Improvements in and connected with Cord Grips for Flexible Conducting Cords.
Year: 1899

page_text: Date of Application, 6th May, 1899
Completo Connifination Loft 10th Enh
4000
ABIL
1000
by AVIEN ESELLSCHAFT MIX & ENEST, Mectrical
Engineers, of Bulow Strasse 67, Berlin, W., in the German Empire.
Improvements in and connected with Cord Grips for Flexible
Conducting Cords.
I, HERMANN OPPENHEIMER, Electrical Engineer of 55, Redcross Street,
Barbican, London, E.C., do hereby declare the nature of this invention to be
as follows:-
The cord grips hitherto in use on lampholders have had the disadvantage
that the flexible cords were generally not separated from each other, but pressed
together close to each other, thereby frequently causing short circuit. This dis-
advantage is entirely avoided by using the arrangement which is hereinafter
described. Not only are the two strands of flexible cord kept apart from each
other by the cord grip, but as the latter is made of insulating material such as
porcelain, steatite, ebonite, etc., it prevents short-circuiting even if the insulation
of the flexible cord should get destroyed.
The cord grip itself is of such a permanent and reliable character that an
accidental loosening of same is almost impossible. The guide ring made of
insulating material, such as porcelain, etc., through which the leads are entering
the lamp-socket or other electric light accessory, is either of conic or cylindric
shape, but it can also be of a different form such as bell-shaped or having a
slanting construction, just as the circumstances may render one or the other
more effective.
The guide ring is situated. inside the threaded nipple which latter forms
part and parcel of either the lamp-socket, wall-plug, or ceiling rose, or similar
apparatus where a cord grip is required.
A bell-shaped metal cap presses the two flexible cords towards the insulating
piece, which latter's pressure plane corresponds with the form of the guide
ring.
The cord grip, which terminates upwardly in the shape of a cone, may be
provided with grooves to allow the cords to be placed therein. The mounting
of the cord grip can easily be done in the following manner:-
After having introduced the flexible cord into the guide ring and the nipple,
the bare ends of the flexible cord are connected to the contact terminals of either
the lampholder, wall-plug, or ceiling rose, etc. Then the guide ring is placed
inside the threaded nipple, the flexible cords are separated above such nipple,
and the cord grip inserted between the two strands of the cord, whereupon the
metal cap of the cord grip is screwed on.
!
The cord grip, in keeping the two strands of the flexible cord apart from each
other, presses both strands firmly towards the guide ring, in which position they
are retained. Instead of the threaded can, one can also use a cover with a flange
which is held down by means of screws, thus producing a pressure in the direction
of the current-carrying part of the guide ring. The guide ring and the cord

page_text: grip may also be arranged in an opposite, manner to what is described above.
Furthermore, the guide ring can form a fixed part of any accessory, such as
> lampholders ceiling roses, or wall-plugs, etc.
The same can be done with the cord grip,. the latter being brought into per-
!manent connection with an accessory instead of being arranged as a separate 5
and loose part.
TC1
1000
COMPLETE SPECIFICATION.
Improvements in and connected with Cord Grips for Flexible
Condueting Cords.
I, HERMANN OPPENHEIMER, Electrical Engineer of 55, Redcross Street,
Barbican, London, E.C., in the County of Middlesex, 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:-
The cord grips hitherto in use on lampholders have had the disadvantage
that the flexible cords were generally not separated from each other, but pressed
together .close to each other, frequently causing short circuit. This dis-
advantage is entirely avoided by using the arrangement which is hereinafter
described. Not only are the two strands of flexible cord kept apart from each
other by the cord grip, but as the latter is made of insulating material such as
porcelain, steatite, ebonite, etc., it prevents short-circuiting even if the insulation
of the flexible cord should get destroyed.
The cord grip itself is of such a permanent and reliable character that an
accidental loosening of same is almost impossible. The guide ring made of
insulating material, such as porcelain, etc., through which the leads are entering
the lamp-socket or other electric light accessory, is either of conic or cylindric
shape, but it can also be of a different form such as ball-shaped or having a
slanting construction, just as the circumstances may render one or the other
more effective.
In the accompanying tracing I shew a cord grip in two different arrangements,
represented by the Figs. 1, 2, 3, 7, 8, and 4, 5, 6, 9, 10, respectively.
The porcelain guide ring a as shewn in Fig. 1, is of conical construction while
in that shewn under Fig. 4 the gripping surface is in a zig-zag form.
The guide ring is situated inside the threaded nipple b which latter forms part
and parcel of either the lamp-socket wall-plug, ceiling rose, or similar apparatus
where a cord grip is required. A bell-shaped metal cap c is somewhat reduced
at its top end d, and when screwed home presses the 2 flexible cords towards the
insulating piece e which latter's pressure plane corresponds with the form of
the guide ring a. The insulating piece e serves the purpose of keeping apart
the flexible cord g at the point and to grip this and the guide ring a after
the metal cap has been. screwed home on the threaded nipple.
In order however to prevent the shifting of the insulating piece e or of the
flexible cord g, especially the twisting of the latter or the abrasion to its insulating
covering, the insulating piece e of. Figs. 1 and 4, are provided with radial
notches or grooves f (Figs. 2 and 3, and 5 and 6 respectively) into which the
flexible cords are laid, while the guide ring a as shewn in Fig. 4 has radial
notches or grooves f² of a different shape as shewn in Figs. 9 and 10. In con-
sequence of this arrangement, the flexible leads remain in that position given.to

page_text: them after having been introduced into the lamp-socket, and are not shifted from
their position when the metal cap is screwed home.
It will be seen that it is impossible that they should get twisted or that the
insulating cover of same could be abrased, as the flexible cords are by means of
the insulating piece e and the guide ring a firmly wedged, and their shifting.
into an opposite direction is impossible. The radial notches or grooves, etc.,
of the guide ring serve the further purpose of facilitating the cords being placed
centrally.
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:-
1. The cord grip in which the flexible electric light cords are by means of 2
suitably constructed insulating pieces, and a centrally arranged threaded cap,
separated from each other, and retained in their proper position, and in which
the 2 insulating pieces are wedging the flexible cord in such a manner and for
such purpose that a twisting of the cords or damage to its insulation is pre-
vented, substantially as and for the purpose set forth.
2. A construction of the cord grip as described under Claim 1, in which the
2 insulating pieces are provided with notches, grooves, or the like, for the purpose
of placing the flexible cords therein, and for the purpose of allowing the cord to
be placed centrally, substantially as and for the purpose set forth.
Datod thie 8th day of Faliruary 1000.
HERMANN OPPENHEIMER.