Improvements in Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 26th May, 1396-Accepted, 1st Aug., 1896
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I THOMAS EDGAR ADAMS, of 938 Case Avenue, Cleveland, in the County of
Cuyahoga and State of Ohio, United States of America, Electrical Engineer, do
hereby declare the nature of my 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 an improvement in electric arc lamps and more
particularly to that class in which the arc is enclosed by a closed inner globe.
In lamps of this class it is important that the arc enclosing globe be air-tight
below and for some distance above the arc. The products of the arc which settle
in the globe and expel the air must rise above the are to insure duration of the
carbon points. This is best attained by a globe having no openings through its
glass except at a point above the arc.
The object of my invention is to so construct an arc electric lamp of the class
above mentioned, that the inner arc enclosing globe shall have its bottom completely
and permanently closed and its upper end normally closed.
A further object is to so construct an arc lamp of the class specified that the
pressure of gas in the are enclosing globe will be prevented from reaching a point
liable to cause the breakage of the globe, without the use of valves.
A further object is to so construct an electric are lamp of the class above
mentioned, that it shall be compact; simple; ornamental in appearance and
effectual in all respects in the performance of its functions.
A further object is to provide an electric are lamp with simple and efficient
means for lowering and sustaining the large outer globe to facilitate trimming the
lamp.
A further object is to construct the lamp in such manner that the rheostat can
be so disposed and arranged as to be efficient and durable.
With these objects in view the invention consists in the combination with the
lamp arm of an electric arc lamp and an arc enclosing globe, of a cover for said
globe projecting from the lamp arm and a spring supported by the lower end of
the lamp arm and acting to force the open upper end of the globe against said
cover.
The invention further consists in the combination with the lamp arm of an
electric arc lamp and arc enclosing globe, of a plate made integral with the lamp
arm and forming a cover for the arc enclosing globe, said plate or cover having a
hole for the passage of the upper carbon of the lamp.
The invention also consists in the combination with the carbons of an arc lamp,
of a closed are enclosing globe, a cover for said globe, through which the upper
carbon passes, a notched flange projecting downwardly from said cover and
surrounding the upper end of the globe and a spring adapted to normally press the
upper edge of the globe against said cover.
The invention further consists in certain novel features of construction and
combinations and arrangements of parts as hereinafter set forth and pointed out in
the claims.
In the accompanying drawings, Figure 1 is a sectional view of an arc lamp
embodying my improvements. Figures 2 and 3 are detail views. Figure 4 is a
view of a modification.
A represents a lamp casing in which two guide rods 1, 1, are disposed vertically,

page_text: and from the floor 2 of said casing, a thin, curved lamp arm 3 projects downwardly.
The lamp arm is provided at its lower end with a vertically disposed tubular
extension 4, for the accommodation of a rod 5 and a spring 6, the latter having a
seat at one end on a shoulder 7 at or near the bottom of the tubular extension 4,
and at its other end against a collar 8 secured to the rod 5 within the upper end of
the tubular extension 4, said collar 8 and rod 5 being limited in their upward
movement by a screw 9 in the upper erd of the extension 4.
The upper end of rod 5 is provided with a cup-shaped holder 10 for the reception
of a tit or projection on the lower end of an arc-enclosing globe 11. The arc-
enclosing globe 11 will thus be yieldingly supported by the spring 6. The bottom
of the globe 11 is entirely closed and the upper end of said globe is normally
closed by a cover 12 having a ground glass joint with the globe. The cover 12 is
preferably made integral with the arm 3, but may, if desired, be made separate and
secured thereto. The cover 12 is provided with a depending notched or scalloped
flange 14 which encircles the upper end of the globe 11, the latter being normally
forced tightly against the under face of said cover by the spring 6. Instead of
providing the cover 12 with the notched or scalloped flange 14, said cover may be
provided with a series of depending pins or pegs 15. The cover 12 and the floor
of the lamp casing are made with a hole for the passage of the upper carbon 16,
which latter is insulated from the cover 12 by means of a lava bushing 17 inserted
in the hole in said cover. The upper carbon is held by a carbon holder 18 carried
by an arm 19 which projects from a block or cross-head 20 but insulated from it,
the latter being disposed between and guided by the rods 1, 1. A clutch blade 21
is also secured to the cross head 20 and projects downwardly through the lamp floor
and terminates at its lower end in a pocket 22 in lamp arm 3.
