Improvements in Socket-holders for Incandescent Electric Lamps.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Socket-holders for Incandescent Electric Lamps.
I, WILLIAM WHITE, of 58 Bread Street, in the City of London, Electrical 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:
My invention relates to a simple and inexpensive construction of socket holders for
incandescent electric lamps in such a manner that within moderate compass I obtain
considerable contact surfaces, and effective insulation of the two lamp conductors
from each other and from the metal case, as I shall describe referring to the accom-
panying drawings.
Fig. 1 is a vertical section (with one of the spring plungers omitted) and Fig. 2
is a plan of a socket holder according to my invention adapted to receive the stem of
an incandescent electric lamp.
Fig. 3 is a section and Fig. 4 is a plan to an enlarged scale shewing one of the
spring plungers fixed to the base of insulating material.
Fig. 5 is a section shewing a modified construction of the fitting for the spring.
plunger.
In all these figures similar reference letters indicate corresponding parts.
A is a base of ceramic or other like insulating material having a ridge or partition B
extending quite across the base and standing up between the two conducting fittings E
and F. Each of those fittings is secured by two screws J J' to the base A. Under
one of these screws J in each case is fixed the end of one of the two conducting wires
which are brought separately through two holds G and H through the base A and are
kept quite separate by the ridge B, so that there is no danger of their touching each
other and so establishing a short circuit. As shown in Figs. 1 and 3 the tubular part
of each of the fittings E and F, after receiving the spring D and the plunger C which
is made with a collar at its base, has its upper lip burred over so as to prevent the
plunger C from coming out. In order to facilitate this burring over, the upper edge
of the tubular part is somewhat thinned by boring out metal in its inside, and then
after is introduced, the lip d is forced inwards by a suitable punch. Instead of thus
retaining the plunger and spring D the construction shewn in Fig:
adopted.
may be
In this case the tubular part is made as a separate piece from the base Land is
formed with an inwardly projecting collar at its upper end. The head of M one of
the screws for fixing the base L is made with an external screw thread and the tubular
part K is made with an internal screw thread at its lower end, so that after inserting
the plunger Cand spring D from below, the tubular part K is screwed firmly on the
head of the screw M. The metal casing consists of a base part P containing the
insulating base A, the tubular part Q and a screw union R which holds P and Q
together. The tubular part Q is made with a bayonet catch notch at each side
to receive studs projecting from the stem of the incandescent electric lamp. This
stem presents as usual on its lower face two insulated metal plates connected
respectively to the two lamp wires; when the stem is pushed into the socket. Q, those
plates bear upon the heads of the plunger forcing them down in opposition to the
springs D, and the lamp stem having its studs engaged in the bayonet notch q
the pressure of the spring D holds the lamp steady and makes good contact with the
plunger C..
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A socket holder for an incandescent electric lamp having enclosed within a metal

page_text: casing an insulating base made with a ridge or partition separating two spring
plunger fittings screwed to the base, each fitting having its tubular part burred
over at its upper edge to retain the collar of the spring plunger, substantially as
described.
2. The modified construction of spring plunger fitting wherein the tubular part is
made with an internal collar at its top and is at its base screwed on to the head of one
of the fixing screws.
Untad sh: 17:1
De 1000
•
ABEL & IMRAY,
Agents for the Applicant.