Year: 1897

page_text: Date of Application, 20th May, 1897
Complete Specification Left, 17th Mar., 1898-Accepted, 23rd Apr., 1898
I, GERALD WILLIAM PARTRIDGE, of 25A, Cockspur Street, Charing Cross, in the
City of Westminster, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to a construction of electric switch in which inter
alia the spring used for effecting a quick break between the fixed and movable
contacts is put under full stress only when the switch is being opened so that
there is little or no liability of the spring taking a permanent set and failing to
effect a quick break on opening, as sometimes happens when the spring is put
under stress when closing the switch and the switch is allowed to remain closed
for a long period. In one construction of switch according to this invention the
rotary switch arm or contact is pivotted centrally and arranged to be moved into
and out of contact with fixed spring contacts by two pins or projections that are
carried by an insulated operating handle and loosely embrace the rotary contact
between them. This rotary contact is provided at its centre with an extension
that is larger in one direction than the other, for example of approximately
elliptical shape in plan, and which fits between spring blades that are connected
together at their ends and serve as the spring device for effecting a quick break
between the contacts. This spring device is loosely connected to the operating
handle, as for example by a pin and slot connection, so that the handle can move
for a certain distance before it operates the spring device which is capable of partial
rotation between stops. The arrangement is such that on moving the operating
handle to close the switch, one of the pins or projections carried thereby forces
the rotary contact into connection with the fixed spring contacts but has no direct
action upon the connected spring blades which however are or may be slightly
pressed apart by the projection on the rotary contact. By this means it is
impossible to have the rotary contact not making good contact with the fixed
spring contact. On moving the handle to open the switch, it first moves idly,
then turns the connected springs about the projection on the rotary contact so that
they are forced apart by such projection and energy stored in them after which
the second pin or projection on the handle engages the rotary contact and dis-
engages it from the fixed contact whereupon it is quickly moved into its inoperative
position by the reaction of the spring blades. The rotary fixed contacts are or
may be enclosed in a cylindrical box of insulating material for example porcelain,
that is provided with raised parts upon which the fixed contacts are mounted and
between which the spring device is arranged to move.
The box may advantageously be mounted concentrically within a cylindrical
iron case between which and the box an annular space is left so that water enter-
ing this space can readily flow away without entering the box. The operating handle
extends through corresponding slots in the peripheries of the box and case. The
case or the box may be provided with a wire or other spring to hold the handle

page_text: in its inoperative position, but so nevertheless as to permit of its being intentionally
moved to close the switch. The case is provided with a removable cover and with
holes fitted with insulating bushes for the electric leads.
When using the switch with high tension currents, for which it is specially
suitable, the iron case is earthed, and arranged to make contact by means of a
brush with the operating handle, which may be of ebonite. In this way all liability
of the switch operator receiving a shock is obviated.
Improvements in Electric Switches.
I, GERALD WILLIAM PARTRIDGE, of 25A, Cockspur, Street, Charing Cross, in the
City of Westminster, Civil 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:-
―
This invention has reference to an improved construction of electric switch in which
inter alia the spring used for effecting a quick break between the fixed and movable
contacts is put under full stress only when the switch is being opened so that
there is little or no liability of the spring taking a permanent set and failing to
effect a quick break on opening, as sometimes happens when the spring is put
under stress when closing the switch and the switch is allowed to remain closed
for a long period.
:
Figs. 1 and 2 of the accompanying illustrative drawings show in plan and with
the cover removed, one construction of switch according to this invention, Fig. 1
showing the switch fully open and Fig. 2 showing the parts in the act of effecting
a break between the fixed and movable contacts. Fig. 3 is a part vertical section
on the line A B of Fig. 1. Fig. 4 shows, in underside view, a portion of the
apparatus. ig. 5 is a detail view more particularly showing one of the fixed
spring contacts.
The rotary switch arm or contact 1 is pivoted centrally and arranged to be moved
into and out of contact with fixed spring contacts 2, 2, by two pins or projec-
tions, 3, 3, that are carried by an insulated operating handle 4 and loosely embrace
the rotary contact 1 between them. This rotary contact is provided at its centre
with an extension or projection 5 that is larger in one direction than the other,
for example of approximately elliptical shape in plan, (Fig. 4) and which fits be-
tween spring blades 6 that are connected together at their ends and serve as the
spring device for effecting a quick break between the contacts. This spring device
is loosely connected to the operating handle 4, as for example by a pin and slot
connection comprising a pin 7 on the spring device and a slot 8 in a plate 8° fixed
to the handle, so that the handle can move for a certain distance before it will
operate the spring device 6 which is capable of partial rotation between stops 9°.
As will be seen, the arrangement is such that on moving the operating handle 4
in the direction of the arrow a (Fig. 1) to close the switch, one at least of the pins
or projections carried thereby, riz. 3. or it may be both pins or projections 3, 30,
as in the arrangement shown, will directly force the rotary contact I into connec-
tion with the fixed spring contacts 2 but has no direct action upon the connected
spring blades 6. The spring blades however may be, and in the example shown
are, slightly pressed apart by the cam-like projection 5 on the rotary contact

