Year: 1886

page_text: Date of Application, 29th Mar., 1886.
Complete Left, 24th Dec., 1886.
Complete Accepted, 22nd Feb., 1887.
I, FREDERICK THORNTON of 109 Farringdon Road in the County of Middlesex;
Telegraph Engineer do hereby declare the nature of my Invention to be as follows:-
--
The object of one part of my Invention is to simplify the mechanism by which the
feeding of the upper carbon is effected. This part of the Invention has especial
reference to lamps of the kind described in an application for Patent 7390 of 1885 vizt.
lamps in which the upper carbon or carbon holder passes through a hollow core of a
solenoid by which the arc is struck. Hitherto in such lamps it has been necessary to
use wheels and pinions between the upper carbon holder and the pendulum arrangement
by which the feeding of the carbon is controlled. According to my present invention
I dispense with these wheels and pinions and I fix upon the spindle of the pendulum a
pallet in such a position that it engages directly with the teeth on the upper carbon
holder so that the said pallet forms a direct escapement for the said holder. I may
also dispense with guide rollers for the Carbon holder by making the said holder and
the openings through which it passes so that the latter act as guides for the holder.
Another part of my Invention relates to an arrangement by which several sets of
Carbons can be arranged in one lamp so that they are all operated from one solenoid
and core either altogether or one after the other as desired. According to this part of
iny invention I provide Carbon holders situated around a central solenoid and core
and I provide extensions from the solenoid and core to hold a pendulum and detent or
other regulating arrangement for each set of Carbons. When the sets of Carbons
are to be burnt in rotation the arrangement of the regulating mechanism is such that
the resistance through the Carbons is least in the set of Carbons to be first burnt,
greater in the second set and so on.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for Frederick Thornton.

page_text: I FREDERICK THORNTON of 109 Farringdon Road in the County of Middlesex
Telegraph Engineer 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 :-
:-
The object of one part of my Invention is to simplify the mechanism by which the
feeding of the upper carbon is effected. This part of the Invention has especial
reference to lamps of the kind described in the Specification of the Patent No. 7390 of
1885 videlicit lamps in which the upper carbon or carbon holder passes through a
hollow core of a solenoid by which the arc is struck. Hitherto is such lamps it has
been necessary to use wheels and pinions between the upper carbon holder and the
pendulum arrangement by which the feeding of the carbon is controlled.
According to my present Invention I dispense with these wheels and pinions
and I fix upon the spindle of the pendulum a pallet in such a position that it
engages directly with the teeth on the upper carbon holder so that the said pallet
forms a direct escapement for the said holder. I may also dispense with guide
rollers for the carbon holder by making the said holder and the openings through
which it passes in the hollow core so that the latter act as guides for the holder.
Another part of my invention relates to an arrangement by which several sets or
pairs of carbons can be arranged in one lamp so that they are both or all operated
from one solenoid and core, either both, or all, together or one after the other as
desired. According to this part of my invention I provide carbon holders situated
around a central solenoid and core and I provide extensions from the solenoid and
core to hold a pendulum and detent or other regulating arrangement for each set of
carbons. When the sets of carbons are to be burnt one after the other the arrangement
of the regulating mechanism is such that the resistance through the carbons is least in
the set of carbons to be first burnt, greater in the second set, and so on if more than
two sets be used.
And in order that my said Invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheets of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figures 1 and 2 are views at right angles to each other of so much of an electric arc
lamp as is necessary to illustrate my improved apparatus or means according to the
first part of my Invention for controlling the upper carbon and Figure 3 is a
horizontal section taken along the line 1-2-Figure 2-Figure 4 represents an
arrangement for automatically bringing several pairs of carbons into operation either
one after another, or for working two or more pairs simultaneously as required.
Referring first to Figures 1, 2 and 3 the upper part of the lamp frame consists of a
metal tube A having upon it two flanges B, B¹ which may form part of the framing
of the lamp and between which is wound a solenoid coil C which is placed in the lamp
circuit, the current entering by the terminal D and passing thence through the

