IMPROVED ELECTRIC ARC LAMP
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Herbert Trott and Charles Frederick
Fenton at the Office of the Commissioners of Patents on the 21st February
1883.
EERBEKT TROTT, of High Street Battersea Surrey Engineer and CHARLES
FREDERICK FENTON of River Bank Twickenham Middlesex. Gentleman
IMPROVED ELECTRIC ARC LAMP
AN
The improvement relates firstly to a mode of regulating the Feed of Carbons of
an Electric Arc Lamp by means of a flat horse shoe Maguet wound with coarse
and fine wire, the fine being laid in an opposite direction to the coarse.
The Poles of said Magnet are flat and turned up at right angles to the hub and
are bored out to admit of the free rotation of an iron Disc or Wheel Armature
therein the said Armature being attached to the last notion of a Train of Four
Wheels, the first motion of which is in connection with the upper Carbon holder
and Rod the said train of wheels being actuated by the weight of above rod the
two being connected together by a Metallic band hereinafter mentioned.
The Fine Wire on Regulating Magnet is in connection with the coils of another
Magnet of considerable resistance, the Iron core of which on Arc being struck and
a current therefore passing around it attracts a soft iron armature with a small pad
in connection thereto such pad being thereupon lifted from the periphery of Rotary
Armature above described and allowing train of wheels freedom but on break of
current the pad again falls thereby arresting motion of train and feed of upper
carbon.
The resistance of wire of above Magnet also affects the amount of Shunt current
passing the coils of Regulating Magnet with which it is in connection thereby
varying the strength of Magnetism in its flat poles by neutralizing the main current
which is also passing around it and therefore allowing the rotation of the Iron
Wheel Armature.
This arrangement also making the Lamp suitable to be worked with others in
Series.
The Invention relates secondly to the application of Metallic Bands for the
purpose of conveying motion from upper Carbon Rod to double drum, such drum
being fixed on the first motion of the train of Wheels.
The Band from top of said Rod is attached to one side of Drum left handed, and

page_text: from bottom of same rod to other side of Drum right handed the effect of this
arrangement being to cause an even motion between train of wheels and rod.
To spindle of first motion of train is attached a ratchet wheel and against same
but loose on spindle a tooth wheel the first gearing wheel of said train and on same
is fixed a pawl which engages in the teeth of the said ratchet wheel on the descent
of upper carbon rod; but on raising same to renew the carbons the pawl frees itself
and passes over the teeth of said ratchet wheel, the train of wheels and locked
rotating armature in the meantime remaining stationary.
The Invention thirdly relates to a novel description of double pole Reel Arc
Magnet attached to lower rod of lamp thereby allowing said rod to be made a
fixture at top on underside of frame which magnet has two circular shaped pole
pieces one at each end of Iron reel, the two soft iron armatures belonging thereto
being connected by a brass guide rod passing through and fitting said reel which
top armature is attached to the lower carbon holder but insulated therefrom.
The Brass guide rod is hollowed out at bottom to admit of a spiral spring being
inserted therein which spring bears against solid top of guide rod and internal
bottom pole piece of magnet reel.
-
Through centre of spiral spring and fixed into the solid guide rod at top is a
small brass rod which rod passes through an orifice in bottom pole piece and is
threaded and has adjustment nut theroon for the regulation of the length of Arc.
This Magnet is wound with coarse wire and is in the main circuit.
The Invention further relatos to the construction of an Electric Arc Lamp
having two or more pairs of Carbons and for the regulation it is proposed to use
the same self acting feed arrangement as before described but in order to divert the
current from one pair of Carbons to the other a switch magnet is employed with
short circuiting device.
The consumption of the first pair of Carbons causes the lowering of upper carbon
rod a. pin in which rod makes contact with a metallic pad on one end of a Tilting
lever thus causing shunt current to be diverted to Switch magnet at the same time
canting the above lever out of contact with pad in connection with fine wire on
first regulating magnet and into contact at other end of lever with a pad in circuit
with second regulating Magnet.
On the current passing the coils of Switch magnet the Armature belonging
thereto is attracted thereby lifting detent fixed to said armature out of a catch
plate on a spring lever which lever and detent form part of circuit of above magnet
which action causes lever to fall over breaking. switch contact and tripping a pad
off second train of wheels thereby allowing train to run and carbons to meet thus
short circuiting the main current from first pair of same..
On Lamp requiring the Carbons to be renewed the act of returning upper carbon
rod to the top causes a metal. projection on same rod to strike a pin standing out
under top frame of lamp and in connection with spring lever above referred to
causing same to be returned and locked by detent in old position thus making
circuit to switch magnet through detent and catch.-plate on lever complete again
and also allowing pad to fall on second Train of Wheels.
It is finally proposed as an alternative to use the Rack motion instead of the
Metallic Band herein described as a connection between upper down Rod and Train
of Wheels.