CONSTRUCTING & REGULATING ARC LAMPS
Year: 1888

page_text: Date of Application, 11th Feb., 1888
Complete Specification Left, 11th Dec., 1888
Complete Specification Accepted, 11th Feb., 1889
WALTER ROWBOTHAM 39 Lever Street Manchester Electrical Engineer do hereby
declare the nature of my invention for CONSTRUCTING & REGULATING ARC LAMPS to
be as follows :-
-
In this invention 1 employ a tube which acts as a guide to the top centre holder
and at the top end of the tube i fix a platform carrying on its underside two solenoids,
one wound with thick wire and connected in the main circuit known as the series
solenoid and the second of fine wire connected in a by pass to the lamp circuit known
as the shunt solenoid.
On the top side of the platform I fit two bearers carrying a spindle, on which is
fixed a wheel which works inside a loose wheel, there being a suitable known lever
break attachment between the fixed wheel and loose wheel, the loose wheel being
grooved I attach a chain from the aforesaid lever break which passes round the
grooved wheel and is attached at the other end to an iron core which works in the
aforesaid shunt solenoid. I employ a similar iron core in the series solenoid attaching
at the top end a chain which passes round the grooved pulley and is fixed to it clear
of the break.
•
About the centre of the spindle I place a toothed wheel over which passes a flexible
rack then through the aforesaid guide tube which is fitted on the body of the lamp
and then attach it to the top or positive carbon holder whilst the other end of the
flexible rack passing over a guide pulley through a hole in the body of the lamp
is fixed on to the lower or negative carbon holder but insulated therefrom in the
usual manner.
The negative carbon holder being guided by the usual guide sides
and as I more heavily weight the upper carbon holder the two carbons are brought
together by the preponderance of this weight.
The action of the lamp being as follows when a current passes through the lamp it
Hows also through the series solenoid and causes the said solenoid to exert a magnetic
force and so lifts its core up it being so arranged that the lift is approximately pro-
portional to the amount of current flowing and as the shunt core is weighted so that

page_text: by means of its preponderance of weight it applies the break and turns the grooved
pulley thereby separating the carbons until checked by the series core then as the
voltaic arc increases by the consumption of carbon less current passes through the
Lamp circuit thereby letting the series core descend into the series solenoid, this
motion continues until the series core is down low enough for the series core to release
the break thereby letting the wheel rotate under the controle of the balancing forces
of the said shunt core and the balance weight mentaining a constant distance between
the points of the carbons, the shunt core and solenoid being soley used as a balance
weight to the top or positive carbon holder and also to increase the delicacy of the
movement of the series core as a portion of the current passes through the shunt
solenoid it being in a by pass to the lamp circuit.
Dated this Tenth day of February One thousand eight hundred and eighty-
eight.

page_text: COMPLETE SPECIFICATION
An Improved Method of Constructing and Regulating Arc Lamps.
1 WALTER ROWBOTHAM of Nos. 25 & 27 Sidney Street, Salford Manchester
Electrical Engineer and Manufacturer 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 :-
According to my invention I employ a tube which acts as a guide for the positive
or upper carbon holder and at the top end of the said tube I fix a platform J Figs. 1
& 2, carrying on its underside two solenoids one A wound with thick wire and
connected in the main circuit known as the series solenoid and the other B of
fine wire connected as a by pass or shunt to the lamp circuit known as the shunt
solenoid.
On the top side of the platform J Figs. 1 & 2. I fix two hearers carrying a
spindle H, Figs. 1. 2. 3. on which spindle is placed a wheel E which works inside
a larger loose wheel F there being a suitable known lever or other brake attachment I
between the fixed wheel E and the loose wheel F.
The loose wheel F being grooved I attach a chain to the aforesaid brake wheel F
which chain is partly passed round the loose wheel and is attached at its other end
to an iron core B' which works in the aforesaid shunt solenoid B.
•
1 employ a similar iron core A¹ in the series solenoid the chain from which is
attached to the loose wheel F clear of the brake.
The centre part of the wheel E is toothed over which passes a flexible rack passing
down the aforesaid guide tube and is then attached to the upper carbon holder (the
other end of the flexible rack passing over a guide pulley and is fixed to the negative
or lower carbon holder D but insulated therefrom in the usual manner.
The negative carbon holder D is guided by the usual arrangement of rods and as
I more heavily weight the positive carbon holder C the carbons are brought together
by the preponderance of this weight.
The action of the Lamp is as follows, on a current of electricity passing thro the
lamp, it passes also thro the series solenoid A and causes the said solenoid to exert a
magnetic force & so lift the iron core A¹ it being so arranged that the lift is approxi-
mately proportional to the amount of current Howing through & the shunt core B¹
being weighted, it applies the break and turns both wheels thereby separating the
carbons until checked by the series core A¹ then as the voltaic arc increases by the
consumption of carbon less current passes thro the lamp circuit allowing the series
core A to descend and this motion continues until the series core A' is low enough
to allow the shunt core B to release the break I thereby allowing the wheel E.
to rotate under the control of the balancing forces of the shunt core B₁ and the
balance weight C maintaining a constant equal distance between the points of the
carbons.

page_text: The shunt core B' and solenoid B are solely used as a balance weight to the
positive carbon holder C and to increase the delicacy of the movement of the series
core A¹
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. An arc lamp in which the regulation is effected by the series core being lifted,
thereby allowing the voltaic are to be struck by either a balance weight or shunt core
and regulated by the current varying in the series solenoid said variation being caused
by the increase or decrease of resistance of the voltaic arc.
2. An arc lamp in which the series solenoid raises its core allowing either a counter-
weight or shunt core to regulate the voltaic arc.
Dated this Tenth day of December 1888.