Improvements in connection with the Supply of Current to and Governing Arc Lamps.
Year: 1897

page_text: Date of Application, 16th Mar., 1897
Complete Specification Left, 16th Dec., 1897-Accepted, 5th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in connection with the Supply of Current to and
Governing Arc Lamps.
I, FRANK MICHAEL LEWIS, of Blackman Lane, Leeds, in the County of York,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:
.
This improvement in connection with the supply of current to and governing of
arc lamps consists of means or apparatus which whilst changing the alternating
pressure from the supply mains to that required by the lamp at the same time
governs the lamp through any well known or suitable means.
The means or apparatus for obtaining this result consists of a fixed coil or coils
and a moveable coil or coils mounted over a laminated iron circuit of suitable
shape, the connections of the coils and to the supply mains being such that whilst
the alternating pressure is changed by an inductive action between the coils to
that required by the lamp the moveable coils are repelled by the fixed coils with
a force depending on the (amount of) current flowing through the lamp and thus
governs the lamp through any well known or suitable means.
The apparatus may be modified by using instead of the moveable coil or coils
a moveable keeper so placed between the coils and near the laminated iron circuit
or frame on which they are mounted that whilst the alternating pressure of the
current is changed by an inductive action in the apparatus to that required by the
lamp, the motion of the keeper governs the lamp by any well known or convenient
means.
D121. 1
1 1005
Improvements in connection with the Supply of Current to and
Governing Arc Lamps.
I, FRANK MICHAEL LEWIS, of 111, Gloucester Road, Brighton, in the County of
Sussex, formerly of Blackman Lane, Leeds, in the County of York, 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 relates to improvements in connection with the supply of current
to and governing arc lamps, by means of which certain advantages are obtained:
My invention is based upon the employment of what for the purposes of this

page_text: "
Specification I shall term a transforming actuator" "that is to say a device which
whilst performing the functions of a transformer in changing the alternating
pressure of the current supplied from the mains at the same time performs the
function of striking the arc and regulating the distance between the carbons during
burning.
""
**
In carrying my invention into effect I employ a transforming actuator of one of
three types, one of which I shall for the purposes of this specification term the
"movable coil transforming actuator type, the second the fixed coil transform-
ing actuator" type and the third the "compensating transforming actuator type.
In the accompanying drawings,
"
Figure I is a diagram illustrating the employment of the movable coil type of
transforming actuator.
Figure II a diagram illustrative of the fixed coil type of transforming
actuator.
Figure III is a diagram illustrating the known principle of a compensator.
Figure IV is a diagram illustrating the employment of a compensating trans-
forming actuator.
Figure V is a side elevation partly in section of the working parts of an arc
lamp constructed under my invention, and
Figure VI is an end elevation of the same parts.
Referring now to Figure I, 1, 1 are the supply mains and 2 the arc between the
carbons 3, 3. 4 is the magnetic circuit of a transformer of which the coils 5, 5
form the primary winding and 6, 6 the secondary winding. The primary coils 5,5
are connected directly to the mains or leads 1, 1 as shown whilst the secondary
coils 6, 6 are connected as shown to the carbons. Coils 6, 6 are stationary upon the
magnetic circuit whilst coils 5, 5 are connected together by a rigid support and
with the said support are capable of angular movement around the axis 7. When
the current is switched on to coils 5, 5 a secondary current is induced in coils 6, 6.
Repulsion will then take place between the movable and fixed coils as will be
readily understood and this movement is transmitted by any desired mechanical
transmitting mechanism to the carbons so as to regulate or govern the length of
the arc.
Figure II is a diagram illustrating a transforming actuator of what I have
termed the fixed coil type. In this case, 5 is the primary coil connected with
the mains and 6 the secondary coil connected with the arc 2. In this case it will
be noticed that both coils are fixed. 8 is a projecting pole piece upon the magnetic
circuit 4, and 9 is a soft iron keeper or armature hinged for example to the said
magnetic circuit. Here it will be seen that variations in the arc will cause
variation in the attraction between the projecting pole piece 8 and the keeper 9.
By connecting the carbons to the said Keeper 9 by means of suitable mechanism
the arc will be regulated as will be readily understood.
66
Figure III is a diagram illustrating the known principle of the compensator
(or what is sometimes termed an economy coil") which need not be described
here further than to say that the arc 2 is in shunt to part 6 of the coil.
Figure IV shows the application of the principle of the compensator to the form
of transformer shown in Figure I so as to constitute one form of a compensating
transforming actuator. Here it will be seen that the connections are the same as
in Figure III and that the length of arc is governed by the movement of the
coils 5, 5 as before.
I shall now proceed to describe an actual form of are lamp constructed in accord-
ance with my invention and which gives good results in practice. This form is
illustrated in Figures V and VI. I desire it to be understood that I lay no claim
to the mechanism by which the movement of the movable coils is transmitted to
the carbons. Referring now to these figures, 4 is the magnetic circuit of the com-
pensating transformer consisting as usual in transformers of thin laminae of soft
iron. 5, 5 are the movable coils and are rigidly attached together and free to
turn angularly on the centre 7. 6, 6 are the fixed coils. 10 is a connecting rod

