MENTS IN SAFETY." CUT-OUTS" FOR ELECTRIC LIGHTING & OTHER ELECTRIC CIRCUITS
Year: 1884

page_text: I, ARTHUR WILFRED BREWTNALL, of Thelwall, near Warrington, Lancashire,
Electrical Engineer, do hereby declare the nature of my invention for IMPROVE-
MENTS IN SAFETY." CUT-OUTS" FOR ELECTRIC LIGHTING & OTHER ELECTRIC
CIRCUITS to be as follows:—
The invention consists of an apparatus for automatically cutting out a circuit
in connection with a dynamo or other source of electricity, when from short
circuiting or other cause, the current becomes abnormally great & therefore
dangerous in such circuit. The apparatus to be. of a form which will enable it
to be reset readily by hand or to reset itself automatically, without having to
provide fresh & separate junction pieces after the "cut-out "has been brought
into action.
This object is effected by making a star-shaped wheel or piece of metal or other
substance, either stamped from a sheet to the requisite shape, with any convenient
number of arms, or by using two or more discs or plates of metal or other material.
held together by screws or other suitable means and clamping between their
surfaces any convenient number of any suitable form of fusible connection,
arranged radially. The outer ends of such connections to be bent into a hook, or
to be of such a shape that a lever may engage with them, the lever being either
fixed or actuated by a spring. The said lever may be arranged to give either
a visible or audible signal to show which circuit requires attention, when
necessary.
In the first-mentioned form when it is desired to remake the connection after
the "cut-out" has been brought into action, the star-wheel must be moved round
& the lever lifted or made to engage with the next tooth or spoke.
In a second form this is done automatically. In this form the star-wheel &
lever are mounted on two spindles with toothed wheels on them gearing into each
other & so proportioned that whilst the lever moves round into a position in
which it can engage with a fresh tooth or arm, the star-wheel has moved a fresh
tooth or arm into place. These wheels to be actuated by a coiled spring or other
suitable means, and when desirable, a fly or other governor may be put in train
with the wheels to allow any convenient interval to elapse before a new connection
is made.

page_text: In a third arrangement I use a straight bar or holder in lieu of the star-shaped
wheel, (or it may be curved to any radius), with the fusible connectors fixed to it
or held by it at an angle, the second portion to be employed as above described or
in other suitable manner.
Under certain circumstances where it is advantageous to add some resistance to
a circuit after it has been once cut out, before it is completed again, the arms of
the said star-wheel or straight holder may be connected up by resistances at their
inner ends to their contact surface.
This repeating "cut-out" may, amongst other uses be employed as a safe-guard
for the shunt-coils of arc-lamps & may then be so arranged as to short-circuit the
lamp altogether or cut it out for any fixed time.

