IMPROVEMENTS IN SOCKETS OR HOLDERS FOR ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to Edward Hibberd Johnson of Holborn Viaduct in the
City of London for an invention of "IMPROVEMENTS IN SOCKETS OR HOLDERS
FOR ELECTRIC LAMPS"
PROVISIONAL SPECIFICATION left by the said Edward Hibberd Johnson at
the Office of the Commissioners of Patents on the 7th March 1882.
EDWARD HIBBERD JOHNSON of Holborn Viaduct in the City of London
"IMPROVEMENTS IN SOCKETS OR HOLDERS FOR ELECTRIC LAMPS "
My invention has for its object the production of a socket or holder for Electric
lamps which shall possess the advantages of simplicity in construction (being
composed of only a small number of simple parts) non-liability to derangement
and facility for attachment and detachment of the lamp without the aid of any
tool or instrument.
In carrying out my Invention in order to effect this object the socket or holder
is composed of the following parts:-
1. A base (which may be made of any suitable material) provided with a screw
threaded aperture for the passage of the main conductors and for the attachment
of the base to a bracket or suitable support.
2. A contact carrier formed mainly of non conducting material but provided
with a metallic screw thread on its periphery to which one of the main conductors
is connected and with a central binding screw or contact piece to which the other
main conductor is connected, the said carrier (after the base is secured to its
bracket or support) being attached to the base by causing counterpart projections
and recesses on the respective parts to engage or interlock
3. A hollow metallic screw or junction piece one extremity of which is screwed
on to the peripheral thread of the carrier
4. An enclosing case (formed of or lined with non-conducting material) which
is screwed on or into the base (provided with a suitable screw thread for the
purpose) thereby maintaining the several parts rigidly in position. The lamp

page_text: itself is provided at one extremity with a peripheral metallic screw-thread in which
one of the wires from the burner terminates and with a central contact piece in
which the other wire from the burner terminates
The peripheral screw thread of the lamp is screwed into the free end of the
hollow metallic screw or junction piece leading from one of the main conductora
thus making electrical contact therewith whilst the central contact piece of the
lamp makes electrical contact with the central binding screw or contact piece of
the carrier to which the other main conductor is connected, a flange or shoulder
on the lamp being caused to abut against or rest upon the end of the enclosing
case
The continuity of one conductor is thus formed by the peripheral external
metallic screw threads whilst the continuity of the other conductor is formed by
the central contacts, the act of screwing the parts together by hand being sufficient
to form the necessary rigid connection.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Hibberd Johnson in the Great Seal Patent Office on the
2nd September 1882.
EDWARD HIBBERD JOHNSON of Holborn Viaduct, in the City of London
"IMPROVEMENTS IN SOCKETS OR HOLDERS FOR ELECTRIC LAMPS
13
My said invention has for its object the production of a socket or holder for
electric lamps, which shall possess the advantages of simplicity in construction
(being composed of only a small number of simple parts) non liability to derange-
ment and facility for attachment and detachment of the lamp without the aid of
any tool or instrument.
In carrying out my said Invention in order to effect this object, the socket or
holder is composed of the following parts viz.
1 A base (which may be made of any suitable material) provided with a screw
threaded aperture for the passage of the main conductors, and for the attachment
of the base to a bracket or suitable support.
2 A contact carrier formed mainly of non conducting material, but provided with
a metallic screw thread on its periphery to which one of the main conductors is
connected, and with a central binding screw or contact piece to which the other
main conductor is connected, the said carrier (after the base is secured to its
bracket or support) being attached to the base by causing counterpart projections
and recesses on and in the respective parts to engage or interlock
-
3 A hollow metallic screw or junction piece, one extremity of which is screwed
on to the peripheral thread of the carrier.
4 An enclosing case (formed of or lined with non conducting material) which is
screwed on or into the base (provided with a suitable screw thread for the purpose)
thereby maintaining the several parts rigidly in position.
The lamp itself is provided at one extremity with a peripheral metallic screw

