Improvements in or relating to Arc Lamps.
Year: 1899

page_text: Date of Application, 14th Feb., 1899-Accepted, 5th Aug., 1899
COMPLETE SPECIFICATION.
Improvements in or relating to Arc Lamps.
A communication by CHRISTIAN JENSEN TOERRING, of 3214, Arlington Street,
Philadelphia, in the State of Pennsylvania, United States of America,
Electrical Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham, in the County
of Warwick, and 322, High Holborn, in the County of Middlesex, Civil 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 primary object of this invention is to produce an arc lamp in which the
temperature of the are enclosure is above that attained by lamps now on the
market and shall be as high as possible. This is done by making the arc enclosure
of a transparent part, the heat radiating surface of which shall be as small as
possible and of a heat retaining part which is composed of a non-heat conducting
material. In the present invention, instead of passing the upper carbon through
a closely fitting opening in the upper part of the are enclosure, (which construc-
tion will necessarily permit the leakage of some air at the upper part of the
enclosure where such leakage is undesirable) the upper non-heat conducting
part of the are enclosure is constructed so as to completely surround and enclose
the upper carbon pencil and a portion of the lamp operating mechanism. By
this expedient a construction is attained in which there is no air leakage at the
top of the enclosure, which fact, combined with the heavy mass of non-heat
conducting material comprising the upper part of the are enclosure which my
correspondent is enabled to use, permits the attainment of a very high temi-
perature of the enclosed gases. This temperature may be increased by embedding
a resistance wire in the non-heat conducting material constituting the upper
part of the arc enclosure.
The construction thus outlined prevents leakage of the air at the upper and
lower parts of the arc enclosure and permits a small leakage only at the joint
between these parts. It has been found that the attempt to make an arc enclosure
completely air tight is false in theory, since it results disadvantageously in
blackening the globe and otherwise. The feature to be aimed at is rather
the highest possible temperature of the gases contained in the enclosure than
its absolutely air tight character. The ingress of a very small quantity of air at
points where it will not materially interfere with the temperature of the enclosed
gases has been found beneficial, the best results being attained with a globe
closed at all points except at some point between the top and bottom of the
enclosure.
Another feature of the invention relates to the use of a device for conveying
current to the carbon, which is in the form of a clutch and is arranged to be
in immovable contact with the carbon at those moments when the feeding

page_text: and current carrying clutch is out of touch therewith so that current may at all
times be conveyed to the carbon pencil at a point near the arc, whatever be
the position of the feeding clutch.
The drawings represent a longitudinal cross-section of a lamp embodying
this invention.
The upper portion of the are enclosure consists of a tube 3, surrounded by a
heavy coating of insulating material 12, which may in turn be protected by an
outer tube or casing 10, having an extended plate 101 at the bottom. The tube 3
is air tight at the top, being closed by the cylinder of a dash-pot 8, of ordinary
construction, and at the bottom has secured to it in any convenient manner an iron
plate 13.
To the upper face of the cylinder of the dash-pot 8 is secured a block 18 by
means of a screw 21. The outer edge of this block is threaded onto the outer
tube or casing 10 as shown. A piece of non-heat-conducting material 20 may be
interposed between the block 18 and the dash pot, so as to confine all the con-
duction of heat from the inside tube 3 to the outside casing, to the narrow path
through the screw 21. Since however the touching metal surfaces are small,
this is not strictly necessary. It is plain from this description that the upper
portion of the arc enclosure is especially adapted to prevent the escape of heat
and thus to keep the temperature of the gases confined therein at a maximum.
Within the tube 3 slides a tube 4, within which the carbon pencil 5 moves,
the upper end of the pencil being pushed into a split tube.6 which constitutes
its holder. The upper end of the tube 4 is attached to the piston of the dash-
pot 8.