page_text: て
"
I, ARTHUR WILFRED BREWTNALL Electrical Engineer, of The Clough, Thelwall,
near Warrington, in the County of Lancashire, do hereby declare the nature of
my invention for " IMPROVEMENTS IN SAFETY " CUT-OUTS FOR ELECTRIC
LIGHTING & OTHER ELEC. CIRCUITS" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to provide an improved means for automatically
cutting out a circuit in connection with a dynamo or other source of electricity,
when, from short-circuiting, or other cause the current becomes abnormally great
& therefore dangerous in such circuit. The apparatus to be of a form, which shall
enable its being re-set readily by hand or to re-set itself automatically, without
having to provide fresh & separate "junction pieces" each time the "cut-out" is
brought into action.
This object is effected by making a star-shaped wheel or piece of metal or other
substance either stamped from a sheet to the requisite shape as shown in Fig. 1, a.,
in the accompanying drawings with any convenient number of arms (the drawing
showing 8) or by using two or more discs or plates of metal or other suitable
material held together by screws or other means, one of which is shown in Fig. 3,
and clamping or holding between their surfaces any convenient number of any
suitable form of fusible connections arranged radially as shown in Figs. 1, 2, & 3.
The outer ends of such connections to be bent into a hook as shown in the accom-
panying drawings or to be of such a shape that a lever or arm, being either fixed,
or pivotted & actuated by a spring, may engage with any one of them. One form
of pivotted arm is shown at b, Fig. 1, pulled by a spring c which tends to move the
end d of the lever outwards away from the star wheel.
The disc or star-wheel in the one form above described & shown in Fig. 1, is
fitted on to a post with a nut to clamp it when put in position for use. The said
post is connected by any suitable means to one end of the circuit wire & the other
end is attached to the lever or arm so that when the lever is made to engage with
one arm of the star-wheel as hereinbefore described the circuit is completed through
the medium of the said fusible portion.
When the "cut-out" has been brought into action & the arm, say No. 1, Fig. 1,
has been fused the lever takes up the position shown in dotted lines & may readily
be made to ring a bell to give an audible signal that something is wrong at the
same time uncovering a red disc signal R or by other means, giving a visible signal
to show which circuit requires attention. To re-make the connection the nut
clamping the star-wheel is loosened, the wheel moved round so that the arm 2, can
be made to engage with the lever & then the nut is tightened & the circuit again
ready for use.
Fig. 1 shows one of the simplest arrangements but is obviously only one of
a number of ways of disposing the parts.
In the automatic "repeater" form which is shown in Fig. 2, I make use of a
similar disc & arm as hereinbefore described & shown in Fig. 1 but in this case
the lever is mounted on a shaft which can revolve, having a pinion on it gearing
into a toothed wheel on a second shaft on which the disc or star-wheel is mounted,
as indicated, & the two toothed wheels are so proportioned that one revolution of
the lever shaft, if fitted with one arm, & half a revolution, if fitted with two arms
(which latter form is shown in Fig. 2) brings the end of the lever into such a
position that it engages with the next hook or other part of the star-wheel formed
for its reception. One or other of the shafts is to be fitted with a spring, weight,

page_text: or other actuating power, & controlled by a fly, or other governing device, so that
when brought into use & having one arm fused the parts move as above described
& re-make the circuit. The amount of time which is allowed to elapse between
the breaking & re-making of the circuit is dependent on the governing device
which can be made to suit any requirements. This form of "repeating cut-out "
will be useful when the cause of the increase of current is only momentary,
breaking the circuit for a sufficient time for the current to settle down to its
normal amount. This automatic form may be arranged so that the circuit when
broken will be re-made, say two or three times, & if the cause of the extra
& dangerous current is still taking effect that it will permanently break the circuit
& give a signal either audible or.visible or both to the attendant.
In another form I use a straight holder as depicted in Fig. 4, with the fusible
connections clamped in it in any suitable way and with any convenient number,
& protruding at an angle from the said holder, which is made to slide up & down
on a rod or other guide. The arms may be stamped out of a sheet of suitable
material in sets of, say 8, or may be made separately & clamped simultaneously in
the holder as shown in Fig. 4. In this form the lever may be either fixed or
pivotted as described for the first mentioned pattern, & the holder may be made
heavy & used to actuate a wheel gearing with a second wheel fixed on a shaft on
which the lever is mounted when it is desired to make its action automatic. The
action of the "cut-out to be controlled by a governing device, substantially as
above described for the second form.
I further propose using holders or plates of any form either curved or straight in
which are held, clamped, or cut any number of arms of any suitable material
substantially as herein before described & for the purposes set forth.
°
Under certain circumstances where it is or would be advantageous to add some
resistance to a circuit after it has been once cut out & before it is re-made
I connect up the arms of the said star-wheel or straight or other holder at their
inner ends by means of resistances to their contact surfaces, such resistances being
made of any desired amount.
Having now particularly described & ascertained the nature of my said
Invention, & in what manner the same is to be performed, I declare that what
I claim is
I. The use of a star-wheel with the arms forming safety fusible connections for
electric circuits, such star-wheel to be either stamped from a sheet or plate
of suitable material, or built up of parts, substantially as herein described
and set forth.
II. The use of a straight holder or plate sliding or otherwise, to which are
attached or in which are clamped or cut any number of arms forming
fusible connections for electric circuits as herein described & for the
purposes set forth.
III. The use of a holder or plate either curved or straight in which are held,
clamped, or cut any number of arms of any suitable material, substantially
as described.
Dated this twenty-second day of December,.eighteen hundred and eighty-four.