IMPROVEMENTS SOCKETS OR HOLDERS FOR ELECTRIC LAMPS
Year: 1881

page_text: LETTERS PATENT to Joseph Wilson Swan, of the Town and County of
Newcastle-on-Tyne, Chemist, for an Invention of “IMPROVEMENTS
SOCKETS OR HOLDERS FOR ELECTRIC LAMPS."
IN
PROVISIONAL SPECIFICATION left by the said Joseph Wilson Swan at the
Office of the Commissioners of Patents on the 28th December 1881.
JOSEPH WILSON SWAN of the Town and County of Newcastle on Tyne Chemist.
"IMPROVEMENTS IN SOCKETS OR HOLDERS FOR ELECTRIC LAMPS."
My Invention relates to improvements in sockets or holders for electric lamps
whereby a lamp without any external fittings can be readily attached to the
conducting wire and a good contact between them and the terminal hooks or eyes
of the lamp can be effected and maintained.
In carrying out my Invention the holder is, provided with two hooks or
equivalent devices insulated from each other and terminating in binding screws
or contact pieces on opposite sides of the holder or suitably arranged for making
concentric contacts by the act of screwing the holder to the lamp bracket or other
support for the lamp. In either case contact between the lamp and the lamp socket
or holder is effected by engaging the two books or their equivalents belonging to
the socket with the two eyes or other counterpart devices which constitute the
terminal conductors of the lamp. Firm contact between the hooks and the eyes or
their equivalents of the lamp and socket is produced by the action of a spring
placed in compression or in tension by the act of making the connection between
the lamp and its socket or by the act of screwing or sliding towards the lamp an
external tube so that an outward pressure may be exerted upon the lamp tending
to put the hooks and eyes or their equivalents into tension and thus effecting and
maintaining a good electrical contact.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent file
by the said Joseph Wilson Swan in the Great Seal Patent Office on th
28th June 1882.
JOSEPH WILSON SWAN of the Town and County of Newcastle-on-Tyne Chemist
"IMPROVEMENTS IN SOCKETS OR HOLDERS FOR ELECTRIC LAMPS."
My Invention relates to improvements in sockets or holders for electric lamps
whereby a lamp without any external fittings can be readily attached to the
conducting wires and a good contact between them and the terminal hooks or eyes
of the lamp can be effected and maintained.
In carrying out my Invention the holder is provided with two hooks or
equivalent devices insulated from each other and terminating in binding screws
or contact pieces on opposite sides of the holder or suitably arranged for making
concentric contacts by the act of screwing the holder to the lamp bracket or other
support for the lamp. In either case the connection between the lamp and the lamp
socket or holder is effected by engaging the two hooks or their equivalents belonging
to the socket with the two eyes or other counterpart devices which constitute the
terminal conductors of the lamp and firm contact between the hooks and the eyes or
their equivalents of the lamp and socket is produced by the action of a spring
which is placed in compression or in tension by the act of making the connection
between the lamp and its socket or by the act of screwing or sliding towards the
lamp an external tube so that an outward pressure may be exerted upon the lanp
tending to put the hooks and eyes or their equivalents into tension and thus effecting
and maintaining a good electrical contact.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings the saine letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a side elevation of an
incandescent electric lamp fitted to a socket or holier constructed and arranged
according to one mode of carrying out my said Invention. Figure 2 shews the
socket or holder detached and Figure 3 represents details of the socket or holder.
Figure 4 illustrates another modification of socket or holder and Figure 5 represents
details of the same. Figures 6 and 7 and Figures 8 and 9 illustrate two further
modifications.
Referring to Figures 1, 2 and 3 A is the lamp the globe of which terminates in a
small pendent bulb or stem B through which passes the terminals from the lamp
the ends of such terminals being formed into eyes or loops a, a'. C is the holder
which consists of a body b carrying two hooks c c' insulated from each other and
terminating in binding screws or contact pieces d d' on opposite sides of the body b
and of a helical spring e connected at one end to the body b and made of a size
adopted to encircle the stem B of the lamp A. In the example illustrated in the
Drawings the body b is assumed to be made of insulating material such for example
as vulcanite, wood, vulcanized fibre, steatite, and the like but it may be made of
any material provided that the two hooks with their contact pieces are respectively
insulated from each other. The body b may be screwed or otherwise attached to
any suitable bracket or support. The connection between the lamp A and the
holder C is effected by engaging the two hooks c c' of the holder with the two eyes
or loops a a' which constitute the terminal conductors of the lamp and firm contact
between the said hooks and eyes is produced by the action of the spring e which is
placed in compression by the act of making the connection between the lamp and
its holder so that an outward pressure is exerted upon the lamp tending to put the
hooks and eyes into tension and thus effecting and maintaining a good electrical
contact.
In lieu of the hooks of the holder being connected to binding screws or contact
pieces placed on opposite sides of the holder the said hooks may be arranged for

page_text: making concentric contacts as for example in the manner illustrated in Figures 4
and 5.
In this example the hooks c c¹ are connected the one to a central tube d' and
the other to an outer tube & the two tubes being separated by insulating material g
and the whole forming a compound tube D which is slit or divided at its lower
end by cuts at right angles to each other.
In the central tube d' is inserted one end of one of the external conducting wires g¹
the other conductor is formed by the tubular bracket piece or lamp support g
abutting against the lower end of the outer tube d efficient electrical contact being
established between the wire gl and the tube d' and between the conducting
bracket piece g and the tube d by the act of connecting the holder to the said
bracket piece or support by screwing up the nut of the union joint thereby
contracting the split end of the tube D and causing it to clamp the end of the
conducting wire and hold it securely therein. The compound tube D is attached
to the body b by a flanged nut i the hooks c c' passing through the body b. Tho
spring e acts as in the arrangement Figures 1. 2 and 3.
In lieu of the helical spring e enveloping the lamp stem B it may be caused to
act upon a tube adapted to the said stein whereby a similar effect will be obtained.
An example of this modification is illustrated in Figures 6 and 7 in which tho
hooks c c are connected to binding screws or contact pieces on opposite sides of
the holder in a manner substantially similar to that illustrated in Figures 12
and 3 but the parts may be arranged for concentric contacts as hereinbefore
described with reference to Figures 4 and 5 e' is the tube adapted to the lamp
stem B which tube is fitted between the body b and an external tube k and is
acted upon by a spring e. In this example the hooks c c are also acted upon by
springs in a state of tension but these may be dispensed with if desired. As
a further modification of the improved socket or holder the spring e may be
dispensed with the body b of the holder being formed with a screw thread as
shewn in Figures 8 and 9 and the tubo el being formed with a corresponding
internal thread so that by the act of screwing up the tube c¹ the required tension
is placed upon the books and eyes and efficient electrical contact is effected and
maintained.
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 :-
First. The employment of sockets or holders adapted to incandescent electric
lamps without external fittings and so arranged that efficient electrical contact is
made and maintained between the hooks or their equivalents of the socket or
holder and the lamp terminals by the outward push of a spring interposed between
the lamp and the lamp socket or holder or by the act of screwing or sliding towards
the lamp an external tube substantially as hereinbefore described.
Second, The peculiar constructions arrangements and combinations of parts
constituting sockets or holders for electrical lamps substantially as hereinbefore
described and illustrated in Figures 1, 2 and 3 Figures 4 and 5 Figures 6 and 7
and Figures 8 and 9 of the accompanying Drawings.
In witness whereof, I the said Joseph Wilson Swan have to this my Specifi-
cation set my hand and seal this Twenty-second, day of June Oue thousand
eight hundred and eighty two
JOSEPH WILSON SWAN. (L.S.)