AN IMPROVED AUTOMATIC ELECTRICAL CURRENT REGULATOR to be as follows
Year: 1884

page_text: We, JOHN GILMORE, of the Vicarage, Lower Norwood, in the County of Surrey,
Clerk in Holy orders, and WILLIAM RICHARD CLARK, of 3 Danby Road, Peckham,
in the County of Surrey, Mechanician, do hereby declare the nature of the said
invention for "AN IMPROVED AUTOMATIC ELECTRICAL CURRENT REGULATOR to
be as follows:-
"
Our invention relates to the regulation of electrical currents, and consists of an
appliance operated automatically by the variations in the force of the current,
so as to cause a diversion of part of the current into a shunt circuit when the
current is in excess of a fixed maximum.
Our device consists of a bar composed of two diverse metals, having different
degrees of expansion by heat, the bar being preferably of the constituents, nature,
and form, or modifications of form, as patented to us jointly under number 563 and
bearing date the twelfth day of February 1879.
The main electrical circuit is carried round and round the said bar of diverse
metals through a wire,.of such a diminished section or of such materials, resisting
electrical conduction to a greater extent than the rest of the main circuit, as to
develope heat in consequence of such resistance, more readily at such part of the
circuit surrounding the bar than elsewhere; and we may coat the said wire by a
suitable envelope non-conducting to heat, so as to prevent its radiation and loss.
The said regulating bar is mounted with one extremity a fixture upon a suitable
stand, and with the other extremity free to move.
Insulated upon the other moving extremity of the bar is fixed a double pronged
metal foot, and the end of the main circuit wire wound round the regulator bar is
attached thereto.
The said foot rests with each prong upon an insulated contact piece of variable
resistance; as for instance composed of strips of vulcanite, platinum, German silver,
copper, etc., in order of their electrical conductive powers; the two contact pieces
being arranged in inverse order, that is, both best, or both worst conductors are to
the inside.
The operation of our device is as follows:-
When in its normal position with normal current flowing, the current passing
through the wire coiled round the regulating har does not heat the same appreciably.

page_text: and the bar remains at rest with one prong completing the main circuit through
the best conducting strip of metal of one contact piece, the other prong resting on
the non-conducting strip of the shunt contact piece. When the current exceeds its
normal force, heat is developed in the wire embracing the regulating bar, and is
communicated thereto, causing a deflection of the bar by unequal expansion. The
main circuit prong is thus moved from the best conducting strip of the one contact
piece to a strip conducting in a less degree, and the other prong is moved from its
non-conducting strip on the shunt contact piece to a strip conducting to some extent,
and thus a certain proportion of the main circuit is diverted into an alternative
shunt circuit, which may be utilized to ring an alarm bell, to regulate the speed of
the driving engine if a dynamo is used, to pass into an accumulating battery, or to
effect any other useful purpose.
It is evident that many alternative compositions of diversely expanding metals
may be used for our regulating bar, and that various forms of variably resisting
circuit contacts may be employed. As for instance a roller or a slide may be
attached to the end of the regulating bar, passing over two wedge shaped main
and shunt circuit contact pieces, so placed diagonally to one another that the roller
or slide passes from the apex of one to the base of the other, making a relatively
increasing and decreasing area of contact by its movement. As also modifications
in the form, length, or combinations of bars; as more fully described in our said
letters patent Number 5631870, may be employed by us in the perfecting of our
device, and to be hereafter more fully detailed without departing from the principle
of our invention herein before described.
FELL & WILDING,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
We, JOHN GILMORE, of the Vicarage, Lower Norwood, in the County of Surrey,
Clerk in Holy Orders, and WILLIAM RICHARD CLARK, of 3 Danby Road, Peckham,
in the County of Surrey Mechanician, do bereby declare the nature of our
invention for "AN IMPROVED AUTOMATIC ELECTRICAL CURRENT REGULATOR " 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 the regulation of electrical currents, and consists of an
appliance operated automatically by the variations in the force of the current, so as
to cause a diversion of part of the current into a shunt circuit, when the current
is in excess of a fixed maximum.
In order that our invention may be the better understood, we now proceed
to describe the same with reference to the drawings hereto annexed, and to the
letters and figures marked thereon. Like letters refer to similar parts in the
different figures.
Figures 1 and 2 are a side elevation and plan respectively of one form of our
regulating device.
Figure 3 is an end view of the same, showing arrangement of the electrical
contacts.
Figures 4 and 5 are an elevation and plan respectively of our device with
alternative form of regulating contact.
Figure 6 is an end view of the same.
Our device consists of a bar A, composed of two diverse metals, having different
degrees of expansion by heat, the bar being preferably of the constituents, nature,
and form, or modifications of form, as patented to us jointly under number 563 and
dated the 12th day of February 1879. The main electrical circuit B is carried
round and round the said bar A of diverse metals through a wire b, of such
a diminished section or of such materials resisting electrical conduction to a greater
extent than the rest of the main circuit as to develope heat in consequence of such
resistance more readily at such part of the circuit surrounding the bar than
elsewhere.
To prevent the radiation of the heat so generated, and to ensure its maximum
effect upon the bar, we may envelope the said wire by a suitable material non,
conducting to heat, such as asbestos.
The wire b, is insulated from metallic contact with the bar A either by the usual
insulating covering with which the whole of the wire is coated, or by two or more
packing pieces C C figure 1, of nonconducting and refractory material, round which
the naked wire may be wound, and is thus held off the said bar A, and prevented
from being in metallic contact with the same. Care must be taken, where the.
naked wire is used, that it shall be so wound that the different laps of the wire
cannot touch each other.
'
The regulating bar A is mounted with one extremity a fixture upon a suitable
stand D, and with the other extremity E free to move. Upon this moving
extremity E of the bar A is fixed a metal foot or projection F, and the end of the
main circuit wire B, which passes round the regulator bar A, is attached thereto.

