IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the O.fice
of the Commissioners of Patents on the 12th August 1882. Communicated
to him from abroad by Nicolas Emile Reynier, of Paris, France.
OR
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake and Co., Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN ELECTRIC LAMPS
[A communication to him from abroad by Nicolas E.uile
LIGHTING APPARATUS
Reynier, of Paris, France.]
This Invention relates to electric lamps or lighting apparatus and consists in
certain improvements based upon a very simple geometric property of prismatic
rods tapered at one end. When two prismatic rods of carbon of polygonal or
curved section tapered at one end are placed in the same plane nearly parallel to
each other, if the pointed extremities are brought together so that they touch each
other, the point where the contact is made will be situated above the two points
and towards the commencement of their tapered portion. The points being free
can be supported upon two electric contact-pieces and an incandescent system of
lighting thus obtained in which the electric current traverses successively, in
inverse directions, the two tapered ends, passing from one to the other by their
mutual lateral contact.
In order to maintain these conditions notwithstanding the wear or consumption of
the carbons, it is only necessary that they should be pushed continually in the
direction of their axes, giving to the electric contact-pieces a suitable obliquity. The
carbon rods, free laterally, should be guided in their common plane. Under these
conditions, the carbons preserve their tapered form, remain in contact with
the said supports, and with each other, at a certain distance above their points;
I will call this latter the mutual contact to distinguish it from the other contacts.
I prefer to push the carbons in the direction of their axes by means of weights
sliding upon two metal guides. The oblique contact-pieces are made of two plates
of copper fixed in brass curved pieces or armis. Two pairs of insulated flanges
connect the two halves of the lamp; the first pair is of wood and furnished with a
hook for suspending the apparatus; the second is of slate and forms a refractory
slot which guides the carbons in their common plane; the said weights are insulated
from the carbons by means of ivory tips or other suitable means.

page_text: This combination of two incandescent points brought very close to each other,
and three adjacent contacts, procures a concentration of heat favorable to the
production of light by the apparatus, and forms the essential characteristic of the
said Invention.
As it is of the greatest importance to ensure the contacts and to maintain the
equilibrium of the carbons during their consumption, I sometimes form longitudinal
cavities or recesses in the inclined planes which terminate the contact pieces, so as
to receive and hold the points of the carbons; the length of these inclined planes is
such that one of the carbons meets the stop which terminates each of them, the
inclination of the other part constantly tending to bring the two carbons together
and ensure their mutual contact.
The above described apparatus may be modified as may be deemed expedient in
practice. The carbons may be round or of other section, and I may arrange in
various manners a larger number of carbons to procure a greater amount of light.
The said apparatus may be operated either in the open air or in a closed
receptacle,