Improvements in Electric Arc Lamps.
Year: 1893

page_text: Date of Application. 5th Aug., 1893
Complete Specification Left, 7th May, 1894-Accepted, 9th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps.
We, HENRY HAYES COOPER of 64 Victoria Street, London, S. W. Electrician
and THE ELECTRICAL INSTALLATION COMPANY LIMITED, also of 64 Victoria
Street, aforesaid, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in electric arc lamps for alternating or
continuous currents and has for its principal object to provide an automatic regulator
whereby feed motion of the carbons is effected in so gradual and efficient a manner
as to have no perceptible effect on the light.
The invention consists essentially in a pneumatic feed regulator in the form of a
bell chamber sealed by immersion in glycerine or other liquid in combination with
an air valve controlling the admission or escape of air to or from the chamber, as
the case may be, and actuated by the core of a solenoid in a shunt to, or in series
with the arc.
It is preferred that the pneumatic regulator should act by vacuum, the external
air pressure upon the bell chamber being applied to counterbalance the upper
carbon holder and its adjuncts as hereafter described, the feed of the carbons
depending on the admission of air to the bell chamber by the air valve under the
control of its operating solenoid.
The air valve is spring-closed and it may be opened either by hand for bringing.
the carbons together at first starting or by its operating solenoid for subsequently
controlling the feed.
The bell chamber is preferably cylindrical and is suitably guided in its vertical
motion and within it rises the air admission tube.
The bell chamber is suitably loaded to counterbalance the carbon holders to
which it is connected by a chain or other flexible connection passing over pulleys,
the arrangement being preferably such that the range of motion of the upper carbon
holder is double that of the bell chamber whereby a purchase is obtained.
The invention further consists in making the arc-striking electro-magnet movable
with the upper carbon holder so that its weight is utilized to overcome friction and
the weight of the lower carbon holder. For this purpose the electro-magnet is
suspended by the chain, counterbalanced by the air chamber as above mentioned,
and arranged to slide on vertical guide rods, the upper carbon holder being attached
to the armature which retracts the upper carbon the proper distance for striking
the arc.
The magnet is in series with the arc and the descent of the magnet and holder
together under the control of the air chamber produces the feed as above mentioned.
The invention further consists in the combination, with the pneumatic regulator,
of a brake applied by a spring and released by the air valve operating solenoid at
the moment when the feed takes place, so that the motion is at other times checked
in such manner that the excessive feed by reason of vibration or shock, or the
magnet overcoming its armature by its acquired momentum under careless handling
or otherwise is prevented. This brake is in the form of a strap encircling a brake
wheel on the axis of one of the suspension chain wheels and operated by a lever
which is acted on by the solenoid core in opposition to a spring.
The invention further consists in an adjustable carbon holder whereby to rectify
defective alignment of the two carbons by reason of either carbon being bent or not
fitting its socket and being consequently forced by the clamping screw out of the
centre line.

page_text: The improvement which is applied to the lower carbon holder consists in
mounting the carbon socket on an eccentric screw stud which. passes through a
slot in the cross-bar of the holder and is secured by a wing nut, so that by sliding
the stud in the slot, or turning the socket upon the stud as a centre, adjustment in
any desired direction of the lower carbon with regard to the upper one may be 5
effected.
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
We, HENRY HAYES COOPER, of 64, Victoria Street, London, S.W., Electrician,
and THE ELECTRICAL INSTALLATION COMPANY, LIMITED, also of 64, Victoria
Street, aforesaid, 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:-
This invention relates to improvements in electric arc lamps for alternating or
continuous currents, and principally to a pneumatic regulator whereby the feed
motion of the carbons is effected so gradually as to have no perceptible effect on
the light.
The pneumatic feed regulator comprises a bell chamber sealed by immersion
in liquid, in combination with an air valve controlling the admission or escape of
the air and actuated by a solenoid in a shunt to, or in series with, the arc.
It is preferred that the pneumatic regulator should act by vacuum and that the
external air pressure upon the bell chamber should support the unbalanced weight
of the upper carbon holder and its adjuncts, the feed of the carbons depending on
the admission of air to the bell chamber through the air valve under the operation
of its actuating solenoid.
With the pneumatic regulator is combined a brake to check the feed motion,
this brake being released by the motion of the solenoid core when the air valve is
opened to permit the feed to take place, the brake serving to prevent excessive
feed in consequence of vibration, shock, or careless handling.
The invention further consists in making the arc-striking electro-magnet
movable with the upper carbon carrier so that its weight is utilized to overcome
friction and the weight of the lower carbon-carrier.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein
Figure 1 is a sectional front elevation of the lamp, the section being taken
through the pneumatic regulator and valve.
Figure 2 is a side elevation of the lamp.
Figure 3 is a plan, with the top plate removed, and
Figure 4 is a horizontal section, on line 1-1.
The same letters of reference denote the same parts in all the figures.
The pneumatic feed regulator consists of a bell chamber A preferably in the
form of a cylinder open at bottom and closed at top. It is guided by circum-
ferential rings a in a cylinder B mounted on the frame of the lamp and the mouth
of the bell is sealed by immersion in glycerine or other suitable liquid contained in
said vessel. The vessel B has a chamber B' beneath it, from which an air tube b
rises within the bell chamber to a point above the level of the liquid in B. Air is

