Improvements in Means for Automatically Controlling the Carbon Feed in Electric Arc Lamps.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in Means for Automatically Controlling the Carbon
Feed in Electric Arc Lamps.
I, HENRY JAMES FISHER, of 102, Shooter's Hill Road, Blackheath, in the
County of Kent, Electrical 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.:--
My invention has for its object the better self-controlling and self-regulating of
the carbon feed in electric are lamps whereby a finer feed and a steadier light are
obtained and also economy of space in the lamp is effected.
My improvements comprise a novel arrangement of feed controlling gear and a
simple variable resistance device for hot wire operating systems. In my improved
feed controlling gear I employ one wheel (hereinafter called the "carbon actuating
wheel") adapted to directly operate the upper carbon holder; it is immaterial how
such operation be effected, whether by teeth upon said wheel engaging a rack as
usual or by a groove and flexible cord and weight or otherwise. The said wheel is
fixed on a spindle carried by the lamp frame, and it is placed in operative
connection with a brake wheel mounted loose upon the same spindle, or upon a
separate spindle in same axial line, and such operative connection is effected by
any suitable kind of multiple, epicyclic, internal, or other multiplying gear in such
manner that the brake wheel will move at a greater speed than the first said wheel
for the purpose of ensuring fineness of feed. Upon the same spindle or arrange-
ment of spindles carrying the two said wheels is also mounted a rocking frame or
oscillating structure of limited motion, such motion being duly effected by the
action of solenoids or equivalents as hereinafter described. The brake acting on
the brake wheel is of suitable kind and mounted upon the rocking frame and
adapted to engage or free the wheel at the times and in any of the various manners
hereinafter fully set forth in reference to the annexed drawings illustrating my
invention and which will now be described seriatim.
Fig. 1 is an internal elevation of a focussing lamp generally arranged in the
usual manner except in regard to the feed gear; and Fig. 2 is plan at top thereof
showing one arrangement of my invention.
A is the carbon actuating wheel shown grooved and connected to the upper
carbon holder C by a cord c. This wheel is fixed on a spindle a, upon which is
also loosely mounted the brake wheel B, and the two wheels A and B are connected
by an intervened speed gear G, Fig. 2, of such kind as to impart 'to 'the wheel B
a very much higher speed of rotation than that of the carbon actuating wheel A.
R is the oscillating structure or rocking frame mounted upon the same spindle a,
and rare its fixed bearings. ss are adjustable stops for limiting the oscillation of
the frame R. S' is the main or series solenoid, S2 a shunt solenoid, 'both electrically
connected in the circuit in any usual way, for example as shown. are
respectively the cores of the two said solenoids. Dis the oscillating brake lever
centred at d upon a standard r, Figs. 1 and 2, 6ixed upon frame R, and overlying
the wheel B so as to engage same when required; the lengths of its arms are so
proportioned as to give the required leverages. The extremities of the arms
of said brake lever D are connected by links d' d' respectively to pivotted
extensions ss of the cores & 2 of the two solenoids S' S². Upon each link dd³
is a stop or stop bar a' a' working in and adapted to engage at times respectively
with chairs or guides 9' g fixed upon the frame R. These stops a' a' are adjustable
on the links d' d' so as to regulate as required the length of arc, and the solenoids

page_text: and guides yg may also be horizontally adjustable to suit the length of brake
lever D required.
Normally with no current on the carbon points are separated and the brake is on
the wheel B; therefore when the current is switched on to the lamp it will flow
through the shunt solenoid S, draw down its core and link d³, this removing
the brake D from wheel B, and the carbons will run together by gravity. Then
the current will flow through solenoid S' and the carbons, the core then draws
down through link d and stop al of that end of the frame R, and this serves
through the motion of wheel A to separate the carbons and strike the arc, at the
same time re-applying the brake and preventing the feed mechanism from moving
until the brake is again released. Should the carbons be in contact when current
is switched on to the lamp; the current passing through the series solenoid S' will
separate them as above described and brake the wheel.
