Improvements in Sockets or Holders for Electric Lamps.
Year: 1897

page_text: Date of Application, 6th Nov., 1897-Accepted, 18th Dec., 1897
COMPLETE SPECIFICATION.
Improvements in Sockets or Holders for Electric Lamps.
I, SAMUEL HUMES RUSSELL, of Watsonville, County of Santa Cruz, California,
U.S.A., 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 more particularly to a special form of automatic cut off
for electric lamps wherein fusible material is employed. With the use of the
invention any deficiencies due to a burned out condition or a short circuit may
be easily located.
In the accompanying drawing Fig. 1 is a side elevation of the fusible socket
of this invention with the outer casing removed. Fig. 2 an elevation of the
opposite side thereof. Fig. 3 a side view taken from the left side of Fig. 1, and
Fig 4 a view from the right side. Fig. 5 a central section through Fig. 1.
Fig. 6 a section of Fig. 1 taken at right angles to that of Fig. 5. Fig. 7 a bottom
and Fig. 8 a top view. Fig. 9 a perspective view of the socket within its casing.
Fig. 10 a preferred form of construction for the fusible wire.
1 is a holder constructed of any suitable non conducting material, such as
porcelain, glass, or the like, and preferably having a cylindrical form as shewn.
Its periphery is cut away or recessed to provide a seat in which to locate the
several parts without liability of their contacting with the outer casing.
The base 2 of the holder is also formed of non conducting material and is
provi le upon its outer face with the contacting plate 3 rigidly secured thereto
by screws which reach through the base into and connect with the standards
5, 6 extending upward and forming a rigid connection with the holder 1 by
having their upper ends seated in the recesses 7.
The upper ends of the standards 5, 6, are held in their operative seats by means
of the screws 8 which pass entirely through the holder from one standard to the
other, and thus provide for the retention of these within their seats and also for
an electrical union thereof through the holder.
Preferably, upon the right hand side of the holder is located the standard 9
(Fig. 3) substantially shaped in form, the horizontal section or base 9" of which
is adapted to fit within a transverse recess provided in the inner face of the base 2
where it is rigidly secured by means of the screws 10 seated within the base, or
by brazing it to the stem 34.
The upper end of the standard 9 is seated in the recess 11 provided in the
holder, and there held by the screws or bolts 12 arranged to pass entirely through
the holder to convenient points on the opposite side thereof.
The switch plate 13 is seated in the recess 14 and extends downwardly to the
lower end of the holder 1 when it is bent substantially at right angles and extends
nearly across the end of the holder and is provided with a corrugation or bend 15
said corrugation or bend being adapted to engage with the rounded end of the
switch block 16 constructed substantially in the usual manner and mounted upon
its operating shaft 17 seated in suitable bearings or apertures 18 provided in the
standards 5, 6 and adapted to be rotated therein by means of the thumb piece 19.

