Improved Method for the Regulation of the Carbons in Electric Arc Lamps by the Expansion and Contraction of Metallic Wires.
Year: 1890

page_text: Date of Application, 17th Feb., 1890
Complete Specification Left, 17th Nov., 1890-Accepted, 20th Dec., 1890
PROVISIONAL SPECIFICATION.
Improved Method for the Regulation of the Carbons in Electric Arc
Lamps by the Expansion and Contraction of Metallic Wires.
OLIVER CORNWELL 117 Ditchling Rise London Road Brighton Sussex
Electrical Instrument Maker, do hereby declare the nature of this invention to
be as follows:-
An improvement in the feed and regulation of the carbons in electric arc lamps
by the expansion and contraction of metallic wires either in series or in shunt with
the electric arc such expansion and contraction being caused by the greater or lesser
flow of the electric current which acting upon the wires regulates the consumption
of the carbons. When the current passes through the wire or wires the wires become
heated & by expansion become longer, when the current becomes less the wires
become cooler & contracts & it is by this expansion & contraction that the electric
arc is controlled.
The action of the lamp is as follows, attatched to the wire or wires is a lever and
weight in connection with a cord passing over a pulley when the wire expands the
lever is lowered and by means of a weight suspended on the same cord on the opposite
side of the pulley the cord becomes taught thus causing friction on the pulley turns
it slightly in one direction.
The carbon rod being suspended on a cord and made fast on to the rim of a second
pulley on the same spindle but tending by gravitation to fall in a opposite direction
to the movement transmitted to the first pulley by means of the lever and weight,
on to a third pulley on the same spindle is connected by means of a cord a dash pot
containing glycerine or oil to prevent the carbon from decending to quickly and
thus short circuiting the are, when the current enters the lamp the wire or wires
become hot and expand thus lowering the lever and tightening the cord over the
pulley turning it in one direction and thereby seperating the carbons and establishing
the electric arc, when the arc becomes to wide by the consumption of carbon the
current becomes less the wire becomes cooler and by contraction draws up the lever
untill the friction becomes so small as to allow the carbon rod to decend by its own
weight in a opposite direction and thus automatically regulate the electric arc.
March 7th 1890.
OLIVER CORNWELL.
COMPLETE SPECIFICATION.
Improved Method for the Regulation of the Carbons in Electric Arc
Lamps by the Expansion and Contraction of Metallic Wires.
I, OLIVER CORNWELL, of 117, Ditchling Risc, Brighton, in the County of Sussex,
Electrical Instrument Maker, 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 for its object the controlling or regulating of the feeding
mechanism of arc lamps, and consists in the employment for that purpose of suitable
metallic wires or strips or other conductors, which are heated by the passage of the
current & which by their consequent movements of expansion & contraction are made
to control the said feeding mechanism & maintain a constant and steady light.
This invention may be applied to arc lamp mechanisms in various ways.
Fig. 1 of the accompanying drawings illustrates the principle of an arc lamp in
which my invention is applied. The current enters at the terminal T and passes
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through the wire or wires or other suitable conductors X to the upper carbon C by
way of the lever L and a flexible conductor or it may be a rubbing contact.
conductor X is kept taut by a weight or spring P. The expansion of X caused
by the heating effect of the current produces a movement of the lever "L," which is
pivotted at F, and from the free end "" of which a cord, wire or chain passes over
the pulley A to the other end of the cord carrying a weight P. On the same
spindle as A is another pulley A' from which depends the upper carbon C which
rests on the lower carbon C when no current or only a very small current is
passing.
The action is as follows:-The current traversing the conductor X causes an
expansion of the same and a lowering of the end 7 of the lever L. The cord or chain
from the point grips the pulley A frictionally and rotates it, the weight P being
raised. The carbon C is at the same time raised and an arc formed between the
two carbons C and C. As the carbons consume the current is weakened somewhat,.
the conductor X being therefore less heated, contracts, an upward movement of "1"
takes place & the carbon C is lowered. This action is continued until the arc
is again of the right length. In the event of an interruption of the current or a
considerable reduction in its amount, the weight PI descends until it rests on the
stop D, when the cord attached to it (and passing over the pulley to the lever L)
becomes slack, the frictional grip on A being lessened allowing the carbon C to
descend rapidly. T¹ is the negative terminal.
Fig. 2 illustrates diagrammatically the application of the principle of my invention
to the washer or ring clutch mechanism of the Brush arc lamp.
The lamp rod R carrying the upper carbon C contains glycerine or other suitable
liquid. When not controlled by the washer W the rod R falls slowly until the
upper carbon C rests upon the lower carbon C¹. The current enters the lamp at T
passes down the wires or strips X, which are thereby heated, then to the rod R and
by way of the carbons C and C to the terminal T.
When no current or only a small current passes the conductor X, which is then
cold and in a contracted condition raises one end and lowers the other end of the
lever L, which is pivotted at p, allowing the washer W to rest in a horizontal
position and leaving the rod R free to fall till the carbons C and C' are in contact.
On the passage of a suitable current the conductor X expands, the end of the
lever L is raised and the washer W being lifted at one side or canted, raises
the rod R and an arc is formed between the carbons C & C As the carbons
are slowly consumed the distance between their ends increases and the current is
in consequence somewhat reduced, thus lessening the heating effect and the
expansion of the conductor X, which then contracts and by lowering the end ¹
of the lever L allows the rod R to descend until a suitable length of arc is
attained.
The spring S, but which may be replaced by a weight on the end of the
lever L, is for the purpose of adjustment and to ensure that the motion of the
lever L always follows that of the conductor X.
The foregoing descriptions illustrate methods by which I may apply my invention,
but I do not limit myself to such methods, as the application may be made in a
large number of ways, without departing from the principle of the invention.
Thus, I may apply it to control the feeding mechanism of the lamps, which are
regulated by a train of clockwork, causing the train to be started or stopped by
the expansion or contraction of a conductor acting as a detent or as a brake
applied to the last wheel of the train. Or I may apply it to act on a pendulum
or other escapement arrangement and I may use it in conjunction with electro
magnetic devices for the purpose described.
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 :-
(i.) In arc lamps, the use of wires, strips or other conductors, heated by the

