IMPROVEMENTS IN ELECTRIC LAMPS
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by James Fyfe at the Office of the
Commissioners of Patents on the 23rd February 1881.
.
JAMES FYFE, of No. 30, Jewin Crescent, Aldersgate Street, in the County of
Middlesex. "IMPROVEMENTS IN ELECTRIC LAMPS."
"
My Invention relates more particularly to that construction of electric lamps
described in the Specification to Abel's Patent, No. 1397, of 1880 (a communication
from Krizik and Piette), but is also applicable to other electric lamps wherein the
regulation of the carbons is effected by means of two solenoid coils, one of which,
being of low resistance, is included in the lamp circuit, while the other, being of
high resistance, is in a branch circuit connecting the conductors to and from the
Jamp.
In such electric lamps as heretofore constructed, the one carbon has always been
connected either directly or through the intervention of a lever or arm to the soft
iron core or cores which is or are acted upon by the before mentioned solenoid coils
of high and low resistance, and these coils being thus of necessity situated close to
the carbons, they not only more or less obstruct the light of the lamp, but also
render this of somewhat unsightly appearance.
My present Invention has for its object to obviate these defects, and consists in
certain constructions and arrangements, whereby I am enabled to place the said
regulating coils at a distance from the carbons, which constructions I will now
describe. According to one arrangement, applicable to street lamps, or lamps
situated on pedestals, each carbon is carried by a small crosshead, by preference
provided with antifriction rollers at its ends bearing against two parallel guide
bars fixed within the globe of the lamp, so that the crossheads in being moved to
and from each other along such guide bars, as will be presently described, cause the
carbons to approach towards or recede from each other.
The said guide bars are insulated from each other, and the one is electrically
connected to the one conducting wire for conveying the current, while the other is
connected to the other conducting wire, and the said crossheads are so arranged
that each one is in electrical contact with one of the guide bars, and is insulated
rom the other, so that the current passes from the one conducting wire and guide
bar through the one crosshead and carbon, and thence through the other carbon and
rosshead to the second guide bar and conducting wire. The conducting wires pasa
.
•

page_text: down the hollow pedestal of the lamp, in the base of which are situated the before
mentioned solenoid coils with the soft iron core or cores, the base being provided
with a door for gaining access thereto.
The coils are connected to the conductors in the manner before described, and to
the core or cores is connected a thin nonconductor leading up through the pedestal
to the crosshead of the lower carbon, so that the motion of the core produced by the
action of the solenoid coils is imparted to the lower carbon, whose crosshead is
connected to thin wires or threads of nonconducting material passing up over fixed
pullies at the top of the lamp, and thence down to the crosshead of the upper
carbon, so that the weight of the upper carbon and crosshead is nearly balanced by
the lower one, and the movement of the latter by the core or cores of the solenoids
also produces a reversed movement of the former, whereby the carbons are made to
approach or recede from each other.
In applying my Invention to a bracket lamp, the same arrangement of the
carbons, crossheads, and guide bars is employed as above described, and the solenoid
coils with their cores are arranged in a box or recess in the wall to which the
bracket is attached, or they may be in a recess formed in the bracket itself, and
the wire connecting the core with the crosshead of the lower carbon is led along
the bracket and over a guide pulley beneath the crosshead.
In applying my Invention to a pendant lamp, I also employ the same arrange-
ment of the carbons, crossheads, and guide rods as above described, the solenoid
coils and cores being either arranged in the ceiling above, or in the wall at the
side, and the wire connecting the core with the one carbon being either led to the
upper crosshead, or over a guide pulley to the lower one.