AN IMPROVED ELECTRIC ARC LAMP
Year: 1884

page_text: I AMOS WILLIAM RICHARDSON of 11 Devonshire Street Chorlton-on-Medlock
Manchester in the County of Lancaster Engineer do hereby declare the nature of
my invention for "AN IMPROVED ELECTRIC ARC LAMP "to be as follows:-
The object of this invention is to maintain a constant arc by the action of
clockwork.
In the first place a toothed wheel of the clockwork gears into a rack forming the
upper carbon holder and is raised to form the arc by means of a main magnet the
core of which is wound round with a coarse wire.
"
The armature: is fixed in two side levers, the other end of which carries the clock
work, and when the armature is attracted by the magnet it raises the rack and
clockwork and brings a brake wheel in the clockwork up into contact with a brake.
This brake is fixed on an armature which is raised by an inverted "shunt"
magnet. The brake wheel has a reciprocating motion like the balance wheel of
a watch and is driven by a verge escapement from the crown wheel of the
clockwork.
;
When the tension spring is adjusted to the are resistance, the brake is raised by
the "shunt" magnet every few seconds and thus lowers the upper carbon tooth by
tooth which maintains the arc at all times the same size.
The brake or balance wheel can be fitted with adjusting screws in the rim. which
can be drawn out to reduce the speed and cause the carbons to come together more
slowly.
.
.
The lamp is fitted with a cylindrical iron case constructed with the top frame
work, and the clock movement with the magnets complete is attached to the top
cover which when fixed in place is secured by a screw.
GEORGE DAVIES,
Agent for the Applicant,
4, St. Ann's Square, Manchester.

page_text: COMPLETE SPECIFICATION.
I, AMOS WILLIAM RICHARDSON of 11 Devonshire Street Chorlton-on-Medlock
Manchester in the County of Lancaster Engineer do hereby declare the nature of.
my invention for "AN IMPROVED ELECTRIC ARC LAMP" 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 this invention is to maintain a constant are by the action of
clockwork.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the annexed sheet of drawings and the following explanation thereof.
Fig. 1 is a front view and Fig. 2 a side view of my improved arrangement of
mechanism for this purpose, both views being drawn partly in section.
In the first place a toothed wheel a, a of the clockwork gears into a rack b, b
forming the holder for the upper carbon point c, the lower carbon point c¹ being
carried in a fixed holder in the usual manner; and the rack b, b (together with the 1
whole of the clockwork) is raised to form the arc by means of the main magnet d, d
the core of which is wound round with coarse wire.
The armature e, e of this magnet is fixed in or attached to two side levers f, ƒ
the other ends of which carry the frame g, g of the clockwork, and when the
armature c, e is attracted by the magnet d, d it raises the rack b, b and the clock-
work, and brings a brake wheel h, h in the latter into contact with a brake lever i, i
as shown on the drawing.
This brake lever i, i is held down by an adjustable tension spring k, k and has
fixed to it an armature l, which is raised (as hereinafter described) by an inverted
"shunt" magnet m, m.
The brake wheel h, h also acts as a balance wheel, having a reciprocating
movement like the balance wheel of a watch and is driven by a verge escapement
from the crown wheel n, n of the clockwork, the weight of the rack b, b being the
motive power.
The tension spring k, k having been adjusted to the arc resistance, whenever that
resistance becomes increased by the burning away of the carbon points the "shunt"
magnet m, m becoming stronger in proportion overcomes the resistance of the
spring k,k and raises its armature and the brake lever i, i and sets free tho
clockwork.
This occurs every few seconds and thus the upper carbon c is lowered by the
rack b, b tooth by tooth precisely at the speed required which maintains the
electric arc at all times the same size and thus the light is kept perfectly steady.
The brake or balance wheel h, h can be fitted with adjusting screws in the rim
which can be drawn out to reduce the speed and so cause the carbons c, c¹ to come
together more slowly if desired.
The apparatus is fitted with a cylindrical case o, o and is carried by a
frame p. p.
Fig 3 is a diagram illustrating an alternative or differential arrangement of the
main and shunt magnets or solenoids so that they act together and the brake lever

page_text: is dispensed with. The coils q, q are both made hollow and the two bolts or
cores r, which act as armatures are connected together or they may be formed in
one. The lever fis connected to the clockwork at the other end and raises it against
a fixed brake.
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 an electric-arc lamp mounting the clockwork which actuates the upper
carbon holder upon a lever or levers, the other end of which is attached to the
armature of the main magnet, so that when the armature is attracted or solenoid
the clockwork and the carbon-holder are raised together to form the arc, and the
brake wheel of the clockwork is held against the brake lever to stop the action of
the clockwork,
Secondly attaching the armature of the "shunt" magnet to the brake lever so
that whenever the arc resistance becomes too great by the burning away of the
carbon points, the increase of the shunted current will raise the brake lever and
allow the clockwork to lower the upper carbon holder until the arc resistance
becomes normal.
Thirdly the construction of the clockwork with the verge escapement and brake
wheel substantially as hereinbefore described and illustrated, and
Fourthly claim the alternative or differential arrangement shown in Fig. 3
where the inverted shunt magnet or solenoid is placed above the main magnet or
solenoid and the two cores or bolts are so connected that they work together.
A.