An Improved Combined Electric Switch and Connecting or Coupling Device.
Year: 1890

page_text: Date of Application, 13th Sept., 1890
Complete Specification Left, 12th June, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
An Improved Combined Electric Switch and Connecting or
Coupling Device.
We, RICHARD BROWN EVERED, of the firm of Evered & Co., 27 Drury Lane,
in the County of Middlesex, Brassfounders, and THOMAS RUDLING, of 47 Parma
Crescent, Lavender Hill, in the County of Surrey, Electrician, do hereby declare
the nature of this invention to be as follows :-
This invention relates to an improved device for permitting the connection of
movable electric conductors with an electric circuit and the disconnection of the
same therefrom.
Our said invention is chiefly designed to obviate the liability to the formation of
accidental or wilful short circuits, and to ensure the locking of the connecting
device when the circuit is completed and the interruption of the circuit when the
connecting device is unlocked.
In carrying our said invention into practice we construct our improved device in
such a manner that it is necessary to make two distinct contacts in order to
complete the connection of the movable conductors with the electric circuit, that
is to say, we combine a switch with a wall-socket or other socket having suitable
terminals, and adapted to receive a plug having corresponding terminals, in such a
manner that the act of completing the circuit effects the locking of the said plug
in the socket, and the act of unlocking the said plug to permit its removal from
the socket effects the breaking or interruption of the circuit. Therefore when the
circuit is once completed, the plug is not liable to accidental displacement, and
before the said plug can be removed the circuit must be interrupted.
We find it advantageous to make our improved device as follows, that is to
say-Upon a porcelain, slate or other suitable base plate we provide a socket
piece or structure having a central cylindrical perforation lined with brass or other
suitable conductor and a stud or projecting piece of brass or other suitable metal
situated axially within the said perforation. This socket piece is adapted to turn
upon an axis coincident with that of the said cylinder. The stud or projecting
piece is placed in connection with one terminal of the circuit while the aforesaid
brass lining can be put in connection with the other terminal by means of the
switch hereinafter described.
This switch comprises preferably a fixed brass piece or clip provided with means
for connecting it with one of the conductors of the circuit, and a movable brass
arm or the like adapted to be moved into or out of contact therewith by the
turning of the aforesaid socket piece upon its axis in one or the other direction.
For this purpose the said movable arm is preferably secured rigidly to the said
socket and is moreover in electrical connection with the brass lining thereof so that
by turning the said socket the said lining can be connected with the circuit wire at
pleasure.
A plug piece or the like having an outer brass or other conducting lining and an
axial perforation with a similar conducting lining is adapted to enter the aforesaid
socket, the outer lining thereof making contact with the lining of the perforation
in the said socket and the lined perforation being adapted to receive the brass stud
or projection thereof. Morcover the two conducting linings on the plug are placed
one in connection with one terminal and the other in connection with the other
terminal of the movable conductors or apparatus so that when the above mentioned
switch is turned in the proper direction the current can pass by means of the
movable arm of the said switch and the lining of the socket to the outer lining of
the plug thence through the movable conductors or apparatus back to the lining of

page_text: the axial perforation in the plug and thence by the stud or projection in the socket
to the other circuit terminal, or vice versa.
To prevent the possibility of the plug being removed from the socket till the
same has been turned in such a direction as to break the circuit by means of the
aforesaid switch, the said plug and socket are adapted to engage with one another
by means of a bayonet joint or the like, the recess or cut away portion of the
joint being formed on the lining of the socket while the stud or projection thereof
is formed on the outer lining of the plug.
In some instances instead of constructing the parts in the manner above
described we may construct the same with a fixed socket having a conducting
lining. At the inner end of the perforation we provide a rotary brass or conducting
plate secured to a suitable pivot in line with the axis of the said perforation, which
dise is insulated from the said conducting lining and carries the movable contact
piece or arm of the switch herein before described. The plug in this instance is
provided with an outer lining adapted to make contact with the lining of the said
socket, and with a brass disc on the extremity thereof adapted to make contact
with the aforesaid rotary brass plate. The plug is moreover adapted to be locked
in the socket by a bayonet joint, the recess of the said joint being preferably
formed in the said socket and the projection thereof being formed on the plug.
