Wall-sockets, and Electric Lead Connectors.
Year: 1888

page_text: Wall-sockets, and Electric Lead Connectors.
We, CHARLES MARK DORMAN of 24, Brasenose Street, Manchester in the County
of Lancaster, Electrical Engineer and REGINALD ARTHUR SMITH, of 24, Brasenose
Street, Manchester in the County of Lancaster, 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:-
Our invention relates to that class of lampholders which are used for capped
incandescent lamps, to socket connectors for use with the plug terminals of flexible
electric leads, and generally to apparatus for connecting capped lamps to their leads,
or for connecting leads together.
Our invention consists partly of an improved method of holding the contact springs
to the porcelain or other insulator used by means of a single metallic stud to each
spring, the same stud also serving as a terminal for the attachment of one of the
leads; also of an improved method of securing the covering hood of a lampholder,
wall-socket, or other similar connector without the use of screws and in such a
manner that it can easily be detached and replaced without the use of a screw-driver or
other tool; and also of the general arrangement of the various parts and the method
of holding the same together.
Referring to the drawings accompanying this specification:-Fig. 1. is a section
of a lampholder on the line. c.; Fig. 2. is a section of the same on the line y. y. ;
Fig. 3 is a plan of the poreclain or other insulator showing the position of the contact
springs and holding down screws; Figs. 4. and 5. are a plan and underplan of the
same with the springs and screws removed; Fig. 6. is an external elevation of a
complete lampholder; Fig. 7. is an elevation and Fig. 8. a plan of the covering hood;
Fig. 9 is a side elevation of the locking ring; Fig. 10. is a plan and Fig. 11. an
elevation of the metallic base of a lampholder; and Fig. 12. shows the same arrange-
ments as applied to a wall-socket.
The contact springs a. a. (which in the case of a lampholder we generally fit with
pegs to press against the plates in the base cap of the lamp) are secured to the porcelain

page_text: or other insulator b. by metallic studs c. c. In order to increase the length of
these springs and so increase their elasticity we sometimes bend them back over them-
selves, getting the benefit of extra length without increasing the ground-space occupied
on the insulator.
These studs c. c. which are made square or any other suitable section or are fitted
with steady-pins in order to prevent them turning round in the holes d. d. of the
insulator b. are drilled and tapped right through their axis, and are fited at each end
with a screw the lower ones e. e. securing the springs against the insulator b. by means
of collars on the top of the studs, while the upper screws ff. are used for attaching
the wires conveying the current to the respective contact springs, the said wires being
brought through a large hole in the centre of the insulator.
The insulator b. is attached to the metallic base by means of screws or rivets g. g.
passing through the insulator and screwed or riveted into the metallic base.
The covering hood h. is fitted at its top end with the usual bayonet slots k. k. for
receiving the pegs in the side of the lamp-cap or plug-terminal, and at its lower
end is fitted with two diametrically opposite lugs or pegs l. 1. projecting outwards.
These lugs slide in two vertical slots m. m, made, by completely cutting away
the sides of the metallic base n. at these points, and so prevent the hood turning round
in the base.
The hood h. and the base n. are firmly locked together by means of the locking ring
shown in Fig. 9. This ring fits on the outside of the base n. and is capable of being
turned round into any position but is prevented from being pulled off the base in an
upward direction by means of the collar p. on the base n. The ring has two
diametrically opposite slots of the shape shown in Fig. 9 made by either completely
or partly cutting away the inetal of the ring at these points or by merely indenting
the ring from the inside.
It will be seen that if the locking ring be turned round on the metallic base until
the vertical parts of the slots q. q. coincide with the slots m. m. in the base, the hood h.
can be inserted into the base, the projecting lugs 1. 1. (which are long enough to
project through the base into the slots of the locking ring) sliding down the coincident
slots. If the locking ring be now turned round, the horizontal parts of the slots q. g.
will embrace the lugs 1. 1. and the hood h. will be firmly and effectually locked to the
base n.
When the lampholder is for use with those lamps whose base caps have only one
central contact plate, only one contact spring is used in tho lampholder; the
return current passing from the cap of the lamp through the hood and base of the
holder.
The base n. of the lampholder shewn in the drawings is screwed for attachment to a
tube or nipple but we do not confine ourselves to this form; sometimes preferring to
fit the base with a projecting flange or palms whereby it may be attached to a flat or
other surface by means of screws, bolts, or rivets.
In the wall-socket shown in Fig. 12. the same letters refer to the same parts as are
shewn in the other figures. The pegs in the contact springs are in this case generally
dispensed with, and a porcelain or other insulating covering . placed inside the hood
over the contact springs to prevent accidental or wilful insertion of undesirable
articles. This cover . is loose and can revolve in the hood and is fitted with two
holes for admitting the contact pegs s. s. of the terminal plug t., these pegs being left
long enough to enter the holes in the cover . before the side-pegs u. u. of the
terminal plug t. can enter the vertical parts of the bayonet slots in the hood, which
are of the same shape as in the lampholder hood. This arrangement is necessary in
order that should the cover r. have been misplaced, it can be turned round by
means of the pegs s. s. into its right position before the terminal plug t. is fully
inserted.
We do not in the case of wall-sockets and similar fittings confine ourselves to the
locking device described in the case of lampholders, but sometimes merely screw
the hood down to its base by means of screws passing through a flange or lugs
projecting from the hood

page_text: Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :-
(1.) In socket lampholders, wall-sockets, and similar coupling arrangements the
method of attaching each contact spring to the insulator by means of a single stud,
the stud being drilled and tapped at each end of its longer axis and fitted with a
screw at each end of the stud, one of them clamping the contact spring between a
collar on the stud and the insulator, and the other being used for clamping the wire
conveying the current to the same stud which is used as a terminal, substantially as
described and shewn.
(2.) In socket lampholders, wall-sockets, and similar coupling arrangements the
method of securing the covering hood to the base by means of one or more outward
projections on the hood fitting into one or more vertical slots in the base, thereby
preventing the hood being turned in the base; the hood and base being securely held
together by means of a locking ring on the outside of the base, which ring is capable
of being turned round on the base but incapable of motion in a direction towards the
lamp end of the holder, this ring having one or more ↳ shaped slots cut right through,
partly through, or merely indented into it, and being so arranged that when the
locking ring is turned into the position in which the vertical slots in the base and
locking ring coincide the hood can be inserted or withdrawn from the base, the
projections on the hood, which are long enough to project through the slots in the
base into the slots of the locking ring, sliding in the coincident slots; but when
the locking ring is turned round, the horizontal parts of the ✓ shaped slots embrace
the projections on the hood, thus securely locking the hood to the base, substantially as
described and shewn.
(3.) The improved lampholder as a whole substantially as described and shown.
(4.) The improved wall-socket as a whole substantially as described and shewn.
T
TA
T
1
1000
CHARLES MARK DORMAN.
REGINALD ARTHUR SMITH.