Improvements in Sockets for Incandescent Electric Lamps.
Year: 1892

page_text: Date of Application, 20th Dec., 1892-Accepted, 4th Feb., 1893
COMPLETE SPECIFICATION.
Improvements in Sockets for Incandescent Electric Lamps.
I, BENJAMIN Joseph Barnard MILLS, of 23 Southampton Buildings, in the
County of Middlesex, Patent Agent, do hereby declare the nature of this inven-
tion (a communication to me from Joseph Hutchinson, of 292 Avenue B, in the
City, County and State of New York, in the United States of America, Inventor),
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The present invention relates to lamp sockets adapted to receive the necks of
incandescent lamps and connect the filament terminals to the supply circuit, and
the object of the invention is to improve and simplify such sockets. According to
this improvement insulating socket bodies are formed of proper shape, and terminals
and also a metal shell are clamped thereto, instead of connecting said parts to the
body by screw connections or by moulding the insulating socket body around them,
as is commonly done, thereby gaining important advantages. The main body of
the improved socket is generally made of porcelain, this material being preferred
because of its cheapness, good insulating qualities and ability to resist heat, as well
as because it can be readily moulded to the desired shape. But it is found that
the bodies moulded of such material are not always of exactly regular shape or
size, and, owing to the difficulty of working porcelain with tools, it is practically
impossible to make the bodies uniform. For this reason it is difficult to attach
terminals and a shell to the body in the manner generally employed with bodies
of other insulating material, such as rubber or vulcanized fibre which can be readily
worked. The terminals, as well as the shell, are therefore clamped to the body in
such manner that the irregularities that exist in the size and shape of the bodies
will not materially affect the connection of said parts.
In the drawings
Figure 1 is a side view of a socket with a lamp in place, the shell of the socket
being broken away on the section line - shown in Figure 3.
Figure 2 is a side view of the insulating body of the socket at right angles to
the view shown in Figure 1.
Figure 3 is a section through the shell at right angles to the section of Figure 1,
showing the overlapping edges.
Figure 4 is a side view of a modified construction.
Figure 5 is a section thereof taken on the line y-y of Figure 4.
Figure 6 is a view similar to Figure 1 of a slightly modified construction.
Figure 7 is an end view of the socket body detached, but having the terminals
in place thereon.
Figures 8 and 9 are bottom and side views respectively of a switch device to be
described.
Figures 10, 11 and 12 are details also to be described.
Figure 13 is a view of a modified form of socket, and
Figure 14 is a view of a fixture arm to which a socket shell and terminals may
be clamped.
Referring to Figures 1 and 2, 1 is the insulating body of a pendent socket, pre-
ferably of moulded porcelain, having a central perforation through which the circuit
wires 2, 3 may extend. The body 1 is preferably formed with integral exten-
sions 4, 5, around which the terminals 6, 7 can be clamped, the free ends of said
terminals being drawn together to a greater or less extent by the screws 8, thereby
firmly securing them to the insulating body in an exceedingly simple and easy
manner. The terminal 6 is provided with an arm or extension 9 at the end of
which is a screw 10, on to which the central terminal of an ordinary Thomson-
Houston lamp 11 is adapted to screw, thereby connecting one end of the lamp

page_text: The
filament to the terminal 6. The second terminal 7 is made in the form of a switch
member having a band portion 12 (see Figures 8 and 9) adapted to surround the
extension 5, and a spring 13 bent so as to extend back under the wiper 14 connected
to the spindle 15 by a pin 16 adapted to strike one edge or the other of a notch in
the wiper, so as to give a loose connection between the spindle and wiper.
spring 13 rests over the ring or plate 17 on the end of the lamp, and, when the
wiper is in the position shown in Figure 1, makes contact with said ring or plate,
but when the wiper is turned, the spring rises and breaks the connection.
The
extension 5 on the socket body has a notch 18, in which the spindle, which passes
through both sides of the clamping terminal, rests. The switch member or
terminal made as described is bodily removable by loosening the clamping screw 8.
As shown in Figure 1, the circuit wire may be connected to the terminal by a nut
on the clamping screw, or it can be connected by being clamped under the head of
the sciew.
The socket shell 19 is divided at one point, as shown in Figure 3, and has over-
lapping edges with projecting ears 20, which can be pulled together more or less,
as required by the size and shape of the socket, by suitable screws 21, thus
avoiding trouble from. irregularities in the size or shape of the socket bodies. The
shell is notched at n so that it can fit over the spindle 16. The socket shell may
be made in two sections 22, 23, as shown in Figures 4 and 5, the edges on one side
being connected by a tongue and slot connection, as indicated at 24, or by other
suitable means, and at the opposite edges being connected by screws 25 in ears 26.
Ordinarily these edges would overlap instead of meeting end to end as shown in
the figure.
In Figure 6 the terminal 7 forming the removable switch member is not provided
with a switch spring 13 as in the device illustrated in Figure 8, but the wiper 14
is adapted to make contact with a spring or plate 27, which is supported on the
inner side of an insulating ring or plate 28, around which the shell 19 is clamped at
the same time that it is clamped around the socket body 1. Figure 6 shows also
the terminal 6 clamped around the extension 4 and the switch member terminal 7
clamped around the extension 5. A spring arm 29 is provided on the terminal to
hold the wiper 14 in place. In this construction the screw 10 projects through
the ring or plate 28, so that a lamp can be screwed on to it, and a terminal 30 is
located on the outside of the plate against which the second terminal of a lamp,
such as 17 Figure 1, is adapted to bear.
Figures 10, 11 and 12 show the preferred construction of the ring or plate 28
and parts carried thereby. The contact spring 27 is preferably in the form of a
ring tending to move away from the face of the plate 28, so that it will act as a
spring to throw the wiper when it has been partially turned by hand.
In Figure 13 the clamping shell 19 clamps the socket body and at the same
time the insulating ring 35, which carries a screw threaded sleeve 36, against which
an arm 37, projecting from one of the terminals, bears. The other terminal has
an arm 38 projecting into the centre of the screw threaded sleeve and forms a
contact device for a central lamp terminal, the screw threaded sleeve being the
contact device for the other terminal, as common in Edison sockets.
It is proposed in some cases to provide a cup 31 forming a part of a fixture arm
or bracket, such as 32, and to firmly secure an insulating body 33, corresponding to
body 1 of Figure 1, therein by means of suitable cementing material 34. To this
body the clamping shell 19 and the clamping terminals above described can
readily be connected. It is found advantageous to thus mount the insulating
body, making it a part of the fixture rather than of the socket in some cases.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The combination of a socket body, preferably of porcelain, and terminals of
suitable shave clamped thounds
1

page_text: 2. The combination of a socket body, preferably of porcelain, and a switch
member adapted to be clamped thereto, substantially as described.
3. The combination of a socket body, preferably of porcelain, and a metal
shell clamped to the body in the manner described.
4. The combination of an insulating body supported at the end of a fixture
arm, and a socket shell and terininals adapted to be secured thereto, as described.
Dated this 20th day of December 1892.
B. J. B. MILLS,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.