Improvements in Electrical Switches.
Year: 1896

page_text: Improvements in Electrical Switches.
I, GEORGE WILKINSON of No. 12 Dragon's View, High Harrogate, in the
County of York, Electrical Engineer do hereby declare the nature of this invention
to be as follows:-
My invention relates to certain improvements in switches for electrical circuits
in which the desired contact may be made by the tension of a cord or its equivalent
by the ordinary action of pulling, and said contact may be broken by a repitition
of said action, which is in other words, an alternating make and break whenever
said cord or its equivalent is operated. The object of the said invention is the
adaptability of said switch as herein briefly described, to ordinary lighting or
power installations in which no break or branch need occur in a cornice or ceiling
lead beyond that of the simple switch coupling, wherever the interposition of a
switch is desirable.
In carrying my invention into effect, I employ an ordinary switch base with a
switch lever pivotted so as to have a vertical movement, and establishing an
electrical circuit when depressed against the tension of a spiral spring, by brush
or other suitable elastic contacts fixed upon the base. I attach to the switch
lever a cord or equivalent, which passes over a pulley or roller in the recessed
base at the back thereof, and depending within hand reach. A light pawl provided
with a back "tail" or extension is pivotted within the recessed base, upon
pulling the cord and depressing the switch lever as aforesaid, a light counter-
balance upon the pivotted pawl causes it to fall and hold the switch lever in
contact position against the tension of the spring, but a second pull upon said cord
or equivalent and a slight angular movement thereof, depresses the extension of
the pawl, which is shaped and placed close to the cord behind the base, disengages
the pawl and liberates the switch lever thus opening the electrical circuit.
The pawl may be perfectly insulated from the electrical connections of the
switch proper, and is in construction so light as to form no impediment to the use
thereof.
I may modify the construction of the device bereinbefore described, by employing
a radial switch arm or lever, which is controlled by a spiral, volute, or coiled
spring, so that when said spring is active the electrical circuit is broken. A cord
or the like attached to said arm causes it to make contact with the plates therefor
provided against the tension of the spring aforesaid and the pivotted pawl holds
it in said position. A slight pull upon the cord or the like causes the tension
thereof to act upon the "tail" or extension depressing it, and raising the pawl,
when the switch arm is caused to break contact by the action of the spring
attached thereto.
I may further modify the device according to my said invention without
departing from the essential features thereof, by employing a plunger or equivalent
instead of an ordinary switch bar, or lever, either operated by the direct pull of
the cord or the like or through a cranked lever. In this case the plunger would
be kept normally out of contact by the intervention of a spiral or other spring or
springs in tension or compression and either make and break contact by the entry
or withdrawal of a tapered head or heads within or from corresponding brushes,

page_text: or a mere face contacts with an elastic surface. In this case, as in the modifica-
tions before referred to, the contacts are normally broken, but when the plunger
is depressed by the cord or the like the pawl falls into a recess provided for it, and
the slack cord passing the "tail" or extension thereof allows of the next move-
ment in the same direction releasing the pawl and allowing the plunger aforesaid
to be returned to its normal position by the action of the spring. In some cases
where use a separate contact plunger or plate I prefer to mount my fuses
thereon.
I may adapt my said invention to any known form of switch, but preferably
use either of the types described in the foregoing modifications, which are specially
constructed to fulfil the object 'inview, which is the operations of making and
breaking an electrical circuit by a simple pull upon a cord or equivalent thereto.
Dated this 1st day of Juue 1896.
FREDK. WALKER,
73 St. Stephen's Road, Upton Park, London, E.C.
Improvements in Electrical Switches.
I, GEORGE WILKINSON of No. 12 Dragon's View, Harrogate, in the County
of York, Electrical Engineer 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 :-
My invention relates to certain improvements in switches for electrical circuits,
in which contact may be established by the tension of a cord, or any equivalent
thereof, and said contact may be broken by the same means. The object of this
invention is to adapt a switch constructed as hereinafter described, to ordinary
lighting or power installations, in which no break or branch need occur in a cornice
or ceiling lead beyond that of the simple switch coupling wherever the interposition
of a switch is required.
In order that my said invention may be clearly understood, I have appended two
sheets of drawings, of which the following is a schedule.
Figure 1 Sheet 1 is a sectional view of a single pole switch, upon the line 1-2
of the plan view Figure 2, in which the cover is removed.
Figure 3 is a sectional view of a modification, and Figure 4 is a plan view
thereof.
Figure 5 is an end elevation partly in section, of a two pole switch, and
Figure 6 is a front elevation thereof, the cover being removed. Figure 7 is a
side elevation of the same, partly in section, and
Figure 8 is an elevation of a method of obtaining a rapid break, which may be
applied to either of the switches shown.
Figure 9 is a sectional view of a quick break movement, which may be applied
to any of the modifications hereinbefore shown.
Similar letters of reference are used' to 'indicate corresponding parts throughout
the several views.
In Carrying my invention into effect" I employ a switch base A of any insulating
material, with a switch lever B, pivotted at a, so as to have a vertical movement,
and establishing an electrical circuit when depressed against the tension of a spiral
spring S, by brush or other suitable elastic contacts bb, which are fixed upon the
base and attached to terminals t t as shown by Figure 1. A cord C or equivalent
is attached to the switch lever B at e, and passes over a pulley or roller D in the
recessed basé A Figure 1. A 'pawl E,' provided with a back extension F is

