An Improved Electric Arc Lamp for Optical Lanterns and other purposes.
Year: 1895

page_text: Date of Application, 30th Mar., 1895
Complete Specification Left, 24th Dec., 1895-Accepted, 1st Feb., 1896
PROVISIONAL SPECIFICATION.
An Improved Electric Arc Lamp for Optical Lanterns and other
purposes.
GEORGE DAVENPORT, 19, John Street, Adelphi, London, W.C. Clerk, do
thereby declare the nature of this invention to be as follows:-
This invention consists of an arrangement of parts for holding, regulating, and
feeding together the two carbons of an electric arc lamp, either by hand or
automatically as described below.
To a base made of slate, vulcanized fibre, or other suitable material, a metal
plate marked A in drawing is fixed. This plate has grooves or other shaped
guides attached to or cut in it, in which the foot of the tube B for carrying the
upper carbon holder is placed, so that it is capable of sliding or being moved to
and fro by a rod working in screw guides from the back of the lam, or by other
suitable contrivances. If desired the foot of the tube carrying the upper carbon
holder may be fixed directly to the base of the lamp.
The tube B has a slot cut in it longitudinally along the greater part of its
length. In this tube B a metal rod or tube C slides up and down having a
toothed rack fastened along the greater part of its length, which runs in the slot
cut in the tube B already described. To the upper end of the tube a metal arm
or carbon holder D is attached, as shewn in drawing, having at one end a circular
or other shaped hole cut, in which the upper carbon can be placed and secured by
a screw.
To the upper end of the tube B bearings are fastened in which a toothed
pinion E, attached to a rod F, works. The teeth of the pinion engage in the
toothed rack of the tube C in such manner that, when the rod carrying the pinion
is turned or revolved the tube.C is raised or lowered as the case may be.
The bottom carbon holder consists of a slotted metal tube G, somewhat similar
to the tube B, which is fastened to the base of the lamp, in front of the tube B, or
may be arranged to slide in a grooved base similar to A.
In the tube G a tube H slides, having a toothed rack fastened along its length
which works in the slot cut in the tube G. The tube H is raised and lowered by
a rod I and pinion J similar to the one already described for working the upper
carbon holder, and shewn in drawing.
To the upper part of the tube H a metal collar or carbon holder K is fastened
having screws or other contrivances attached so that the lower carbon may be
clamped in the collar.
Both the upper and lower tubes carrying the carbon holders may be arranged
vertically, or preferably at an angle as shewn in drawing.
The rods carrying the pinions E and J for raising and lowering the carbon
holders pass through holes or bearings in a plate or plates at the back of the lamp,
such plates consisting of slate, vulcanized fibre, or other suitable material, or if of
metal, having collars or bearings of an insulating material through which the
rods pass.
The rods carrying the pinions E and J have toothed wheels L and M fastened
to them at the back of the lamp, as shewn in drawing. These wheels L and M are
carefully insulated from the metal rods to prevent any chance of short circuit
between them, and by means of an intermediate wheel N or a train of wheels are

page_text: placed in gear with one another so that, on turning any one of the wheels the other
wheels are revolved and the tubes or rods carrying the upper and lower carbons of
the lamp are raised or lowered at rates depending on the relative diameters of the
wheels L and M. The wheel N is fastened to a rod P and is arranged so that it
may be thrown in or out of gear with the wheels L and M by a catch R or by
springs or other contrivances. When thrown out of gear, as described, the rods
carrying the pinions E and J will be capable of independent movement and allow
adjustments in height of the carbons and carbon holders to be readily made.
In place of the toothed wheels L, M, and N, above described, the rods F and I
may be actuated by cords, pulleys, or other contrivances passing over them, or
over grooved or other shaped wheels or guides attached to them, so that the
motion of one rod may be communicated to the other, or the rods carrying the
pinions E and J may be used without any connection with one another so that
they may be turned independently when feeding or regulating the carbons of
the lamp.
The apparatus above described forms an electric arc lamp in which the feeding
and regulating of the carbons requires to be done by hand, but by suitable gearing
or mechanism worked or controlled by springs electro-magnets or by electrical or
other motive power, the feeding and regulating of the carbons may be made
automatic or otherwise as desired.
Dated this 20th ML 100-
COMPLETE SPECIFICATION.
An Improved Electric Arc Lamp for Optical Lanterns and other
purposes.
GEORGE DAVENPORT 19, John Street, Adelphi, London, W.C. Clerk, 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 :-
This invention consists of an arrangement or combination of parts for holding,
adjusting, and feeding together or separating, the two carbon holders and carbons
of an electric arc lamp, by hand, as described below.
To a base made of slate, vulcanized fibre, or other suitable insulating material, a
metal plate, marked A in drawings Figs. 1 and 2 is fixed. This plate has grooves,
or other shaped guides, attached to or cut in it, in which the foot of the tube B for
carrying the upper carbon holder aud carbon is placed, so that it is capable of
sliding or being moved to and fro by a rod, working in screw guides, from the back
of the lamp, or by any other suitable contrivance. If desired, the foot of the tube
carrying the upper carbon holder may be fixed directly to the base of the lamp.
The tube B has a slot cut in it, longitudinally, along the greater part of its
length. In this tube B a metal rod or tube C slides up and down, having a
toothed rack fastened or cut along the greater part of its length, which runs in the
slot cut in the tube B already described. In the upper end of the tube C a metal
head is fitted which is capable of revolving in a plane at right angles to the length
of the tube C, and which can be fixed in position by a screw or other contrivance.
This head has a hole in which a short tube S is fitted. In this tube the carbon
holder D slides, having at one end a hole or other arrangement in which the upper
carbon can be placed, and clamped or secured by screws or other contrivances.
The other end of the carbon holder slides in the tube S and has grooves cut in it in
which guide pins attached to the tube S fit, so that the carbon holder, when set, is
capable of sliding to and fro without turning. The end of the carbon holder D
which slides in the tube S has a male screw cut on it, and this screw fits or threads
into a screw collar attached by guides to the tube S, as shewn in drawings Figs. 1

