Improvements in and relating to Electric Arc Lamps or Lighting Apparatus.
Year: 1891

page_text: Date of Application, 6th June, 1891
Complete Specification Left. 7th Mar., 1892-Accepted, 4th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electric Arc Lamps or Lighting
Apparatus.
1, Hugh WatT, of 64 Victoria Street, in the City of Westminster, Member
of Parliament, do hereby declare the nature of this invention to be as follows:-
My invention relates to electric lamps or lighting apparatus and is chiefly
designed to improve the construction of arc lamps of the kind or class described in
the Specification of former Letters Patent dated 12th March 1887 No. 3767, and
to adapt such lamps for working in parallel or multiple arc.
the same.
The lamp described in the said former Specification comprises a frame in which
is supported the upper carbon, and clockwork or other motor mechanism for feeding
This frame is arranged to be moved upward through a short distance
by a solenoid or by an electro-magnet for the purpose of forming or striking the
arc. The action of the said clockwork or mechanism is controlled by a brake or
equivalent device, which is applied to a wheel forming a part of such clockwork
or mechanism.
.
An important feature of my present invention is the construction of an electric
arc lamp in such a manner that a solenoid or electro-magnet for striking the arc,
and a smaller solenoid or electro-magnet for controlling the feeding of the carbon,
are arranged in series with each other and with the arc. By these means, when
the carbons are in contact and the current is allowed to flow through the same, the
said solenoids will be energized and the larger solenoid will effect the striking of
the arc, whilst the smaller solenoid will apply the brake and thus prevent the
feeding of the carbon until, by reason of the increase in the length of the arc due
to the consumption of the carbons, the resistance is augmented to such an extent as
to diminish the strength of the said solenoid and thus reduce the power applied to
the brake sufficiently to permit the feeding of the carbon. As soon as the are
is of the normal length, the smaller solenoid will again apply the brake, and so
The movement of the mechanism will thus be permitted, prevented and
retarded as required to ensure the proper working of the lamp.
on.
Another feature of my said invention is the combination, with a brake-lever
for controlling the feeding of the carbon, of two springs which act differentially
upon the said lever in opposite directions, and which are provided with adjusting
devices for regulating their action so that the said brake-lever will be approximately
in equilibrium, and one of the said springs will be extended (or compressed) when
the said lever is moved by the smaller solenoid, and will, by its reaction, take off,
or tend to withdraw the brake when the flow of the current through the_said
solenoid ceases or diminishes. By the proper adjustment of these springs, I am
enabled to ensure a very efficient action of the brake.
I find it advantageous to so arrange the brake and brake-lever and the solenoid
for operating the same, that the raising of one arm of the said lever by the solenoid
will cause the depression of the other arm thereof, and the consequent application
of the brake to a wheel forming part of, or suitably connected with the clockwork.
Instead of employing clockwork actuated by a spring as shown in the said former
Specification, I prefer, in some instances, to employ a heavy carbon-holder for the
upper carbon, and to utilize the weight of this holder and of the carbon for effecting
the downward movement or feeding of the said carbon. In such cases, I use the
clockwork simply for controlling, and not for effecting the feeding of the carbon.
For this purpose, I prefer to make 'the said carbon-holder with a rack which
is geared with a spur-wheel fixed upon the spindle of one of the wheels of the

page_text: clockwork. It is evident, however, that I can, if desired; employ the clockwork
as a motor, in conjunction with my other improvements herein set forth.
For guiding the upper carbon-holder, I sometimes employ one or more guide-
rollers, and I form in the lower plate of the lamp-frame, a suitably shaped hole in
which the said carbon-holder is fitted to slide. Or I attach to the said lower plate,
a bridge-piece having a suitably shaped hole in which the said carbon-holder is
fitted to slide.
When the lamp is constructed substantially as described in the said former
Specification for use in a series circuit, that is to say, a circuit in which several
lamps are arranged in series, I find it advantageous to provide for directly connecting
the two terminals of the lamp and thus short-circuiting the solenoid and other parts,
should the upper carbon or carbon-holder descend below the movable guide-roller.
I thus provide for preventing the extinction of some of the lamps in the series by
the interruption of the circuit in another lamp by such descent of the carbon
therein. For this purpose, I employ, in conjunction with the lever carrying the
movable guide-roller for the upper carbon or carbon-holder, suitable contact-pieces
which are connected respectively with the lamp-terminals but are insulated from
each other. These parts are so arranged that, should the carbon or carbon-holder
descend below the said roller, the spring connected with the said lever will move
the same into such a position that it electrically connects the said contact-pieces.
The said lever is, for this purpose, preferably made with a T-shaped arm adapted
to bear against the said contact-pieces.
By my present improvements, I provide for working are lamps in parallel without
variation, or with but slight variation in the resistance, that is to say, without any
material loss of E.M.F. in the lamp furthest from the dynamo-electric machine or
electric generator, or last in circuit. I am thus enabled to obtain a higher candle-
power per horse-power and consequently to supply a greater number of lamps than
has heretofore been practicable.
Although my improvements are chiefly designed to be applied to lamps of the
kind or class described in the said former Specification, the said improvements or
some of them are also applicable to other forms of electric are lamps.
Dated this 6th day of June 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Arc Lamps or Lighting
Apparatus.
I, HUGH WATT, of 64 Victoria Street, in the City of Westminster, Member
of Parliament, 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 :-
My invention relates to electric lamps or lighting apparatus; and is chiefly
designed to improve the construction and increase the efficiency of arc lamps of the
kind or class described in the Specification of former Letters Patent dated
. 12th March 1887, No. 3767, and to adapt such lamps for working in parallel or
multiple arc.
The lamp described in the said former Specification comprises a frame in which
is supported the upper carbon, and clockwork or other motor mechanism for
feeding the same. This frame is arranged to be moved upward through a short
distance by a solenoid or by an electro-magnet for the purpose of forming or
striking the arc. The action of the said clockwork or motor mechanism is con-
trolled by a brake or equivalent device, which is applied to a wheel forming a part
of such clockwork or motor mechanism.

