IMPROVEMENTS IN THE MANUFACTURE OR CONSTRUCTION OF INCANDESCENT ELECTRIC LAMPS AND IN
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 OR CONSTRUCTION OF INCANDESCENT ELECTRIC LAMPS AND IN
PROVISIONAL SPECIFICATION left by the said Alfred Swan at the Office of
the Commissioners of Patents on the 19th June 1882.
$5
ALFRED SWAN of the Borough of Gateshead in the County of Durham Engineer
IMPROVEMENTS IN
THE MANUFACTURE OR CONSTRUCTION OF INCANDESCENT
ELECTRIC LAMPS AND IN MACHINERY OR APPARATUS TO BE EMPLOYED THEREIN
"
My Invention has for its object the simplification of the means whereby the
glass and wire portions of Incandescent Electric Lamps are produced or combined
According to my said Invention I form the bulb by blowing and rotating the
molten glass in a mould such mould being made of a compound of finely pulverized
coke and plumbago mixed with Tar into a paste compacted into a solid mass by
pressure and by baking in a furnace the desired shape being given to the mould
either before or after baking in a furnace-Or the mould may be made of coke or
plumbago or other suitable form of carbon mixed with clay or other suitable
cementing material-Or it may be formed from Steatite-The mould is preferably
of such a form as to shape the neck so as to mask or conceal the line of junction
between the bulb and stem
I form the stem of the lamp by placing molten glass enamel or other suitable
material in a mould in which the conducting wires with or without loops already
forined thereon are placed and held in their proper position and I so arrange the
wires that on pressing the two portions of the mould together and forcing molten
glass thereinto the wires are firmly embedded in the glass. This mould is so
constructed that a flange or cup of glass is forned below the terminal loops or
protruding wires the size and shape of which flange or cup exactly corresponds to
that of an aperture left in the neck of the bulb. The edges of the two parts, that
is, the neck of the bulb and the flange or cup of the stem are joined by fusion-

page_text: I cut and fashion the conducting wires to be placed in the before mentioned mould
to the required length and bend them into U form by an instrument constructed
as follows: The wire is laid on a plate or bed having at one end a stop and at the
other a cutter attached to a spindle extending along one side of the plate which
cutter when depressed cuts off the wire to the required length. Attached to the
aforesaid spindle half way between the Cutter and the stop and at right angles to
the length of the spindle is a short cylindrical rod which descending at the saine
time as the knife fits into a corresponding slit or groove in the bed plate thereby
bending the wire exactly in the middle of its length into a U shape; the cylindrical
rod may be made with portions of different diameters to suit different thicknesses
of wire. The tool by which the terminal loops for the attachment of the conducting
wires outside the lamp are formed consists of interlocking wheels adjusted so that
the interval between their axes is equal to that required between the centres of
the loops. The spindles of these wheels are brought through and project above the
plate to which they are attached. The U shaped wire above described is laid on
this plate its curve being placed round a button which holds it firmly by means of
a spring or otherwise-The ends of the wire are placed in slits or recesses at the
projecting portions of the spindles. The revolution of the wheels beyond a point
necessary to form the loops and tags hereinafter mentioned is prevented by a stop.
Upon causing the wheels to revolve the ends of the wire are bent into loops having
short tags or ends which tags or ends facilitate the thorough attachment of the
loops to the glass in which they are subsequently partially embedded.
1 form the ends of the wire into sockets for the reception of the carbon filament
in the following manner-The curve of the U shaped wire (preferably after the
wire has been embedded in the glass) is divided in the centre and straightened and
flattened by means of a press into diamond shaped or tapering blades. This press
for giving the flattened form to the wires inay consist of cam like rolls, the opposed
pressing faces of which are cut away to a shape corresponding to the gradually
flattened out form to be given to the wires as distinguished from a sudden
flattening from thick to thin which gives an objectionably weak point in the wire.
