Improvements in Electric Arc Lamps.
Year: 1895

page_text: Date of Application, 22nd Jan., 1895
Complete Specification Left, 14th May, 1895-Accepted, 20th July, 1895
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
I Sir CHARLES HENRY AUGUSTUS FREDERICK LOCKHART Ross, Baronet,
of Balnagowan Castle, Ross-shire, N.B., do hereby declare the nature of this
invention to be as follows:-
The object of this invention is to produce an electric arc lamp of simple and
economical construction, and in carrying out this invention I employ, by
preference, four carbons, which are mounted in tubes set at a convenient angle, so
that the carbons will feed by gravity as they burn away.
I prefer four carbons, two positive and two negative, because the two carbons
of each pair will support one another, and thus be prevented from sliding through
the tubes, except as they burn away.
The lamp consists of a frame formed of two parts suitably insulated from one
another, and each part carries, on pivots, a rocking frame provided with tubes to
receive the carbon, and which frames I may designate the carbon holders.
The main frames also carry electro magnets, which are energized by the current,
and so placed as to act on the carbon holders, and rock them, in order to separate
the positive and negative carbons, and thus produce the arc.
Instead of two rocking carbon holders, it is evident I may employ one rocking
holder with its magnet, and one fixed holder without a magnet.
In this way I can produce a perfect arc lamp for general purposes at an
exceedingly small cost compared with arc lamps as at present constructed.
Dated this 22nd day of January 1895.
NEWTON & SON,
Agents for the Applicant,
Improvements in Electric Arc Lamps.
I Sir CHARLES HENRY AUGUSTUS FREDERICK LOCKHART Ross, Baronet,
of Balnagowan Castle, Ross-shire, N.B., 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 this invention is to produce an electric arc lamp of simple
construction, and thereby to effect a material economy in its manufacture.
In carrying out this invention, I employ, by preference, two pairs of carbons for
the positive and negative poles, mounting them in tubes or troughs set at a
convenient angle for the two carbons of each pole to abut against each other,
and afford the requisite support for one another, leaving them free to feed by
gravity as they burn away.
In the
nanning drawings

page_text: In these views, A is a rigid frame suspended from a pendent insulating block B,
to which are fitted two terminals bb, the terminal being connected with the
frame A, and the terminal 6 with an electro-magnet or differential solenoid,
hereafter called the "magnet."
C is a second rigid frame of like construction to A.
Affixed to the frame A is a pair of tubes A', braced together by bars A', A³,
and inclined towards each other, so that their axes would meet at a
point in the
centre of the lamp. These tubes are intended to receive a pair of carbons a a,
which form, say, the positive pole of the arc lamp.
Attached to the frame C by pivot screws c, is a rocking frame C', consisting of two
tubes set at an inclination to each other (like the tubes A¹), and braced together by
two cross bars, the upper one of which is made of soft iron, and clothed with a covering
of brass, or equivalent diamagnetic material. The tubes of this frame are intended
to receive the carbons cc, which form, say, the negative pole of the are lamp, and
the carbon holders of the two frames are so arranged with respect to each other,
as to ensure contact between the two carbon poles a c, when the lamp is not in use.
The rocking frame C₁ is weighted, but may be supported in its normally inclined
position by means of catches c', carried by the fixed framing C, which catches
prevent the frame overbalancing when the carbons have been consumed. D is the
magnet "carried by the fixed frame C, and serving to attract the soft iron bar of the
rocking frame, and draw that frame into the dotted position of Fig. 1, for
the purpose of striking the arc. This "
magnet rests, for convenience, upon a
plate carried by the cross bar of the frame C, and it is held thereto by a clamping
piece and screwd, but it may be otherwise conveniently held in position, according
to the purpose for which the lamp is constructed, and its coil is connected with the
terminal b¹.
66
"
The parts above mentioned constitute the complete lamp, and, by reason of
the simple character of the parts, a cheaply constructed, efficient arc lamp is
obtained.
On the making of the circuit, the current will flow from the terminal 6 to the
frame A; thence by the carbons a to the carbons c on the rocking frame C₁, from
which it will pass to the rigid frame C, and so. through the "magnet" D which it
carries, and back by the terminal 61 to the source of electricity, or vice versa, the
current in all cases flowing through the "magnet." On the "magnet" D being
energized by the passage of the current through its coils, the soft iron bar of the
rocking frame C will be attracted, and the frame rocked, to strike the arc.
the breaking of the circuit, the frame C¹ will fall by its own weight into the drawn
position of Fig. 1, when the carbon poles will be in contact.
On
Figs. 4 and 5 shew in side elevation and front view, a slight modification of the
lamp, the electro-magnet being situate below the rocking frame C¹, so as to attract
the bottom bar of that frame, which is weighted, as before, but has its soft iron bar
at its lower, in place of its upper, end. The electro-magnet in this case is carried
by a bracket-shaped plate, which passes through the rocking frame, and is made
fast to the fixed frame C.
Figs. 6, 7, and 8 shew a simple form of lamp constructed on the principle of
that shewn in Fig. 1, but in connection with a parabolic reflector.
A A is the reflector, which carries the several parts of the lamp. It is fitted
with a block B at its centre, from which rises an eye for the suspension of the
lamp, which eye, being screwed into the block, serves to hold in position a bracket
piece C. This bracket piece carries, by pivot screws c*, a weighted rocking
frame C, constructed like that already described for receiving the pair of
carbons c. The tubular carbon holders of this frame project through holes made
for the purpose in the reflector, and on the opposite side of the centre of the
reflector A, are fitted the insulated tubes A' (which represent the fixed frame A
of Fig. 1) for receiving the carbons a, which meet the carbons c, as already fully
described.
D is the "magnet," clamped to a plate carried by the bracket C, and situate so

page_text: as to attract the soft iron bar of the rocking frame C¹. 66' are the terminals,
which connect respectively with the holders of the carbons a and the electro
magnet. The action of this lamp will be similar to that above described, the arc
being struck below the reflector, thus affording a brilliant concentrated or focussed
light.
Fig. 9 shews the mechanism of the lamp contained within the reflector, instead
of outside, as shewn in Figs. 6, 7, and 8.
It will be observed that in all the examples described, the same simplicity of
construction is retained, the object being to place upon the market a cheap and
efficient automatically-feeding arc lamp, free of all appliances which require
adjustment, except the electro-maguet or differential solenoid.
It may be here remarked that it may be convenient to use an electrical appliance,
such as a resistance, so as to allow the lamp the desirable number of volts and
ampères.
I have shown the appliance for striking the arc applied to one pair of carbons
only. Such arrangement is, in my opinion, the best. But without departing from
my invention, both pairs of carbons may be controlled by such mechanism.
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 :-
The arrangements of arc lamps described with reference to the drawings, in
which a rocking frame, constituting a holder for a pair of converging (preferably)
carbon electrodes, and weighted to make contact, is actuated directly by a fixed
electro-magnet or differential solenoid, and caused to withdraw its carbons (for the
purpose of striking the arc) from those of a carbon holder constructed to carry its
pair of carbons in such a manner that they converge to a point common to all the
carbons, when in contact, as and for the purpose above set forth.
Dated this 14th dor of Mar 1895
NEWTON & SON,
Agents for the Applicant.