IMPROVEMENTS IN THE MANUFACTURE OF INCANDESCENT ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to Alfred Swan of the Borough of Gateshead in the
County of Durham, Engineer, for an Invention of IMPROVEMENTS IN THE
MANUFACTURE OF INCANDESCENT ELECTRIC LAMPS
"
"
PROVISIONAL SPECIFICATION left by the said Alfred Swan at the Office
of the Commissioners of Patents on the 20th November 1882.
ALFRED SWAN of the Borough of Gateshead in the County of Durham Engineer
"IMPROVEMENTS IN THE MANUFACTURE OF INCANDESCENT ELECTRIC LAMPS"
My Invention relates to the manufacture of incandescent electric lamps and has
for its object to give a inore complete adhesion between the glass or the like and
the terminal wires which pass through the said glass or the like to the carbon
filament and prevent the formation of air bubbles along the track of the wires.
According to my said Invention I pass an electric current through the wires at
the same time that the glass or the like is being pressed around them. This may
be effected in any convenient or suitable way. When for example the stems are
being cast in moulds as described in the Specification of my Patent N° 2898
A.D. 1882. I may insulate portions of the metal of the said moulds so as to lead
the current wires up to and through the wires which are to be embedded in
the stem.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Swan in the Great Seal Patent Office on the 19th May
1883.
ALFRED SWAN of the Borough of Gateshead in the County of Durham, Engineer.
"IMPROVEMENTS IN THE MANUFACTURE OF INCANDESCENT ELECTRIC LAMPS
My Invention relates to the manufacture of incandescent electric lamps and has
for its object to give a more complete adhesion between the glass or the like and
the terminal wires which pass through the said glass or the like to the Carbon
filament and prevent the formation of air bubbles along the track of the wires.
According to my said Invention I pass an electric current through the wires at
the same time that the glass or the like is being pressed around them This may
be effected in any convenient or suitable way. When for example the stems are
being cast in moulds as described in the Specification of my Patent N° 2898 in the
Year of Our Lord One thousand eight hundred and eighty two I may insulate
portions of the metal of the said moulds so as to lead the current up to and
through the wires which are to be embedded in the stem.
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 same letters of reference
indicating corresponding parts in all the figures.
Figure 1 represents an opened out mould constructed with an insulating portion
for the purpose of carrying my Invention into effect and Figure 2 is a transverse
section on the line 1-2 Figure 1 The part marked a (in which the recesses in
which the glass is cast are made) is of a non-conducting material or comparatively
non-conducting material. bare studs pins or pegs on one half of the mould over
which the loops of the terminal wire pass the said wire being also passed over &
stud pin or peg c formed upon a plate c² screwed or otherwise secured to the
material a The pegs bare carried to the exterior of the casing of the mould
being surrounded by the material a as shewn in Figure 2 and there terminating in
contact plates 62 When the wire is placed in position as shewn in figure 1 the
pegs bare brought into contact with a battery or other source of electricity, which
may conveniently be effected by causing the contact plates 62 to come into contact
with other plates in the "press" or receiver in which the mould is held during the
casting of the glass therein the last named plates being in metallic connection with
the positive and negative wires of the source of electricity Thus when the mould
is put in place a current of electricity is passed through the terminal wires at the
same time that the glass is pressed around them whereby a very complete adhesion
of the glass to the wires is obtained. d are pegs for retaining the wires in
proper position.
Figure 3 represents an opened out mould and Figure 4 a section on the line 3, 4
Figure 3 in which mould the pegs b in the one half of the mould and the
recesses b³ in the other half, into which the said pegs fit when the mould is closed,
are surrounded by insulating material as shewn at a². The pegs b are continued to
the exterior of the mould for connection to the source of electricity as herein before
described I do not limit myself to any particular form of the moulds nor of the
recesses therein for the reception of the glass and the said moulds may be
constructed of any suitable material provided that insulation is provided for the
purpose of directing an electrical current through the wires during the embedding
of the wires in the glass or the like.
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

page_text: 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 improvements in incandescent electric lamps consisting in passing an
electric current through the terminal wire whilst the glass or the like is being
pressed or formed around it substantially as hereinbefore described.
Second. In the manufacture of incandescent electric lamps the employment of
moulds for forming the portions of glass or the like through which the terminal
wires pass the said moulds being forined or provided with insulating material to
direct an electrical current through the wire whilst the glass or the like is being
pressed or formed around it substantially as hereinbefore described with reference
to the accompanying drawings.
In witness whereof I the said Alfred Swan have to this my Specification set
my hand and seal this fifteenth day of May, One thousand eight hundred
and eighty three.
ALFRED SWAN (LS.)