An Improved Holder for Incandescent. Electric. Lamps..
Year: 1890

page_text: Date of Application, 26th Sept., 1890
Complete Specification Left, 25th June, 1891-Accepted; 25th July, 1891
PROVISIONAL SPECIFICATION.
An Improved Holder for Incandescent. Electric. Lamps..
I, HARRY SOUTH, of 10 and 12 Garrick Street, Covent Garden, in the County
of London, Electrical Engineer and Contractor, do hereby declare the nature of this
invention to be as follows:-
In the ordinary form of screw contact holders, for incandescent electric lamps,
there is sometimes a tendency for the metal parts of the holders to become over-
heated, and thus lead to the failure of the lamps. I have found this to be the case
in lighting theatres, particularly behind the scenes, owing to the close proximity of
the lamps and the heat evolved therefrom; the failure of a lamp or lamps -being
first indicated by the falling of the parts upon the stage.
The object of my invention is to provide a safer and more suitable holder for the
purpose indicated, and for other uses. My improved holder is especially applicable
where the lamp bulb is suspended downwards, as there is but little danger of its
parts separating, from any heat to which it is liable. Moreover, I do not employ
vulcanite or other similar combustible or fusible material; and the holder is com-
posed of fewer parts.
My improved holder consists of a perforated disc or base of earthenware, with
a screw formed upon its periphery to receive a correspondingly screwed cover or
cap, also of earthenware. The cap is so formed and proportioned, that when
screwed home upon the base a sufficient interior space is left between the two for a
brass nut of hexagon shape. The nut is screwed to engage with the screw
metal collar upon the lamp, and the interior side of the base is recessed to receive
a portion of the depth of the nut, and to prevent it turning when the lamp is
screwed or unscrewed therein; a central orifice being formed in the cap to admit
the neck of the lamp for this purpose. The disc base has a central orifice to
receive a small tubular brass screw, secured in position by a nut on the inside.
The tubular screw forms a terminal for one of the conductors which is placed
within the same, and soldered in place with the nut, the interior face of the latter
serving as the central contact piece of the lamp when screwed home. The
earthenware base has also four small holes situated between the flats of the nut
recess and the circumference. Two of these holes, oppositely placed, are used
for screwing the base to its seat, either of the other two holes being used, as found
convenient, for the passage of the second conductor. A small hole is tapped
through one side of the hexagon nut for the reception of a small set screw, and this
forms the terminal of the second conductor. Consequently the hexagon nut
forms the second contact for the lamp, so that the two contacts of the lamp are
made by putting the screwed neck of the lamp through the central orifice of
the earthenware cap, and screwing it into the hexagon nut until the central contact
piece of the lamp comes in contact with the face of the nut of the tubular
screw before mentioned.
Dated this 24th day of September 1890.
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant..