Around the tube, at a point corresponding to an enlargement of the tube 3,
is secured an armature 2 which is within the field of force of a solenoid 1 and
is actuated thereby. A metal bushing 9 surrounds the tube 4 above its lower
end. This bushing tends to guide the tube and also to convey some current to
it. The joint between the bushing and tube need not be air tight but is sufficiently
close to prevent the passing of dust into the upper chamber. To an extension
from the lower end of the tube 4 is linked a ring or other clutch 40, surrounding
the carbon and resting on a bed or stop 46 fastened to a bracket 7 depending
from the plate 13.
The negative carbon holder 16 passes through the plates 13 and 101 and is
insulated therefrom in any suitable manner.
Current passes into the lamp through the conductor 60, down to a sliding
conducting ring 61, thence through the resistance wire 17, coiled on the outside
of the tube 10, to the resisting wire 11, embedded in the insulation 12, thence
into the solenoid 1 and to the inner tube 3, from which it passes by way of the
bushing 9 and the clutches to the positive carbon thence to the negative carbon
and out of the lamp in a manner not necessary to show. The action of starting
the arc and of feeding the upper carbon by means of movements conveyed to the
tube 4, through the armature 2 and thence to the ring clutch 40 is well understood
and need not be further described.
The lower portion of the arc enclosure 14, which is of transparent material,
is made, as will be seen with as small a heat radiating surface as possible. Its
upper edge abuts against the plate 13, the joint between the globe 14 and the
plate 13 constituting the only place where air may possibly leak into the globe.
As before stated it is necessary for a little air to leak into the arc enclosure and
the point here selected, has been found best adapted for the purpose, especially
when the enclosure is completely air tight at all other points.
An outer protecting and ornamental casing is also provided which carries the
outer globe at its lower end. This need not be further described than to say
that brackets 70 are secured to the tube or casing 10 on which the sections of
the outer casing 71 are mounted. A ring 72, carried by a canopy 73, and carrying
screws 74 serves to hold the outer globe in place. The top of the outer globe,.
it will be noticed, is above the top of the inner enclosure 14. The hood 190 is
held in place by the screw plug 19.

page_text: The current-feeding clutch-devices, will now be described which are employed.
When the current is fed to the lower end of the carbon pencil through the
feeding clutch, it is plain that at the moment when the carbon is slipping through
the clutch or when the clutch is moving with relation to the carbon preparatory
to taking hold to strike the arc, that considerable arcing must result from this
relative motion of the clutching surface, which is at the same time a current
carrying surface, and the carbon. To obviate this difficulty, a second current
carrying device is employed so constructed as to have an immovable contact with
the carbon at all times when the contacting surface of the feeding clutch is moving
with reference to the carbon.
To the plate 13, which is charged with current during the operation of the lamp,
is secured a bracket 45, carrying a lever 43, to which is secured a link 42, on
which is pivoted a current carrying or feeding plate 41. A stop 44 is carried
by the tube 4 and acts upon the lever 43. The feed plate 41 has an extension
to the left, as shown, for the purpose of normally giving the plate a tilt and
securing an instantaneous grip at the proper times.
The operation of these devices is as follows:-The armature 2 raises one end
of the clutch 40 until it has firmly gripped the carbon. The stop 44 has also
been raised during this time but does not come in contact with the lever 43
until the ring clutch 40 has obtained its grip. In consequence, during this period,
current is conveyed to the carbon by the part 41 which has no move-
ment relative to the carbon during this time and therefore causes no arcing.
The tube 4 is now drawn still further up, striking the are. The clutch 40 has a
tight grip of the carbon and therefore the plate 41 may now be moved with
relation thereto without causing arcing. This is done by the stop 44. On account
of the leverage, the plate 41 is raised to a greater extent than the clutch 40.
When, therefore, the are grows too long, and the tube 4 falls, allowing the clutch
40 to be disengaged from the carbon by action of the clutch plate 46 and the
carbon to feed, the current carrying or feeding plate 41, has a distance downward
through which it may move without moving relatively to the carbon, to make
up for the amount of carbon consumed, that is for the amount of feed. Thus
at all points of the carbon feed, arcing is prevented.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent I declare that what I claim is: --
1. An arc enclosure having a light transmitting portion and a heat retaining
portion shaped to enclose an electrode, substantially as described.