These cam like rolls are mounted upon axes furnished with gearing wheels for
giving equal motion to the said rolls so that owing to their configuration they
gradually grip upon and flatten out the wires inserted between them. The flattened
ends are then cut to a tapering figure in a cutting press of any convenient forin-
The point of the flattened end of the blade is then placed on or against a small
steel mandril or needle inserted in a spindle the said flattened end being held
against the mandril or needle by a claw. The spindle being rotated by turning a
handle or otherwise the flattened blade is wound upon the said mandril or needle
into a hollow spiral of such form and size, as is suitable for the reception of the
carbon filament to be used-The spindle may be screwed to limit the motion to the
requisite number of turns.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alfred Swan in the Great Seal Patent Oflice on the 12th December
1882.
ALFRED SWAN of the Borough of Gateshead in the County of Durham Engineer
"IMPROVEMENTS IN THE MANUFACTURE OR CONSTRUCTION OF INCANDESCENT
ELECTRIC LAMPS AND IN MACHINERY OR APPARATUS TO BE EMPLOYED THEREIN."
"
My Invention has for its object the simplification of the means whereby the
Glass and wire portions of incandescent electric lamps are produced or combined.
According to my said Invention I cut and fashion the conducting wires to the
required length and bend them into U or equivalent form by an instrument
constructed as follows. The wire is laid on a plate or bed having at one end a
stop and at the other a cutter attached to a spindle extending along one side of the
plate which cutter when depressed cuts off the wire to the required length.
Attached to the aforesaid spindle half way between the cutter and the stop and at
right angles to the length of the spindle is a short cylindrical or other shaped rod
which descending at the same time as the knife fits into a corresponding slit or
groove in the bed plate thereby bending the wire exactly in the middle of its
length into a U shape The cylindrical rod and groove may be made with portions
of different diameter or shapes to suit different thicknesses and different widths or
forms of wires and the cutter at one end and stop at the other end of the bed
plate may be made to slide on a spindle and thus be adapted to cut various
lengths of wire. The tool by which the terminal loops for the attachment of the
conducting wires outside the lamps are formed consists of interlocking wheels
adjusted so that the interval between their centres is equal to that required
between the centres of the loops. The spindles of these wheels are brought through
and project above the plate to which they are attached. The U shaped wire above
described is laid on this plate its curve being placed round a button which holds
it firmly by means of a spring or otherwise. The ends of the wire are placed in
slits or recesses at the projecting portion of the spindles. The revolution of the
wheels beyond a point necessary to form the loops herein before mentioned is
prevented by a stop. Upon causing the wheels to revolve the ends of the wire
are bent into loops having short tags or ends which tags or ends facilitate the
thorough attachment of the loops to the glass in which they are subsequently
partially embedded.
I form the stem of the lamp by placing molten glass enamel or other suitable
material in a mould in which the conducting wires with or without loops already
formed thereon are placed and held in their proper position and I so arrange the
wires that on pressing the two portions of the mould together and forcing molten
glass there into under pressure the wires are firmly embedded in the glass. This
mould is so constructed that a flange or cup of glass is formed on the stem near
the terininal loops or protruding wires the size and shape of which flange or cup
exactly corresponds to that of an aperture left in the neck of the bulb.
The edges
of the two parts that is the neck of the bulb and the flange or cup of the stem are
joined by fusion.
I form the ends of the wire into sockets for the reception of the carbon filament
in the following manner The curve of the U shaped wire (preferably after the
wire has been imbedded in the glass) is divided in the centre and straightened and
fattened by means of a press into parallel sided blades. The press for giving the
flattened form to the wires may consist of cain-like rollers the opposed pressing
faces of which are cut away to a shape corresponding to the gradually flattened
out form to be given to the wires as distinguished from a sudden flattening from

page_text: thick to thin which gives an objectionably weak point in the wire. These cam-like
rollers are mounted upon axes furnished with gearing wheels for giving equal
motion to the said rollers so that owing to their configuration they gradually grip
upon and flatten out the wires inserted between them. The flattened ends are
then cut to a tapering figure in a cutting press of any convenient form. The point
of the flattened end of the blade is then placed on or against a small steel mandril
or needle inserted in a spindle the said flattened end being held against the
mandril or needle by a claw. The spindle being rotated by turning a handle or
otherwise the flattened blade is wound upon the said mandril or needle into a
hollow spiral of such form and size as is suitable for the reception of the carbon
filament to be used. The spindle may be screwed to limit its motion to the
requisite number of turns.
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 corresponding figures.