page_text: pivotted at f, and the catch thereof passes through a slot G, in the lever B and
retains it in its contact position by gravity against the tension of the spring S,
when so placed by pulling the cord C. A slight angular movement of the cord C,
by depressing the back extension F releases the pawl E and the action of the
spring S raises the switch lever B out of contact.
In the modification shown by the sectional elevation Figure 3, and the
corresponding plan view Figure 4 the parts are the same as in Figures 1 and 2,
with the exception that a slotted draw bar m suspended by a spiral spring is
attached to the cord C. When said cord C is released after the switch lever B
is pulled into the "on" position the distended spring S contracts to its original
position thus raising the draw bar m and slackening back the upper part of the
cord C between the draw bar n and the switch lever B as shown in Fig. 3. The
pawl E is released by the angular movement of the aforesaid cord C, causing
the draw bar m to press against the extension F of said pawl E. At the same
time a pin a passing through the base A and the head of which is in contact with
the extension F is forced out by the action of releasing the pawl E, and presses the
switch lever B out of the contact position between the plates 66 against any
tendency to stick that may exist. This action by reason of the slack cord before
named and shown in Fig. 3 affords a quick break. A fuse d may or may not
be interposed between the contact plates as shown by the drawing, Figure 4.
In the double pole switch shown by Figures 5, 6, 7 and 8 the switch lever B is
dispensed with, and a head or plate B substituted therefor, which slides upon
guide bolts a a' and is normally kept out of contact by the springs S S¹. The
cord C or an equivalent is attached to said bead B, and when it is pulled down-
wards in a vertical direction, the head B aforesaid is drawn back against the
springs S S until the contact plates upon it are in electrical contact
with the fixed spring or brush contacts bbb The pawl E and E' then fall
into position by gravity, and retain the head in contact. The cord C passes through
an extension of the pawls E E which are pivotted at, so that a second pull
upou said cord C, easing the tension of the springs S Si, slightly in an angular
direction, releases said pawls E E' as shown by the dotted outline, and the head B
is returned to its normal position, out of contact, by the springs S S', against the
stop or guard plate a which may have elastic washers threaded upon the guide
bolts a a to ease the impact. Safety fuses d d are used to connect the
contacts according to the condition of usage, it being an essential
feature in switches according to my invention that in circuits of high potential,
such fuses may be replaced when the switch is in the off "contact" position without
risk of completing the circuit through the body or like accidents. The whole
switch is enclosed in a metal box or case K, with a weather proof cover L having
in some cases, a glass or other transparent front. The whole of the interior
connections are perfectly insulated, and lugs I are provided so that when necessary
several switches may be placed in line, and the main lead connected by an ordinary
metal bar, common to all the switches in the series.
In releasing, the switches shown by Figures 1, 2, 4, 5 and 6, a certain drag is
imposed by the cord C and consequently the breaking of electrical contact
is impeded. In order to effect a quick "break" I may modify the construction of
any switch according to the device illustrated by Figure 8. In this case the
bar B, carrying the contacts his depressed against the tension of the springs S S
upon the guide boits a a' by means of a head r, pivotted to a plunger P, to which
the draw cord C is attached. It is not absolutely necessary that the head should
be pivotted, except that in such case the two flat edges bearing upon the bar B
may prevent side strains and thus diminish the friction upon the guide balts a a².
The plunger P passes freely through a hole in the bar B, and entera a tube
containing a spring o against which it presses, and which returns it to rost against
the guard plate e (as shown by the drawing) after the cord C is released. The
bar B is shown in contact position, any kind of brush or spring contacts being
provided to engage with the contacts & A upou the bar B. The device for keeping

