AN IMPROVED ADJUSTABLE PENDANT OR SUPPORT FOR ELECTRIC LAMPS
Year: 1885

page_text: I ALBERT EDWARD JONES of 2 Westhill Terrace, Chapel Allerton, Leeds in
the County of York, Electrician do hereby declare the nature of my invention for
AN IMPROVED ADJUSTABLE PENDANT OR SUPPORT FOR ELECTRIC LAMPS, to be as
follows:-
This invention relates to an improved adjustable pendant or support for electric
lamps the object in view being to provide a support and especially a hanging
support which shall have a considerable range of movement in circular or oblique
directions and which will remain in any position to which it has been moved or
adjusted.
This adjustable lamp support is especially intended for use in workshops and
draughtsmans offices and will enable the men to readily shift the light to any side
of their work and up or down as may be required.
The invention in its simplest form consists of a tubular telescopic rod or support
terminating below in a lamp or lamp socket and above in metal cup or hemisphere
fitted within a metal case of hemispherical form open at the bottom and adapted
to be secured by its upper part to the ceiling. The metal cup or hemisphere is
provided with a central tubular stem extending above the level of its rim and
terminating in an insulated metal button or head of rounded form or cup shape
against which a piston or plunger of correspondingly rounded form or it might be
a link or thrust rod is tightly pressed by a powerful spring mounted centrally
within the case.
The metal cup and the lower part of the case in which it is fitted constitute a
ball and socket joint the parts of which are so proportioned and so tightly forced
together that the friction of contact is sufficient to hold the telescopic rod,
extending from the metal cup, rigidly in any position to which it may be moved.
In order to provide for the insertion of the metal hemisphere or cup, the casing
by which it is supported and through which it works is made in two parts which
screw together. The insulated button at the top of the central stem of the metal
cup is connected by a wire with one terminal and the cup itself is in electrical
connection with the other terminal. The telescopic portions of the pendent lamp
support are suitably insulated and contact is maintained between the corresponding
moving parts by means of flexible springs.

page_text: Owing to this arrangement the pendent decreases in size and weight towards
the lamp socket and the position of the spring piston link or thrust pin and the
button or head against which it hears or to which it is connected is so arranged
with respect to the centre of motion that, as the lamp support is moved into its
extreme positions of obliquity and the leverage increases the pressure tending to
hold it in the said positions is applied to greater advantage.
The form of the piston or its equivalent by which pressure is applied to the
stem of the movable hemispherical cup it is obvious may vary considerably without
departing from the tenor of my invention and means may be provided if necessary
for adjusting the spring to vary its pressure or power.
From the foregoing it will be seen that by this novel combination and arrange-
ment of parts the lamp may be moved through a complete circle of large or small
diameter and its stem be lengthened or shortened as required.
I am aware that telescopic electric lamp supports have been proposed; and also
that ball and socket joints for electric lamp supports have been used to prevent
injury to the conductors from accidental blows but I am not aware that any rigid
electric lamp pendant has yet been devised which can be swung from a central
point through complete circles or angles of large or small diameter and will remain
automatically extended in any position, out of the vertical, to which it has thus
been moved.

page_text: I, ALBERT EDWARD JONES of 2 Westhill Terrace, Chapel Allerton, Leeds in the
County of York, Electrician 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 :-
This invention relates to an improved adjustable pendant or support for electric
lamps, the object in view being to provide a support, and especially a hanging
support, which shall have a considerable range of movement in circular or oblique
directions, and which will remain in any position to which it has been moved or
adjusted.
This adjustable lamp support is especially intended for use in workshops and
draughtsmen's offices, and will enable the men to readily shift the light to any side
of their work, and up or down, as may be required.
The invention, in its simplest form consists of a tubular telescopic rod or support
terminating below in a lamp or lamp socket, and above, in a metal cup or hemi-
sphere fitted within a metal case or socket of hemispherical form, open at the
bottom, and adapted to be secured by its upper part to the ceiling. The metal cup
or hemisphere is provided with a central tubular stem extending above the level of
its rim, and terminating in an insulated metal button or head of rounded form,
against which a piston or plunger of correspondingly rounded form is tightly
pressed by a powerful spring mounted centrally within the case.
The metal cup, and the lower part of the case in which it is fitted, constitute a
ball and socket joint, the parts of which are so proportioned, and so tightly forced
together, that the friction of contact is sufficient to hold the telescopic rod,
extending from the metal cup, rigidly in any position to which it may be moved.
The accompanying drawing shows, in longitudinal section, an adjustable lamp
support or pendant constructed according to my invention, with an electric
incandescent lamp screwed in place at the end thereof.
A is a hollow metal casting divided horizontally by a plate a.-The upper edge
of this casting is secured by screws to the ceiling, and the lower edge is threaded
externally to receive the socket B, which is threaded internally to correspond.-
C is a hemispherical cup, forming, with the socket B, a ball and socket joint, and
having a cylindrical tube c standing centrally within it.-Secured within the
tube c, and in electrical connection with it, is the outer tube d of the telescopic
rod D. Within the tube d is a smaller and shorter tube d, closed at its upper end
by a round headed button do, which overlies the upper ends of the tubes c and d,
but is electrically insulated from them, as also is the short tube d', by rings of
vulcanite or similar insulating material, shown in black in the drawing.
Immediately over the button d¹*, _and_depending from the plate a of the
casting A, but electrically insulated from it, is a hollow casting a' adapted to
receive the shaft of a headed plunger a², the head being hollowed out to fit the
rounded_button d¹*, and give an even bearing surface thereto. A coiled spring
surrounding the casting a¹, and bearing against the under side of a shoulder

page_text: thereon, and upon the upper side of the head of the plunger a², presses the said
plunger firmly against the button d*, thereby causing sufficient friction between
the cup C and the socket B, to hold the pendent telescopic rod D in whatsoever
position it may be placed.
Within the lower part of the tube d, and electrically connected with it by means
of springs, is a tube d² carrying a socket d³ for the electric lamp, and within the
tube ; and insulated from it by a coating of vulcanite, is a rod d, extending
from the socket d³ up into the tube d, and connecting with it electrically through
its split head. When the lamp is screwed into the socket ³, one end of the
filament is in connection with the rod d through an abutting metal rod e running
through the insulating neck E; the other end of the filament is connected to a
wire which passes through the neck E, and is soldered to a ring c¹, against which
the socket d³ bears.
It will now be seen that the electrical circuit is complete, from a screw in the
top of the casting a¹ (to which a conducting wire is attached) through the said
casting and plunger a², button d*, tube d, rods d and e, to the filaments; and
through the ring e¹, socket d³, tubes d' and d, cup C, casting A, to a screw upon
the plate a connected to the other conducting wire.
It will further be evident that the electrical circuit will remain unbroken
notwithstanding that the telescopic rod D may be elongated by drawing out the
socket tube d² from the outer tube d, and notwithstanding, also, the position of the
rod D with regard to the ceiling, for it is capable of universal movement to a
considerable extent, and may either be hanging vertically, as shown in the drawing,
or it may take the position indicated by the centre lines, or it may occupy any
intermediate position, always remaining in whatever position it has been placed, by
reason of the friction between the socket B and cup C, caused by the pressure of
the spring plunger a² upon the button di*.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
An adjustable support for electric lamps constructed substantially as shown and
described with reference to the drawing, such support being capable of considerable
movement in circular, oblique, or vertical directions, and retaining its adjusted
position for the purpose set forth.