An Improvement in the Construction of Electric Arc Lamps.
Year: 1894

page_text: Date of Application, 31st Dec., 1894
Complete Specification Loft 20th Aug 1895 Accented 29th Feb. 1895
PROVISIONAL SPECIFICATION.
An Improvement in the Construction of Electric Arc Lamps.
We HARRY HEWITT and ANDREW CASEY both of 2 North Wharf Road,
Paddington, in the County of London, Mechanical Engineers, do hereby declare
the nature of this invention to be as follows:-
The apparatus consists of two or more carbons arranged to form the positive
pole of the electric arc lamp, and two or more carbons to form the negative pole.
The carbons are to run, slide, or work in four or more tubes or holders made of
metal or other suitable material.
The tubes or holders are set at suitable angles to each other, and arranged so as
to cause the points of the carbons forming each pole to impinge upon one another,
i.e., the carbons of the positive pole to impinge upon each other and the carbons of
the negative pole to impinge upon each other.
The carbons as consumed, are to be made to move forward by a constant
pressure exerted by springs or other available means.
The angles at which the carbons are arranged being always constant, the apexes
formed by their meeting together will always be in exactly the same positions with
regard to each other no matter how fast the carbons are consumed, thus
maintaining a constant arc without the aid of the complex clockwork mechanism
necessary in the existing forms of electric arc lamps.
Dated this 31st day of December 1894.
An Improvement in the Construction of Electric Are Lamps.
We, HARRY HEWITT and ANDREW CASEY, Mechanical Engineers, both of
No. 2 North Wharf Road, Paddington, in the County of London, 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 :-
Our invention relates to an improvement in the construction of electric arc
lamps.
And in order that our invention may be thoroughly understood, we now proceed
to describe the accompanying drawings thereof, reference being had to letters and
figures marked thereon.
Fig. 1, is an elevation of a vertical lamp.
Fig. 2, is a plan of a flat lamp.
Fig. 3, is a section on line A B of Fig. 2.
The apparatus consists of two (or more) carbons A as in Fig. 1, arranged to
form one pole of the electric arc lamp, and two (or more) carbons A to form the
opposite pole.
The carbons are to run, slide, or work in four or more tubes or holders B made
of metal or other suitable material. The tubes or holders B are set at suitable
angles to each other and arranged so as to cause the points of the carbons forming

page_text: each pole to impinge upon one-another, i.e., the carbons of the positive pole to
impinge upon each other and the carbons of the negative pole to impinge upon
each other.
The carbons as consumed are made to move forward by a constant pressure
exerted by springs C or other available means.
The angles at which the carbons are arranged being always constant, the apexes
formed by their meeting together will always be in exactly the same positions with
regard to each other, no matter how fast the carbons are consumed; thus
maintaining a constant are without the aid of the complex clockwork mechanism
necessary in the existing forms of electric arc lamps.
The particulars of the apparatus shown in Fig. 1, are as follows:-
Letters A are the carbons.
B the holders.
C section of holder showing spring.
D frame of apparatus.
E sliding bar.
F regulating screw.
G iron core.
H solenoid coil.
I tension screw.
T terminals.
The particulars of apparatus shown in Figs. 2 and 3, are as follows:-
Letters A & A' are the carbons.
B the holders.
D frame of apparatus.
T terminals.
The current entering at terminal T shown on right of Fig. 1, is conducted
through insulated wire which is continued to form solenoid H from thence it passes
along slide bar E through both metal holders B to the two carbons A (the sliding
bar E being insulated from frame D). It then passes through carbons A to carbons A,
both sets being of course brought into contact prior to current being switched on,
thence through metal holders B of said carbons A' through frame D to terminal T on
left of drawing thus completing circuit. On completion of circuit the solenoid H
magnetises the iron core G causing it to move upwards separating points of
carbons A and A' as shown on drawing thus forming the electric arc. The tension
screw I which is insulated from sliding bar E is for adjusting the distance of
upward movement of said sliding bar produced by action of solenoid thus regulating
length of electric arc.
In Figs. 2, and 3, we construct an alternate lamp by forming four holders B on
a ring or frame D. The two carbons A are arranged so as to meet each other,
point to point, in the same straight line, and the two carbons A' form the opposite
pole arranged in the same manner but in a different plane. The electric current
in this case passing between the carbons forming the opposite poles at the point
where the two poles cross.
The frame of the apparatus shown in Figs. 2, and 3, is insulated where
required. The electric current enters at terminal T on the right hand side of
Fig. 2, and will pass down the holder B to carbons A' it then will pass to carbons A.
The circuit is made complete when the connecting wires are fitted to each
terminal T.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The meeting at any suitable angle of two or more carbons to form each
pole of the arc lamp, substantially as herein described.
2. The meeting of two carbons in the same straight line forming one pole of the
arc lamp, and the meeting of two other carbons in the same manner forming the

page_text: opposite pole, substantially as herein described and according to the accompanying
drawings.
3. The spiral springs which exert a constant pressure keeping the carbons
forming each single pole in contact with one another and the combination of the
apparatus, substantially as herein described and according to the accompanying
drawings.
Dated thin 20th dow of Avout 1905
HARRY HEWITT,
ANDREW CASEY,
Applicants.