Improvements in Electric Lamps..
Year: 1891

page_text: Date of Application, 3rd Feb., 1891-Accepted, 9th May, 1891
COMPLETE SIMULTICATION.
Improvements in Electric Lamps..
I ALEXANDER MELVILLE CLARK, of the firm of A. M. & Wm. Clark
of 53 Chancery Lane in the County of Middlesex Fellow of the Institute of
Patent Agents do hereby declare the nature of this invention (a communication
to me by James W. Easton of the City, County and State of New York, United
States of America) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention relates to electric arc lamps, and has for its object the production
of an are lamp, simple in its construction, both in its electrical and mechanical
features, positive and reliable in its operation, and capable of being cared for by
comparatively unskilled persons.
To this end, the invention consists in the novel electrical and mechanical features
and in the arrangement, combination, and construction of devices, parts, and details,
hereinafter described and specifically pointed out in the claims.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein
Figure 1 is a front elevation (partly in section) of the operating parts of a lamp
embodying the invention;
Figure 2 is a side elevation thereof, and
Figure 3 is a diagram of the clectric circuits.
The operating parts of the lamp are enclosed within a suitable casing A and are
The carbon
secured to the top and bottom boards B B in any suitable manner.
carrying rod C is provided with a rack c and slides freely through holes in the top
and bottom boards B B. A pinion D rigidly mounted upon the axle d meshes
with rack c.
The axle d is journaled in a pivotally-supported frame E and carries
the ratchet or escapement wheel F rigidly secured to the axle. The frame E is
pivotally supported by the bearing screws e which are carried by the lugs or arms g
projecting from the standards G which within the standard G form the framework
of the lamp. The bearing screws e may be adjusted and are held in place by the
jamb nuts e. The core of a solenoid H is suspended from, or attached to, one
end of the frame E and to the opposite end of said frame is secured a mass of
magnetic material I which is adapted to act as an armature to the electro-magnet.J
which is provided with the downwardly-projecting pole pieces jj. This weight of
the armature I also tends to depress its end of the frame E when the solenoid H
and magnet J are de-energized as hereinafter described. This last mentioned
function of said armature may be conveniently assisted by the spiral spring K, the
tension of which may be properly regulated by the thumb nuts kk, although, of
course, if the armature be sufficiently heavy, the spring K may be dispensed with.
An escapement L engaging with wheel F is journal in bearings in the
arms which are secured to the standard G. These arms are provided with slots
to receive the screws so that their position relatively to the escapement wheel F
may be adjusted as desired. To the axle of the escapement L is secured the fan l
to govern the movement of the escapement and from one end of said escapement
projects the pin with which, under certain conditions, the upwardly-extending
arm M secured to frame E is adapted to engage. For the purpose of carrying the
escapement wheel F out of engagement with the escapement L and thus permitting
the carbon rod C to be moved freely up and down the rod N is provided. The
When
rod N slides freely in the sleeve suitably placed in the bottom board B.
it is desired to clean or trim the lamp, or replace the carbons, the rod N is lifted up
carrying with it the end of frame E and lowering the escapement wheel Fout of
engagement with escapement L. At the same time the arm M engages with the
71

page_text: pin and prevents that end of the escapement L from following the escapement
wheel F as the latter is lowered. When the escapement wheel F is lowered
sufficiently the rod N is turned so that the pin n¹ enters the bayonet slot n³ of
sleeven thus holding the wheel F and escapement L out of engagement and
permitting the carbon rod to be moved freely up and down until such time as the
rod N is lowered when the action of spring K and the weight of armature I will
carry the wheel F and escapement L into engagement again.
A compound weund electro-magnet O having the pole face o and the pivoted
armature is secured to the bottom board B. When the magnet. O is energized,
the armature ol is attracted to the pole face o and when the same is de-energized
said armature falls and comes into electrical contact with the contact piece P secured
to the bottom board B'.
The foregoing description of the invention relates chiefly to the novel mechanical
features comprised in the same, and I will now proceed to describe a novel arrange-
ment of electro-magnets and electric-circuits by means of which the same may be
rendered operative, although I wish it clearly understood that I do not intend to
limit the invention to any particular arrangement of said magnets and circuits, as
the mechanical features of the invention may be used in connection with other and
different electrical features.
The main or are circuit of the lamp lies through a conductor 1, of low resistance,
which leads from the binding post p, to which one terminal of the working circuit
is connected, to the carbon rod C passing round the core of electro-magnet O and
forming thereon the coil ². From the carbon rod C the main circuit lies through
the carbons to the conductor 2 of low resistance and thence to the binding post 2
to which the other terminal of the working circuit is connected. A conductor 3 of
very low resistance is connected with conductor 1 at p³ and with the pivoted
armature o' of magnet O and the path of the current lies through said armature to
the conductor 4 which passes around the core of magnet J forming thereon the
coil and thence to the binding post. This circuit forms a shunt of low resist-
ance around the main circuit of the lamp. A second shunt circuit, but of high
resistance, is formed by the conductor 5 which is connected with the conductor 1
at p³, passes thence around the core of magnet O, forming thereon the coil o³, to the
solenoid H, and thence to the binding post p².
The operation of the invention will now be readily understood, and is as follows:
The carbon rod C having been properly adjusted so that when no current is on the
lamp the carbons will be separated being held out of contact by the weight of
armature which tends to depress its end of frame E thus raising the escapement
wheel F until it is locked by engagement with escapement L. If now the current
be turned on, it finds a circuit of low resistance through conductor 1 armature o
contact piece P conductor 4 and coil and energizes the electro-magnet thus
attracting the armature I towards the pole faces jj. The escapement wheel Fis.
thereby lowered sufficiently to entirely release it from engagement with escape-
ment Land the carbon rod C accordingly descends until the carbons come together.
When the contact between carbons is established a current is completed through
the main circuit of the lamp which includes the coil o³ of maguet O. This causes
the magnet O to become energised and the tongue or armature o¹ is attracted to the
pole o of the magnet, thus breaking the shunt circuit first described and de-energizing
the magnet J which permits the armature I to descend and the carbon rod C is
thereby lifted sufficiently to separate the carbons and establish the arc. As the
carbons are consumed, the resistance of the arc and consequently of the direct
circuit is increased and when such resistance becomes excessive a portion of the
current will flow through the high resistance shunt circuit and will energize the
solenoid H. the core of which will be drawn into the coil. The end of frame E to
which the core is attached will thus be depressed sufficiently to permit the
escapement L to vibrate and thus permit the carbon rod C to descend and bring
the carbons nearer together. Should it descend more rapidly than the rate of
consumption of the carbons will warrant, the resistance of the arc is decreased the