page_text: solenoid to the core E and upper carbon holder to the upper carbon, thence to the
lower carbon and through its holder or support to the terminal D¹. Within the
tube A and the solenoid the tubular soft iron or magnetic core E is capable of
moving freely up and down. The extent of the downward motion of the core is
limited to about the maximum length of the arc it is desired to maintain and it is
guided in its motions by an arm e thereon sliding on a smooth pin e* and the upward
motion of the core is limited by the arm e coming in contact with the flange B of the
frame. A portion of the weight of the core and attached parts is sustained by
springs connected at one end to the underside of the flange B and at the other end
to screws f passing through arms projecting from opposite sides of the core near
the lower end thereof and provided with nuts f³ for adjusting the tension of the
springs f
The upper carbon holder 6 passes through the core E and is provided with rack
teeth with which engage an anchor or pallet n mounted in an oscillating frame K
pivotted at K' to the core E of the solenoid. This frame is maintained in position by
a spring 7 to admit of the anchor or pallet n working in the teeth of the rack b¹ but
capable of being oscillated so as to disengage the anchor or pallet n from the rack
teeth when it is necessary to impart a rapid movement to the carbon holder.. A
pendulum o is fitted on one end of the arbor or spindle n' of the anchor or pallet n
and is provided at o¹ with a roughened or finely toothed surface which is acted upon
by a projection or detent p on the flange B to arrest the oscillations of the said
pendulum when the desired are is formed. The carbon holder (which may be square
in horizontal section as shewn in Figure 3, or of any other suitable shape) is guided
in its vertical movements by correspondingly shaped openings through which it passes
formed in plates fitted in the core E as shewn in Figure 3.
P
When the core E is attracted by the solenoid so as to strike the arc it carries up
with it the pendulum o bringing the roughened part o' thereof against the detent
whereby the oscillations of the pendulum are arrested. As the carbons burn away
the resistance to the current is increased whereupon the core descends slightly so as to
release the pendulum o which commences to oscillate thus causing the anchor or
pallet n to lower the carbon holder b and thus restore the carbons to their requisite
distance apart to maintain the arc as herein before described. As the current through
the solenoid then increases the core E is attracted and the oscillations of the pendulum
and the feed of the carbon are arrested by the engagement of the parts o¹ and pas
herein before described.
Figure 4 represents in front elevation an arrangement according to the second part
of my Invention by which several sets of carbons can be employed in one lamp so as to
be all operated from one solenoid and core either one after the other or altogether as
desired. The drawing shews two carbon holders so arranged from which the application
of the Invention to a greater number will also be readily understood. The solenoid C
is provided at the lower end with an enlarged flange or an extension B2 through which
the holder of each of the upper carbons passes into guides or protecting tubes A on
the frane of the lamp. The mechanism for controlling the position of the upper carbon
of each pair, may consist of the arrangement hereinbefore described with reference to
figures 1-2 but for the purpose of illustrating more clearly the possible variation of
this part of my Invention and to avoid mere repetition I have illustrated a modification
as applied to Figure 4. Each of the upper carbon holders marked Z and X is
provided with rack teeth with which in each case a pinion i gears for controlling
the motion of the carbon holder the said pinion being carried on the arbor of the escape
wheel m the motion of which is governed by the pendulum o operating the anchor
or pallet n. The controlling mechanism is carried on an extension E³ of, or a plate
fixed to, the lower end of the core E (which may be either solid or tubular) of the
solenoid which extension or plate serves in conjunction with the extension B on 'the
solenoid to guide the carbon holders in their vertical movements. The whole of the
carbons may be in use at one time if desired, the drawing however represents an
arrangement for automatically bringing several pairs of carbons into operation one after
another, and consists of a lever r centred at y to the core E of the solenoid, one end y

page_text: of which lever bears upon one of the arms of a lever w turning on a centre carried by
the plate E¹ the other end y³ of the said lever engaging with the pendulum o of the
mechanism which controls the position of the adjacent pair of carbons so as to prevent
it oscillating. When the pair of carbons (that at Z for example) is exhausted the
solenoid core E will have fallen to its lowest position whereupon a pin or projection a
on the carbon holder will by acting on the end 10¹ of the lever to cause the arm y2 of
the lever to be raised and its opposite end y³ to be lowered thus releasing the
pendulum o of the adjacent pair of carbons at X which pendulum will then be free to
oscillate so as to regulate the upper carbon at X to maintain the arc in the said
adjacent carbous.
When more than two sets of carbons are combined in one lamp they may be brought
successively into operation substantially in the manner described by means of releasing
levers w and in connection with each pair of carbons and when it is desired to
operate several pairs of carbon simultaneously this may be effected by detaching the
releasing levers from the springs x so that the ends y³ of the said levers will fall
out of the range of motion of the pendulums o and thus permit of all the upper carbon
holders desconding without interruption as the carbons burn away.
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-
First. In electric arc lamps the combination of an upper carbon holder having rack
teeth, an anchor or pallet engaging directly therewith, and a pendulum for controlling
the motions of the anchor substantially as and for the purpose herein before described
with reference to Figures 1, 2 and 3 of the accompanying drawings.
Second. In electric arc lamps the combination with a toothed rack on the upper
carbon holder of an anchor or pallet engaging directly therewith and a pendulum
carried on oscillating frame pivotted to the core of the solenoid substantially as and
for the purpose hereinbefore described with reference to Figures 1, 2 and 3 of the
accompanying Drawings.
Third. In electric are lamps the combination with a single solenoid in the lamp
circuit of two or more pairs of carbons operated from the one solenoid either all at one
time or one after another substantially as hereinbefore described with reference to
Figure 4 of the Drawings.
Fourth. The general construction combination and arrangement of parts constituting
the improvements in Electric are lamps substantially as hereinbefore described and
illustrated by Figures 1, 2 and 3 of the drawings.
Fifth. The general construction combination and arrangement of parts constituting
the improvements in electric arc lamps substantially as hereinbefore described and
illustrated by Figure 4 of the Drawings.
J. HENRY JOHNSON,
Agent.