The rotary brass plate is also provided with a projection adapted to enter a recess
in the circumference of the aforesaid disc on the extremity of the plug so that it is
necessary to turn the said plug a certain distance sufficient to effect the engage-
ment of the bayonet joint before the edge of the recess acts upon the projection of
the brass plate to effect the rotation of the same and thereby the completion of
the circuit. In this construction the current passes either from the movable arm
of the switch to the rotary brass plate, and thence when the plug is in position to
the brass disc on the extremity thereof which is connected with or forms one
terminal of the movable circuit or apparatus, while the lining of the said plug is
connected with or forms the other terminal thereof and makes contact with the
lining of the socket, with which one of the main circuit conductors is in connection,
the other main-circuit conductor being in connection with the movable arm of the
switch or vice versa.
We prefer to combine with our improved electric switch and connecting or
coupling device a safety fuse or the like.
It is obvious that our invention may be somewhat modified without departing
from the essential nature thereof. Thus we may so arrange the parts as to
substitute a sliding motion of the socket in order to complete the circuit after the
nsertion of the plug; instead of a turning motion as hereinbefore described.
Dated this 13th day of September 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improved Combined Electric Switch and Connecting or
Coupling Device.
We, RICHARD BROWN EVERED, of the firm of Evered and Co., 27 Drury
Lane, in the County of Middlesex, Brassfounder, and THOMAS RUDLING, of 47
Parma Crescent, Lavender Hill in the County of Surrey, Electrician, 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 improved device for permitting the connection of
movable electric conductors with an electric circuit and the disconnection of the
same therefrom.
Our said invention is chiefly designed to obviate the liability to the formation of

page_text: accidental or wilful short circuits, and to ensure the locking of the connecting
device when the circuit through the movable conductors is completed, and the
interruption of the said circuit when the connecting device is unlocked.
We construct our improved device in such a manner that two distinct movements
of a contact making plug are required in order to complete the connection of the
movable conductors with the electric circuit. We combine a switch with a wall
socket or other socket or holder having suitable terminals and adapted to receive
a plug having corresponding terminals. This combination is arranged in such a
manner that the act of completing the circuit effects the locking of the said plug
in the socket, and the act of unlocking the said plug to permit its removal from
the socket effects the breaking or interruption of the circuit. Therefore when the
circuit is once completed the plug is not liable to accidental displacement, and
before the said plug can be removed the circuit must be interrupted.
We find it advantageous to make our improved device in the manner now to be
described with reference to the accompanying drawings which illustrate one form
or modification of the same.
Figure 1 is a sectional elevation of the apparatus with the plug inserted.
Figure 2 is a sectional elevation of the plug and of the handle or knob to which
it is attached.
Figure 3 is an underside view of Figure 2.
Figure is a sectional plan of Figure 1, on the line aa of that figure showing
the plug acting upon the movable arm of the switch, the arm being shown in the
position in which it completes the circuit, and being also shown by dotted lines, in
the position it occupies when the circuit is broken.
Figures 5 and 6 show portions of the apparatus hereinafter referred to.
Similar letters of reference are applied to corresponding parts in all the figures.
Upon a base plate A of porcelain, slate or other suitable insulating material is
secured by fangs or tail-pieces B the metal bridge C; to this bridge is attached
by screws or otherwise the socket piece D of any suitable insulating material,
having a central perforation E lined at the upper portion of its depth with brass
or other suitable conducting material as at F. A handle or knob Ġ of insulating
material carries the plug H which plug is adapted to turn within the socket
piece D. The construction of the plug H is clearly shown in Figure 2, whence
may be seen that it consists of three portions, that is to say, a central metallic
pin I in electrical connection with one terminal of the movable electric conductor
by the wire J, a tube K of insulating material, and an outer metallic tube L.