page_text: b.
.
An Improved Holder for Incandescent Electric Lamps.
I, HARRY SOUTH, of 10 & 12 Garrick Street, Covent Garden, in the County of
London, Electrical Engineer and Contractor, 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:-
In the ordinary form of screw contact holders, for incandescent electric lamps,
there is sometimes a tendency for the metal parts of the holders to become over-
heated, and thus lead to the failure of the lamps.
I have found this to be the case in lighting theatres-particularly behind the
scenes owing to the close proximity of the lamps and the heat evolved therefrom;
the failure of a lamp or lamps being first indicated by the falling of the parts upon
the stage.
The object of my invention is to provide a safer and more suitable holder for the
purpose indicated, and for other uses. My improved holder is especially applicable
where the lamp bulb is suspended downwards, as there is but little danger of its
parts separating, from any heat to which it is liable. Moreover, I do not employ
vulcanite or other similar combustible or fusible material; and the holder is
composed of fewer parts.
My improved holder consists of a perforated disc or base of earthenware, with
a screw formed upon its periphery to receive a correspondingly screwed cover
or cap, also of earthenware. The cap is so formed and proportioned, that when
screwed home upon the base a sufficient interior space is left between the two
for a brass nut of hexagon shape. The nut is screwed to engage with the screw
metal collar upon the lamp, and the interior side of the base is recessed to
receive a portion of the depth of the nut, and to prevent it turning when the
lamp is screwed or unscrewed therein; a central orifice being formed in the cap
to admit the neck of the lamp for this purpose. The disc base has a central
orifice to receive a small tubular brass screw, secured in position by a nut on
the inside. The tubular screw forms a terminal for one of the conductors which
is placed within the same, and soldered in place with the nut, the interior face
of the latter serving as the central contact piece of the lamp when screwed
home. The earthenware base has four small holes situated between the flats of
the nut recess and the circumference. Two of these holes, oppositely placed,
are used for screwing the base to its seat, either of the other two holes being
used, as found convenient, for the passage of the second conductor. A small
hole is tapped through one side of the hexagon nut for the reception of a small
set screw, and this forms the terminal of the second conductor. Consequently
the hexagon nut forms the second contact for the lamp, so that the two contacts
of the lamp are made by putting the screwed neck of the lamp through the
central orifice of the earthenware cap, and screwing it into the hexagon nut
until the central piece of the lamp comes in contact with the face of the nut of
the tubular screw before mentioned.
In the further description of this invention, reference is made to the accompanying
drawings, in which
Fig. 1 is an elevation and Fig. 2 a plan of a lamp holder, Fig. 3 is a sectional
elevation of the same, and Fig. 4 a plan with the cover removed. Fig. 5 is also an
elevation and Fig. 6 a plan of a slightly modified form of holder; Fig. 7 is a
sectional elevation and Fig. 8 a plan of the same, with the cover removed.
The reference letters used refer to the same or similar parts, or parts having the
same function throughout the drawings.
The improved holder is secured upon a base a of any suitable kind, form, or
material, and has mounted thereon a perforated disc b of earthenware (or other
suitable insulating material) having a screw formed upon its periphery to receive a

page_text: correspondingly screwed cover c, also of earthenware or other convenient material,
which has a hole in the top to admit the neck of the lamp. A brass nut d of
hexagon form is placed between the disc b and cover c which fits into a slight recess
in the disc to prevent its turning, and the nut is screwed within (as shown in Fig. 3)
to engage with a screwed metal collar fitted upon the glow lamp in a manner well
known. A metal screw and nut e is passed through the centre of the disc b, to
form a terminal or central contact piece of the lamp when screwed home. Holes
are made in the base a and disc 6 for securing the disc b to the base a and for the
passage of the conductors, as shown in Figs. 3 and 4, one of which is connected to
the nut d by a small screw on the side. The other conductor is electrically con-
nected to the central contact screw and nut e, the screw of which may be made
tubular to conveniently receive the conductor.
Figs. 5 to 8 inclusive, show a slight modification in the method of making the
connections when used for stage purposes, or the like. In this case, several holders
are usually mounted upon the base a, which is slightly channelled beneath to
receive a longitudinal copper strip conductor e, that serves to convey current to the
central contact screws e as well as to act as nuts therefor. If a separate nut is used
for each central contact, then short links of conductors may be screwed beneath the
nut e to connect the several holders. The other conductor is also passed within the
channelling of the base a and electrically connected to either of the side screws f,f,
which secure the nut e to the base a, and which nut is flanged to receive the said
side screws.
Furthermore, the nut d has a thread cut on the flange to receive a
correspondingly screwed cover c, thus dispensing with the disc b before mentioned.
The base a is conveniently made of slate or earthenware in suitable lengths for the
purpose mentioned.
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. An improved holder for incandescent electric or glow lamps, comprising a
circumferential contact nut secured upon a base or support and prevented from
turning thereon, a central contact mounted on the said base and within the said
nut, and an enclosing cover of non-conducting material secured upon the said base
and having an opening therein to admit the neck of a lamp to the contact nut,
substantially as and for the purpose herein described.
2. An improved holder for incandescent electric or glow lamps, comprising a
circumferential contact nut secured upon a base or support and prevented from
turning thereon, a central contact mounted on the said base and within the said
nut, and an enclosing cover of non-conducting material, engaging with a screwed
flange upon the said contact nut, substantially as and for the purpose herein
described.
3. The combination of a base or support adapted to receive electrical connections
on one side and one or more holders for electric glow lamps on the other, substan-
tially as and for the purpose herein shown and described.
Dated this 25th day of June 1891
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicant.