Improvements in Electric Arc Lamps.
Year: 1891

page_text: Date of Application, 6th July, 1891
Complete Specification Left, 6th Apr., 1892-Accepted, 6th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
HOWARD DUDLEY NORMAN of 2 Rochester Gardens Brighton in the County
of Sussex England, Electrical Engineer HENRY ALFRED PAYNE 28 Cannon Place,
Brighton Schoolmaster do hereby declare the nature of this invention to be as
follows:-
In my improvements I wind my solenoid upon a bobbin of toughened glass, or other
similar material, which cannot be charred by the heat generated by Foucault currents,
I also claim the use of toughened glass or other similar material, for the prevention
of heat generated by Foucault currents in any electrical instrument or machine
either used as a bobbin or in other form.
The improvements in the striking & feeding mechanism are substantially as
follows: From the bottom of the iron solenoid core, which is hollow so as to
allow the upper carbon carrier to pass through it, two arms are pivotted at opposite
ends of a diameter of its circular section, the lower ends of these are again
pivotted to two other arms, which point in towards the upper carbon carrier; the
ends of this pair of arms, nearest the upper carbon carrier, are shaped so as to form
a clutch, with, or without springs; the other ends being hinge jointed to two
standards which also form the support for the top of the lamp.
The action of the lamp is as follows:-When no currrent is passing the clutch
ends of the lower arms hang slightly downwards & are free of the upper carbon
carrier, therefore, by reason of its own weight, the upper carbon rests upon the
lower carbon.
As the
When the current is turned on the hollow solenoid core is attracted upwards,
bringing with it the two pairs of arms mentioned above, the clutch ends of the
lower arms are thus pulled up, and, by reason of their point of suspension, together,
gripping the upper carbon carrier & raising it, thus striking the arc.
carbons burn away the resistance of the arc increases & the solenoid permitts its
core to fall slightly, with the result, that the clutch releases the upper carbon
.carrier which descends by its own weight & and re-establishes the proper length of
arc. The force of gravity & the pull exercised by the solenoid are thus
continually balancing each other with the result that a constant length of arc
is. maintained.
Dated this 27th day of June 1891.
H. DUDLEY NORMAN.
H. A. PAYNE.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
We HOWARD DUDLEY NORMAN Electrical Engineer, of 69 Brunswick Place
Brighton, in the County of Sussex England & HENRY ALFRED PAYNE School-
master of 28 Cannon Place, Brighton in the County of Sussex, England 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:-
In these our improvements we use a former of toughened glass or other similar
material 1 upon which is wound the solenoid 2 this solenoid may be either shunt &
series or simply, series, the method of winding depending on whether the circuit