Figure 1 of the accompanying drawing represents in plan and figure 2 in
front elevation an apparatus constructed according to my Invention for bending
the wires into a U shape as hereinbefore described. The said apparatus consists
of a bed plate a having at one end a stop band at the other end a cutter lever c
aflixed to a spindle d as a centre the said spindle extending along the side of the
bed plate a and turning in lugs e thereon. Affixed to the said spindle half way
between the cutter lever c and the stop bis a cylindrical rod f whose length is
situated at right angles to that of the spindle d. The bed plate a is furnished with
rests into which the wire (Figure 3) to be cut and bent is placed when the
cutter lever c is in the raised position represented in Figure 2 one end of the wire
abutting against the stop band the other end passing beneath the cutter lever c
On depressing the said cutter lever c the said wire is cut to the proper length and
the cylindrical piece fat the same time descends into the semi cylindrical recess a²
in the bed plate a and thereby bends the wire at its centre and forms it into a U
shape as indicated in dotted lines in figure 2. Figure 4 shews the bent wire
removed form the apparatus.
2
The apparatus may be formed to cut and bend wire of but one thickness and
length or wires of two or more different thicknesses and lengths or to form loops
of different widths or formation. The drawing represents an apparatus adapted
for cutting and bending wires of three different thicknesses the cylindrical piece f
being made with portions of three different diameters with corresponding rests
to accomodate the three different thicknesses of wire.
Figure 5 represents in plan and figure G in side elevation an apparatus con-
structed according to my Invention for coiling the ends of the wires into eyes or
loops as hereinbefore described. Figure 7 is an enlarged plan of a part of the same.
Upon a bed plate h I fix a stop picce h of the form shewn and a button h³ which
may be provided with a bead or a spring catch as shewn at h to retain the wire
loop in position. In a framing i beneath the bed plate are carried spindles
21, 22, 23, furnished with gearing wheels for transmitting motion to both of the
spindles when the button on the spindle is rotated. The spindles i² and i³
project above the bed plate h as shewn on either side of the end of the stop
piece h the distance between the axes of the said spindles being equal to that
required between the centres of the loops to be made in the wire. The projecting
ends of the spindles are formed with slits or recesses which may be made
either by cutting them in the substance of the projecting ends of the spindles or
by pins attached to the spindles and placed near to the said projecting ends
thereof as shewn. The wire bent into the U form shewn in Figure 4 is placed
around the button with its legs or side pieces lying along the sides of the stop h
and the two ends of the said wire are placed in the slits or recesses in the pro-
jecting ends of the spindles as shewn in full lines in Figures 5 and 7. On
partially_rotating the spindle by means of the button thereon the gearing

page_text: wheels cause also the spindles ³ ³ to partially rotate until prevented. from
further rotating by the stop h² so that the spindles are brought into the
position shewn in dotted lines in Figure 7 and by this partial rotation (as the
ends of the wire are confined in the slits or recesses in the ends of the said
spindles) the said ends of the wire are bent into a loop form at j as shown in
dotted lines in Figure 7 and also in Figure 9 which represents a bent wire
removed from the apparatus short tags or cuds being formed as at which tags or
ends serve to effect the secure attachment of the loops to the glass when they are
subsequently imbedded therein It will be seen that the button h³ and stop h²
may
be in one piece if desired or may be arranged to slide and to be capable of
adjustment to different lengths of wire
Figure 10 represents opened out a mould constructed according to my Invention
for casting the stems as herein before described and Figure 11 is a plan of the
same closed. The said mould is formed in halves hinged together each half
being provided with handles for opening and closing the same. The said mould is
formed with an opening or "get" leading into a portion of the mould at lin
which the flange of the stem is formed this portion of the mould opening into
the portion in which the stein proper is formed. At m are two projections for
receiving the eyes of the terminal wires to be embedded in the stem during the
process of casting the said stem, the said projections when the mould is closed
fitting into corresponding recesses in the other half of the mould. In figure 10 a
loop of wire is shewn in position pieces at 13 forming a filling for the bottom of the
portion of the mould. The terminal wire being placed in position as in Figure 10
the mould is closed and molten glass (or enamel or other material of which the
stem is to be formed) is introduced into the mould by the "get" and is pressed
by means of a plug worked by a lever or otherwise into the portions and the
wires being enveloped or imbedded in the said stem the tags j¹ of the wires giving
a very firm hold of the wires in the glass or material of the stem Figure 12
represents a stem cast in this mould.