page_text: action of the solenoid is weakened and the weight of the armature will depress
the opposite end of frame E thus raising the rod C until the arc is of the proper
length, when the feed is resumed as before. On the other hand should the feed be
too slow, the solenoid H. will become stronger and the vibration of the escapement L
and consequently the rate of descent of the rod C will be increased. By means of
the slots in the supports g' of the escapement L, the position of the escapement may
be varied so that the voltage at which the lamp will feed may be altered as desired.
Should the carbon rod stick and refuse to descend at all, the resistance of the are
circuit will gradually increase as the carbons are consumed and when it becomes so
great that the potential necessary to force the current through the increased
resistance increases the magnetizing power of coil o so that it equals that of coil o²
the coils will neutralize each other and the armature will fall into contact with the
piece P thus re-establishing the low resistance shunt circuit and depriving the main
circuit and coil o² included therein of current. As the resistance of this shunt
circuit is so low compared with that of the high resistance shunt circuit, the coil o³,
which is included in the latter, will receive only a negligible amount of current and
the magnet O will remain inactive permitting the armature to remain in contact
with piece P until the carbons come together again, when the act of lighting and
the feeding of the carbons will proceed as before.
When the carbons are not in
the lamp and the current is turned on, the main circuit will be open and the current
will flow through the low resistance shunt circuit.
It is obvious that an electro-magnet or other equivalent mechanism may, if
desired, be substituted for the solenoid H without departing in the least from the
invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed. I declare that what I
claim is
1. In an arc lamp, the combination of the carbon carrying rod an escapement
wheel adapted to control the movement thereof a pivoted frame on which said
escapement wheel is mounted an escapement mounted on the fixed frame of the lamp
for controlling the movement of said wheel and means for adjusting the position of
the axis of said escapement whereby the lamp may be arranged to feed at any
desired voltage, substantially as and for the purposes set forth.
2. In an arc lamp, the combination of the carbon rod of an escapement wheel
connected therewith of a pivoted frame in which said escapement wheel is journaled
of an escapement controlling the niovement of said wheel and of a stop on the said
frame adapted to engage with said escapement and prevent it from swinging into
contact with the wheel when the latter is lowered beyond a certain point, substan-
tially as and for the purposes set forth.
3. In an arc lamp, the combination of the carbon rod of an escapement wheel
connected therewith of a pivoted frame in which said escapement wheel is journaled
of an escapement controlling the movement of said wheel and of a stop on said frame
adapted to engage with said escapement and prevent it from swinging into contact
with the wheel when the latter is lowered beyond a certain point and of a support N,
substantially as and for the purposes set forth.
4. In an arc lamp, the combination of the carbon rod an escapement wheel mounted
on a pivoted frame or lever and adapted to control the movement of said rod an
escapement mounted on the fixed frame of the lamp for controlling the movement of
said wheel a high resistance magnet arranged in a shunt of the main circuit for
controlling the movement of the feeding mechanism a low resistance magnet also in
a shunt of the main circuit and operating when energised to release the feeding
mechanism and complete the main circuit of the lamp and a magnet arranged in the
main circuit for throwing said low resistance shunt magnet out of action when the
main circuit is completed, substantially as and for the purposes set forth.
5. In an are lamp, the combination, with the carbon rod and feeding mechanism,
substantially as described, for controlling the movement thereof, of a solenoid or

page_text: electro-magnet arranged in a high resistance shunt of the main circuit of the lamp
of an electro-magnet provided with two coils wound, in opposite directions to oppose
each other's action one coil being in permanent connection with the main circuit of
the lamp, and the other coil being in permanent connection with said high resistance
shunt circuit and of a low resistance shunt circuit adapted to be closed when the
action of one of said coils neutralizes the effect of the other, substantially as and for
the purposes set forth.
6. In an arc lamp, the combination of the carbon rod of the escapement wheel
and escapement controlling the movement thereof of a pivoted frame in which said
escapement wheel is journaled of a solenoid or electro-magnet arranged in a high
resistance shunt of the main circuit of the lamp and having its core or armature
connected with said frame of an armature of electro-magnet arranged in a low
resistance shunt of the main circuit and having its armature attached to said frame
of an electro-magnet provided with a pivoted armature and with two coils wound in
opposite directions, one coil being in the main circuit of the lamp and the other in
the said high resistance shunt circuit the armature of said last mentioned magnet
acting as a switch to close the said low resistance shunt circuit when the core of
its magnet is de-energized, substantially as and for the purposes set forth.
7. In an automatic cut-out for are lamps, the combination of a magnet having a
differentially wound core, one coil thereof being in the main circuit of the lamp and
the other coil thereof being in a high resistance shunt of said main circuit, of a
pivoted armature and a contact point both in a low resistance shunt of the main
circuit, substantially as and for the purposes set forth.
Dated this 2nd day of Wehman 1901
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.