A suitable clutch 23 is adapted to grasp the clutch blade, and to this clutch an
upwardly projecting rod 24 is connected. The upper end of the rod 24 is pivotally
attached to a pivoted lever 25, the other end of which is pivoted to a lug 26
depending from a plate 27 secured to the solenoid 30. The plate 27 is made with
a depending arm 28, to which one end of a lever 29 is pivoted, and said levers 25, 29
are pivotally connected together between their ends by means of a link 31, and the
lever 29 is also pivoted between its ends to the core 32 of the solenoid. The free
end of the lever 29 is pivotally connected with the plunger of an air pot 33.
An arm or bracket 34 projects from the cover 12 or upper portion of the lamp
arm 3 and depends into the are enclosing globe 11, terminating at its lower end in
a laterally projecting holder 35 for the reception of the lower carbon 36.
From the construction and arrangement of parts above described it will be seen
that when the accumulation of gas in the arc enclosing globe reaches an abnormal
degree, or such degree as to render explosion possible or should explosion occur,
the pressure of the gas would act to depress the globe 11 against the resistance of
the spring 6, which latter will, of course, be adjusted to withstand a predetermined
pressure. A very slight descent of the globe will cause its upper edge to pass
below the upper ends of the notches in the flange 14, and thus numerous gas outlets
or vents will be formed at the upper edge of the globe. It is apparent that the
movement of the globe for this purpose need be but very slight, and that as soon
as the pressure within the globe is relieved the latter will be immediately forced
up against its scat on the cover 12, and the globe again tightly closed without
admitting air. In lamps of this class it is important that the are enclosing globe
be air-tight below, and for some distance above the arc. The products of the arc
which settle in the globe and expel the air, must rise above the arc to insure
duration of the carbon points. This is best attained by a globe having no openings
through its glass except at a point above the arc. My arrangement therefore of a
bracket, or arm, to descend from the lamp parts above, down into a cup-shaped
globe, and hold the lower carbon in proper alignment with the upper is valuable,
for instead of the lower carbon entering one opening in the bottom of the globe,
and the upper carbon another opening at the top, the lower, or difficult opening to
keep air-tight, is dispensed with.

page_text: B represents a frame adapted to be secured to the ceiling of a room or other
place and to the center of the base plate 37 of which, a hook 38 is secured, said
hook depending through the center of the skeleton cover 39 of said frame B, and
adapted to receive a hook or link 40 secured to the lamp casing. A series of
insulators 41 are secured to the base plate 37, and on these insulators two
sections x, y, of resistance is supported. The sections of resistance are electrically
connected at their ends to plates a, b, and c, d, respectively. The current from the
line first passes through one section of the resistance and then to the positive
terminal of the lamp which is connected with one end of the coil of the solenoid
and the other end of said coil is connected, by a flexible conductor with the
upper carbon holder. The current passes from the upper to the lower carbons;
then through the bracket supporting the lower carbon, to the cover 12 or arm 3
and guide rods 1, 1, to the minus terminal of the lamp, and thence through the
other section of the resistance, to the line.
The large outer globe 42 is supported by a globe holder 43 and the latter is
removably secured to the extension 4 of the lamp arm 3. The globe holder is
connected with the lamp arm 3 by means of a chain 44, so that when the outer
globe and its holder are removed while the lamp is being trimmed, they will be
supported in a suspended position by the said chain.
