Improvements in or Connected with Holders or Sockets for Incandescent Electric Lamps.
Year: 1889

page_text: Date of Application, 27th Aug., 1889-Accepted, 5th Oct., 1889
Improvements in or Connected with Holders or Sockets for
Incandescent Electric Lamps.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been com-
municated to me from abroad by James Walter Collier of the City County and State
of New York in the United States of America) and in what manner the same is to
be performed to be particularly describod and ascertained in and by the following
statement:
The socket or holder is made of hard rubber or other non-conducting material into
which are moulded and imbedded all the contacts and fixed circuit connections so
that the screws and other appliances and fittings heretofore used for securing in
place these parts are dispensed with. The holder has a socket proper for the
reception of the neck of the lamp and a chamber for the reception of the metallic cam
or switch piece by which the circuit through the holder is controlled, the said
chamber and socket being formed on opposite sides of a permanent non-conducting
diaphragm or partition formed in one piece with the body of the bolder.
The switch or cam chamber is closed by a cap through which the current conducting
wires pass the said cap being removable, and serving not only as a means by which
the holder can be attached to a supporting bracket, and by which the switch chamber
is sealed, but also as a means whereby the conducting wires, without other instru-
mentality, are clamped in place into secure connection with their respective connections
in the holder.
In the accompanying drawings-
Figure 1 is an external view; Figure 2 is a longitudinal central section in the
plane of the switch or circuit controlling cam; Figure 3 is a similar section in a plane
at right angles to the plane of section of Figure 2; and Figure 4 is an end view of
the cap end of the holder with the cap removed.
The body A of the holder is made of any suitable non conducting material
preferably by moulding from a plastic material; bard rubber is used by preference.
It is formed with a lamp socket a, a cam receiving chamber b, and an intermediato
diaphragm or partition c, which is in one with the remainder of the body of the
holder.
The lamp contacts are shown at d d the switch or cam contacts at ee and the
contacts for the current supplying or conducting wires at ff. The contacts d and e
are connected electrically by the connecting strip g; the contacts d' by the con-
necting strip ; and the contacts el f¹ by the connecting strip i. All of these contacts
and connections are moulded and imbedded in the holder during the operation of
forming the latter, and, by the subsequent vulcanizing, where that is employed, they
are most firmly and permanently held in the body of the holder, no part of them being
exposed save the mere contact surfaces themselves.
The chamber b is closed and sealed by a cap B of non conducting material preferably
of vulcanite or hard rubber, which cap screws on to the chamber end of the holder.
Through a central aperture pass the insulated conducting wires kk to their respective
contacts ff. In order to provide a convenient and sure connection the contacts ff
are made tubular as shown. The wires kk are beat as indicated, and, after being
passed through the cap (not yet applied to holder), their bent ends are respectively
inserted into the contact sockets ff. The cap is then screwed on to the holder; and
in screwing it down into place the annular internal shoulder 1 with which it is formed
will press upon and clainp the wires most securely in place as shewn clearly in
Figure 2.

page_text: and
The cap B also serves as a means by which the holder can be secured in place;
to this end, its aperture jis screw threaded and made of a size to fit the stem
employed in the electric light fixtures.
Inasmuch as the cap is to screw both upon the stem of the fixture, and upon the
holder and the wires therein. means must be provided for preventing the wires from
being twisted during this operation. To this end, inasmuch as the aperture j, must
have a right hand screw thread, in order to fit the standard screw threaded
bracket or supporting stem now generally used, the end of the cap which screws upon
the holder has a left hand screw thread. In this way the cap can be screwed upon its
supporting stem and the holder simultaneously, and by the time it has clamped the
wires, it has been screwed sufficiently upon its supporting bracket.
The metallic cam or switch piece may be of any suitable construction or form.. In
the position shown it has closed the circuit between the contacts e and e' and the circuit
through the lamp is completed. By giving it a quarter turn from the position shown
the circuit will be interrupted. This circuit controlling cam has in its centre a square
hole to receive the squared inner end of the key D which passes through a bearing in
the side of the holder. The key, when engaged with the cam, is held in that position
by a tongue m, sliding in a guide way formed for it in the body of the holder and
entering an annular groove n in the stem of the key. By withdrawing the tongue the
key can be drawn out, and the cam (which is really the only movable part in the holder,
and the only piece of metal appertaining to it which is not embedded in the hard
rubber) can readily be removed and replaced.
At the point in the side of the holder where the key passes through into the cam
receiving chamber, a stuffing box is preferably provided which stuffing box
surrounds and packs the stein of the key to prevent entrance into the chamber
of moisture or other corroding or oxidizing agent which might injure the efficiency of
the switch.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. The combination with the body of the holder, and the contacts for the wires
leading the current to said holder, of the non-conducting cap serving both as a cover
for the said chamber and as a clamp whereby each leading wire is clamped and firmly
held to its contact, substantially as hereinbefore set forth.
2. The combination of the non conducting holder body the tubular contacts ff
imbedded therein, and the cap B, substantially as and for the purposes hereinbefore
set forth.
3. The non-conducting holder having the socketed main wire contacts ff and
their permanent connections and provided with the non conducting right and left
screw cap B adapted simultaneously and by the same movement to clamp the main or
leading wires in place and to screw upon the bracket or support for the said holder, as
set forth.
4. The moulded holder of non conducting material, and with a switch chamber
formed therein, in combination with the movable circuit controlling switch or cam-
piece in the said chamber, and the key stem extending through the side of the holder
into the said chamber to engage the cam piece and detachably connected with both the
holder and the cam piece, substantially as hereinbefore set forth.
gust
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.