IMPROVEMENTS IN HOLDERS FOR INCANDESCENT ELECTRIC LAMPS
Year: 1884

page_text: COMILLIE
DIVIFICATION,
"
I, CARL Dornfeld of Cologne in the German Empire, Electrician do hereby.
declare the nature of my invention for IMPROVEMENTS IN HOLDERS FOR
INCANDESCENT ELECTRIC LAMPS" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,
reference being had to the accompanying drawings and to the figures and letters
marked thereon, that is to say:
This invention consists in a new construction of holders or so called "settings"
for incandescent electric lamps. The object of the construction is to enable the
lamp holders to be conveniently screwed on to gaseliers, chandeliers &c, to fit the
conducting wires in the lamp holder in a commodious way, to protect the same from
contact or any external disturbance, as well as to fix the lamp itself into the holder
in the simplest way and thereby to ensure its contact with the conductors.
For the attainment of this object, the lamp holder is constructed of two easily
separable parts and the neck of the lamp provided with a particular contrivance.
The lamp holder consists, as stated, of two easily seperable parts which can be
screwed to one another. The upper portion forms a metal plate with socket shaped
shoulder, the latter having a screw thread made in its centre for union of the whole
holder with gas-pipes, chandeliers, bracket lamps, etc. On the other side of the
plate & disc of insulating material is fixed by two screws, which disc has a screw
thread formed on its periphery. This disc carries two Z-shaped (that is to say,
biangular) brackets of metal which are screwed on to the same, and whose screws
project into the interior of the lamp holder and are each provided with a nut.
These nuts are for the purpose of fastening the conducting wires to the Z shaped
metal brackets.
i
On the insulating disc are placed, underneath the Z shaped brackets small metal
plates projecting towards the centre. These small metal plates as also the opposite
ends of the Z brackets are drilled through in a vertical direction and serve as
guides for a vertically arranged pin. Each of the Z brackets has a pin of this
description. These pins are surrounded by spiral springs which, on one side rest
on the metal plates and on the other side are so attached to the pins that they tend
to press these downwards to a certain limit.
Figs. 1 and 1 of the accompanying drawings shew respectively vertical sections
at right angle to each other and a plan of this upper part of the lamp holder. a ir
.

