IMPROVE- MENTS IN OR RELATING TO INCANDESCING ELECTRIC LAMPS AND MEANS CONNECTED THEREWITH
Year: 1882

page_text: LETTERS PATENT to Thomas John Handford of 42 Southampton Buildings
"
in the County of Middlesex Patent Agent for an Invention of "IMPROVE-
MENTS IN OR RELATING TO INCANDESCING ELECTRIC LAMPS AND MEANS
CONNECTED THEREWITH Communicated to him from abroad by Thomas
Alva Edison of Menlo Park in the State of New Jersey United States of
America
PROVISIONAL SPECIFICATION left by the said Thomas John Handford
at the Office of the Commissioners of Patents on the 18th August 1882.
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex, Patent Agent, " IMPROVEMENTS IN OR RELATING TO INCANDESCING
ELECTRIC LAMPS, AND MEANS CONNECTED THEREWITH " a communication to me
from abroad by Thomas Alva Edison of Menlo Park in the State of New Jersey,
United States of America,
This Invention relates to a mode of connecting the carbon incandescing
conductors, of electric lamps to the wires which convey current thereto, and which
are sealed in the glass of the lamp; the object being to produce economically a
joint of good electrical conductivity and one not liable to fracture or dis-union
In carrying out the Invention the enlarged ends of the carbon, which is a flexible
filament of specifically high resistance, are electro-plated with a metal, preferably
copper, in a suitable bath as will be well understood.
The ends of the leading-in wires which ends are also preferably of copper are
placed in contact with the electro-plated ends of the carbon filament, and by the
use of a blow-pipe, or soldering iron the metal is fused at the point of junction, so
that when cool the wire is attached securely to the metal deposit on the carbon, or
this may be done by a solder fused by a blow pipe flame, or by means of a hot
soldering iron.
In using the blow pipe or soldering iron, however some danger exists that injury
may be done to the carbon.

page_text: In order to prevent this a suitable metal covering is placed over that part of the
carbon adjacent to the electro-plated portion, so as to shield it from injury, the
electro-plated ends projecting from such covering. The carbon may be laid on a
block of metal with its ends only projecting beyond the edge, and another block
laid upon it, so as to cover a portion of the carbon but leave the plated ends
exposed.
By the above means a secure and durable joint is formed without any damage
being caused to the carbon filament.
The wires fused or soldered to the electro plated ends of the carbon filament may
be the ends of the leading-in wires of the lamp, or short wires which are afterwards
fused or soldered to such leading-in wires.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas John Handford in the Great Seal Patent Office on the
17th February 1883.
")
THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent "IMPROVEMENTS IN OR RELATING TO INCANDESCING
ELECTRIC LAMPS AND MEANS CONNECTED THEREWITH A communication to me
from abroad by Thomas Alva Edison of Menlo Park in the State of New Jersey,
United States of America
The said Invention relates to a mode of connecting the carbon incandescing
conductors of electric lamps to the wires which convey current thereto and which
are sealed in the glass of the lamp; the object being to produce economically a
joint of good electrical conductivity and one not liable to fracture or disunion.
In carrying out the said Invention the enlarged ends of the carbon (which is a
flexible filament of specifically high resistance having enlarged ends formed of the
same material as the filament itself) are electro plated with a metal preferably
copper in a suitable bath as will be well understood. The ends of the leading-in
wires which ends are also preferably of copper are placed in contact with the
electroplated enlarged ends of the carbon filament and by the use of a blow pipe
or soldering iron the metal is fused at the point of junction so that when cool the
wire is attached securely to the metal deposit on the carbon; or the same effect
may be accomplished with the use of a solder fused by a blow-pipe flame or by
means of a hot soldering iron.
In using the blow pipe or soldering iron, however some danger exists that injury
may be done to the carbon. In order to prevent this a suitable metal covering is
placed over that part of the carbon adjacent to the electro-plated portion, so as to
shield it from injury the electro plated enlarged ends projecting from such covering.
For this purpose the carbon is laid on a block of metal with its ends only projecting
beyond the edge and another block is laid upon it, so as to cover a portion of the
carbon but leave the plated enlarged ends exposed.
By the above means a secure and durable joint is formed without any damage
being caused to the carbon filament. The wires fused or soldered to the electro
plated enlarged ends of the carbon filament, may be the ends of the leading-in
wires of the lamp or short wires which are afterwards fused or soldered to such
leading-in wires."
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the two figures on the accompanying sheet of drawings the same Letters of reference
indicating corresponding parts in both the figures.
Figure 1, of the accompanying drawings is a view in elevation of the
interior parts of an incandescing electric lamp embodying the said Invention and
Figure 2, is a perspective view of a suitable apparatus used in carrying out the
said invention.
A is the interior neck or stem of the lamp, and 1, 2, are the leading-in wires
sealed therein at the point a. B is the carbon flexible filament having enlarged
ends b b (formed of the same material as the filament) for attachment to the
wires 1. 2. In carrying out the present invention the enlarged ends bb are electro
plated preferably with copper, and in any suitable manner. The carbon is then
placed as shown in Figure 2 with the electro plated portions bb projecting just
over the edge of the lower portion of the metal block C, which has pins projecting
up from it.
The upper half of the block has holes corresponding to the pins, and

page_text: is set on the lower half so that the carbon is held between the two, and that portion
adjacent to the electro plated portion is covered up and protected from damage
which might occur during the next stage of the process; this consists in placing
the ends of the wires 1, 2, against the electro plated enlarged ends bb of the
carbon, and melting the metal of both by means of a blow pipe or soldering iron
so that when cool they will be attached together, or a solder may be used to unite
the parts.
Instead of fusing or soldering the wires 1, 2, directly to the electro plated enlarged
ends of the carbon filament short wires may be first so fused or soldered and then
fused or soldered to the wires 1, 2.
Having now described and particularly ascertained the nature of the 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 :-
Securing the flexible carbon filament of an Incandescing Electric lamp to the
leading-in wires, by providing such filament with enlarged ends formed of the same
material as the filament itself, electro-plating such enlarged ends, and then fusing
or soldering the ends of the wires and the electro deposited metal together by
means of a blow pipe or soldering iron, the portions of the carbon filament
adjacent to the electro plated enlarged ends being covered and protected during the
fusing or soldering operation, substantially as herein before described.
In witness whereof I the said Thomas John Handford have hereunto set my
hand and seal this seventeenth day of February in the year of our Lord One
thousand eight hundred and eighty three.
SHAS
TH. J HANDFORD
(·CUIT)