Improvements in Electric Arc Lamps.
Year: 1892

page_text: Date of Application, 5th Dec., 1892
Complete Specification Left, 5th Sept., 1893-Accepted, 4th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
I ARNOLD FRANK HILLS of The Thames Iron Works and Shipbuilding
Company Limited, Orchard Yard, Blackwall, London, Engineer, do hereby declare
the nature of this invention to be as follows:-
The object of the present invention is to improve the construction and general
arrangement of electric arc-lamps and of the parts constituting the same.
In carrying out my invention, 1 support the upper or positive (+) carbon in
a holder suspended by a copper ribbon, or other flexible conductor, wound on a
spring drum. The spring of this drum is not sufficiently strong to support the
weight of the carbon and holder, altho' there is power enough in it to wind up the
conductor, when relieved of the weight of the holder and carbon. The unwinding
of the druin, under the weight of the carbon and holder, is controlled by a clock-
work escapement device, which regulates the feed of the carbon according to
requirement.
The spring drum, and the escapement device, are mounted in a frame or bracket
hinged to the upper part of the frame of the lamp. This hinged bracket is provided
with soft iron horns of special curvature, which form the armature of an electro-
magnet, in a shunt or derived circuit, the pole pieces of the cores of which magnet
are curved to correspond with the curves of the armature.
A spring is provided to hold the escapement device against a fixed stop, to
prevent its action, except when the electro-magnet is energized, in which case, the
hinged frame is pulled over by means of the armature attached thereto, thereby
tending to release the escapement, and permitting the feed of the carbon to
proceed.
The special form of the pole pieces and armature horns, is that of circular arcs
struck from the same centre, which is also the centre of movement of the hinged
bracket or frame carrying the escapement device, the object being to secure a
nearly uniform pull of the magnet over a long range.
In lamps intended for parallel working, the carbons are apart when no current
is flowing. To strike the arc, the shunt circuit is energized by the passage of the
current switched on; the escapement is thereby released from the stop, and the
feed of the carbon takes place until contact between the carbons is produced. On
the passage of the main current through the touching carbons, the shunt electro
magnet loses its excitement, and permits the hinged frame, under the influence of
the antagonistic spring, to part the carbons, by lifting the drum with the flexible
conductor which supports the upper carbon thereon, and strikes the arc.
To strike the arc in lamps adapted for series working, the operation would be
somewhat different. The armature would in that case be provided with curved
horns looking either way, and would rock between the pole pieces of the shunt
electro magnets already described, and those of a differentially wound magnet
placed on the other side of the frame. One of the differential coils would be in
the main circuit, and the carbons would be in contact when the current was not
flowing. On the excitement of this magnet by the passage of the current
through the series coil, the carbons would be pulled apart and the arc "struck."
The carbon holders are by preference arranged to take carbons of any size, the
latter being held in position by set screws.
The positive (+) carbon holder is guided, in its descent, by rods of prismatic
section, so as to reduce the surface contact between the rods and the cylindrical
guiding hole in the carbon holder.
The base which supports the lower carbon holder is carried by iron rods in

page_text: electrical connection with the negative main, while the hinged frame, clockwork,
guides, and flexible ribbon conductor, are all electrically connected to the
positive (+) main.
Dated thin 5th 1D
1000
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
| ARNOLD FRANK HILLS of The Thames Iron Works and Shipbuilding
Company Limited, Orchard Yard, Blackwall, London, 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 the present invention is to improve the construction and general
arrangement of electric arc lamps, and of the parts constituting the same.
In carrying out my invention, I support the upper or positive (+) carbon in a
holder suspended by a copper ribbon, or other Hexible conductor, wound on a
spring drum. The spring of this drum is not sufficiently strong to support the
weight of the carbon and holder, although there is power enough in it to wind up
the conductor, when relieved of the weight of the holder and carbon. The
unwinding of the drum under the weight of the carbon and holder, is controlled
by a clockwork escapement device, which regulates the feed of the carbon according
to requirement. The varying weight of the conductor and carbon, as the former
unwinds and the latter burns away, is compensated for, when desired, by the use of
a coned pulley or fusee, or by the addition of counterbalance weights or chains, or
in accordance with any of the well known methods for preserving the moment of a
varying weight constant.
The spring drum and the escapement device are mounted in a frame or bracket
hinged to the upper part of the frame of the lamp. This hinged bracket is con-
nected, either directly, or through the medium of a system of levers or linkwork,
with soft iron horns of special curvature, which form the armature of an electro
magnet, or electro magnets, the pole pieces of the cores of which are curved to
correspond with the curve of the armature.
A spring is provided to hold the escapement device against a fixed stop, to
prevent its acting except when the electro-magnet is, or the electro magnets are,
energised, in which case the hinged frame is pulled over by means of the armature
attached thereto, thereby tending to release the escapement, and permitting the
feed of the carbon to proceed.
The special form of the pole pieces, and of the armature horns, is that of con-
centric circular arcs struck from the centre of motion of the armature frame,
the object being to secure a nearly uniform pull of the magnet over a long range.
There are several ways in which lamps designed in accordance with the above
description may be constructed, and the figures of Sheets I and II are intended to
show two typical instances of carrying the method into practice.
Figs. 1 and 2, Sheet I, show respectively the back and side elevation of a lamp
constructed according to my invention, and adapted for parallel working. In this
case, the coils of the electro magnet M form a shunt or derived circuit across the
terminals of the lamp.
The armature A is mounted directly upon the frame F which carries the spring
drum and escapement mechanism, and which is capable of moving bodily about
the fixed centre O. The carbons are held apart and the escapement kept at rest,
when no current is flowing, by reason of the spring S', which is carried by the fixed
bracket B pulling the frame over, until the escapement is brought into contact with
the stop S, which is supported upon an adjusting pillar P.
1,

