An Improved Cup and Ball Joint for Electrically Connecting and Disconnecting Electric Light Fittings.
Year: 1895

page_text: Date of Application, 22nd Mar., 1895-Accepted, 11th May, 1895
COMPLETE SPECIFICATION.
An Improved Cup and Ball Joint for Electrically Connecting and
Disconnecting Electric Light Fittings.
1, ROBERT WALTER BRAHAM of 76 St. Agnes Place, Kennington Park in the
County of Surrey, Metal Spinner and Electrical Brass Finisher 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 :-
My invention relates to an improved cup and ball joint whereby electric light
fittings may be easily detached from the main wires without the necessity of
unwiring, which is the case, with the arrangements now in use.
According to my invention I make a cup and socket on the same principle as
is used for gas the cup of which is suitably insulated, and I fix therein a circular
piece of vulcanite or some other suitable non conducting material, on the underside
of which I place the terminals for the electric wires, on the other or top surface
of the vulcanite or similar non-conductive material, I arrange two spiral springs
which are connected in any suitable manner with the aforesaid terminals. In the
upper part of the case I fix another plate of vulcanite or similar non-conducting
material on the upper surface of which I fix two more terminals and on the under
surface I arrange two circular pieces of brass the outer piece of which is made
with a shoulder or lug, (as shown in the drawing), on the inner side, which
prevents the outer spring, which is fixed on the underneath disc, from slipping
and breaking contact when the upper and lower parts of the case are screwed
together.
In some instances where my improvements are applied to electroliers or similar
fittings, I arrange the upper disc of vulcanite upon the ceiling block, in which
case preferably arrange the two terminals, which are in the upper part of the
case, on the outside of the non conducting material as illustrated in the drawing,
(Figure 1) or I may fix the terminals in any other couvenient manner.
Reference being had to the accompanying drawing in which
Figure 1 is a sectional elevation showing my improvements.
Figure 2 is a similar view but in another form.
Figure 3 is a plan shewing the top or ceiling connections.
Figure 4 is a view shewing the top and bottom connectious disconnected.
Letters of reference indicate corresponding parts throughout the drawing.
A is the case, B is the insulated cup in which the circular disc of vulcanite C
is fixed. D. D. are the terminals arranged on the underside of the vulcanite
disc C. EE are the spiral springs which are suitably connected with the
terminals D D. F is another disc of vulcanite which is fixed in the upper part
of the case A, on the upper surface of which I arrange two more terminals G G,
or I may arrange the terminals in any other convenient manner, such for instance
in Figure 1 where they are placed on the outside of the vulcanite. On the
under surface of the vulcanite I arrange two circular pieces of brass H. H. the
outer one of which is provided with a lug or shoulder I on its inner edge,
the inner piece is provided with a projecting piece J so as to prevent the springs E E
from slipping and thus breaking contact when the upper and lower cases A are
screwed together. By this arrangement I effect a perfect and constant contact.
The great feature of this invention is that the fitting finds its own level when
fixed to ceiling and it may be twisted or swung in any direction which is an
advantage when it is found necessary to change the globes. The above feature
has never to my knowledge been attained with electrical fittings.

page_text: Of course my invention could be quite as advantageously used with a rigid fitting
without interfering in any way with the contact.
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 :-
First. An improved cup and ball joint comprising two discs of vulcanite, or
other non conducting material, upon the lower disc of which is mounted, the
terminals and two springs suitably connected with the terminals and on the upper
disc is mounted two more terminals suitably connected with two circular pieces of
brass the outer one having a shoulder piece, and the inner one formed with a
projecting piece or stud substantially as and for the purposes specified.
Second. The combination with electric light fittings of an improved cup and ball
joint comprising two discs of vulcanite, or other non conducting material upon
the lower disc of which is mounted the terminals and two springs suitably connected
with the terminals and on the upper disc is mounted two more terminals suitably
connected with two circular pieces of brass, the outer one having a shoulder piece,
and the inner oue formed with a projecting piece or stud substantially as and for
the purposes specified.