IMPROVEMENTS IN ELECTRIC INCANDESCENCE LAMPS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the Office
of the Commissioners of Patents on the 3rd March 1883. Communicated to
him froin abroad by Jean Marie Anatole Gerard-Lescuyer of Paris, France
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
"IMPROVEMENTS IN ELECTRIC INCANDESCENCE LAMPS." [Communicated to him
from abroad. by Jean Marie Anatole Gerard-Lescuyer of Paris, France]
This Invention relates to improvements in electric incandescence lamps and it
consists in the arrangement and combination of a pair of straight or curved fine
pencils or of carbon pressed at their free ends against a block of carbon placed
between them or against one another so as to effect a certain and renewable contact
in case of wear, and in the means of supporting or fixing the carbons in this
position, and also in the support for the bulb or envelope in which the lamp is
enclosed.
The block of carbon interposed between the pair of carbon pencils (hereafter
referred to as the carbons) is in the form of a small disc grooved around its
circumference and held up in position between the free ends of the pair of carbons
by a platinum wire which serves only for the purpose of a support for the disc.
Against its opposite faces press the free ends of the two carbons which may either
be straight or curved, and which alone become incandescent and give out light.
The other ends of these carbons are tightly fixed in tubular sockets of carbon,
which sockets are tightly bound by ligatures of copper wire to the upper extremities
of the platinum electrodes so as to make an excellent contact. The platinum
electrodes have loops formed in them so as to act as springs always pressing the
carbons against the carbon disc, even if their points should wear away slightly.
The carbon sockets in which the carbons are fixed do not become incandescent and
consequently their contact with the platinum wires is not exposed to the action of
the heat.
The platinum wires are sealed through the neck of the bulb in which the lamp
is enclosed which is exhausted in the usual way. Instead of platinum wires other
forms of springs of any other metal or even of glass may be used. The lamp as
above described is simple and strong and may be enclosed within a globe mounted

page_text: in a movable socket or holder to facilitate replacing the lamp, and presents the
advantage that existing stick carbons may be used.
The support of the bulb is as follows:-The platinum electrodes and the central
wire supporting the carbon disc have eyes at their external ends. Into the eye of
the central wire engages a small hook screwed to an insulating supporting block.
At opposite sides of said block are mounted terminals and binding screws for the
attachment of the leads. To these terminals are fixed the ends of copper or other
wires bent to a loop form so as to act as springs whose other ends are hook shaped
and engage with the eyes of the platinum electrodes, the contact being ensured
under all vibratory or oscillating movements of the bulb by the outward tendency
or pressure of the springs which thus put the platinum electrodes in communication
with their respective terminals.