Improvements in Sockets or Holders for Incandescent Electric Lamps.
Year: 1899

page_text: Date of Application, 27th May, 1899-Accepted, 1st July, 1899
COMPLETE SPECIFICATION.
Improvements in Sockets or Holders for Incandescent Electric
Lamps.
We, ALBERT VANDAM, and THOMAS HERBERT MARSH, both of 39, Victoria
Street, Westminster, in the City of London, Electrical Engineers, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
Our invention relates to sockets or holders for incandescent electric lamps, and
has for its object to construct improved devices of this description which shall be
capable of being attached to the leads with greater facility than is the case with
lamp sockets as heretofore constructed. Our improved sockets have the further
advantage that the contact pieces with which the terminals of the lamp make
connection are not readily shortcircuited owing to the fact that each is almost
entirely enclosed by insulating material.
According to our invention the contacts which are of the wellknown plunger
type, are secured to or within a block of insulation material which is separate
from that part of the socket to which the leads are permanently connected, this
latter part being provided with an insulation piece carrying two metallic pieces
to which the leads are clamped by screws in the usual manner.
Our invention is exemplified in the accompanying drawings in which
Figure 1 is a cross section of one of our improved sockets or holders taken on
the liner, Figure 7.
Figure 2 is a plan.
Figure a side elevation, and
Figure 4 an under plan view of the insulating piece which carries the plungers,
and
Figures 5, 6 and 7 are similar views to Figures 2, 3 and 4 respectively, shewing
the insulating piece carrying the metallic pieces to which the leads are connected.
Figure 8 is a cross section taken through both plungers of another construction
of socket according to our invention.
Figures 9 to 14 are views similar to Figures 2 to 7 respectively of the parts
of the holder shewn in Figure 8.
Like letters denote similar parts throughout the drawings.
1 is a cap of any suitable design through an orifice 2 in the top of which the
leads 3, 4 shewn in dotted lines pass. 5 is a base of insulating material to which
are secured metallic pieces 6, 7, to which the leads 3, 4 are secured by clamping
screws 8, 9 (see Figure 7). The parts 6, 7 are secured in the piece 5 by means
of screws 10 or other suitable means. 11 is an insulation block carrying the
plungers 12, 13, with which the terminals of the lamp, not shewn in the draw-
ings, make contact; said plungers are adapted to slide in tubes 14, 15 secured to the
part 11 by any suitable means, the screwed washers 16 for example. 17 are
springs adapted to press the plungers 12, 13 downwards in the usual manner
so as to make good contact with the lamp terminals. The connection between
the plungers 12, 13 and the parts 6 and 7 when the various parts of the lamp
socket or holder are assembled together is in the example shewn in the drawing
effected by means of additional plungers 18, 19 provided in the upper parts of
Price 811

page_text: the tubes 14, 15, and projecting from the upper face of the block 11. We thus
ensure that a low resistance connection shall be made between the plungers 12, 13,
and the parts to which the leads are secured. It is not, however, necessary that
this manner of connection should invariably be employed, as the upper parts
of the tubes 14, 15 may themselves be arranged to make contact with the
parts 6, 7 when the parts are assembled.
In order to ensure the substantial registering of the plungers and the
parts (6, 7) when the piece 11 is placed opposite the piece 5 we provide a
diametrical groove or slot 20 in the first mentioned piece with which a fin 21
projecting downwardly from the piece 5 can engage. Said fin, which is of insu-
lating material prevents any liability of an arc occurring between the parts 6, 7
or the plungers when connected to the leads. The fin may be provided on the
part 11 and a slot or depression in the part 5 if desired. Owing, however, to
the relative thickness of these parts we prefer the construction shewn.
The method of assembling the various parts and connecting the socket or
holder to the leads is as follows:
The cap 1 is first slipped on to the leads, and the bared ends of the latter are
then passed into the orifices prepared for them in the parts 6, 7, to which they
are secured by the clamping screws 8, 9. The part 11 to which the plungers
are permanently attached is then placed opposite the part 5, so that the fin 21
enters the slot 20. An outer enclosing tube 22, provided with a shoulder 23 to
receive the lower part of the piece 11, is then slipped on, and an annulus 24
provided with a shoulder 25 is passed over the tube 22 and screwed to the lower
part of the cap 1 securing everything in place. These arrangements for
assembling and securing the parts in position are wellknown to persons skilled
in the art, and can be varied within considerable limits.
In the construction shewn in Figures 8 to 14 the plungers 18, 19 make contact
with those parts of the metallic pieces 6, 7 which receive the leads 3, 4 as will
be seen from Figure 8 the remaining parts of the socket are substantially the
same as herein before described.
It will be seen that when the socket is connected to the leads the only metallic
parts which are not covered with insulation are the ends of the plungers 12, 13,
and within the socket the plungers 18, and 19, although bare, are separated by a
partition formed by the insulating fin 21. The leads 3, 4 passing down to the
parts 6, 7 are of course insulated in the usual manner.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, wo declare that what
we claim is: -
1. For incandescent electric lamps, a socket or holder in which the spring
plungers for making contact with the lamp terminals are not permanently con-
nected with the electric light leads, but make connection with plugs to which
said leads are permanently secured, when the various parts of the socket are
assembled in position.
2. In a socket or holder for an incandescent electric lamp, the provision of an
insulating piece to which are secured plugs adapted to be permanently connected
to the electric light leads, and a second separate insulating piece to which the
plungers for making contact with the lamp terminals are secured, substantially as
described.
3. Electric lamp sockets or holders, constructed substantially as hereinabove
described with reference to the accompanying drawings.
11- 031
3
"
C
1000
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.