Improvements in Electric Arc Lamps.
Year: 1892

page_text: Date of Application, 22nd Feb., 1892-Accepted, 14th May, 1892
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I, GEORGE HUGHES, of 38, Chancery Lane, London, in the County of London,
Patent Agent, (a communication to me from abroad by Charles Henri Octave
Japy and Oscar Helmer, of No. 5, Rue Guilhem, Paris, France) 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 consists of a new or improved differential electric lamp producing
a voltaic arc with a fixed luminous beam or burning centre, operating either with
continuous or alternate electric currents.
In this improved electric lamp the continuous feeding of the carbons takes
place at short intervals as well as when the ignition takes place, the whole being
actuated by a jointed mechanism combined with clock work provided with an
equilibrated pallet escapement, or a fly escapement pivoting about the axis of the
toothed motor wheel and raising the upper carbon at the same time as the lower
carbon is lowered, this motion being differentially carried out under the action of
the electric current by means of a solenoid with fine wire for the one direction and
by means of a solenoid with coarse wire for the other, the first being placed in
derivation upon the two binding screws of the lamp and the second in the main
circuit.
2)
We use two solenoids having two cores of soft iron coupled by a beam pivoting
centrally upon its axis and the stroke of which is limited by stop pieces; this beam
actuates the clock work pivots with the aid of a connecting rod and is regulated by
an antagonistic spring for the purpose of obtaining in the same lamp different
luminous intensities.
We also use a chain or equivalent acting as a yielding rack, turning upon the
toothed motor wheel which operates the two carbon holders when they are brought
in close proximity one to the other, with a view to avoid that the lamp should be
too high, and to restrict its mechanism. The two carbon holders are guided by two
uprights which are connected by a tie-bar for the purpose of consolidating them and
maintaining them at a fixed distance.
This tie-bar acts also as a support for a small globe, the diameter of which
depends upon the size of the lamp and which is fixed thereto by a bayonet joint or
other equivalent device. Besides its simplicity of adjustment and its small
dimensions this small globe has another advantage, which is to concentrate the light
and protect the uprights of the lamp from the sparks and dust which may be flying
from the carbons.
In the accompanying drawings,
Fig. 1, Sheet 1, is a side view of our improved electric lamp and
Fig. 2 a front view thereof partly in section.
Fig. 14 is a detail of the connecting rod which causes the clock work to
oscillate.
Fig. 1 shows the comb serving to disconnect the clock work and intended as a
substitute for the screws shown in Fig. 1°.
Fig. 3 is a plan of the lamp.
Like letters of reference indicate corresponding parts throughout the figures.
S and S¹ are solenoids one wound with fine and the other with coarse wire ;
they are arranged one in derivation upon the screw posts of the lamp and the
other in the main circuit, these solenoids contain two soft iron cores N and N'.

page_text: M is a clockwork insulated from the base plate P of the mechanism and
capable of turning about its axis. P is the base plate supporting the mechanism.
mm are the uprights of the lamp, serving as guides for the upper and lower
carbon holders and insulated from the plate P.
C g. is a chain acting as a flexible rack and actuated by the toothed-motor
wheel R.
R. is a toothed motor wheel serving to feed the carbons c c¹ as well as to separate
them when starting.
B. is a beam pivoting centrally and supporting the two soft iron cores N. N¹.
N. N' are the soft iron cores drawn by the solenoids.
G. is the upper carbon slide.
H is a frame insulated from the plate P and supporting the clock work M.
pare the carbon holders and c c the carbons.
E is a pallet escapement and b. b' are insulated binding screws.
10 is a soft conductor serving to establish an intimate contact between the
negative carbon holder and the upright m and forming the complement of the
connection with the current supply y Fig. 2.
Another soft conductor w' starting
from the positive screw-post may be arranged to convey the positive current to the
upper carbon.
C. is a small pillar fixed to the beam B. by a screw furnished with a nut or of
any other device, and supporting the connecting rod coupled at c² with the
clockwork M. by means of a rectangular piece of metal Q jointed and screwed
upon the clockwork plate (Figs. 14 and 3, Sheet 1).
We use for disconnecting the clockwork shown in Sheet 1, a small insulated
toothed comb (Fig. 1B) or merely a screw V passing through the plate A and
in which is forced a point 1 of ivory or other suitable insulating material, or an
insulated metallic point I Fig. 1º.
We may also use instead of the uprights shown in Figs. 1 and 2 (Sheet 1) the
arrangement shown in Fig. 4 (Sheet II) that is to say, the rods fixed to the
lower carbon holder, sliding within the uprights m m¹ of the lamp, and held in a
concentric position by small guides y, the base of one of these rods being likewise
guided within the upright by means of a contact spring c.
The lamp operates as follows: The carbons being separated, (Fig. 5 Sheet 2.)
the electric current arrives at the screw post b, passes through the fine wire
solenoid S, and returns to the screw post when the core N is drawn within the
solenoid S and pulls the beam B, which pivots centrally at O.
As the beam B is coupled to the clockwork by means of a jointed connecting
rod el c (represented in Fig. 5 by a single rod t), it lowers the clockwork M
pivoting at o and places the carbons in contact, which causes the main current to
pass through the coarse wire solenoid S₁ which in its turn draws the soft iron
core N¹ the latter putting back the beam B in its original position. The lamp is
thus lighted.
As the carbons are being burnt off and the resistance increases, the current
derived into the fine wire solenoid S increases likewise while gradually drawing
the soft iron core N until the pallet escapement E allows the clockwork to run,
when it is disconnected from the small toothed comb or from the screw V carrying
an ivory or insulated metallic point. The carbons are then moved towards one
another, but only to a slight extent as the beam B returns forthwith to its original
position under the action of the coarse wire solenoid S¹.
The operation is thus rendered continuous by means of short intervals. The
carbons are actuated by the chain C g. passing over the toothed motor wheel R.
The upper carbon holder is insulated at i from the said chain which acts as a
flexible rack; it acts thus as the moving weight of the lamp.
The spring serves to regulate the lamp by means of the nut v.
We may modify the form and dimensions of our improved electric arc lamp
according to requirements, without departing from the nature of our invention.

page_text: 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 :-
1. The various improvements in electric arc lamps substantially as herein
described and shown.
2. In electric arc lamps the use of a suitable chain or equivalent device
actuating directly the two carbon holders and effecting the lighting at starting,
this chain acting as a flexible rack, substantially as herein described and shown.
3. In electric arc lamps the combination of the chain above claimed, with
the toothed motor wheel having a pallet or fly escapement in order to obtain
a lamp with a fixed luminous source, substantially as herein described and shown.
4. In electric are lamps, the beam and core mechanism in combination with two
solenoids, one wound with coarse wire and the other with fine wire, in order to
obtain a differential lamp, substantially as herein described and shown.
5. In electric arc lamps, the mechanism whereby is effected the separation
between the two carbons over a distance which is equal to twice the length of the
periphery of the toothed motor wheel, the upper carbon being raised at the same
time as the lower carbon is lowered, substantially as herein described and shown.
6. In electric arc lamps the uprights acting as guides for the carbon holders,
substantially as herein described and shown.
7. In electric arc lamps, the arrangement of a tie-bar for imparting solidity to the
lamp, and serving as a support for the globe placed between the two uprights and
which may thus be of very small size so as to concentrate the light and protect the
uprights of the lamp, substantially as herein described and shown.
Dated this 22nd day of February 1892.
HUGHES, SON & Co.,
38, Chancery Lane, London, Agents.