Improvements in or connected with Electric Lampholders, Sockets, or Connections.
Year: 1894

page_text: Date of Application, 30th June, 1894
Complete Specification Left, -28th Mar., 1895-Accepted, 15th June, 1895
PROVISIONAL SPECIFICATION.
Improvements in or connected with Electric Lampholders, Sockets,
or Connections.
1, JOHN BENJAMIN VERITY of Plume-Works, Aston, in-the-County-of-
Warwickshire, Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention consists of the herein described improvements in or connected with
electric lampholders connections and the like and the object of this invention is to
so construct lampholders sockets or connections that the insulation of the contact
plungers may be more perfect than is usually the case and a better action obtained.
In carrying out this invention I use a moulding block of china or other insulating
material provided with the necessary connection screws and contact plungers
mounted in such a manner that the china or other block itself forms the guides or
cylinders in which the contact plungers and their springs are placed without the use
of metal cylinders which have hitherto always been used. I also use metal parts on
the lower face of the insulating block in which the contact plungers make a tight fit
ensuring good electrical contact and a second bearing so that the contact plungers
can never get loose or out of the perpendicular.
Dated this 29th day of June 1894.
Improvements in or connected with Electric Lampholders, Sockets,
or Connections.
I, JOHN BENJAMIN VERITY, of Plume Works, Aston, Birmingham, in the
County of Warwick, Electrical Engineer, 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 consists of the herein described improvements in, or connected
with electrical lampholders connections, and the like, and the object of this invention
is to so construct electrical lampholders, sockets or connections that the insulation of
the contact plungers may be more perfect than is usually the case, and a better
action may be obtained.
In carrying out this invention I use a single or double tube of china or other
insulating material, provided with the necessary connection screws and contact
plungers, mounted in such a manner that the china or other insulating material
itself forms the guides or cylinders in which the contact plungers and their springs
are placed, without the use of metal cylinders, which have hitherto always been used
in electrical lampholders of the ordinary bayonet type.
I also use metal parts on the lower face of the insulating tube in which the
contact plungers make a tight fit, ensuring good electrical contact, and a second
bearing, so that the contact plungers can never get loose, or out of the
pernendicular.

page_text: I will now proceed to describe my invention and the manner in which it is to be
performed by reference to the accompanying drawing.
Fig. 1 is an elevation of one form of a double tube made according to my
invention, and is shown complete with the spring plungers, & terminals for the
connecting wires.
Fig. 2 is a plan of the same double tube seen from above.
Fig. 3 is a plan of the same article seen from below.
Fig. 4 is a horizontal section taken on the dotted line indicated on Fig. 1.
Fig. 5 is a vertical section of the same double tube fitted with the metal parts
which are described in detail in Figs. 9 & 10 and by letters B. C. D. E. F. G. H.
Fig. 6 is an elevation of a form of single insulating tube provided with spring
plunger and terminal, and made according to my invention, the electric wire being
clamped at the base of the insulating tube, as shown, instead of in a connected
terminal tube as is the case in Fig. 5.
Fig. 7 is a vertical section of the same single insulating tube.
Fig. 8. is a horizontal section of the same article.
These tubes are intended for use quite independently of each other, as shown, for
single pole centre contact lampholders or two or more may be held apart at a given
distance by dises or other means, which may either form part of the tubes as in
Figs. 1. to 5 or may be independent therefrom.
Fig. 9. is an elevation of one form of spring plunger fitted with expanding wire
brush, spring, & bearing, made according to my invention, and as used in
conjunction with the double insulating tube illustrated by Figs. 1. to 5. The
spring C is here shown compressed as it would be when the lamp was in position.
Fig. 10 is a vertical section of the same spring plunger showing the spring
extended and as illustrated in position in Fig. 5.
The whole of the parts described above are suitable for use in the ordinary case
or exterior of the usual form of electrical lampholder which is in every day use and
need not be described or illustrated herein.
Like parts are lettered with like letters of reference.
A is the china or other insulating tube forming the guide or cylinder in which the
spring plunger or plungers are enclosed.
B is the spring plunger.
C is the spring actuating the plunger.
D is the metal part forming the bearing in which the expanding wire brush E
makes a tight, elastic, and sliding fit.
F is the metal plate or shoe to convey the electric current from the contact
terminal G to the brush E and plunger B.
His the binding or pinching screw which holds the electric supply wire in
position in the contact terminal G.
I is the slot in the edge of the china or other insulating tube A to keep it in its
proper position in the outer tube in the ordinary way.
-
J is the electric wire.
K is the clamping screw or terminal.
It will be understood that according to my invention I can use one china or other
insulating tube with a single spring plunger, in cases where the outer metal case of
the lampholder forms a path for the return of the electric current, or I can use two
tubes and two spring plungers for double pole lampholders, or three tubes and three
spring plungers, or more if desirable.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
Firstly. The use in the electric lampholder, socket, or connection of china or
other insulating tubes to form the cylinders in which the plungers or spring contact
makers are contained instead of metal cylinders as hitherto employed in all electric
lampholders of the type known as the bayonet.

page_text: Secondly. In an electric lampholder, socket, or connection, the use of metal parts
on the under side of the insulating cylinder or tube, so arranged as to form a second
bearing at a considerable distance from the top bearing, thus preventing the spring
plunger from getting out of the perpendicular.
Thirdly. In an electric lampholder, socket, or connection, the arrangement of
parts whereby, owing to a second bearing the electric current is carried to the lamp
through the plunger or spring contact maker instead of having to depend partially
upon the spring for its path.
Fourthly. In an electric lampholder, socket or connection, the use of a number of
wires so arranged as to form a brush which makes a sliding and elastic contact in
the second bearing hereinbefore mentioned.