page_text: An important feature of my present invention is the construction of an electric
arc lamp in such a manner that a solenoid or electro-magnet for striking the arc,
and a smaller solenoid or electro-magnet for controlling the feeding of the carbon
are arranged in series with each other and with the arc. By these means, when
the carbons are in contact and the current is allowed to flow through the same, the
said solenoids will be energized and the larger solenoid will effect the striking of
the arc, whilst the smaller solenoid will apply the brake and thus prevent the
feeding of the carbon until, by reason of the increase in the length of the are due
to the consumption of the carbons, the resistance is augmented to such an extent as
to diminish the strength of the said solenoid, and thus reduce the power applied to
the brake sufficiently to permit the feeding of the carbon. As soon as the arc is of
the normal length, the smaller solenoid will again apply the brake and so on.
The
movement of the mechanism will thus be permitted, prevented and retarded, as
required, to ensure the proper working of the lamp. Moreover, by these means,
the regulation or control of the feed by the brake can be effected without the
attractive force exerted by the smaller solenoid being directly varied by the action
of the said brake, as in cases where the current passes through the brake or through
a contact-piece attached to the brake-lever.
Another feature of my said invention is the combination, with the brake-lever for
controlling the feeding of the carbon, of two springs which act differentially upon the
said lever in opposite directions, and which are provided with adjusting devices for
regulating their action, so that the said brake-lever will be approximately in
equilibrium, and one of the said springs will be extended (or compressed) when the
said lever is moved by the smaller solenoid, and will, by its reaction, take off or
tend to withdraw the brake when the flow of the current through the said solenoid
ceases or diminishes. By the proper adjustment of these springs, I am enabled to
ensure a very efficient action of the brake.
In the accompanying drawings, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a side elevation of a lamp or lighting apparatus constructed according
to my present invention, the lamp-frame and a portion of the globe being shown in
vertical central section.
Figure 2 is a side elevation looking from the left hand side of Figure 1, the lamp-
frame and other parts being shewn in vertical section.
Figure 3 is a side elevation looking from the right hand side of Figure 1, a
portion of the lamp-frame being removed.
Figure 4 is a sectional side elevation, and
Figure 5 a front elevation showing a device hereinafter described for short-
circuiting the lamp.
Like letters indicate corresponding parts throughout the drawings.
A is the lamp-frame; B is the lower carbon, which is held in a socket B' con-
nected with the said frame in the usual manner. C is the upper carbon, which is
passed through holes in the said frame and in a guide-piece a attached thereto, and
is supported and fed downward as hereinafter described. D is the movable frame
for forming or striking the arc. b, are the rollers between which the upper
carbon is held, and one of which (6) is operated by the motor mechanism for the
purpose of effecting the feeding of the said carbon. E is a solenoid, the core E¹ of
which is coupled to one arm of a lever F pivoted at F" to a cross-bar A', the other
arm of the said lever being connected to an extension D' of the frame D by a pin d
working in a slot in the said extension. This frame is acted upon by a spring D'
which tends to draw it downward. G is another solenoid, the core G' of which is
coupled to, but insulated from a lever H, which is pivoted at H¹ to the frame D,
and is provided with a brake shoe or block H2 adapted to bear against the
periphery of the wheel I of the motor mechanism, when the solenoid G is
energized. The movement of the levers F and H is limited by means of adjustable
stops F³, H.
The roller is fixed upon the arbor c¹ of the wheel c of the mechanism. On this