"
Figure 13 represents a mould for casting cup like flanges upon the stem. The
mould is formed in hinged parts and with a get" as in the mould herein before
described but the portion is cup shaped and the portion 12 is formed in a core
piece capable of being slidden into and from the mould the inner end of the core
piece and the portion of the mould giving between them the necessary shape
to the cup-flange of the stem.
To enable the wire to be inserted the core piece may be made in halves The
terminal wires pass through a slit between the closing pieces 13 as shewn in
Figure 13. It will readily be seen that when the mould is closed and the molten
glass or other material is introduced into the "get" that the said glass or
material will flow under pressure into the cup shaped recess at and thence into
the portion in the core piece the wires becoming imbedded in the said material
By means of the lever n the core piece is raised from the mould immediately
after casting to prevent risk of fracture of the stem. To facilitate more complete
adhesion between the wire and the glass and so effectually get rid of air bubbles
along the track of the wire I insulate portions of the metal forming the mould
so as to be able to pass an electric current through the wires and so heat them
to a white heat at the moment the molten glass is being pressed in around thein.
Figure 14 represents a cup flanged stemn produced in this mould.
It will be understood that the wires may be cast on the stem before the eyes are
formed in the said wires but I prefer to cast them after the said eyes have been
formed as then the tags are firmly imbedded in the glass and a secure attachment
is thus inade.
Figure 15 is a front view and Figure 16 is an end elevation of the press for
flattening out the ends of the wires to be afterwards coiled.
The cam like rollers pp are mounted in a framing p² and are geared together
by toothed gearing at p2 and one of them is provided with a handle p³ for
turning the rollers. The opposed pressing faces of the said cam rollers p p are cut

page_text: away to allow of the introduction to their full extent and thickness of the portions
of wire projecting beyond the stem of glass or the like. The said cam rollers pp
owing to their shape at the parts extending from the point at which they begin to
act upon the wire (the positive shewn in Figure 16) to the part at which the
flattening takes place gradually grip upon and gradually flatten out the ends of the
wires inserted between them thus avoiding the weakness resulting from a sudden
transition from thick to thin The looped form of the wire imbedded in the glass
after leaving the mould is represented at Figure 17 while Figure 17 A shews the
wire loop cut or severed ready for being bent and passed between the before
described can pressing rollers. The ends of the flattened out blades (enlarged views
of which are shewn in Figure 18) are then cut off by means of a cutting press of
any convenient form to an angle which determines or is determined by the pitch of
the spiral to be produced. Figure 19 represents a wire end thus bent and flattened
out and cut.
Figure 20 represents in sectional elevation an apparatus constructed according
to my Invention for coiling the flattened out ends of the wires into sockets for the
reception of the carbon filament and Figure 21 is an end view of the same. In the
tubular picce q carried by the standard g is mounted a spindle or mandril
capable of being rotated in the said tubular piece q by means of the handle 2.
The said spindle has projecting from its end n needle 3 of the size and shape
(tubular flat or other shape) of the carbon to be inserted in the coiled ends of the
terminal wires. A clip piece s is centred at s² to the spindle being furnished
with a tail piece s³ engaging behind the flange 23 of the tubular piece q the
spindle being forced back by the spring t the end of the said catch piece s presses
upon the root end of the needle 3. By pressing forward the spindler against the
spring the catch 8 is lifted off the needle owing to its tail pieces being
retained behind the flange q³ and the tip of the end of the wire to be coiled, (bent,
flattened and cut as hereinbefore described) is placed upon the needle so that
when the spindle is released and again forced back by the spring t the clip piece s
pinches the said tip of the flattened end of the wire down upon the needle 3. On
rotating the spindler by the handle and keeping the flattened end of the wire
at the requisite angle to the said needle the said flattened end is coiled upon the
needle into a tubular or other form suitable for the reception of the ends of the
carbon filament. I may attach to the stand of the apparatus an adjustable arm
upon an upright support and with a slot in it which when the arm is in its proper
. position acts as a guide to the wire whilst it is being coiled round the needle.