page_text: When the current is switched on, the magnet M attracts its armature A, and
the escapement is thereby released from the stop, and the feed of the carbon takes
place until contact between the carbons is produced. On the passage of the main
current through the touching carbons, the electromagnet M loses its excitement,
and permits the hinged frame F, under the influence of the antagonistic spring S¹,
to part the carbons, by lifting the drum with the flexible conductor which supports
the upper carbon, thus striking the arc. The length of arc maintained in steady
burning will depend upon the position of the armature A, which again depends
upon the relation between the strength of the electro-magnet M and the tension
of the spring S¹.
Adjusting screws are provided for varying the tension of the spring S', the
position of the controlling stop S3, the angle of rotation of the rocking frame F,
and the position of the pole horns H H.
In lamps adapted for working in a group containing several in series, the
operation of striking the arc must be performed differently. The carbons must be
in contact when no current is flowing, and must be parted upon the switching on
of the main current. In one arrangement, I provide the armature with curved
horns looking either way, and capable of rocking between the pole pieces of the
shunt electro magnets already described and those of a series-wound magnet placed
on the other side of the frame, the spring S¹ being so adjusted that the carbons are
in contact when the current is not flowing. On the excitement of this magnet by
the passage of the current through it, the carbons are pulled apart and the arc
struck. As the arc lengthens, the feeding of the carbons is performed by the
attraction of the shunt electro magnet for its armature, assisted by the tension of
the spring S¹, overcoming the now enfeebled series electro magnet.
the
I prefer, however, to construct series lamps with a single pair of coils wound
differentially, so that the series and shuut coils oppose one another in the manner
common in arrangements for a similar purpose. The armature now acts upon
rocking frame through the medium of a system of levers or linkwork, of which
one arrangement is shown in Figs. 3 and 4, Sheet II. The armature A is carried
upon a lever L', centred at C, which now becomes the centre of curvature of the
polar horns, and this lever is connected, by means of a link L³, to L³, an arm or
crank rigidly attached to the rocking frame F. The other parts of the
arrangement correspond to similar parts in the lamp shown in Sheet I, and are
lettered accordingly.
The carbons being together, the effect of switching on the current is to energise
the series coil which causes the armature A to be attracted, and L³ to be lifted,
thereby rotating the frame F, and striking the arc.
The feeding is accomplished as in the last described instance, and the adjustment
of the arc at any moment depends on the attraction due to the resultant action of
the shunt and series coils of the electro-magnet and the tension of the spring St.
Similar adjustments are provided as in the parallel lamp. It is obvious that a
lamp constructed as in Figs. 3 and 4, may also be used on parallel circuits.
The positive (+) carbon holder is guided in its descent by rods of prismatic
section, so as to reduce the frictional contact between the rods and the cylindrical
guiding hole in the carbon holder.
The base which supports the lower carbon holder is carried by iron rods in
electrical connection with the negative main, while the hinged frame, clockwork,
guides, and flexible ribbon conductor, are all electrically connected to the
positive (+) main. I do not, however, base any claim upon these points.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved construction and arrangement of electric arc lamp herein
described and shown in the accompanying drawings.
2. The combination of a flexible conductor supporting the upper carbon holder,

page_text: and wound on a spring drum, a hinged frame carrying the said drum, and clock-
work escapement mechanism for regulating the feed of the carbon, with electro
magnetic arrangements for effecting the movement of the rocking frame, áll
arranged and operating substantially as described with reference to the drawings.
3. Mounting the winding drum of the flexible conductor supporting the upper
carbon holder of an electric arc lamp in a hinged frame, the rocking of which frame
in the manner described with reference to the accompanying drawings, lifts the
carbon holder to strike the arc.
4. The specially curved iron horns and poles for the magnet and armatures as
shewn and described, and for the purpose set forth.
Dated this 5th day of September 1893.
NEWTON & SON,
Agents for the Applicant.