowing to each
lamp and consequently no waste of electricity in the day time.
Although I show only one form of switch it will of course be understood that
I do not wish to limit myself to the exact form of switch or its exact location in
reference to the keeper.
From this description it will be seen that the proprietor of an hotel or building
will be able to save a considerable sun in his electric lighting bill when a meter is
employed. It will also be seen that a very simple and efficient convenience is
provided for the guest of an hotel or lessee of an office in a building as the case
may be.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. A door lock switch for electric lights consisting of the combination of the bolt
of the lock and a switch located within the keeper opposite to and operated by the
bolt and interposed between the wire leading from the main circuit to the electric
lamp as and for the purpose specified.
2. The combination with the bolt B of the lock A of the switch C having the
wedged or V-shaped portion c, and provided with the spring a and designed to come
in contact with the plates f, f, g, g, so as to complete or break the circuit through
the wires D as and for the purpose specified.
Dated this 5th day of October 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.