Year: 1894

page_text: Date of Application; 9th June, 1894
Complete Specification Left, 9th Mar., 1895-Accepted, 8th June, 1895
I, FREDERICK RICHARD BOARDMAN, of 1 Percy Road Leytonstone, in the
County of Essex, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
The object of my invention is to produce a simple, cheap, and effective electric
lamp for use in theatrical entertainments, as search lights, in signalling, and for
other useful purposes.
For the object in view I combine some suitable substance of a refractory nature
(such as lime or marble) with the ordinary carbon electrodes and placed between
them so as to expose the said substance to the electric arc, but making provision
for bringing the electrodes together for the purpose of striking the arc, and
adjusting the distance between them as waste occurs in burning, by two racks
placed parallel to each other, and respectively connected to each carbon holder.
A small pinion provided with a head is mounted between the two racks and gears
into them, so that on turning the pinion by the head thereof the two racks move in
opposite directions. Consequently when the head of the pinion is turned in one
direction, each rack being connected to the carbon holder by a standard or arm it
causes its particular carbon to advance (for instance) towards the other one, which
is moved in like manner. By turning the head the reverse way the two carbons
are separated from each other, so that they simultaneously advance or recede
towards or from each other, and from the centre of the refractory block as they
are adjusted by the hand moved pinion, while the centre of the source of light
always occupies the same spot. The parts are suitably insulated in the manner
well known. The refractory block preferably surrounds the two ends of the
carbons in such a manner that they may touch each other at the central part of
the block, and an opening for the emission of light is made at that part of the
block for the purpose, but more than one opening may be made if required. In
using the lamp with alternating electric currents a single pinion is used so as to
move each rack and the carbon it controls at the same rate; but in using direct
currents it is sometimes desirable to have a double pinion so arranged as to move
the racks at differential speeds, and thus provide for the greater waste of the
positive carbon, so as to use carbons of the same diameter. The parts are suitably
carried by a slate or other .base which I mount in any convenient way within or to
a portion of the frame or casing. of a lamp, which is also adapted to receive a lens
or reflector. Suitable means are also employed to adjust the lamp, or the lens or
reflector, relatively to each other; and the lamp, or case is sometimes mounted on"
gimbals, journals, or a ball and socket joint. .
Dated this Sth day of Jung *100%
FAIRFAX'& WETTER,'.
433, Strand, London, Agents for the Applicant

page_text: An Improved Electric Lamp.
I, FREDERICK RICHARD BOARDMAN, of 1 Percy Road, Leytonstone, in the
County of Essex, Electrical 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 :-
The object of my invention is to produce a simple, cheap and effective electric
lamp for use in theatrical entertainments, as search lights, in signalling, and for
other useful purposes.
In the further description of this invention reference is made to the accompanying
drawings, in which
Fig. 1 is a side elevation showing the framework, carbon electrodes, and block
holder of my improved electric lamp; Fig. 2 is a front elevation, and Fig. 3 is a
plan, of the same.
Fig. 4 is a partial view of part of the racks and actuating pinion;
Fig. 5 is an elevation of the lamp mounted on the hinged back of the casing of a
search light; and
Fig. 6 shows an application of a lamp to a reflector as used for photographic
purposes.
For the object in view I combine a block a of some suitable substance of a
refractory nature, (such as lime or marble), with the ordinary carbon electrodes b, b
and placed between them so as to expose the said substance to the electric arc.
Provision is made for bringing the electrodes together, by hand adjustment, for the
purpose of striking the arc, and adjusting the distance between them as waste
occurs in burning, by two racks c, c, placed parallel to each other, and respectively
connected to each carbon holder d, d, by a standard or arm e, e.
A small pinion f
provided with a head is mounted between the two racks and gears into them, so
that on turning the pinion by the head thereof the two racks c, c, move in opposite
directions. Consequently when the head of the pinion is turned in one direction,
each rack being connected to its carbon holder d by the corresponding standard or
arme, it causes the particular carbon 6 to advance (for instance) towards the other
one which is moved in like manner. By turning the head the reverse way the two
carbons b, b, are separated from each other so that they simultaneously advance or
recede towards or from each other, and to and from the centre of the refractory
block a as they are adjusted by the hand moved pinion; while the centre of the
source of light always occupies the same spot, as indicated by Figs. 1 and 2. The
parts are suitably insulated in the manner well known. The refractory block a
preferably surrounds the two ends of the carbons in such a manner that they may
touch each other at the central part of the block, and an opening for the emission of
light is made at that part of the block for the purpose; but more than one opening
may be made if required. A block holder g is mounted upon a base h which, with
the plate, secured to it by screws, (as shown in Fig. 1), forms the frame to carry
the racks c, c, and pinion f. A pivotal handle is sometimes combined with the
plate for moving the lamp to any required position.
In using the lamp with alternating electric currents a single pinion is used so as
to move each rack and the carbon it controls at the same rate, and this arrange-
ment is shown in Figs. 1, 2, 3 and 4. But in using direct currents it is sometimes
desirable to have a double pinion so arranged as to move the racks at differential
speeds, and thus provide for the greater waste of the positive carbon, so as to use
carbons of the same diameter. In some cases, however, I may use an enlarged
positive electrode, as indicated in Fig. 5. For a search lamp 1 mount the lamp in
any convenient way to a hinged portion of a frame or casing (as indicated in Fig. 5)
and combine therewith a suitable lens and reflector. Suitable means are also

page_text: employed to adjust the lamp, or the lens or reflector, relatively to each other; and
the lamp or case is sometimes mounted on gimbals, journals, or a ball and socket
joint; and similar means are indicated in Fig. 6, in combination with the lamp,
and reflector k, which arrangement is suitable for photographic purposes.
The carbon holders d, d, are bored through, so that the carbon electrodes are
placed therein endways, and secured in position by an eccentrically arranged
clamping ring and set screw 1, or other equivalent means. The terminals are
conveniently mounted upon the arms e, e, and these are suitably insulated from the
racks c, c, as indicated in Fig.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that
what I claim is ;-
1. In a hand adjusted electric lamp the combination of two racks movable in
opposite directions by an actuating pinion placed between the said racks and
engaging therewith, a carbon holder mounted upon each rack and adapted to carry
an electrode and convey current thereto, a refractory block having two end
channels adapted for the reception and movement therein of the electrodes and an
orifice for the emission of light, and a block holder and base adapted to receive
and form a frame for the said racks, substantially as and for the purpose herein
described.
2. The combination of a hand adjusted electric lamp, having carbon electrodes
movable within a refractory block, with a casing adapted to enclose the said lamp,
and to carry a suitable lens, substantially as and for the purpose herein described
and shown with reference to Fig. 5.
3. The combination of a hand adjusted electric lamp, having carbon electrodes
movable within a refractory block, with a reflector substantially as and for the
purpose herein described and shown with reference to Fig. 6.
4. The combination of parts forming a hand adjusted electric lamp substantially
as herein described and shown with reference to Figs. 1, 2, 3, and 4 of the
drawings.
Dated this 9th day of March 1895
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.