2. An arc enclosure having a light transmitting portion closed at the bottom
and a heat retaining portion closed at the top and shaped to enclose the carbon
pencil, the joint between these portions permitting the passage of a minute
quantity of air, substantially as described.
3. An arc enclosure having a light transmitting portion, practically air tight
at the bottom and a heat retaining portion closed at the top and shaped to enclose
the carbon pencil, substantially as described.
4. An arc enclosure having a light transmitting portion and a heat retaining
portion closed at the top and shaped to enclose the carbon pencil, and means for
permitting the ingress of a minute quantity of air located between the top and
bottom of the enclosure, substantially as described.
5. An arc enclosure having a light transmitting portion, and a heat retaining
portion, shaped to enclose a carbon carrying tube moving therein, substantially
as described.
6. An arc enclosure having a light transmitting portion, and a heat retaining
portion consisting of a tube and a coating of non-heat-conducting material, sub-
stantially as described.
7. An arc enclosure having a light transmitting portion and a heat retaining
portion consisting of a cylinder of non-heat-conducting material, a dash-pot at

page_text: the top thereof, a carbon carrying tube therein and a carbon feeding device
carried by the tube, substantially as described.
8. An arc enclosure composed of a light transmitting portion and a heat retain-
ing portion having a current carrying resistance wire, substantially as described.
9. An arc enclosure having a light transmitting portion and a heat retaining
portion of non-heat-conducting material having a resistance wire embedded
therein, substantially as described.
10. An arc enclosure having a heat retaining portion closed at the top and
ending in a base plate and a light transmitting portion closed at the bottom
and abutting against the base plate to make a leak joint, substantially as
described.
11. An are enclosure having a light transmitting portion and a heat retaining
portion shaped to include a carbon carrying tube, in combination with said tube,
and with a carbon feeding device carried by the tube and actuated by a coil
outside the enclosure, substantially as described.
12. An arc enclosure consisting of a cylinder of non-heat-conducting material,
a solenoid surrounding the cylinder, a carbon carrying tube moving within the
cylinder, an armature and feeding devices on the tube and a light transmitting
enclosure for the arc, substantially as described.
13. An are enclosure composed of a substantially cylindrical metal tube and
a coating of non-heat-conducting material surrounding the tube in a manner
to offer no substantial path for the conduction of heat from the inside to the
outside of the enclosure.
14. An are enclosure consisting of a light transmitting portion with a small
heat radiating surface, and a heat retaining portion shaped to enclose the carbon
pencil and to prevent the passage of heat from the inside both by conduction and
radiation, substantially as described.
15. An arc enclosure consisting of a light transmitting portion and a heat
retaining portion composed of two substantially disconnected tubes and a layer
of non-heat-conducting material between them, substantially as described.
16. The combination of a carbon feeding device and a current carrying device
arranged to have an immovable relative contact with the carbon when the feeding
device is changing its hold, substantially as described.
17. The combination of a carbon feeding device and a current carrying device
arranged to have an immovable relative contact with the carbon when the feeding
device is preparing to strike the arc, substantially as described.
18. The combination of a carbon feeding device, a movable current carrying
device and a stop timed to change the point of contact of the same with the carbon
after the feeding device has taken its grip, substantially as described.
19. The combination of a carbon feeding device, a movable current carrying
device and motion multiplying mechanism for causing a contact of the same with
the carbon at a point sufficiently high to make up for the motion of the feed,
substantially as described.
20. The combination of a clutch, a current feeding device mounted from a
lever and a stop moving with the clutch and timed to act on the lever after the
clutch has gripped, substantially as described.
21. The combination of the electrodes of an electric-arc lamp and arc-inclosing
envelop therefor, said envelop being made in two readily separable parts, the
upper part shaped to enclose the electrode, the joint between said parts being
located between the top and bottom of said envelop, said joint adapted to allow
the admission of a limited amount of air to the interior of the envelop, sub-
stantially as described.