page_text: on which the lamp is to be used is either of varying or constant potential. The
lamp may be used equally well on either alternating or direct current circuits. The
object of using a bobbin core of glass or other similar material is to prevent
heating due to Foucault or eddy currents which are liable to destroy the insulation
of the solenoid & finally to short circuit it altogether: The glass bobbin core
above mentioned is a distinct feature of our improvements as hereinafter stated,
the arrangement of the bobbin is such that practically no strain is put upon
the glass.
At
The bottom end 3 of the solenoid bobbin in Fig. 3 has a cavity.4 on its upper
side into which the glass is fixed, the bottom cavity 5 forms a dash pot in which
the hollow metal piston 6 works, to the top of the said piston is fixed the soft iron
solenoid core 7 also hollow, through which passes the upper carbon carrier rod 8
also of Fig. 7, from the bottom of hollow piston 6 two arms 9 & 10 are hinged or
pivotted hanging downwards at opposite ends of a diameter of the said piston as
shewn in Fig. 1; the length of these arms can be varied to adjust the striking &
feeding of the lamp. The position of solenoid 2 can also be altered either up or
down for the same purpose of adjusting the striking & feeding of the arc.
their lower ends the arms 9 & 10 are pivotted by a moveable pivott to the arms 11
& 12 the said arms 11 & 12 being at their outer extremities hinge-jointed to the
supports 13 of the solenoid bobbin & top plate or to standards specially provided.
The ends of the arms 11 & 12 adjacent to the upper carbon carrier rod 8 are formed
so as to grip the said rod when pulled up. This clutch end 14 may be made with
or without springs, the object of the said springs being to prevent the arms 11
& 12 from getting jammed too tightly against the upper carbon carrier 8. Some
forms of the clutch are shewn in Fig. 4, but these of course may be very much
varied, the two drawings on the left hand of Fig. 4 represent a plan & elevation
of one form of this clutch in which the clutch itself is carried at the end of a flat
spring about one inch long, the centre drawing shews a form without springs but
which may be supplied with a facing of rubber or other similar material. The
right hand drawing of Fig. 4 represents a form of clutch in which the arms 11 & 12
of Fig. 1 are hollow & contain a spiral spring shewn in the said right hand
figure of Fig. 4 & against which the clutch works.
When no current is passing through the lamp the clutches & solenoid core 7 are
prevented from dropping by stops placed in the hinge joint 15 of the clutch arms.
The arms being in position shewn in Fig. 1 it will be seen that the upper carbon
carrier 8 is quite free except where it passes through the gland 16 which is screwed
to the sole-plate 17, the object of the gland 16 is to keep the upper carbon carrier
rod 8 in a perfectly vertical position. The actual carbon carrier 18 is made
slightly taper & tapped with a thread on the outside it has also several saw cuts
in the direction of its axis, so that to fix in carbon pencils 26 & 27 it is only
necessary to turn milled nut 19 of Fig. 5 the loops 20 are for hooking into the
chain or braid which passes over the pulleys 21 to lower carbon holder, the said
braid or chain being of course insulated from the lower carbon holder.
The guides 22 of the lower carbon holder are electrically insulated from the sole
plate 17 by means of collars & washers of ebonite or other insulating material &
by means of the stop 23 in the said guides the circuit is automatically broken by
preventing the bottom carbon from rising, & thus lengthening the arc until the
lamp is put out, thus preventing the burning of the holders 18 should the lamp be
accidentally left on too long, the stops may be also used for putting the lamp out
at any stated time by simply shifting them up or down.
The action of the lamp is as follows-In its normal position upper carbon rests
upon lower carbon by reason of its slightly greater weight, on the currents being
turned on, it enters the lamp say by terminal 24 passes through solenoid 2 on to
the nut forming the top of the rod 22 & up through bottom carbon & top carbon to
case & terminal 25 which is fixed to case, terminal 24 is of course insulated from
In passing through solenoid 2 current exerts an upward pull on its iron
core 7 drawing it into bobbin & bringing with it the two armis 9 & 10 which in turn
case.

page_text: pull up & by reason of their point of suspension together the clutches 14 which
grip the upper carbon carrier rod 8 & raise it, thus striking the arc.
As the carbons burn away the resistance of the arc increases with the result
hat less pull is exercised by the solenoid on its iron core 7 which slightly descends
freeing the upper carbon carrier of the clutches 14 & allowing it to descend &
re-establish the proper length of arc. In practice the lamp is so adjusted that only
very slight movement takes place, the force of gravity & the pull of the
solenoid tending to balance each other with the result that a constant length of are
s maintained.
Fig. 1 shews section of lamn.
pull up & by reason of their point of suspension together the clutches 14 which
grip the upper carbon carrier rod 8 & raise it, thus striking the arc.
As the carbons burn away the resistance of the arc increases with the result
hat less pull is exercised by the solenoid on its iron core 7 which slightly descends
freeing the upper carbon carrier of the clutches 14 & allowing it to descend &
re-establish the proper length of arc. In practice the lamp is so adjusted that only
very slight movement takes place, the force of gravity & the pull of the
solenoid tending to balance each other with the result that a constant length of arc
s maintained.
Fig. 1 shews section of lamn.
Fig. 2 shews side elevation.
Fig. 3 shews dash pot, piston, core & upper carbon carrier rod in section
& plan.
Fig. 4 shews some proposed forms of clutch.
Fig. 5 shews actual carbon carrier or holder.
Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is :-
:―
1st. The useing of a former of glass or other similar material for the prevention
of heating due to Foucault or eddy currents.
2nd. The general arrangement of dash pot, core & clutches.
3rd. The arrangement of carbon carrier rod for its easy removal for cleaning &
inspection by simply unhooking the braid or chain from the top of the carbon
holder or carrier.
4th. The use of variable stops in the guide rods for the bottom carbon carrier,
for automatically breaking the circuit when the carbons are sufficiently burnt away,
or at any time.
5th. The form of carbon carrier or holder shewn in Fig. 5.
H. D. NORMAN.
H. A. PAYNE.