I prefer to act upon the wires in this apparatus when they are imbedded in the
glass stem. Figure 22 represents the wires after having been coiled by the apparatus.
The apparatus may be provided with a surface u upon which to rest the said stem
whilst the apparatus is operating.
Figure 23 shews a modification wherein the spring t is dispensed with and the
catchs is provided with a thumb piece 8 to be depressed against the spring 85 for
raising the tip of the catch piece s from the needle. In this modification I have
also shewn the spindler as being provided with a screw thread working in a
screw in the tubular piece q the number of turns of this screw corresponding with
the number of coils to be given to the ends of the wires so as to prevent over-
winding. In this modification I have also shewn the fore end of the spindle as
being tapped to receive a stock piece or nipple in which the needle is mounted.
Needles when broken can then be readily replaced or a fresh stock piece carrying a
needle of any desired size or shape can be introduced. The sealing of the carbon
filament into and over the wire socket may be completed by deposition of carbon
in the ordinary manner.
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 :

page_text: First, In apparatus for bending wires for incandescent Electric lamps the
combination of the recessed bed plate a and bending piece f adapted for bending
wire of one thickness and length or wires of different thicknesses and different
lengths and forming loops of different widths or formation substantially as described
and illustrated in figures 1 and 2 of the accompanying Drawings.
Second, In apparatus for bending wires for Incandescent Electric lamps, the
combination of a cutter lever c and bending piece suited for bending wire of one
thickness and length or wires of different thicknesses and different lengths and
formation or loops of different widths, the said parts operating together upon a
recessed bed plate a substantially as described and illustrated in figures 1 and 2 of
the accompanying drawings.
Third, In apparatus for bending wires for incandescent Electric lamps the
combination of the cutter lever c and bending piece f with a recessed bed plate and
a stop b to effect the cutting and bending of wire of one thickness and length or
wires of different thicknesses and different lengths or different widths and formation
of loop substantially as described and illustrated in the said figures 1 and 2 of
the accompanying Drawings.
Fourth. In apparatus for bending wires for incandescent Electric lamps the
combination of the cutter lever c bending piece f spindle d recessed bed plate a
rests g and stop 7 for cutting and bending wire of one thickness and length or wires
of different thicknesses and different lengths or different widths and formation of
loop substantially as described and illustrated in the said figures 1 and 2 of the
accompanying Drawings.
Fifth. The herein before described apparatus for forming loops or eyes in the
terminal wires for incandescent electric lamps, the essential feature of which
apparatus is the combination of the rotating spindles 2, 3, (recessed or slotted or
otherwise formed for the reception of the ends of the wire to be bent into loops or
eyes) with the stop h² (or stops ², ) substantially as herein before described and
illustrated in figures 5, 6 and 7 of the accompanying Drawings.
Sixth, Forming stems for the bulbs or globes of incandescent electric lamps and
imbedding wires (with or without terminal loops formed thereon) in them by
pressure in a mould substantially as herein before described.
Seventh, The moulds for forming stems for the bulbs or globes of incandescent
Electric lamps and securing the terminal wires therein substantially as described
and illustrated in figures 10, 11 and 13 of the accompanying Drawings.
Eighth, The apparatus for flattening the terminal wires of incandescent electric
lamps consisting of the combination of the cam rollers p, p formed as described with
means for actuating them substantially as and for the purpose described and
illustrated in Figures 15 and 16 of the accompanying drawings.
Ninth, Forming the ends of wires into sockets for the reception of the carbon
filament of incandescent Electric lamps by coiling or twisting the flattened ends of
the wire as herein before described.
Tenth, The apparatus for coiling or twisting the ends of wires of incandescent
Electric lamps into flat cylindrical or other sockets for the reception of the carbon
filament, the said apparatus consisting in the combination of the spindle carried in
a support and provided with means for rotating it and also with a catch piece 8 for
retaining and releasing the wire substantially as described and illustrated in
figures 20, 21 and 23 of the accompanying Drawings.
In witness whereof I the said Alfred Swan have to this my Specification
set my hand and seal this twelfth day of December one thousand eight
ALFRED SWAN (LS.)