Improvements in Electric Arc Lamps.
Year: 1890

page_text: Date of Application, 24th Nov., 1890-Accepted, 27th Dec., 1890.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps..
A communication from abroad by RALPH HAMILTON BEACH, of St. Paul, in the
County of Ramsey and State of Minnesota, United States of America,
Electrician.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.L.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323. High Holborn, in the County of Middlesex, Civil
Engineer, 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 relates to improvements in electric are lamps, in which the carbons
are automatically advanced and consumed; its object being to secure an unvarying
point of light at the tips of the carbons and an arc of unvarying length.
In the accompanying drawings forming part of this Specification
Figure 1 is an elevation or partial section of the improved lamp;
Figure 2, a detail of the are controlling magnet.
:-
Figure 3 is a detail of a modified construction showing a differential solenoid,
instead of main and shunt solenoids, as in Figure 1, and
Figure 4 is a detail of the automatic cut out.
In the drawings
2 represents the side bars of the lamp frame, 3 the top or cross bar, 4 the base, and
10 the lamp globe, secured to the base by screws 11. 5 and 6 are binding posts
having insulated support in the cross bar 3 and suspending hooks 7, to which posts
are secured the lamp wires and the line wires 8 and 9. 12 and 18 are the carbon
holders inclined toward each other and extending through the base, one fixed in
insulated supports and the other pivoted in electrical connection with the frame..
14, 14 are detaining fingers secured to the holders on opposite sides, and bearing
upon the shoulders of the carbons 15 and 16. Followers 37 are arranged in the
bolders and bear upon the carbons to advance them as consumed.
17 and 18 are
solenoids secured to the lamp frame with their core openings registering with each
other, the solenoid 17 is wound with coarse wire 25, connected at one end to the
binding post 6, and the other to the holder 12, and the solenoid 18 is wound with fine
wire 26, the ends of which are connected to the posts 5 and 6. The common solenoid
core 19 carries a cross bar 20, connected by a link 21 to the carbon holder 13, and by
the spring 22 to the lamp frame, the tension of the spring being regulated by the
screw 23 and the adjusting nut 31. The parts are so adjusted that, when the lamp is
cut out, the spring 22 holds the carbons in contact. The modified form of solenoid 27
is a differential magnet, the wires 25 and 26 being wound together upon it, but
oppositely connected. 32 is a guide or support for the outer end of the core, in the
modified construction. The outer end of the core opening of the solenoids 17 and 27
is closed, so that the inclosed air serves as a cushion to receive the impact of the core.
28 is a magnet arranged vertically between the carbon holders with its lower end
flattened, and is secured in adjusted positions by means of the set screw 23, and
serves to repel the arc, and thus to hold it at the carbon tips. The lamp is cut out
by means of the switch 29 pivoted to the post 5 and making sliding contact with the
post 6. The action of the lamp is wholly automatic. The working current passes
through the coarse wire of the solenoid 17, which thereupon attracts the core 19 and
causes the are to be formed between the carbon points. The resistance of the arc
shunis a portion of the current through the solenoid 8, which acts in opposition to
the solenoid 17, and checks the movement of the core. The normal length of arc is
determined by the adjustment of the tension of the spring 22, as any fluctuations in

page_text: the length of arc while the lamp is in use are immediately corrected by the diverting
of more or less current through the shunt magnet, by which means the core is moved
to adjust the position of the carbons.
The effect upon the arc is the same where the differential solenoid is used. The
attraction of the magnet upon the core being increased or diminished in the same
manner with any fluctuation of the arc. By means of the contact 34 arranged in
each holder and connected with the other holder, either directly or through the frame
of the lamp, by wires 35 and 36 respectively, the current is short circuited when
either carbon has burned down so that its follower strikes the contact, thus auto-
matically cutting out the lamp before the current is broken by the dropping out of
the end of the consumed carbon.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, as communicated to me by my
foreign correspondent, I declare that what I claim is :-
1. In an are lamp, the combination of automatically fed carbons, stops limiting
their lengthwise movement, a magnet controlling the position of the are between the
carbons; means for holding the carbons normally in contact, mechanism for varying
the distance between the carbons, and a differential magnet in the lamp circuit
actuating said mechanism.
2. In an
arc lamp, the combination of automatically arranged carbon holders
movable one from the other, automatically advanced carbons, stops limiting the
forward movement of the carbons, direct and shunt wire coils in the lamp circuit,
their common core connected to the movable carbon holder, and an are repelling
magnet arranged between the holders adjacent to the are, and means for holding the
carbons in contact when out of circuit.
3. In an are lamp, the combination of automatically arranged carbon holders
movable one from the other, automatically advanced carbons, stops limiting the
forward movement of the carbons, direct and shunt wire coils in the lamp circuit,
their common core connected to the movable carbon holder, an are repelling
magnet arranged between the holders adjacent to the arc, and a short circuiting
device operated by the carbon follower when it descends to a predetermined position
in the holder.
4. In an are lamp, the combination of automatically advanced angularly arranged
carbons, stops limiting their lengthwise movement, means for holding the carbons
normally in contact, mechanism for separating and varying the distance between the
carbons and a differential magnet in the lamp circuit actuating said mechanism.
5. In an are lamp, the combination of automatically fed carbons, stops limiting
their lengthwise movement, means for holding the carbons normally in contact,
mechanism for separating and varying the distance between the carbons, and a
differential magnet in the lamp circuit actuating said mechanism.
6. In an arc lamp, having automatically fed carbons, the combination therewith of
followers for said carbons, and a short circuiting device operated by either of the
followers when it has advanced to a predetermined position in the holders.
Dated this 22nd day of November 1890.
WM. P. THOMPSON & Co.,
Agents for the Applicant.