page_text: arbor is also fixed a ratchet-wheel with which engages a pawl 7 pivoted to the
said wheel c and held in engagement with the said ratchet-wheel by a spring h.
A suitable coiled spring, attached at its inner end to the arbor c¹ and at its outer
end to the frame D, affords the motive power, the said spring being wound up
by means of a key fitted on the arbore. The roller is carried by a bent
lever e pivoted at e¹ to the frame D and acted upon by a spring e², whereby the
said roller is pressed against the upper carbon C, so that the latter is gripped
between the two rollers b, b, and will be fed downward by the mechanism through
the medium of the wheel b.
The electric current flows through the conductor, and through the lamp-frame
to the upper carbon, and thence to the lower carbon and through the post A* and
conductor to the coil of the solenoid G, from which it flows through the conductor
and through the coil of the solenoid E to the conductor m.
I find it advantageous to arrange the brake H2 and brake-lever H and the
solenoid G for operating the same, as shewn in the drawings, so that the raising of
one arm of the said lever by the solenoid will cause the depression of the other arm
thereof and the consequent application of the brake to the wheel I. And I com-
bine, with the said lever H, two springs J, J', one on each side of the fulcrum H
of the said lever H, which springs are arranged to act differentially upon the said
lever and thus facilitate the operation of the same, and are adjustable by means of
screws such as that shown at K.
The operation of my improved lamp, when arranged in parallel or multiple arc,
is as follows, viz.:-Assuming that the carbons are in contact, the current flows
through the solenoids E and G, and the core E¹ of the solenoid E is drawn down-
ward, thus raising the frame D together with the upper carbon C and forming or
striking the arc; the core G¹ of the solenoid G is, at the same time, drawn upward,
thus extending the spring and applying the brake H² to the wheel I, the spring Ji
assisting in this operation. As the carbons are consumed and the arc-resistance
increases, the strength of the solenoid being correspondingly diminished, the
spring J, by its reaction, withdraws the brake from the wheel I and permits the
feeding of the carbon C by the mechanism.
By my improvements above described, I provide for working are lamps in
parallel without variation, or with but slight variation in the resistance, that is to
say, without any material loss of E.M.F. in the lamp furthest from the dynamo-
electric machine or electric generator, or last in circuit. I am thus enabled to
obtain a higher candle-power and consequently to supply a greater number of lamps
per horse-power than las heretofore been practicable.
When the lamp is constructed substantially as described in the said former
Specification for use in a series circuit, that is to say, a circuit in which several
lamps are arranged in series, I find it advantageous to provide for directly con-
necting the two terminals of the lamp and thus short-circuiting the solenoids and
other parts, should the upper carbon or carbon-holder descend below the movable
guide-roller. I thus provide for preventing the extinction of some of the lamps in
the series by the interruption of the circuit in another lamp by such descent of the
carbon therein. For this purpose, I employ in conjunction with the lever e
carrying the movable guide-roller & for the upper carbon or carbon-holder, suitable
contact-pieces n, n' (Figures 4 and 5) which are connected respectively with the
lamp-terminals but are insulated from each other. These parts are so arranged
that, when the upper carbon or carbon-holder descends below the said roller 6', the
spring e connected with the said lever e moves the same into such a position that
it electrically connects the said contact pieces n, n' and short-circuits the lamp.
The said levere is, for this purpose, preferably made with a T-shaped arme
adapted to bear against the said contact-pieces.
Instead of employing clockwork or motor mechanism, actuated by a spring as
above described or as shewn in the said former Specification, 1 prefer, in some
instances, to employ a heavy carbon-holder for the upper carbon and to utilize the
weight of this holder and of the carbon for effecting the downward movement or

page_text: feeding of the said carbon. In such cases, I use the clockwork simply for controlling,
and not for effecting the feeding of the carbon. For this purpose, I prefer to make
the said carbon-holder with a rack which is geared with a spur-wheel fixed upon
the spindle of one of the wheels of the clockwork.
Although my improvements are chiefly designed to be applied to lamps of the
kind or class above referred to, the said improvements or some of them are also
applicable to other forms of electric arc lamps.
It is obvious that I can, if desired, substitute electro-magnets for the solenoids
above mentioned.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
First. An electric arc lamp wherein a solenoid or electro-magnet for forming or
striking the arc and another solenoid or electro-magnet for actuating a brake
whereby the feeding of the carbons is regulated or controlled, are arranged in
series with each other and with the arc, substantially as hereinbefore described.
Second. An electric are lamp constructed substantially as hereinbefore described,
with a brake which is actuated by a solenoid or electro-magnet and which regulates
or controls the movement of the mechanism without directly effecting any variations
in the attractive force exerted by the said solenoid or electro-magnet, as above
specified.
Third. The combination, with the brake-lever and the solenoid or electro-magnet
for actuating the same, of two adjustable springs arranged to act differentially upon
the said lever in opposite directions, as, and for the purpose, above specified.
Fourth. The combination, with the pivoted lever carrying the movable guide-
roller, of the T-shaped arm attached to the said lever, and the contact-pieces in
conjunction with which the said arm operates, as, and for the purposes, above
specified.
Fifth. An electric arc lamp having my improvements applied thereto substan-
tially in the manner described with reference to the accompanying drawings and
operating as above specified.
Sixth. The modification of my invention wherein I utilize the weight of the
upper carbon or carbon-holder, or both, for feeding down the said carbon, and
provide for regulating the feed by means of the mechanism controlled by the brake,
substantially as hereinbefore described.
Dated thin 7th day of
1
1000
HUGH WATT.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.