My improvements are simple in construction; comprise few parts, and are
effectual, in all respects, in the performance of its functions.
Slight changes might be made in the details of construction of my invention
without departing from the spirit thereof or limiting its scope, and hence I do
not wish to limit myself to the precise details of construction herein set
forth, but,
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that
what I claim is :-
1st. In an are lamp, the combination with the lamp arm and an are enclosing
globe, of a rigid plate projecting laterally from said lamp arm and constituting
a cover for said are enclosing globe, said plate or cover having a hole for the
passage of the upper carbon and a spring constructed to force said globe against
said plate or cover, substantially as set forth.
2nd. In an arc lamp, the combination with the lamp arm and an arc enclosing
globe, of a plate made integral with the lamp arm and forming a cover for said
are enclosing globe, said plate or cover having a hole for the passage of the upper
carbon of the lamp, substantially as set forth.
3rd. In an arc lamp, the combination with the lamp arm and an are enclosing
globe, of a cover for said globe projecting from the lamp arm, and a spring
supported by the lower end of the lamp arm and acting to force the open upper
end of the globe against said plate or cover, substantially as set forth.
4th. In an arc lamp, the combination with the frame thereof, and an arc
enclosing globe, of an integral arm or plate projecting from said frame and
constituting a fixed cover for said globe, substantially as set forth.
5th. In an arc lamp, the combination with a lamp arm and an are enclosing globe
open only at its upper end, of a fixed cover for said globe projecting from the
upper end of the lamp arm and having a hole for the passage of the upper carbon,
a spring supported by the lower end of the lamp arm for forcing the upper edge
of the globe against said cover and an arın secured to said cover and projecting
down into the globe for supporting the lower carbon, substantially as set forth.
6th. The combination with the lamp arm, the upper portion of which is formed
to close the opening in an are enclosing globe, of an are enclosing globe having
but this one opening, a bracket or arm to descend into said globe and arranged to
support in proper position the lower carbon and a spring attached to said lamp
arm to elastically hold are enclosing globe as set forth.
7th. The combination with the carbous of an arc lamp, of an are enclosing globe

page_text: having a close fitting cover, and a flange depending from said cover and encircling
the upper end of the globe, said flange having an irregular free edge, substantially
as set forth.
8th. The combination with the carbons of an arc lamp, of an arc enclosing globe,
a cover for said globe, through which the upper carbon passes, a notched flange pro-
.jecting downwardly from said cover and surrounding the upper end of the globe,
and a spring adapted to normally press the upper edge of the globe against said
cover, substantially as set forth.
9th. In an arc lamp, the combination with an air tight are enclosing globe and
the lamp arm, of a bracket projecting into said are enclosing globe from said
lamp arm and a lower carbon holder at the free end of bracket, substantially as
-set forth.
10th. In an arc lamp, the combination with the casing, of a lamp arm having a
vertical tubular extension, a rod passing into said tubular extension, a collar on said
rod, a spring in the tubular extension and bearing at its lower end on a shoulder
therein and at its upper end against said collar, a holder at the upper end of said
rod, an are enclosing globe supported by said holder and a fixed cover for said
globe, substantially as set forth.
11th. In an arc lamp, the combination with the casing, of a lamp arm depending
therefrom, a vertically disposed tubular extension at the lower end of said arın, a
rod entering said tubular extension, a collar on said rod, a spring in said tubular
extension bearing at its lower end on a shoulder at the lower end thereof and at its
upper end against said collar, and a cover for said globe projecting from and made
integral with the upper portion of said lamp arm, substantially as set forth.
12th. In an arc lamp the combination with the separating and feeding solenoid,
the carbons and a clutch, of a lever having a pivotal support at one end and at its
other end connected with the clutch, an air pot, a lever pivoted at one end and
connected at its other end with the plunger of said air pot and between its ends
with the core of said solenoid, and a link pivotally connecting said levers
together at points between their ends...
Dated this 26th day of May 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to Applicant.