Improvements in Electric Glow Lamps.
Year: 1893

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by EDWARD ALLEN COLBY, of Newark, New
Jersey, United States of America, Electrical Engineer.]
Improvements in Electric Glow Lamps.
I, HENRY HARRIS LAKE of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, 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 invention consists of a new system of electrical illumination, using a lamp of
the glow or incandescent type. This lamp, instead of having the ordinary glass
receiver with leading-in wires connected to a filament and hence employing a
current of electricity directly led to said filament, has no leading-in wires whatever
and has its filament disposed in the form of a closed ring or rings suitably supported
within a receiver of corresponding annular form. This filament is caused to glow
through the lamp being placed in the varying field of force due to an alternating,
pulsating, or intermittent electrical current; so that it is an induced current which
acts upon the filament. In order to vary the intensity of the light, the lamp may
be moved into different parts of the field, or the field may be modified in strength,
or the lamp may be differently adjusted with reference to the field.
In the accompanying drawings,
Fig. 1 represents the annular lamp with the filament in place.
Fig. 2 shows a number of such annular lamps arranged upon the core of a coil
in which circulates a varying current. The lamps are here shown in cross
section.
Fig. 3 represents a number of lamps strung upon a continuous core, upon which
core are also mounted a number of inducing coils.
Fig. 4 shows another form of said lamp having several ring filaments.
Fig. 5 shows a lamp with a spiral filament, and
Fig. 6 shows the inner tube of a lamp carrying a filament and a coil connected in
series.
Similar letters of reference indicate like parts.
The lamp shown in Figs. 1, 2 and 3 consists of an annular glass receiver, A,
which is substantially exhausted in the ordinary way.
Within this receiver is a
filament, B, which may be of carbon or of any other suitable material. This
filament is held in the axis of the tubular receiver by means of supports, C, of
platinum wires, for example, sealed into the material of the tube. I propose to
cause the filament B to glow and become incandescent by placing the lamp in a
varying field of force, as, for example, in such relation to a transformer or induction
coil as that said filament shall be the secondary coil thereof and thus be caused to
glow by the induced current set up therein due to its location in the field of the
primary coil. In the form shown in Fig. 2, D is a primary coil connected to any
suitable source of varying current. E is the core, preferably made of a bundle of
straight, iron wires. The lamps A are placed upon the core, when the filament B,
being in inductive proximity to the coil D, caused to glow. On the core is a
threaded sleeve, F, upon which the lamps loosely fit. A nut, G, on said sleeve,
then supports the lamps from below, and allows them to be adjusted up and down
as desired. The surface of the core E is to be made bright by silvering, for
example, so as to serve to reflect the light. The filament B may be made in two
or more sections, if so desired, one of said sections being a body of high resistance
which glows or incandesces, and the other a body of low resistance, such as

page_text: platinum wire. In this way,
filament.
may produce a glow only on a part of the
In Fig. 3, the lamps A are strung upon a long core, E, which may be of any
flexible material, and which carries the inducing coils B E connected in series. In
this way I may make what I
66
may term a rope of light," the same being an
illuminating source of any desired length. This I may carry around the cornice of
a room, or bend it to form ornamental shapes or letters; or I may twine it closely
around a pillar or post, or lay it closely over a large surface, and in this way
I may
produce very large areas of illumination. By suitably bending the rope I may
make letters for signalling purposes or for signs. The core E is not necessary in
general in the aforesaid devices, because all that is required is to support the lamp
in inductive proximity to the coil D. This may be done by any suitable support,
not necessarily of inductive material, and not necessarily of any particular shape;
or, if it be desired to thread the lamps upon a support in the manner shown in
Fig. 3, that support may be an ordinary rope of hemp or other flexible substance.
In the device shown in Fig. 2, the luminous intensity of a single lamp may be
altered by moving it nearer to or further from the coil D, or the luminous intensity
of the entire device may be augmented or decreased by adding or subtracting
lamps A as may be desired. In Fig. 2 the device is shown provided with an
ordinary reflecting shade, H, which rests upon the upper surface of the coil D and
below a suitable washer, J. The circuit wires communicating with the coil are
shown at a and b.
The lamp proper in Fig. 4 is an annular glass vessel, K. Within this vessel and
sealed thereto at its ends is a platinum wire support, L, which carries several
filament rings, M, of carbon or other material. These rings in Fig. 4 are shown
parallel. There may be additional supporting wires, L, if desired. The glass
vessel K is to be exhausted or substantially so. The inducing coil D rests upon a
Support, N. Its internal core, E, has an outer threaded covering, F, upon which is
a nut, H. This nut can be turned and thus moved up and down. The lamp rests
on the nut, as shown, and may thus be adjusted in place. The filaments M are all
closed rings and surround the coil D. When the nut G is raised or lowered, the
filament rings are moved in different positions in the field of the inducing coil, and
therefore the intensity of the light which they give is varied. I may use other
means of raising and lowering the lamp, as, for example, by screws acting directly
upon it, or washers interposed beneath it, and therefore do not limit myself to any
particular way of raising and lowering it.
In Fig. 5, the receiver is of the same shape as that shown in Fig. 4. The
supporting wire, L, however, has only one end sealed to the inner tube of the
receiver, and the filament A' is fast to its outer end. The filameut is made in a
spiral form instead of being in a series of rings, as in Fig. 4. In the construction
shown in Fig. 2, the inducing coil D surrounds the lower part of the core E, and
the lamp rests, as shown, upon the coil. In order to increase the potential
difference at the terminals of the filament, may employ a coil, O, of platinum
wire. This coil closely surrounds the inner tube, P, of the receiver, and may be
imbedded in the glass thereof during manufacture. The filament A' and coil O are
connected in closed circuit, and the filament surrounds the coil, so that both filament
and coil receive an induced current from the inducing coil D, when the lamp is in
inductive proximity to said coil.
Having now particularly described and ascertained the nature of the said inven-
tion 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. A glow lamp having a filament or filaments in ring or closed coil or spiral
form completely enclosed within an exhausted receiver and held on supports in said
receiver and having no leading-in wires.
2. A glow lamp having a filament or filaments in ring closed coil or spiral form
contained in an exhausted receiver and having no leading-in wires, in combination

page_text: with an inducing coil or other means of producing a field of force, in which field of
force said lamp is placed and the filament thus caused to glow by induction; the
light intensity of said lamp being variable by moving the lamp with reference to
the field, or the field with reference to the lamp, or otherwise varying the inductive
5 effect of the field upon the filament or filaments.
Dated this 6th day of June 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.