page_text: thread in which one of the wires from the burner terminates, and with a central
contact piece in which the other wire from the burner terminates. The peripheral
screw thread of the lamp is screwed into the free end of the hollow metallic screw.
or junction piece leading from one of the main conductors, thus making electrical.
contact there with, whilst the central contact piece of the lamp makes electrical.
contact with the central binding screw or contact piece of the carrier, to which the
other main conductor is connected, a flange or shoulder on the lamp being caused.
to come flush with the end of the enclosing case.
The continuity of one conductor is thus formed by the peripheral external
metallic screw threads whilst the continuity of the other conductor is formed by
the central contacts, the act of screwing the parts together by hand being sufficient.
to form the necessary rigid connection.
And in order that my said Invention may be perfectly understood I shall now.
proceed more particularly to describe the same, and for that purpose shall refer to
the several figures on the accompanying sheet of drawings the same letters of -
reference indicating corresponding parts in all the figures.
Fig. 1 of the accompanying drawings represents a vertical section of an electric
lamp having attached thereto a socket, or holder constructed and arranged
according to my said invention. Fig. 2 shews the lamp separate from the socket
or holder proper, and Figs. 3. 4. 5. and 6, are details of the socket or holder itself.
The improved socket or holder is composed of the following principal parts viz.
a base A (Fig. 3) a contact carrier B (Fig. 4.) a hollow metallic screw or junction
piece C (Fig. 5) and an enclosing case D (Fig. 6).
The base A (which may be made of any suitable material) is provided with a
screw threaded aperture a, for the passage of the main conductors 1, 2, and for
the attachment of the base to a bracket or suitable support. It is also furnished
with projections b, for engaging or interlocking with recesses 61, in the contact
carrier B (or projections may be formed on the latter and recesses in the base) so
that the carrier (after the base is secured to its bracket or support) is attached
to the base by causing the engagement of the said counterpart projections and
recesses.
The body of the contact carrier B, is formed of non conducting material, but it
is provided with a metallic screw thread c, on its periphery, in electrical communi-
cation with which is a binding screw d, to which the main conductor 2, is secured,
and the said contact carrier is also furnished with an approximately central
binding screw, or contact piece e, to which the other main conductor 1, is
connected.
The hollow metallic screw or junction piece C, is screwed at one extremity on
to the peripheral thread c, of the carrier B, and the several parts are maintained
rigidly in position by means of the enclosing case D (lined with non conducting
material) which is screwed into the base A, the two being provided with suitable
screw threads at f, fi, for the purpose.
The lamp E, itself is furnished at one extremity with a peripheral metallio screw
thread g. in which the wire 4, from the burner F, terminates, and with a central
contact piece h, in which the other wire 3, from the burner terminates, the parts
h, being separated by non conducting material i
The peripheral screw thread g, of the lamp is screwed into the free end of the
hollow metallic screw or junction piece C, leading from the main conductor 2,
thus making electrical contact therewith, whilst the central contact piece h, of the
lamp makes electrical contact with the central binding screw or contact piece e,
to which the main conductor 1, is connected as before mentioned, A flange or
shoulder k, on the lamp being caused to come flush with the end of the enclosing
case.
The continuity of one conductor is thus formed by the peripheral external
metallic screw threads c, C, g, whilst the continuity of the other conductor is
formed by the butt central contacts e, h, the act of screwing the parts together by
hand being sufficient to form the necessary rigid connection

page_text: Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is
1st A socket or holder for electric lamps having a central, or approximately
central butt contact piece, and a peripheral contact piece or surface respectively
forming the electrical continuity of the two conductors, by the act of screwing the
lamp to the socket or holder substantially as herein before described
2nd The combination in a socket or holder for electric lamps of the base, the
contact carrier having a central, or approximately central butt contact piece, and a
peripheral contact piece or surface, the hollow metallic screw or junction piece,
and the enclosing case, all constructed arranged, and combined together, and
adapted for the lamp substantially in the manner and for the purposes hereinbefore
described.
In witness whereof I the said Edward Hibberd Johnson have hereunto set
my hand and seal this Eleventh day of May in the year of our Lord One
thousand eight hundred and eighty two.
Signed sealed and delivered by the
said Edward Hibberd Johnson
in the presence of
GEO: HAYES
his clerk
57, Holborn Viaduct,
London.
EDW³. H. JOHNSON. (L.S.)