page_text: The switch block 10 is substantially oblong in form, and the rectangular
adjusting head 20 is preferably integral therewith. The purpose of said head is
to engage with the depending spring 21 so mounted that it will engage with the
corners of the head when the latter is rotated.
When the switch block is so adjusted that one of its ends will occupy the bent
section 15 the side of the head 20 and the spring 21 will rest parallel to each
other and directly in contact, thus providing that the switch block will be held
in connection with the bent section until the tension of the spring is overcome
by causing the next corner of the head to pass it.
The upper end of the spring 21 is provided with apertures adapted to receive
the screws 8 and is thus secured in position within the recess or seat 7 and between
the upper end of the standard 6 and the holder.
Within the upper end of the holder, preferably on a line with the standard 9
and the secured end of the switch plate are the transverse recesses 23, 24 and
within the same are secured the poles 25, 26 which are securely connected to the
holder by the screws 27.
The screws 27 suitably seated in the holder provide a sure means of anchoring
said poles, which are preferably formed of a piece of suitable sheet metal. At
one end of the plate thus provided (preferably the left end) are the clamping
screws 28 adapted to set up a connection between the electric wires 29 and said
plate, while upon the other end of the plate are the clamping screws 30.
The recesses 23, 24 are connected to the recesses 11, 14, by downwardly
extending grooves 31 adapted to form a seat or housing for the fusible wires 32
extending from the screws 30 downward to the screws 33 located upon the upper
end of the standard 9 and the switch plate 13. By this arrangement of the
several parts it will be seen that an electrical union is set up between the poles
25, 26 and the contacting collar 4 and as the delicately constructed fusible wires
form the connecting link the destruction of said wires, or either of them, will
open the circuit and thus extinguish the light.
The size of the fusible wires forming the automatic cut off will be determined
by practice and experience, thus providing that any undue excess of current will
automatically extinguish the light of the particular lamp upon which it is
applied, leaving all other lights upon the line intact and unaffected.
excess of
If desired, the middle or other preferred section of the fusible wire may be
more thinly or delicately drawn, rendering it more sensitive to an
current, or, if preferred, the wire may be flattened or almost severed at one part
of its length, effecting the same result. Both of these modes of constructing the
fusible wire are shewn in Fig. 10.
Any equivalent for the construction described may be adopted, for instance the
upper ends of the standards 5, 6 could be connected to the holder by encircling
bands properly seated in recesses in the face of the holder and adapted to form
electrical connection between the parts secured.
Connected to the base section 9" and extending diametrically through the base 2
is the threaded anchor or stem 34 adapted to form electrical connection between
the parts thus described and the lamp.
Adapted to enclose the holder 1 and its accompanying parts, is the cylindrical
housing shewn in Fig. 9 and consisting of the cap 35 cylindrical holder 36 and
the cup 37 adapted to fit with each other and held in position by set screws or
their equivalent. A recess 37 is provided in the cup section adapted to accom-
modate the shank of the thumb piece 19 in the usual manner. The cap 35 has a
diametrical opening, through which pass the insulated wires for conveying the
electric current. In order to enable the cap to be easily removed from the
section 36, a bayonet joint 36" is provided in the upper edge of said housing,
adapted to engage lugs or points 35ª formed upon the cap in the manner usual
in joints of this character.
In order to provide for a more perfect insulation of the holder 1 and the parts
attached thereto, it is desirable to add a lining formed, preferably, of mica or the

page_text: like, which will effectively insulate any protruding screw or plate should the
same not be properly constructed and seated.
By the use of this automatic individual cut off for electric lamps it will be
seen that should the wire 32 which is formed of lead, zinc, or any composition
having a suitably low fusing point, become severed, only the lamp to which it is
applied will be disabled.
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. An electrc lamp socket and switch consisting of an insulating holder, a
base consisting of an insulating disc and a contact plate, connected with said
holder by standards in electric union with said plate at their lower ends and with
each other at their upper ends; a switch block and shaft therefor operativel
mounted in said standards; an anchoring stem insulated in and passing through
said base and in electrical union with the feed wire of the lamp; a switch plate
in electrical union with the return wire of the lamp, the free end of said plate
iying in the path of the switch block, and a fusible wire mounted in said holder
and adapted to break the circuit on excess of current, substantially as described
and shewn.
2. As an improvement in fusible sockets for electric lamps, the combination
with an insulating holder of an insulating disc held away from and attached to
said holder by the standards 5, 6; a contact plate connected to the outer face of
said disc and in electrical union with said standards; an anchoring stem pass-
ing through said dise and plate and held insulated from the latter; a fusible
link secured in a recess in the holder; means for connecting said stem and link
with the feed wire of the lamp; a return wire having a fusible link mounted
in the holder; a contact plate in electrical union with said wire; a switch block
having an adjusting head rotatably mounted in said standards; and a securing
spring for the head, all operatively combined, substantially as described and
shewn.
3. The fusible socket for electric lamps consisting of the cylindrical holder and
disc like base, said holder being provided with a series of recesses in its peripheral
face; standards in electrical union with each other connecting said holder ard
base; poles or angle plates 25, 26 recessed in the upper part of the holder and in
electrical union with the lamp; fusible links connected to said poles; means for
connecting said links with the source of electric energy and for opening and
closing the circuit, substantially as described and shewn.
Dated this 6th day of November 1897.
THOMAS R. SHILLITO,
89 Chancery Lane, London, W.C. Agent for the Applicant.