page_text: current and which by expansion and contraction act on the mechanism for the
purpose of control or regulation.
(ii) The arrangement substantially as described with reference to Fig. 1 of the
drawings.
(iii) The arrangement substantially as described with reference to Fig. 2 of the
drawings.
Dated this 14th day of November 1890.
OLIVER CORNWELL.

page_text: Date of Application, 17th Feb., 1890
Complete "Specification Left, 17th Nov., 1890-Accepted, 20th Dec., 1890
PROVISIONAL SPECIFICATION.
Improved Method for the Regulation of the Carbons in Electric Arc
Lamps by the Expansion and Contraction of Metallic Wires.
OLIVER CORNWELL 117 Ditchling Rise London Road Brighton Sussex
Electrical Instrument Maker, do hereby declare the nature of this invention to
be as follows :-
An improvement in the feed and regulation of the carbons in electric arc lamps
by the expansion and contraction of metallic wires either in series or in shunt with
the electric are such expansion and contraction being caused by the greater or lesser
flow of the electric current which acting upon the wires regulates the consumption
of the carbons. When the current passes through the wire or wires the wires become
heated & by expansion become longer, when the current becomes less the wires
become cooler & contracts & it is by this expansion & contraction that the electric
arc is controlled.
The action of the lamp is as follows, attatched to the wire or wires is a lever and
weight in connection with a cord passing over a pulley when the wire expands the
lever is lowered and by means of a weight suspended on the same cord on the opposite
side of the pulley the cord becomes taught thus causing friction on the pulley turns
it slightly in one direction.
The carbon rod being suspended on a cord and made fast on to the rim of a second
pulley on the same spindle but tending by gravitation to fall in a opposite direction.
to the movement transmitted to the first pulley by means of the lever and weight,
on to a third pulley on the same spindle is connected by means of a cord a dash pot
containing glycerine or oil to prevent the carbon from decending to quickly and
thus short circuiting the arc, when the current enters the lamp the wire or wires
become hot and expand thus lowering the lever and tightening the cord over the
pulley turning it in one direction and thereby seperating the carbons and establishing
the electric arc, when the arc becomes to wide by the consumption of carbon the
current becomes less the wire becomes cooler and by contraction draws up the lever
untill the friction becomes so small as to allow the carbon rod to decend by its own
weight in a opposite direction and thus automatically regulate the electric arc.
March 7th 1890.
OLIVER CORNWELL.
COMPLETE SPECIFICATION.
Improved Method for the Regulation of the Carbons in Electric Arc
Lamps by the Expansion and Contraction of Metallic Wires.
I, OLIVER CORNWELL, of 117, Ditchling Rise, Brighton, in the County of Sussex,
Electrical Instrument Maker, 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 for its object the controlling or regulating of the feeding
mechanism of arc lamps, and consists in the employment for that purpose of suitable
metallic wires or strips or other conductors, which are heated by the passage of the
current & which by their consequent movements of expansion & contraction are made
to control the said feeding mechanism & maintain a constant and steady light.
This invention may be applied to arc lamp mechanisms in various ways.
Fig. 1 of the accompanying drawings illustrates the principle of an arc lamp in
which my invention is applied. The current enters at the terminal T and passes
Prin

