Improvements in Switches for Making and Breaking Electric Currents.
Year: 1889

page_text: Date of Application, 8th Nov., 1889
Complete Specification Left, 8th Aug., 1890-Accepted, 11th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Switches for Making and Breaking Electric
Currents.
ALFRED SLATTER 140 Salisbury Court Fleet Street E.C. Electrical Engineer &
WILLIAM RIXOM Merthyr Terrace Barnes Coachmaker do hereby declare the nature
of this invention to be as follows:-
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The object of this invention is the production of a switch for making and
breaking the circuit of electric currents when used for lighting and other purposes.
The said "switch" being so constructed that there can be no partial contact the
circuit being either completely made or completely broken."
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The first purt of our invention consists of the construction and arrangement of a
"switch
which may be suitably enclosed within a casing of wood porcelain, or other
suitable material and worked by a suitable key which may be separate from the
switch and inserted therein when required through a suitable keyhole or opening.
The said key engages with a link one end of which is pivoted on a fixed centre tho
other end of the said link is jointed or hinged to the end of a second link. This
second link has a suitable "slot" formed lengthwise in it. Inserted in the said "slot
is a fixed pin upon which the second link is free to slide. To the end of the said
second link (farthest from the first link) is attached to or in contact with a suitable
spring or springs so arranged as to pull (or push) the second link towards the pivot.
of the first link. Thus when the first link is turned upon its centre by the herein-
before mentioned key (which is arranged and shaped so as to suitably engage with tho
first link) the second link is caused to slide upon the said fixed pin and the said
spring acts in opposition to this movement until the dead centre is passed, when
the said spring accelerates the motion imparted by the said key and the links move
forward with a sudden quick movement independent of the key, the amount of such
movement being limited by the length of the "slot" in the second link or by.
suitable stops suitably arranged.
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To a point at or near the junction of the two said links is formed or attached
a suitable pin or projection, near to this pin or projection is pivotted a suitablo
contact maker and breaker" or movable contact so arranged that when it is
turned upon its pivot in one direction to a certain position the contact is
and when it is turned to a certain other position the contact is broken.
*
made"
The said
contact maker and breaker" is so shaped and arranged that the said pin or projec-
tion upon the said links engages with it in such a mauner that a sudden and definito
angular movement is imparted to it by the action of the said spring or springs sucli
movement making or breaking "the contact or' circuit and being governed by
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"
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the direction in which the said key is turned. The said contact maker or breaker
moveable contact and the fixed contact piece" may be connected to the wires
of the circuit by screws or other suitable well known means.
or
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AD
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The second part of our invention consists of the construction and arrangement of a
switch as in the first part of this invention but having a handle (instead of a
separate key) fixed to the first named link. In this case the first link is provided with
suitable stops and a suitable tangential or circular slot in which a suitable pin
(attached to or upon the end of the second link) is free to slide and so constructed and
arranged that the said pin will be at one or other end of the said "slot" depending
upon which way the said handle is turned, the whole being so adjusted that when
the said handle is turned through a certain definite angle the second link is impelled
by the said spring and engages with the said contact maker or breaker and the
contact is made or "broken."
The third part of our invention consists of the construction and arrangement of a

page_text: "
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switch as in the first and second part of this invention in continuation with a
fixed contact piece so constructed and arranged that the said fixed contact piece'
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or springs suitably shaped and arranged so that when the contact maker or breaker "
or' movable contart is impelled by means of the herein before described links and
fixed contact
spring it is caught in and held by the said fork shaped end of the
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plece
and an absolute contact is insured. In like manner and in some cases a
similar arrangement of fork shaped catch may be provided to catch and hold the
contact maker or breaker out of contact.
6.
Dated this Eighth day of November Eighteen hundred and eighty-nine.
COMPLETE SPECIFICATION.
Improvements in Switches for Making and Breaking Electric
Currents.
We, ALFRED SLATTER, 110 Salisbury Court Fleet Street, E.C. Electrical Engineer
and WILLIAM RIXOм Merthyr Terrace, Barnes, Coachmaker, 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;—
Our invention relates to an improved construction of switch for making and
breaking electric circuits for lighting and other purposes, wherein by a spring action
the switch is made to assume either one of two opposite positions so that there
can be no partial contact, the curreut being either completely made or completely
broken.
The essential feature of the invention consists in the employment of two pivotted
arms or links connected together somewhat like the two links of a toggle but with a
slotted connection, the one link turning on a fixed centre and having a transversely
slotted end into which takes a pin on the end of the second link, this being so
constructed as to have longitudinal spring action. On turning the first link on its
pivot, it carries the other link with it, at the same time forcing it backward, the
connecting piu being situated at one end of the slot, until such piu arrives at the
dead centre or point where it is in line with the pivots of the two links, whereupon a
slight further movement of the slotted link, will cause the spring link to shoot
forward and in coming in contact with a double ended pivotted contact piece, to
throw this over sharply into the opposite position to that which it previously occupied,
thereby causing it either to make or break contact with the leads of the circuit.
In order that our said invention may be readily understood we will describe the
same with reference to the accompanying drawings, which shew the two constructions
of the apparatus which we prefer to employ.
Fig. 1 shews a construction more particularly suited for switches of large size.
Fig. 2 shows a front elevation.
A base A of insulating material carries two contact pieces BB3' to which the circuit
leads are connected, and between these is a plate C on which is pivotted firstly a bridge
shaped contact switch D which can assume either the position shewn in dotted lines at
Fig. 1 in which it makes contact with B 13 and closes the circuit, or the position
shewn in full lines in which it breaks the circuit, the motion in either direction being
limited by stops E E¹.
The switch D turns loose on the pin D' and is pressed down so as to effect good
gontact by a spring D.
Secondly the plate C has pivotied to it at F the link F which may either have a
handle attached to its oufer end as shewn, or it may have a socket into which a
handle is inserted when it is desired to shift the switch. The link has an are shaped
slot through which passes the pivot D' of the switch, and on its inner end is formed a