page_text: and 2 in such manner that, when the collar is turned, it moves the carbon holder
backwards or forwards, and so enables the carbon to be adjusted as desired.
Other arrangements for holding or adjusting the upper carbon may be used if
preferred.
To the upper end of the tube B bearings are fastened in which a toothed
pinion E, attached to a rod F, works. The teeth of the pinion engage in the
toothed rack of the tube C in such manner that, when the rod carrying the pinion
is turned or revolved, the tube C is raised or lowered as the case may be.
The arrangement for carrying the bottom carbon holder and carbon consists of a
slotted metal tube G, somewhat similar to the tube B, which is fastened to the base
of the lamp in front of the tube B, or may be arranged to slide in a grooved plute
similar to A.
In the tube G a tube H slides, having a toothed rack cut or fastened along its
length, which works in the slot cut in the tube G. The tube H is raised or
lowered by a rod 1, and pinion J, similar to the one already described for working
the upper carbon holder, and shewn in drawings, Fig. 1 and 2.
To the upper part of the tube H a metal collar or carbon holder K is fastened,
having screws or other contrivances attached so that the lower carbon may be
clamped in the collar.
Both the upper and lower tubes carrying the carbon holders and carbons may
be arranged vertically or, preferably, at an angle, as shewn in drawings, Fig. 1
and 2.
The arrangement or combination above described, and shewn in drawing Fig. 1,
forms an electric arc lamp in which each carbon is raised or lowered independently
of the other, but, by the addition of gearing described below, the two carbons of
the lamp may be fed together, or separated, at the same time, by one movement,
or, independently, as may be desired.
To obtain this combination of movements, the rods carrying the pinions E and J
for raising and lowering the carbon holders, are arranged to pass through holes or
bearings in a plate or plates at the back of the lamp, such plates consisting of
vulcanized fibre, or other suitable insulating material, or, if of metal, having collars
or bearings of an insulating material through which the rods pass.
The rods carrying the pinions E and J, have toothed wheels L and M fastened.
to them at the back of the lamp, as shewn in drawing, Fig. 2. These wheels L
and M are carefully insulated from the metal rods to prevent any chance of short
circuit between them, and, by means of the intermediate wheel N, or by a train of
wheels, are placed in gear with one another, so that, on turning any one of the
wheels, the other wheels are revolved, and the tube or rods carrying the upper and
lower carbons of the lamp are raised or lowered, at rates depending on the relative
diameters of the wheels L and M. The wheel N is fastened to a rod P, and is
arranged so that it may be thrown and retained in or out of gear with the wheels L
and M by a catch R, or by springs or other contrivances. When thrown out of
gear, as described, the rods carrying the pinions E and J will be capable of
independent movement, and allow adjustments in height of carbon holders and
carbons with which they are connected to be readily made.
In place of the toothed wheels L, M, and N, above described, the rods F and I
may be actuated by cords, pulleys, or other contrivances, passing over them or
over grooved or other shaped wheels or guides attached to them, so that the
motion of one rod may be communicated to the other, or each one be able to turn
independently at will.
The apparatus above described forms an electric arc lamp in which the feeding.
and adjusting of the carbons requires to be done by hand.
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 [
claim is :-
1. The method of emploving two separate slotted tubes or similar contrivances

page_text: attached to or fixed to a common base, and inclined as shewn in drawings, Fig. 1
and 2 in which tubes or rods slide, carrying the carbon holders and carbons for an
electric arc lamp, such tubes or rods having toothed racks attached to or cut in
their sides, longitudinally, in which pinions, running in bearings fixed to the slotted
tubes, work, these pinions being fixed to, and actuated by, rods, so that, by the
turning of the rods with their pinions, the tubes or rods carrying the carbon holders
and carbons are raised or lowered independently of each other in the manner
described above. The combination forming an electric arc lamp in which each
carbon is fed by hand, independently of the other.
2. The method of using toothed wheels, or similar contrivances, attached to the
rods and pinions above mentioned, which can be placed in or out of gear with one
another by a moveable intermediate rod and wheel, as already described, and shewn
in drawing, Fig. 2 so that, when placed in gear with one another, the turning of
any one rod will cause the other rods with their wheels and pinions to revolve, and
the two carbon holders with which the rods are connected to be raised or lowered
at the same time, at rates depending on the relative diameter of the two wheels ;
and when thrown out of gear with one another, will enable each rod with its wheel
-and pinion, to be capable of independent movement, and of raising or lowering
the carbon holder and carbon with which it is connected without interfering with
the other carbon holder.
3. The form of holder and head piece employed for holding and clamping the
upper carbon in position as described above, and the method of adjusting the
holder and its carbon, in the manner before mentioned, and as shewn in drawings,
Fig. 1 and 2.
4. The arrangement and combination of parts, as described above, and shewn in
drawings, Fig. 1 and 2 for holding, adjusting, and feeding together or separating,
-by hand, the two carbon holders and carbons of an electric arc lamp.
Dated this 24th day of December 1895.
GEORGE DAVENPORT.