Improvements in the Means for Controlling Carbon Feeding Mechanisms for Electric Lamps.
Year: 1897

page_text: Date of Application, 14th Apr., 1897
Complete Specification Left, 20th Dec., 1897-Accepted, 12th Feb., 1898
Improvements in the Means for Controlling Carbon Feeding
Mechanisms for Electric Lamps.
I, WILLIAM DODS HUNTER, of 10, Gloucester Terrace, Newcastle-on-Tyne, in the
County of Northumberland, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention relates to improvements in the method or means for controlling
the carbon feeding mechanism for maintaining the proper length of are in electric
arc lamps.
To carry out my invention I place a brake sheave or pulley on the spindle that
carries the pinion which gears into the rack in connection with the carbon holder,
or in cases where a pinion and rack are not used, the brake sheave is in an equiva-
lent position. A band or strap of metal or other material is carried partly round
the sheave, and has its ends fastened to the lever connecting the core of the solenoid
to the dashpot piston rod, but on opposite sides to and at unequal distances from the
fulcrum of the lever, the longer distance from the fulcrum being on the solenoid
side. I can also obtain the same result but not in quite so simple a manner by
providing a separate lever controlled by the lever previously mentioned or the
core of the solenoid and having two arms of unequal length to which the ends of
the brake strap are attached.
With no current, the brake strap will be clear from the sheave. When the
current is on, the core of the solenoid is drawn upwards, and thus tightens the.
strap against the sheave; and owing to the unequal length of the arms of the lever
the sheave will be drawn round, and with it the pinion which gears in the rack, thus
drawing the carbons apart until the arc is struck. As the carbons burn away
the current will be reduced, and allow the solenoid core to fall, thus releasing the
brake, when the carbons will again approach each other by the action of gravity,
and the proper length of arc maintained.
noted this 14th day of April 1907
Improvements in the Means for Controlling Carbon Feeding
Mechanisms for Electric Lamps.
I, WILLIAM DODS HUNTER, 10, Gloucester Terrace, Newcastle-on-Tyne, in the
County of Northumberland, Electrical Engineer, do hereby declare the nature of
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page_text: 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 relates to improvements in the method or means for controlling the
carbon feeding and arc striking mechanism for maintaining a steady feed and
proper length of arc in electric lamps, and is applicable to alternating or continuous
current lamps constructed for series or parallel systems.
To carry out my invention I place a suitable brake wheel or pulley on a spindle
operating directly or indirectly with the feeding mechanism of the carbons, pre-
ferably arranged to work by means of a rack and pinion.
I provide a band chain or cord of metal or other suitable material carried partly
around the circumference of the brake wheel the ends of the bands or chain being
attached on opposite sides and at unequal distances, from the centre of the fulcrum
of the lever connecting the core of the solenoid or solenoids to the piston rod of the
dash pot. This lever is conveniently arranged to rotate upon the same bracket
trunion as supports the brake wheel but operating independently and excentrically.
The distance of attachment of one end of the chain to the lever is preferably
arranged at a greater distance from the fulcrum on the series coil side than on
the other side.
I prefer to obtain a similar result by providing an additional lever having two
arms of unequal length to which the ends of the brake strap are attached & con-
trolled by the lever attached to the cores of the solenoids, as hereinbefore described,
and operating against a suitable adjustable stop secured to the frame of the lamp.
A modification of the arrangement of levers may further be adopted to secure
the same result for which purpose I provide a suitable bracket supporting the brake
wheel and parallel links on each side of brake wheel, these, carry the differential
link to which the brake strap ends are attached, and arranged to move in connec-
tion with and controlled by the levers which are operated upon by the cores of the
solenoids, so that the whole system of links move in unison.
It will readily be understood that with no current passing through the lamp
the brake wheel is free to revolve beneath the strap or chain. When the current is
switched on, the core of the solenoid is drawn upwards and operates the levers in
connection thus, by means of the unequal distance of the attachment of the strap
to the lever, or unequal lengths of arms of lever or link from their fulcrum the strap
is tightened against the circumference of the brake wheel, causing this to rotate
with the pinion which gears into the rack of the carbon holder. In this manner
the carbons are drawn apart until the arc is struck.
As the carbons are consumed the current will be reduced and the solenoid cores
with the attendant levers & brake wheel will move in an opposite direction, thereby
maintaining a proper length of arc.
Upon the further consumption of the carbons contact is made by the differential
link with the adjustable stop, thus releasing the brake when the carbons will again
approach each other by the action of gravity to form a proper arc.
The automatic and sensitive action of my apparatus renders the application of a
brake controlling feed mechanism, for arc lamps, more efficient than heretofore and
permits of a more even and smooth feed of the carbons being maintained.
Fig. 1, of the accompanying drawing shows a vertical elevation and plan of the
feeding mechanism of an arc lamp with brake wheel and strap as herein before
described.
Fig. 2, is an elevation and plan of a similar lamp shewing method of strap or
chain attachment with additional differential link.
Fig. 3, is a modification of levers as shown in Fig. 2.
In Fig. 1, A is the body of the lamp supporting by brackets the solenoid B, and
containing an internal carbon holder C, which is formed with a rack on one side to
gear into the pinion D. Upon the same spindle as the pinion is secured the brake
wheel E, and the whole supported by the brackets F secured to the body of the
lamp. The levers G attached to the solenoid B rotate upon their axis formed by
the bosses of the brackets F so as to move independently and excentrically to the

page_text: brake wheel. The other end of the lever is attached to the dash pot H. The brake
strap J is attached on one side of the brake wheel E to the lever G, and the other
end is also attached to the lever G on the opposite side of the wheel, but at a
greater distance from the centre, so that in raising the lever G the point of attach-
ment of the strap at the solenoid side of wheel is caused to move through a greater
distance than on the opposite side, thus gripping the wheel and causing this to
rotate and raise the carbon holder.
In Fig. 2, the strap is attached to an additional small differential link K working
on a trunion secured to the lever G and an adjustable stop M is provided.
In Fig. 3 a modification of levers is arranged and the differential link K is
supported on each side by parallel links N, fitted at one end to the spindle E and
the other end supported by the lever P, attached to the lever G. A stop M is
provided as in Fig. 2.
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:-
(1) In an electric arc lamp of automatic regulating and carbon feeding mech-
anism, a method of attachment at unequal distances of a suitable brake band or
chain to the lever controlled by the solenoid, to operate as a differential lever in
combination excentrically with a brake wheel as hereinbefore described and shown
in Fig. 1 of the accompanying drawing.
(2) In combination with a brake mechanism for electric arc lamps, a suitable
differential link or lever with arms of unequal length measured from the fulcrum
and attached to the brake strap and solenoid levers substantially as described and
operating for the purpose as shown in Fig. 2, & Fig. 3.
(3) The method of construction substantially described with reference to the
Figs. 1, 2 and 3 of the accompanying drawing, or any mere modification thereof,
and operating for the purpose as above specified.
Dated this day 18th December 1897.