The above fairly illustrates the adaptation of the essential part of my invention
to a two-solenoid lamp, but the same essential principle is easily adaptable to
various kinds or arrangements of lamps and brakes, some of which I will now
describe in reference to the diagrammatic figures given in which the same reference
letters indicate the same or analogous parts to those above described.
In these the wheels, gear, and rocking frame remain the same, but the brake is
differently arranged, though its mode of operation is similar or equivalent. Only
one solenoid may be used either in series or shunt, and for it may be substituted
hot wire arrangements adapted on passage of an electric current to give a small
mechanical motion which is capable of multiplication in any desired degree.
In Diagram 3 one series solenoid S only is used; the brake D acting on wheel B
is centred as shown below the rocking frame R and coupled by link d" to the core s
of an actuating magnetic solenoid S.
Normally with no current the weight of the iron core s holds the brake D off
wheel B and supported by the adjustable stop t, and the carbons touch. On
current being switched on, solenoid S applies brake and lifts the frame R, thereby
causing the are t be struck as above explained.
In Fig. 4 high resistance solenoid S'in shunt upon the carbons is used, the
weight of the core 2 holding the brake on the wheel B so that normally the
carbons are separated. The effect of the current in solenoid S2 is to lift up
the brake and release wheel B; the frame R is also raised and the carbons run
together; then the current dimini-hing in solenoid S the brake is applied, the
frame falls, and the are is thereby struck.
Passing to Fig. 5, a hot wire device H' in series with the carbons is substituted
for the solenoid S in Fig. 4. When the current is off the wires h thereof are cold
and lift brake of wheel as shown and the carbons touch. The heating effect of a
passing current lengthens the wires h, applies brake, and allows frame R to drop,
thereby striking are.
In Fig. 6 is shown an arrangement of brake similar to that in Fig. 3, but here a
hot wire arrangement of high resistance H in shunt upon the carbons is used.
When the current is off, the contraction of the wires in H2 applies brake D to
wheel B and lifts the frame. The heating effect of the passing current serves to
lengthen the wires in H, remove brake, and carbons touch. Then as the current
lessens in the shunt which is of greater resistance than the carbons, the wires cool,
lift the frame, and apply the brake, thus striking the are.
Fig. 7 illustrates a simple device which I have designed for readily varying the
resistance and range of expansion or movement of a hot-wire system. represents
the wire or wires enclosed in a casing M. L is a bar of good conducting material
adapted to slide in a clip guide m fixed to the casing M. To its lower end is fitted
a split arm with clamping screw adapted to embrace the wires à firmly. The.
current flows through bar L and arm l, and such part of the wires has
intervenes, ace rding to the position on. them of the arm I, between said arm / and
the conductor P, and hence the resistance and range of movement of the system
can be varied at will.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The arrangement of gear for automatically controlling the carbon feed in
electric arc lamps in which the carbon actuating wheel A is fixed on a spindle
carrying also a loose brake wheel B, the two being connected by intervened speed.
gear G, and a rocking frame R carrying the brake D, said spindle being mounted
in the frame of the lamp, and the brake being automatically operated as and when
required so that a fine and steady carbon feed action is obtained, all substantially
as above set forth.
2. The arrangement in combination with the feed gear wheels and rocking
frame carried upon one spindle as above described, of the oscillating brake lever
having its ends connected as specified by links to the cores of a series and shunt
solenoid, connected and adapted for automatic operation at the times and practically
in the manner above described in reference to Fig. 1 of the drawings.
3. The arrangement in combination with the hereinabove described feed gear of
one actuating solenoid or one hot wire device, either in shunt or in series with the
carbons and adapted to operate the brake and rocking frame and control the carbon
feed substantially as described and illustrated.
4. The combination with my improved mechanism of the several arrangements
of electro-magnetic and hot wire devices shown respectively in Figs. 2 to 6 of the
drawings, and respectively adapted to operate as above set forth.
5. The use in connection with the feed controlling mechanism of an arc lamp of
a single hot wire device of certain or variable resistance whereby the feed is
effected and also the arc struck when required, as described in reference to
Fig. 7.
Dated thi 101
1100a