The insulating tube K separates the pin I from the outer metallic tube L which
by the wire M is connected with the other terminal of the movable electric
conductor. Or the parts I and L may themselves constitute the terminals of the
movable electric conductors. This tube L is adapted to fit tightly in and to
make a good electrical contact with the metal lining F of the socket piece D
which lining is connected by the wire N with a terminal O secured to the base-
plate and included in the main electric circuit with which the movable wires are to
be connected or disconnected. The wire N may be replaced by a safety fuse.
The other terminal P of the main circuit is also attached to the base plate and
can be put in electrical connection with the insulated metal bridge C by means of
a switch to be hereinafter more fully explained and whose operative member is an
arm or projecting piece Q, carried by the bridge (see Figures 1 and 4) and adapted
This switch
to turn about an axis coincident with that of the socket piece D.
comprises the fixed spring jaw P2, of which the terminal P forms a part (as shown
in Figure 6 the sectional elevation of the baseplate) and the movable metal arm Q
adapted to be moved into or out of contact with the spring of the jaw P2 by the
turning upon its axis of the aforesaid plug H within the perforation E in one or
the other direction. For this purpose the said movable arm has on its inner end
projections q, and a toe i extending from the lower edge of the pin I engages with
these projections. This pin, when in its operative position is pressed down upon
and makes contact with the arm Q so that by rotating the said arm the pin I can

page_text: be connected at pleasure with the main circuit wire attached to the terminal P.
The centre pin of the arm Q is extended below the bridge as shown in Figure 1
and formed with a flattened piece ³ upon which bears a spring q arranged to
retain the arm Q in either its open or its closed position. Moreover the two
conducting portions I and L of the plug H form or are connected as aforesaid
with the two terminals of the movable conductors, so that when the above described
switch is operated in the proper direction in the manner described the current can
pass from the terminal P by the movable arm Q and by the pin I to and through
the movable conductors or other apparatus back to the tube L and the lining F of
the perforation E, and so to the other terminal O of the main circuit, or vice versa.
The mechanism of the wall socket A is enclosed by the protecting screwed
cover S, as shown.
To prevent the possibility of the plug I being removed from the socket till
the plug and the arm Q have been turned in such a direction as to break the
circuit the said plug and socket are adapted to engage with one another by means
of a bayonet joint arrangement as shown in Figure 5 which is an underside view
of the socket piece D. A metal guard plate R is secured to the socket D above
the bridge C and has in it a notch t; the projection i is formed as before explained
upon the pin of the plug. It is necessary in order to operate the arm Q that
the projection i should be passed through the notch and below the edge of the
guard plate R preliminary to the rotation of the arın Q by which closure of the
circuit is effected. The guard plate will prevent withdrawal of the plug until
the projection is again adjusted under the notch which adjustment cannot take
place unless the arm Q has been turned out of contact with the jaw P2 to break
the circuit.
The underside of the guard plate R may be slightly helical and the arm Q
may have a plate spring placed upon it or forming part of it. The result of this
arrangement would he that the lower end of the pin I would have a screw motion,
which would ensure good contact with the spring of the arm and which when the
pressure of the pin I upon the said spring were sufficiently eased would allow the
spring to operate the arm Q very sharply to break the circuit rapidly.
It is obvious that our invention may be somewhat modified without departing
from the essential nature thereof. For example we may so arrange the parts as
to substitute a sliding or a rotating motion of the socket in order to complete the
circuit after the insertion of the plug, instead of operating in the manner herein-
before described.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
First. A combined electric switch and connector wherein for the purpose of
connecting movable electric conductors to and disconnecting them from an electric
circuit two distinct movements of the contact making plug are required, and
wherein the act of making or of breaking the circuit through the conductors
locks or unlocks the said plug.
Second. The construction and arrangement of parts constituting a combined
electric switch and connector as hereinbefore described and illustrated with
reference to the accompanying drawings.
Dated this 12th day of June 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.