page_text: the metal plate provided with socket shoulder. b the disc of insulating material with
screw thread round its periphery, c the screws binding a and b together, d, d' the
Z shaped metal brackets, e, e¹ binding screws of the same, ff1 their nuts, which
serve for attaching the conducting wires, g, g¹ small metal plates, h, h¹ metal pins
vertically arranged, i, i spiral springs.
The lower part of the lamp holder consists of a cylindrical metal casing, on the
inside of the upper end of which is a screw thread, while the lower end is provided
on opposite sides of its diameter, with angular shaped slits, the lower edges of the
horizontal parts of which are inclined downwards slightly.
Fig. 2 shews a vertical section of this part of the lamp holder; the neck of the
incandescent lamp, i.e. that end of the lamp from which protrude the platinum
wires which are connected to the carbon filament, is provided with a cylindrical
shaped piece of insulating material which has on its circumference two diametrically
opposite studs which may be fixed on a ring, and which. has, furthermore, upon its
circular surface, two small metal plates preferably of a segmental shape. These
plates, which are insulated from one another, each receive one of the wires from the
carbon filament, and serve in this way as contacts to the lamp.
Fig. 3 shews a vertical section of the neck of the lamp in this shape; k forms
the insulating piece. both studs, m m¹ the segmental contact pieces and n the
glass bulb.
Figs. 4 and 4 shew an elevation and plan of the lamp and holder fitted
together. This is effected in the following manner:-The wires proceeding from
the chandelier are drawn through the central opening of the upper part of the lamp
holder; this then being screwed on to the chandelier, the ends of the wires are
brought by means of the nuts into contact with the Z shaped brackets. Then the
lower part of the holder is screwed on to the thread of the insulating disc. On
inserting the lamp, the studs provided on its neck piece must catch into the vertical
sides of the angular slits of the holder. The lamp is then pressed upwards as high
as is permitted by the angular slots, whereby the spring pins in the holder are
made to rest upon the contact pieces of the lamp, and tend to push it downwards.
The lamp being turned slightly in a horizontal direction, the studs on its neck are
made to bear, in a similar manner to a bayonet lock, upon the horizontal part of the
slits, and in consequence of the counter pressure of the spring pins in the holder, it
obtains a secure fastening. The electric current flows from the wires through
the Z shaped metal pieces and the spring pins, to the small contact plates of the
lamp.
With the above described construction, it is possible, by turning the outer metal
casing, to put the lamp out of contact. If this is to be avoided, the arrangement
of the lamp holder is as shewn in part sectional elevation and plan at Figs. 5
⚫ and 5*.
The metal casing which has the angular slots in it is in this case fixed to the
insulating disc by means of two binding screws, whereby any turning of this piece,
so as to bring the lamp out of contact, is rendered impossible. In order however,
to be able to fasten the conducting wires conveniently to the Z shaped brackets,
this casing is provided with a corresponding opening, as shewn. Over the whole,
for guarding against external contact of the wires, is covered another metal case,
the same as before, which is screwed to the insulating disc. It is obvious that in
the second casing the angular slots are omitted.
In this arrangement, only one spring contact pin in the interior of the lamp
holder with its corresponding contact plate need be provided, while the second
contact may then be formed by means of the studs of the lamp with the inner
metal casing of the holder, which must be insulated from the outer metal casing.
In many cases it is preferable to be able to put each individual lamp out of
circuit by itself.
In such cases a mechanical arrangement may be provided by which one of the
above described spring pins of the holder is raised or lowered so as to be put in or
out of contact with the lamp.

page_text: According to another modification, to which, however, I make no claim, tlie lamp
holder is so arranged, that the head piece of insulating material which is fastened
to the neck of the lamp takes the form of a cylinder with a disc on its upper
surface. On this disc are fixed, insulated from one another, two ring-shaped pieces
of metal which are in connection with the wires from the carbon filament. The
lamp holder then consists of a single socket shaped piece, having in its interior
two spiral sliding springs. The position and size of the same corresponds
with those of the ring shaped contact pieces on the lamp head. The conducting
wires are connected to the base of the springs, so that the springs now form the
contact holders. If the lamp is fastened to the holder by means of the above
described head piece, either by a bayonet lock or by being screwed thereto, the
spiral springs rub on the metal rings of the lamp, head, and so complete the circuit.
Figs. 6, 6 and 6b shew a vertical section and two plans of this arrangement:
u is the cylindrical head piece with disc v, in which are laid the ring shaped metal
plates w, w on the upper side. is the socket shaped holder, in which rest both
the spiral springs y y. With these springs are connected, by means of screws z, z¹,
the conducting wires, so that, when the lamp is fastened to the holder, the
springs y y rub upon the small metal plates w wol and close the circuit.
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:-
°
1. In holders for incandescent electric lamps, the arrangement of spring pins
with guides, which effect both the electrical contact with the lamp, and, by means
of their vertical pressure against the lamp head, the secure fastening of the lamp in
the holder, substantially as described with reference to Figs. 1 and 4 of the
drawings.
2. The special arrangement of a holder for incandescent electric lamps with
metal plate, insulating disc, guides, spring pins and metal casing, substantially as
described with reference to Figs. 1, 2 and 4 of the drawings...
3. The modification of this lamp holder, herein described with reference to Fig. 5
of the drawings.
4. In incandescent electric lamps, the use of a head piece formed of insulating
material, which has on its circumference two diametrically opposite studs, and on
its circular surface two small metal plates insulated from each other, preferably
segmental, which small metal plates are each in connection with one of the wires
from the carbon filament, substantially as described with reference to Fig. 3 of the
drawings.