An Improved Key Switch for Electrical Oirouits, particularly adapted for Incandescent Lamp Sockets.
Year: 1899

page_text: Date of Application, 6th July, 1899
Complete Specification Left, 6th Apr., 1900-Accepted, 16th June, 1900
An Improved Key Switch for Electrical Oirouits, particularly adapted
for Incandescent Lamp Sockets.
We, VERITYS LIMITED, Electrical Engineers, and WILLIAM REGINALD RIDINGS,
Electrical Engineer, both of Plume Works, Aston, in the County of Warwick,
do hereby declare the nature of this invention to be as follows:-
This invention is an improved key switch for use in electrical circuits for
switching on and off lamps or other apparatus, and has particular adaptability
in the case of incandescent lamp sockets.
The improved key switch according to this invention is characterised by a
conducting rocking piece, loosely fulcrummed at its middle to the base of the
switch so that its tips make contact with two yielding terminals disposed on
the said body on opposite sides of the rocking piece, and a coiled or other dis-
tensible spring whose one end is connected with one of the arms of the rocking
piece, and whose other end is carried by the outer extremity of an arm or
plate mounted upon the stem of the switch's key concentric with the fulcrum of
the rocking piece, and which said arm or plate has a movement independent of
the said rocking piece, on the turning of the key, to throw over the end of the
spring it carries to either the one side or the other of the centre of the said
rocking piece, in order to change the line of pull of the said spring in respect
of the said rocking piece, the said spring being distended between the parts as
aforesaid to which its ends are attached. A catch device is provided upon the
rocking piece so that it cannot be moved when the shifting end of the spring
takes a position which brings the line of pull of the spring straight with the
longitudinal line of the rocking piece; thus always ensuring the full change of
throw of the end of the shifting spring before the rocking piece is operated,
the energy of the distended spring subsequently operating the rocking piece
with a "fly" action.
"
One of the chief points in a key switch according to this invention is that
the first movement of the rotating key, to throw over the line of pull of the
spring at the time the locking piece engages the yielding terminals, causes a
slight movement of the said rocking piece in a "make contact' direction
sufficient to cause a slight rubbing or wiping movement of the rocking piece's
tips upon the terminals in addition to the rubbing contact on "making," ensur-
ing as a consequence a clean and perfect contact at all times.
In carrying the invention into effect in connection with an incandescent
electric lamp socket a short arm, having an outstanding peg upon its extreme
outer end and capable of being thrown over from one side to the other, is con-
nected rigidly to the extreme inner end of the shank of a turning key working
through the body of the lamp's socket, the said peg having connected with it
the one end of a small coiled spring whose other end takes onto a post standing.
out from the tip of the one arm of a bar fulcrummed at its middle to loosely

page_text: surround the stem of the key inwards of the arm as aforesaid; the coiled spring
being normally slightly distended between the said peg and post. The bar,
as aforesaid, is practically a rocking contact piece, whose tips in one position
make contact with yielding terminals attached to the socket's body upon opposite
sides of the said rocking piece, and in another position stand clear of the said
yielding terminals. The arm carrying the peg moves independent of the rock-
ing contact piece, and is thrown over first onto one side of it and then onto the
other to change the line of pull of the spring upon the said contact piece; the
spring then being the means for controlling the position and movement of the said
contact piece. The yielding terminals are preferably limb springs.
In order to avoid the contact piece and the arm and spring being moved as
one piece when the arm, in the act of being thrown over from the one side to
the other of the said contact piece, brings the spring in a dead line with the
contact piece and in an inactive position, a spring-actuated projection is fitted
to the rocking contact piece so as to be forced into engagement with a fixed stop
on the socket's body by the act of the arm crossing, over the contact piece from
the one side to the other: the said arm having a wiping action over the said
projection to depress it.
In operating the contact piece from "on" to "off" the coiled spring is
further distended by the action of the throwing over of the arm, which causes a
rubbing contact of the tips of the contact piece upon the yielding terminals, in
addition to the rubbing contact of these parts in making contact of the terminals.
This invention is applicable with slight alterations in detail to wall switches
operated by a turning key.
'
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Patent Agents for the Applicants.
An Improved Key Switch for Electrical Circuits, particularly adapted
for Incandescent Lamp Sockets.
We, VERITYS LIMITED, Electrical Engineers, and' WILLIAM REGINALD RIDINGS,
Electrical Engineer, both of Plume Works, Aston, in the County of Warwick,
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 follow-
ing statement:-
This invention is an improved key switch for use in electric circuits for
switching on and off lamps or other apparatus, and has particular adaptability
in the case of incandescent lamp sockets.
The improved key switch according to this invention is characterised by a
conducting rocking piece, loosely fulcrummed at its middle to the base of the
switch so that its tips make contact with two yielding terminals disposed on
the said body on opposite sides of the rocking piece, and a coiled or other dis-
tensible spring whose one end is connected with one of the arms of the rocking
piece, and whose other end is carried by the outer extremity of an arm or
plate mounted upon the stem of the switch's key concentric with the fulcrum of
the rocking piece, and which said arm or plate has a movement independent of
the said rocking piece, on the turning of the key, to throw over the end of the
spring it carries to either the one side or the other of the centre of the said