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second arc shaped slot F into which takes the pin G on the end of the second
link G G¹, also pivotted to the plate C at H. This link consists of a tubular part G
containing a strong helical spring G³ against which bears the inner end of the sliding
part G. The spring is so arranged as to have already some compression put upon
it when in the positions shewn in full and dotted lines. When in the position
shewn in full lines, the pin G, which projects both above and below the end of G,
consequently bears against the right hand side of the switch D and holds this in the
When
position indicated, in which it is out of contact with the contact pieces B B².
it is desired to close the circuit, the link F is turned on its pivot by means of the
handle towards the dotted position. During the first part of this motion, the right
hand end of its slot 1 in pressing against the pin Gwill both turn the link G G¹
on its pivot and force the part G₁ of the second link inwards, thereby putting further
compression upon the spring, until the pin G has just passed the dead centre or
position in which it is in line with the pivots and H, whereupon, as the slot F is in
such a position as to allow the link F to yield to the pressure of the spring, this
will throw rapidly forward the part G, causing the pin G, in striking against the
left hand side of the switch D, to throw this rapidly over from the position shewn in
full lines into the dotted position in which it makes contact with B B', at the same
time, the pin G2 passes to the other end of slot F3 and brings the link F also into the
extreme opposite position. II are blocks of insulating material on which the ends of
the switch bear when breaking contact.
The apparatus may be enclosed in a casing having a slot for the passage of the
haudle For of the socket for the reception of the handle.
The modified construction shewn in plan at Fig. 3 and sectional elevation at Fig. 4
is more particularly adapted for small switches. In this arrangement the pin 11
forming the pivot of the link at the same time forms the pivot for the switch D.
The pin F is fixed to the link F and turns with its lower end in a socket on the
plate C while its upper end carries a button F by means of which the link is turned
as before described. The link G instead of being made telescopic as before, is made
of a single piece. slotted to work backwards and forwards and at the same time turn,
upon the pivot screw E. The outer end of the link has a tail G¹ to which is attached
ouc end of the helical spring G³ the other end of which is attached to a loose collar J
on the pin F. The inner end of the link G carries the pin G passing through the
slot of and bearing against the switch D. The action of the instrument is precisely
the same as before: on turning the link F by the button F, the link G is forced
backwards on its pivot, thereby putting additional tension on the spring, until the
pin G passes the dead centre, when the spring G³ will throw G forward, causing its
pin to strike against the switch D and throw it over to the opposite position. It
will be seen from the above described arrangements that the switch D cannot assume
any other than the two extreme positions.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed we declare that what we
claim is:
1. Apparatus or switches for making and breaking electrical contacts, wherein two
pivotted links one of which has a sliding spring action are connected together by a
slotted connection and are so arranged in combination with a pivotted double ended
contact piece, that on turning the one link on its pivot, it first forces backward the
second link against the action of its spring and then after passing the dead centre,
allows the spring to throw the second link forward so as in striking against the
pivotted switch, to reverse its position, substantially as described.
2. In switch apparatus, the combination with the pivotted contact switch D of
the pivotted link F having slotted connections with the pivotted link GG¹ with
spring action, so that when the link is turned on its pivot it first forces back the
part G against the action of a spring and then, after passing the dead centre allows
the spring to throw the part G forward, so as to cause the switch to be thrown

page_text: thereby into the opposite position, substantially as described with reference tō
Figs. 1 and 2 of the drawings.
. In switch apparatus, the combination with the pivotted contact switch D of
the pivotted link having slotted connections with the pivotted link G capable of
sliding backwards and forwards on it: vot F and acted upon by spring G³ so as to
effect the reversal of the position of itch D when turned by means of the link F
substantially as described with reference to Figs. 3 and 4 of the drawings.
"
Dated this 7th day of August 1890.
ABEL & IMRAY,
Agents for the Applicants.