Note: Descriptions are shown in the official language in which they were submitted.
04686~
EACK~RO~ND OF THE INVENTION
This lnventlon relates to soldering irons for solderlng
wlres to a connector, partlcularly to a soldering iron ~or
simultaneously soldering a plurallty o~ wlres to metal llners
in channels of a connector.
In the past, various methods of hand solderlng have
been adopted ~or connecting wires to multi-core connectors whlch
are widely used in eleatronlc devlces. For example, in one
mtthod the coverlngs o~ wlres are peeled of~ one by one and then
the wires are applled and soldered one by one to each metal
llner ln the connector. Another example 19 a method ln which
wires (to which solder has already been applled) are placed in
metal llners (to whlch solder has been applled) and each wlre
1B soldered one at a tlme to the lnslde of lts encompassing
liner by melting the previously applled solder wlth a solderlng
lron. These methods are lnefflclent and requlre great sklll ln
order to accompllsh rellable and neat solderlng.
A wlre posltloning device re¢ently came into use whlch
posltlons the connecting wires parallel and at the proper dls-
20 tances apart ao as to match the corresponding metal liners inthe multl-core connector. T'ne wlre posltioning device auto-
matlcally cuts the wlres, strlps of~ the wire coverings, and
places the stripped conductor of the wlres into each metal llner,
thus sharply reduclng the palnstaklng nature o~ the work at the
tlme of soldering. However, the wlres whlch have been automatl-
cally strlpped and posltloned by the wlre posltlonlng device
must stlll be hand-soldered one at a time to the metal llners.
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Such hand solderlng lacks efflclency and uni~orm hlgh quallty.
SUMMARY OF ~HE INVENTION
It ls an ob~ect of the inventlon to provide a solderlng
ron whlch can automatlcally and slmultaneously solder a plur-
ality o~ wires to metal l~ners ln respectlve channels ln a con-
nector Accordlng to the inventlon, a plate o~ heat conductlng
1046861
material is provided with a plurality of projections on an end
face, The projections are spaced to correspond to the spacing
of the metal liners in the channels of the connector, The sides
of each of the projections converge toward the extremity of the
projection, The projections are dimensioned so that their ex-
tremities can be positioned within the metal lined channels so
that their converging sides contact respective edges of the metal
liners. Thus, the soldering iron can conduct heat to solder the
wires placed within the channels to the corresponding metal liners.
The converging sides of the projections are plated with material
which prevents oxidation and causes the solder to wet the converg-
ing sides, and the surfaces of the plate other than the converging
sides are plated with a second material to prevent oxidation and
to prevent wetting by the solder.
BRIEF DESCRI~TION OF THE DRAWINGS
The invention will now be described in detail with ref-
' erence to the accompanying drawings representing preferred em-
bodiments of the soldering iron according to the present invention.
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In the drawings:
Fig, 1 is a partial side view of a known wire position~
~ ing device suitable for use with the soldering iron of the invention;
,` Fig, 2 is a top view of wires positioned in a connector
by means of the wire positioning device shown in Figo l;
Fig, 3 is a partial cross-sectional end view of a sold-
ering iron having rectangular projections which is shown for com-
parison with the soldering iron of this invention;
Figs. 4a and 4b shownpartial cross-sections in an end
view and a side view, respectively, of a soldering iron according
to the invention;
- 30 Fig. 5 is a partial cross-sectional end view of one
, embodiment of the soldering iron of this invention;
`; Fig. 6 is a partial cross-sectional end view showing
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the use of the soldring iron of this invention;
Fig, 7 is a partial cross-sectional end view of the
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~olderlng lron of Figure 3 havlng rectangular pro~ectlons;
Flg. 8 is a slde view oP two diPferent conPigurations
A and B, of pro~ectlons havlng curved sides according to embodl-
ments of the invention;
Flg. 9 18 a slde view of two different configurations,
C and D, of spaced apart pro~ectlons accordlng to embodlments
Or thls lnventlon; and
Fig. 10 ls a partial ~lde vlew of a solderlng iron
showing its plated surfaces accordlng to an embodlment of this
10 lnvention .
DESCRIPTION OF THE PREFEMED EMBODIMENq~S
The soldering lron of this lnventlon can be used wlth a
known wire posltlonlng devlce 2 such as shown ln Flgure 1.
In thi~ devlce, a multi-wlre cord 4 18 attached to a positlonlng
stand 6, and each indivldual wire 8 18 inserted lnto a groove o~ ~-
an allgnment ~lg 10 whlch has grooves at lntervals correspond-
lng to the intervals at whlch the wires wlll be ~olned to a
connector. The ends of the wlres are held by a wlre holder 12.
In thls fashlon, the wlres are llned up and held. Then a cut- -
20 tlng blade 14 and a strlpplng blade 16 are automatlcally lowered `-
onto a recelvlng stand 18. The wlres 8 are cut at locatlon 9,
and at locatlon 11 the strlpplng blade 16 cuts lnto the wlre
coverings. With the stripplng blade 16 still lowered, the
po~ltlonlng stand 6 is moved and the wire coverings are pulled
ofP by the strlpping blade.
