An Improved Electric Arc Lamp.
Year: 1892

page_text: Date of Application, 13th Dec., 1892
Complete Specification Left, 12th July, 1893-Accepted, 7th Oct., 1893
PROVISIONAL SPECIFICATION.
An Improved Electric Arc Lamp.
George DAVENPORT of 19 John Street, Adelphi, London, W.C. Clerk, do
hereby declare the nature of this invention to be as follows:-
The invention consists of two carbon holders so arranged that while the lower
carbon is maintained in position for burning as mentioned below, the upper carbon
is fed forward by a movement controlled by hand from time to time, as the carbon
is consumed.
The upper carbon holder consists of a rod, tube, or similar contrivance, at the
upper part of which is fixed an adjustable grip for holding the carbon. This rod
or tube has a toothed rack fixed to its side along part of its length, and the whole
arrangement slides in a fixed tube to which is attached a pinion which engages in
the rack and which, when turned, causes the upper rod holding the carbon to be
raised or lowered.
The lower carbon holder consists of a tube attached by preference, to a fixed
upright plate, by a screw working in a slot cut in the plate, so that the height of
the tube may be altered and other adjustments made.
Within the tube is a spiral spring. The lower carbon is placed in the tube so as
to compress the spring and is retained in the tube by a stop held on the upper end
of the tube by a bayonet joint or other means. This stop consists of a metal ring
or collar with one or more projecting picces, in each of which a screw works. The
lower carbon pressed through the ring or collar by the coiled spring is retained in
position by the screws above mentioned which project forward so as to just touch
and restrain the carbon, being so adjusted that as the carbon burns away it is fed
up by the coiled spring within the tube.
The burning point of the lower carbon by this means is always maintained in the
same or nearly the same position until it is consumed.
Dated this 12th day of December 1892.
GEORGE DAVENPORT.
COMPLETE SPECIFICATION.
An Improved Electric Arc Lamp.
GEORGE DAVENPORT 19, John Street, Adelphi, London, W.C. Clerk, do
hereby declare the nature of this invention and in what manuer the same is
to be performed, to be particularly described and ascertained in and by the following
statement :-
This invention consists of two carbon holders so arranged that while the lower
carbon is maintained in position for burning, as mentioned below, the upper carbon
is fed forward by a movement, controlled by hand, from time to time, as the carbon
is consumed.
The upper carbon holder consists of a rod, tube, or similar contrivance A, at the
upper part of which is fixed an adjustable grip B for holding the carbon. This rod
or tube has a toothed rack C fixed to its side along part of its length, and the
whole arrangement slides in a fixed tube D to which is attached a pinion E which
engages in the rack and which, when turned, causes the upper rod holding the
carbon to be raised or lowered.
The lower carbon holder consists of a tube F attached, by preference, to a fixed
upright plate G by a screw H working in a slot cut in the plate, so that the height
of the tube may be altered or other adjustments made. Within the tube is a spiral

page_text: spring. The lower carbon is placed in the tube so as to compress the spring, and
is retained in the tube by a stop J held on the upper end of the tube by a
bayonet joint or other means. This stop consists of a metal ring or collar with one
or more projecting pieces, in each of which a screw works. The lower carbon, pressed
through the ring or collar by the spiral spring, is retained in position by the screws
above mentioned, which project forward so as to just touch and restrain the carbon,
being so adjusted that as the carbon burns away it is fed up by the spiral spring
within the tube. The burning point of the lower carbon, by this means, is
automatically maintained in the same or nearly the same position until it is
consumed.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
'
The combination of parts for holding, feeding, and adjusting the lower carbon, as
described above, with the arrangement for holding and hand feeding the upper
carbon in the manner before mentioned.
Doted this 10th day of July 1802
GEORGE DAVENPORT.