page_text: admitted to chamber B' through a passage c under the control of a valve C which.
is spring-closed and opened by the action of the solenoid K, as hereafter described..
The bell chamber A may be loaded if necessary, so that its weight, together with
that of the lower carbon holder, and the air pressure upon the bell will counter--
balance the weight of the upper carbon holder. For this purpose the chamber A.
is suspended in the bight of a chain D or other flexible connection which is made
fast at one end d to the head of the lamp frame, passes under a pulley a¹ on the
bell chamber over a chain wheel or pulley d¹ mounted on the lamp frame, and is.
attached to the upper carbon carrier, which is thus suspended so that it has a.
range of motion double that of the bell chamber.
The upper carbon carrier comprises a frame E sliding upon guide rods e and'
carrying the arc-striking electro-magnet F to whose armature f is attached the
rod g of the upper carbon holder G. "The electro-magnet F and carbon holder G
move together, the armature and the carbon holder having a limited independent
upward motion for striking the arc, the armature being shewn in the position.
before this retraction has taken place. The magnet F is in series with the arc,..
its coils being connected the one with the insulated terminal T and the other with
the iron of the magnet core, so that the current will pass from the magnet coils.
through the iron of the magnet and through the armature (which in normal
working is always in electrical connection with the iron of the magnet) and thence,.
through rod g, to the upper carbon holder G. The armature slides on brass polar
extensions which convey the current at starting. The magnet F and holder G
descend together, under the control of the vacuum bell, to produce the feed of the
carbons, as above mentioned.
Upon the axis of the chain wheel or pulley is a brake wheel I having a
milled periphery with which a pawlj carried by a lever J is caused to engage, by
the gravity of the lever, or by a spring.
The solenoid K is mounted on the frame and placed in a shunt to the are and by
it both the air inlet valve C and the brake lever J are operated, to permit the feed..
For this purpose the core k of the solenoid is partially counter-balanced by a
spring k, to render the action more sensitive, and is connected at the lower end to a
lever * pivoted to the lamp frame and acting on the stem of the air valve C, whilst
a rod k³, forming an upward prolongation of the core k, carries a collar ** adapted
to act on the lever J to release the brake, provision being made, as shewn, for the
relative adjustment of the parts, so that the brake shall be released just before the-
valve is opened. is a push rod for acting on the lever by hand, in order to
allow the air to escape from the bell A when it is required to be lowered, for the
purpose of inserting new carbons in the holders.
The lower carbon carrier L is suspended by the chain / passing over pulleys and.
attached to the frame E of the upper carbon carrier.
The lamp shewn is a focus-keeping one for an alternating current, and the-
carbons are therefore fed up at equal speed. For a continuous current the proper-
ratio would be maintained between the carbons, by usual means.
It will be obvious that the pneumatic feed regulator, instead of acting by vacuum,
or external air pressure being opposed to the weight of the carbon carrier, may art.
by internal air pressure, that is to say by air confined within it opposing the descent
of the bell chamber, in which case the descent of the carbon carrier would be
regulated by the descent of the bell chamber by reason of the escape of the air-
therefrom under the control of the air valve operated as before described, the
arrangement of the suspension chain and pulleys being, of course, modified to suit.
the altered direction of motion of the bell chamber.
It will also be obvious that the solenoid K might be in series with the arc, in-
which case the air valve would be opened by its spring when the current fails and
closed by the energy of the solenoid overcoming the spring when the current
increases.
Whether the pneumatic regulator work by vacuum or by internal pressure, instead
of the admission or exit of air to or from the bell chamber (as the case may be).

page_text: being controlled by a valve during the normal working, the slow admission or exit
of air may be through a mere pin-hole, which is always open, the pin-hole leading
to the valve chamber, the solenoid in that case merely operating the brake. A
spring-closed valve, such as C, may, however, still be provided and operated by
hand, for permitting the rapid exit or inflow of air, when recarboning.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A pneumatic feed regulator for arc lamps, consisting of a bell chamber sealed
by immersion in a liquid and acting either by vacuum or internal air pressure to
oppose the descent of the upper carbon carrier, a valve controlling the passage of
air to or from the bell being provided with means of permitting regulated or slow
ingress or egress (as the case may be) of air, and combined with a brake actuated
by a solenoid, substantially as specified.
2. A pneumatic feed regulator for arc lamps, consisting of a bell chamber sealed
by immersion in a liquid and acting either by vacuum or internal air pressure to
oppose the descent of the upper carbon carrier and combined with a valve con-
trolling the passage of air to or from the bell, the valve being actuated by a
solenoid, substantially as specified.
3. In a lamp provided with a pneumatic feed regulator controlling the descent of
the upper carbon carrier, as specified, mounting the arc-striking electro-magnet upon
the upper carbon carrier so as to be movable therewith and assist by its weight in
overcoming friction and balancing the lower carbon carrier, as specified.
1004
Dated this 7th day of May
H. H. COOPER,
THE ELECTRICAL INSTALLATION CO., LIM.,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.