page_text: when moving the latter in a direction to close the switch. By this means it is
impossible to leave the rotary contact not making good contact with the fixed
spring contact, because the spring device would then at once act to move the mov-
able contact away from the fixed contacts. On moving the handle in the opposite
direction to open the switch, it first moves idly to an extent dependent upon the
length of the slot 8, then it turns the connected springs 6 about the (for the time
being fixed projection 5 on the rotary contact so that they are forced apart by
such projection (see Fig. 2) and energy stored in them, after which the second pin
of projection 3, or both pins or projections, on the handle engages, or engage,
the rotary contact and disengages or disengage it from the fixed contact whereupon
it is quickly moved into its inoperative position by the reaction of the spring
blades on the projection 3. The rotary and fixed contacts are or may be enclosed
in a cylindrical box 10 of insulating material, for example porcelain, that is
provided with raised parts 9 upon which the fixed contacts 2 are mounted and
between which the spring device is arranged to move, the ends 9* of such parts
serving as stops for the spring device 6. The raised parts 9 also tend to reduce
surface leakage from the fixed contacts when the switch is "off." 11 are terminals
in connection with the respective fixed contacts 2.
The box 10 may advantageously be mounted concentrically within a cylindrical
iron case 12 between which and the box an annular space 13 is left so that water
entering this space can readily flow away without entering the box, The operating
handle 4 extends through a corresponding recess 14 and slot 15 in the peripheries
of the box and case respectively. The case, or the box, may be provided with a
wire or other spring 4 to hold the handle in its inoperative position, but so
nevertheless as to permit of its being intentionally moved to close the switch.
The case is provided with a removable cover 16 and with holes fitted with insulating
bushes 17 for the electric leads.
When using the switch with high tension currents, for which it is specially
suitable, the iron case is earthed, and arranged to make contact by means of a
brush or spring with the operating handle, which may be of ebonite. The spring 4*
will serve for this. In this way all liability of the switch operator receiving a
shock is obviated.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is:-
1. An electric switch in which the spring device for effecting a quick break
between the fixed and movable contacts is so arranged in relation to the operating
handle and movable contact that it will be put under full stress only when the
switch is being opened but will be put under sufficient stress when closing
the switch to prevent the movable contact being left in a position to make a bad
connection with the fixed contacts, substantially as herein described for the pur-
pose specified.
2. An electric switch comprising fixed spring contacts, a rotary contact provided
with a cam-like projection, an operating handle provided with pins or projections
embracing the rotary contact, and a spring device that is connected to the operating
handle by a pin and slot connection, is capable of turning between stops, and in
which energy can be stored by the action of the said cam-like projection, the
arrangement being such that on moving the handle to close the switch, the rotary
contact will be forced into good electrical connection with the fixed contacts
without acting, or only slightly acting upon the spring device, and on moving the
handle in the reverse direction to open the switch, it will first move idly, then
turn the spring device about the cam-like projection so that energy will be thereby
stored in it, after which the handle will disengage the movable contact from the
fixed contacts whereupon the movable contact will be quickly moved into its
inoperative position by the reaction of the spring device, substantially as described.

page_text: 3. The improved electric switch constructed arranged and operating substantially
as hereinbefore described with reference to and shown in the drawings annexed.
Dated this 17th day of March 1898.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.