page_text: In our first alternative form, figures 12 and 3, the said foot F is forked and rests
with each of its prongs upon the contact piece G G of variable resistance, as for
instance, the said contact pieces may be composed of strips of vulcanite gg, strips
of platinum g¹ g³, or German silver and strips of copper g¹, or metals in the order
of their electrical conductive powers. The two contact pieces are arranged in
inverse order, so that both the best or both the worst conductors are to the inside.
Alternatively in figures 3, 4 and 5 the foot F is a slide, making electrical contact
with the two insulated strips of conducting metal G G, the said strips being
separated by a diagonal slot Ĥ.
The operation of our device is as follows:-
When in its normal position, with a normal current flowing, the current passing
through the wire b, coiled round the regulating bar A, does not heat the same
appreciably, and the bar remains at rest-In this position, as shown, one prong Fl
of the fork, with which in our first alternative device the movable extremity of
the bar is fitted, rests upon the best conducting strip of metal g¹¹, of the one of the
contact pieces, the other prong F resting on the nonconducting strip g of the shunt
contact piece. The current thus passes entirely through the conducting contact
pieces g¹¹ to the main circuit wire B¹. When the current exceeds its normal force,
heat is developed in the wire embracing the regulating bar A, and is communicated
thereto, causing a deflection of the bar, by the unequal expansion of its component
parts. The main circuit prong F' is thus moved from the best conducting strip of
one contact piece to a strip g¹, conducting in a less degree, and the other prong F is
moved from its nonconducting strip g to a strip gl, conducting to some extent, and
thus a certain proportion of the main circuit is diverted into an alternative shunt
circuit K, which may be utilised to ring an alarm bell, to regulate the speed of the
driving engine if a dynamo be used, to pass into an accumulating battery, to
control ventilating appliances, to regulate lighting apparatus, or to effect any other
useful purpose.
Similarly in our alternative device, figures 4, 5 and 6, when the regulating strip
is in its normal insulated condition, the contact slide F rests entirely upon the
contact piece G, thus causing the current to pass entirely through the main
circuit B. When however the regulating bar begins to move by reason of its
unequal expansion developed by the heating of the enveloping wire b as before
described, the contact slide F, passes over the slot H dividing the two contact
pieces G G¹, thus causing a partial diversion of the main current through the
alternative circuit K. As the bar A continues its travel by continued excess of
heat, the proportion of current diverted from the main to the shunt circuit increases
in proportion to the relative contact area of the slide F on either side of the slot H.
It is thus evident that the amount of force of the current passing through b, and
transmitted to the main working circuit B¹ will be regulated, and maintained
constant, by the action of this device.
Many alternative compositions of diversely expanding metals may be used for
our regulating bar and various forms of variable resisting circuit contacts, as also
modifications in the form, length, or combinations of bars, as more fully described in
our said letters patent numbered 563,1879 without departing from the principle of
our invention hereinbefore described.
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
1st The combination of a regulating bar of materials diversely expanding under
heat, and wire conducting a current of electricity enveloping the same, to effect the
control and regulation of the force of a current (transmitted through the device to
a working circuit) by the movement of the said regulating bar, under the influence
of the heat generated by excess current in the enveloping wire, substantially as
described:
2nd The combination with such a regulating bar and enveloping conducting wire
of a contact piece or pièces and a pronged fork attached to the moving end of the

page_text: bar, the contact pieces being composed of a series of strips of various conducting
power, and the pronged fork sliding thereon, to effect the diversion into a shunt
circuit of any excess of current above the desired normal, substantially as described.
3rd The combination with such a regulating bar and enveloping conducting wire,
of an alternative contact piece or pieces and a slide or roller tongue at the moving
end of the bar, the contact pieces being divided by a diagonal slot, and the said
slide or roller moving in contact therewith over the said alot, to effect the diversion
into a shunt circuit of any excess of current above the desired normal, substantially
as described.

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FIG.I.
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