page_text: the bar B in contact position, and suddenly releasing it, so that it may be returned
hy the springs S. S¹, consists in a lever R pivotted to the bar B and carrying a
roller E which drops by gravity into the locking position as shown, and retains B
by dropping below the centre, and pressing against the guard plate e. The
lever R and roller E may, to preserve an equal pressure, be duplicated on the
other side of the plunger P and guard plate c. A projection upon the end of
said lever R fits within a fork at the end of a rod V, which is jointed to the end
of a bar H, pivotted at to the base of the switch or frame thereof, and prevented
from falling beyond a certain position by a stop, or by contact with said frame, as
shown. The rod V and lever H may also be duplicated if necessary, one on each
side of the apparatus. An extension F is formed upon or attached to, the lever H
or levers, and at right angles thereto, and in close proximity to the cord C, so that
when the latter is moved inwards, as shown by the dotted outline, the lever H is
raised, carrying with it the forked rod V, thus raising the lever R with the roller E
past the centre of its bearing on the guard plate c.
The action is as follows; The downward pull of the cord C depresses the
plunger P against the tension of the spring o, causing the head to press the
bar B downwards, and carry the latter with it until contact is established. The
lever R, carrying the roller E falls by gravity until it is stopped by the forked
end of V, presuming it to have been in the position of the dotted outline. When
so stopped, it effectually retains the bar B in contact position as shown. Mean-
while, the release of the cord C enables the plunger P to return by the pressure
of the spring o so that the head r again rests against the guard plate c. A slight
angular movement of the cord C causes it to engage with the projection F, and
depressing it upon the pivot fraises the bar H, and the forked rod V and lever R.
carrying the roller E until the latter is past the centre, when the tension of the
springs S S¹ causes the bar B with the contacts hh' to return, pushing the lever R
and roller E in a free position to again descend by gravity to the locking position.
I may adopt a spring buffer w, Figure 9, which is enclosed by a cap y to facilitate
the quick break when the pawl E is released by the back movement of the cord C
pressing against the extension F as hereinbefore described. As this arrangement
is applicable to each or any of the modifications according to my invention, I have
merely shown it diagrammatically.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is;
First. In electrical switches, the combination of a switch lever B pivotted at
one end a and depressed against a spring S by the action of a cord C so as to
establish contact and be so held by a pawl E until released by the engagement of
the cord C against an extension of said pawl E substantially as herein described
with reference to the drawings hereto appended.
Second. In electrical switches, the combination of a switch lever B pivotted at
one end a and arranged as referred to in the preceding claim, with a spring S,
suspended draw bar m and push piu n, to disengage said switch bar when the
cord C is moved angularly, against the extension of the pivotted pawl E
substantially as herein described and shown by the appended drawings.
Third. Iu electrical switches, the combination of a head B with two or more
contact plates working upon guide bolts a a¹ and depressed against a spring or
springs by the action of a cord C so as to establish, single or multipolar contact,
and be so held by a pawl or pawls until released by the engagement of said cord C
against an extension of said pawls substantially as herein described with reference
to the appended drawings.
Fourth. In electrical switches, the depression of a head by a cord operating an
independent plunger, which returns to its normal position when released, said head
being retained by a gravity device and immediately released by a second movement
of the cord, as herein described and shown by the drawings.

page_text: Fifth. In electrical switches, the method of and means for placing safety fuses
upon the moveable part thereof, substantially as herein described and for the
purposes specified.
Sixth. In electrical switches the construction and use of single pole switches as
shown by Figures 1 and 2, 3 and 4, and of a multipolar switch as Figures 4, 5, and 6,
with fuses d d' Figure 5, and with or without rapid break device as Figure 8, and
substantially as herein described with reference to the aforesaid drawings.
Seventh. In electrical switches the construction and use of a spring buffer w
within a cap y in combination with a switch lever or bar B, and cord C
substantially as and for the purposes as herein described with especial reference to
Figure 9 of the appended drawings.
Dated this 26th dox of February 1897
FREDK. WALKER,
73 St. Stephen's Road, Upton Park, E., Agent for the Applicant.