page_text: rocking piece, in order to change the line of pull of the said spring in respect
of the. said rocking piece, the said spring being distended between the parts as
aforesaid to which its ends are attached. A catch device is provided upon the
rocking piece so that it cannot be moved when the shifting end of the spring
takes a position which brings the line of pull of the spring straight with the
longitudinal line of the rocking piece; thus always ensuring the full change of
throw of the end of the shifting spring before the rocking piece is operated,
the energy of the distended spring subsequently operating the rocking picco
with a "Hy" action.
One of the chief points in a key switch according to this invention is that
the first movement of the rotating key, to throw over the line of pull of the
spring at the time the locking piece engages the yielding terminals, causes a
slight movement of the said rocking piece in a make contact' direction
sufficient to cause a slight rubbing or wiping movement of the rocking piece's
tips upon the terminals in addition to the rubbing contact on making," ensur-
ing as a consequence a clean and perfect contact at all times.
«
The invention is, shown carried into practical effect in the accompanying
sheet of drawings in connection with an incandescent electric lamp socket, Fig. 1
being a part-section with the switch in an "off" position, Fig. 2 a like view but
with the casing of the lamp socket and its detachable parts removed, Fig. 3 a
side elevation of Fig. 2, and Fig. 4 a like view as Fig. 2 but with the rocking
piece in the position as in Fig. 1 and the pull of the spring which actuates it in
the act of being thrown over from the one side to the other. In these figs. n
short arm, having an outstanding, peg upon its extreme outer end, and
capable of being thrown over from one side to the other, is rigidly connected
to the extreme inner end of the shank of a turning key d, working through
the body part a of the lamp socket, the said peg having connected with it.
the one end of a small coil spring e whose other end, e, takes onto a post g
standing out on the tip of the one arm g² of a bar g fulcrummed at its middle
to loosely surround the stem of the key d inwards of the arm e as aforesaid.
the coil springe being normally slightly distended between the said peg (2 and
post The bar 7, as aforesaid, is practically a rocking contact piece whose
lips g, g, (the latter on the other arm of the bar g) in one position, Figs. 2
and 3, make contact with yielding terminals h, i, attached to the socket's body
upon opposite sides of the said rocking piece, and in another position stand clear
of the said yielding terminals as in Figs. 1 to 4.
The arm carrying the peg moves independent of the rocking piece g and
is thrown over by the operation of the key d first to the one side of the contact
piece and then to the other to change the line of pull of the spring upon the
said contact piece the said spring then being the means for rocking the piece g
and controlling its position in respect of the position of the line of pull. One
of the leads is connected to the terminal and the other to the conducting piece m
making contact with the connections of the lamp's filament.
In order to ensure the arme having an independent movement of the rocking
piece as defined in the proceeding paragraph the said rocking piece is loosely
mounted to turn upon the inner end of the shank of the turning key and it is
only by the spring that any movement is imparted to the said rocking piece: as
a consequence if the said rocking piece is in either an on or "off" position
in respect of the terminals no movement is imparted to it until the line of pull
of the spring is thrown over onto the other side pass the centre.
"
In operating the contact piece from "on" to "off" the coiled spring is
distended by the action of the throwing over of the arm, which causes a rubbing
contact of the tips of the contact piece upon the yielding terminals before leav-
ing them, in addition to the rubbing contact of these parts in making contact
of the terminals.
This invention is applicable with slight alterations in detail to wall switches
operated by a turning key,

page_text: Having now particularly described and ascertained' the nature of our said
invention, and in what manner the same is to be performed we declare that
what we claim is:--
First. A key switch for electric circuits, characterised by a conducting rock-
ing piece loosely fulcrummed at its middle to the base or body of the switch, two
yielding terminals disposed on the said base or body on opposite sides of the
said rocking piece, a turning key rotating upon a common fulcrum with the
rocking piece but independently thereof and which carries an eccentrically
mounted peg, arm, or its equivalent and a coil spring distended between the said
peg of the key and the one arm of the rocking piece all operating substantially
as described.
Second. In a key switch for electric circuits the combination of a rocking
piece g, yielding terminals h, i, a turning key d having an eccentric arm c upon
it, a post upon the said rocking piece and a coil spring e distended between e
and the extremity of call constructed and operating in the manner substantially
as described and set forth.
Third. A key switch, the parts of which are constructed arranged and made
to operate in the manner described and set forth in the drawings,
WP. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also at Liverpool, London, and Manchester,
Patent Agents for the Applicants.