page_text: The
through the wire or wires or other suitable conductors X to the upper carbon C by
way of the lever L and a flexible conductor or it may be a rubbing contact.
conductor X is kept tant by a weight or spring P. The expansion of X caused
by the heating effect of the current produces a movement of the lever "L," which is
pivotted at F, and from the free end "" of which a cord, wire or chain passes over
the pulley A to the other end of the cord carrying a weight P¹.
On the same
spindle as A is another pulley A.' from which depends the upper carbon C which
rests on the lower carbon C¹ when no current or only a very small current is
passing.
The action is as follows:-The current traversing the conductor X causes an
expansion of the same and a lowering of the end of the lever L. The cord or chain
from the point grips the pulley A frictionally and rotates it, the weight P¹ being
raised. The carbon C is at the same time raised and an arc formed between the
two carbons C and C. As the carbons consume the current is weakened somewhat,
the conductor X being therefore less heated, contracts, an upward movement of "1"
takes place & the carbon C is lowered. This action is continued until the are
is again of the right length. In the event of an interruption of the current or a
considerable reduction in its amount, the weight P₁ descends until it rests on the
stop D, when the cord attached to it (and passing over the pulley to the lever L)
becomes slack, the frictional grip on A. being lessened allowing the carbon C to
descend rapidly. T¹ is the negative terminal.
Fig. 2 illustrates diagrammatically the application of the principle of my invention
to the washer or ring clutch mechanism of the Brush arc lamp.
The lamp rod R carrying the upper carbon C contains glycerine or other suitable
liquid. When not controlled by the washer W the rod R falls slowly until the
upper carbon C rests upon the lower carbon C¹. The current enters the lamp at T
passes down the wires or strips X, which are thereby heated, then to the rod R and
by way of the carbons C and C' to the terminal T¹.
When no current or only a small current passes the conductor X, which is then
cold and in a contracted condition raises one end and lowers the other end 7 of the
lever L, which is pivotted at P, allowing the washer W to rest in a horizontal
position and leaving the rod R free to fall till the carbons C and C¹ are in contact.
On the passage of a suitable current the conductor X expands, the end of the
lever L is raised and the washer W being lifted at one side or canted, raises
the rod R and an are is formed between the carbons C & C As the carbons
are slowly consumed the distance between their ends increases and the current is
in consequence somewhat reduced, thus lessening the heating effect and the
expansion of the conductor X, which then contracts and by lowering the end
of the lever L allows the rod R to descend until a suitable length of arc is
attained.
The spring S, but which may be replaced by a weight on the end of the
lever L, is for the purpose of adjustment and to ensure that the motion of the
lever L always follows that of the conductor X.
The foregoing descriptions illustrate methods by which I may apply my invention,
but I do not limit myself to such methods, as the application may be made in a
large number of ways, without departing from the principle of the invention.
Thus, I may apply it to control the feeding mechanism of the lamps, which are
regulated by a train of clockwork, causing the train to be started or stopped by
the expansion or contraction of a conductor acting as a detent or as a brake
applied to the last wheel of the train. Or I may apply it to act ou a pendulum
or other escapement arrangement and I may use it in conjunction with electro
magnetic devices for the purpose described.
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
(i.) In arc lamps, the use of wires, strips or other conductors, heated by the

page_text: current and which by expansion and contraction act on the mechanism for the
purpose of control or regulation.
(i.) The arrangement substantially as described with reference to Fig. 1 of the
drawings.
(iii) The arrangement substantially as described with reference to Fig. 2 of the
drawings.
OLIVER CORNWELL.