page_text: articulated at its upper extremity 11 to the lower cheek of movable coil 5 whilst
its lower extremity is articulated at the point 12 to the lever 13 which is capable of
angular movement on the spindle 14. Upon the said spindle 14 is mounted a
pulley 15 which is capable of turning independently of lever 13. Over the said
pulley 15 passes the chain 16, 17, to the extremities of which are attached the
carbon holders, the part 17 of the chain leading to the upper carbon and the
part 16 to the lower carbon. The upper carbon holder is weighted so as to tend to
bring the carbons together by gravity. Upon lever 13 is pivotted the click or
break block 18 which is designed to engage either with the pulley or with the
cord itself when its extension piece 19 is unsupported by the stop, preferably
adjustable, 20. 21 is an adjusting weight capable of helical movement along the
threaded extension 22 of lever 13 as will be readily understood. 23 is a dash pot
cmployed for the usual well known purpose of dash pots in arc lamps.
The action of the lamp is as follows. Let us assume that the current is switched off
from the lamp and that gravity has brought the carbons together, the pulley having
turned freely owing to the break 18 being held in its removed position by stop 20
acting on extension piece 19. The carbons are now together as stated and the
coils are in the position shown in Figure V. Let us now assume that the current
is switched on. Coils 5, 5 are now repelled by coils 6, 6. Connecting rod 10 and
extremity 12 of lever 13 are depressed whilst the weighted extremity of the lever
is raised. Break block 18 is now no longer withheld from engagement with the
chain through extension piece 19 being supported by stop 20 and it therefore grips
the said chain and with further repulsion of the coils 5 causes part 17 of the chain
to be raised and the arc to be struck. As the current diminishes with the burning
away of the carbons, coils 5 approach more nearly to coils 6, extremity 12 of
lever 13 is raised and the carbons are brought closer together. Further movement
in the same direction causes disengagement of the brake block from the chain and
by repetition of this cycle of operations the arc is maintained constant.
It will be seen that by my invention several important advantages are obtained and
I am able to run alternating current lamps from the ordinary supply mains with-
out the insertion of resistances or choking coils. Thus in a recent test of one of
my lamps run from a 220 volt circuit, it used 2'67 amperes at that pressure whilst
873 amperes were employed on the arc at a lower pressure.
Of the types of my device specified I prefer the compensating transforming
actuator type.
I desire it to be understood that I do not limit myself to the precise form of
transformer actuator herein decribed. It is obvious that anyone skilled in the
art to which my invention appertains may modify details to an indefinite extent
without departing from the spirit of my invention.
It will be understood that the compensating transforming actuators may be
made with fixed coils as well as with movable coils, the principle of the com-
pensator being applied to the form of transformer shown diagrammatically in
Figure II instead of to that shown in Figure I. Thus under my third type of
transforming actuator I include not only compensating transforming actuators
having a movable coil or coils but compensating transforming actuators having
the coils fixed.
Having now particularly described and ascertained the nature of my
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The improvement in connection with the supply of current to and governing
arc lamps which consists in the employment of a transforming actuator, substan-
tially as set forth.
2. In an arc lamp, the employment of a movable coil transforming actuator,
substantially as and for the purpose set forth.
3. In an arc lamp, the employment of a fixed coil transforming actuator,
substantially as and for the purpose set forth.

page_text: 4. In an arc lamp, the employment of a compensating transforming actuator
whether of the fixed or movable coil form, substantially as and for the purpose set
forth.
For the Applicant,
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Norfolk House, Victoria Embankment, London, W.C.,
Chartered Patent Agent.