Next, the cutting blade 14, the stripping blade 16J the
allgnment ~lg 10 and the recelving stand 18 are moved out of the
way. Then, a connector 20 18 automatlcally posltloned and the
positloning stand 6 18 returned to ltQ orlglnal po~ltlon 80
30 that the conductors of the strlpped wires 22 are applied to the
~- connec'cor 20 as shown ln Flgure 2. Thus the operations needed
- for the connection of wires 8 to the connector 20 are greatly
reduced by use of the wlre po~ltlonlng device 2.
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However, the solderlng of the wlres to the connector ls
~till done by hand, and therefore the process is still ineffl-
clent and uniformly soldered ~oints are difflcult to obtain.
Consequently, a soldering iron i8 needed which solders these
multiple wires automatically and simul~aneously. Figure 3 shows
a proposed automatic soldering iron which was not completely
satisfactory, and is described for comparlson and better under-
standing of the soldering iron of this invention. A~ shown ln
Figure 3, conductors o~ the stripped wires 22 are placed ln
10 metal liners 24 ln channels 26 in the connector 20, and solder
28 is placed over the top of the liners 24. The soldering iron
30 has rectangular shaped pro~ections 33 at intervals corres-
ponding with the metal llners 24, and these proJections 33 are
of such wldth and length that they can be lowered into the metal
llners. This soldering iron 30 is lowered automatically onto
the solder 28 and melts the solder thus attaching the wlres 8
to the metal liners 24 of the connector 20 simultaneou~ly and
!.. ~ automatically. However, a solderlng iron of such a structure
has shortcomings. For example, the amounts of solder getting
lnto the metal liners are not only small but also not unlform.
In the worst cases, some metal lineræ get little solder, thus
maklng rellable soldering difficult. Also, the life of the
soldering lron is short and quite unsatisfactory.
Figures 4a and 4b show the front vlew and the side
vlew of a section of the lron of the present lnventlon. The
lron 32 ls a plate 34 whlch has a heating section 36 and pro-
~ections 38 at the end. Each of the proJectlons 38 has two
converging side~ 40 which appear a8 sides of a triangle in
Figure 4a. The converging sides 40 come into contact with the
30 edges 42 of the metal liner 24 posltloned ln the channels 26
~` o~ the connector 20. The surfaces of the converging sides 40
are plated with material such as electroless nickel 44 which
prevent oxldation and to which solder adheres easlly (wets).
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1046861
The remalning ~urfaces of the iron 32, includlng the non-
converging sides o~ the proJections are plated with materlal
such as hard chrome 46 which also prevents oxidatlon but is not
wet by solder.
Accordlng to the results Or experlments uslng the iron
32 of the above structure, the best soldering results were ob-
tained when the angleO formed by the two converging sides 40
o~ a pro~ectlon 38 was 80 degrees when the metal liners 24
were arranged ln the insulating material 48 at lntervals "d"
10 oP o.8 mm, and the length "a" of the metal llner was 5.5mm,
the wldth "b" was 1.4mm, and the helght "c" was l.Omm. The
conductor of the stripped wlre 22 had an outer dlameter of
0.5mm.
Bad soldering resulted due to delayed heat conductlon
when the angle ~3 was smal and the converglng sldes 40 Or the
proJections 38 were no longer ln contact wlth the edges 42 Or
the metal llners 24. Also, it was found that as the angle e
was gradually made larger the solderlng results became gradually
wor~e. However, the results were satlsfactory for practical
20 use a8 long as molten solder 50 (as shown in Flgure 5) whlch
adhered to the surfaoe near the base 52 of the converglng sldes
dld not get too close and burn the lnsulating materlal 48 be-
tween the metal line rs 24.
The li~e of the iron 32 wlth pro~ections 38 having con-
verging sldes 40 18 also longer than for the iron 30 wlth rec-
tangular pro~ect~on~ 32. The material stock used f`or the iron
was a copper plate wlth a thlckness of 4mm, the heatlng tem-
perature was 300C, and the solder was a stick solder (wlth a
core o~ actlvated flux made Or 60% tln and 40,~ lead. The thl¢k-
3o ness Or the electroless nickel plating was 401l and the thlcknessOr the hard chrome plating was 301l.
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Although the reasons for the superiorlty Or the iron
`--wlth pro~ectlons as in our design over the iron wlth rectangular
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proJectlons are not qulte clear, the ~ollowing has been de-
duced. When, as shown ln Flgure 6, the lron 32 presses inl-
tially (posltion indicated by the solid line in the figure)
on the solder 28 which ls laid over the metal liners 24, the
tips 54 o~ the pro~ectlons 38 flrst ~tart to melt and cut lnto
the solder. As the pro~ections 38 proceed, the converglng
sldes 40 gradually enter lnto and melt the solder 28 as in-
dicated ln Figure 4 by means of broken lines alternatlng wlth
single dashes. Therefore, the ~ull length oP the solder i8
10 melted and it adheres to the ~ull length of the converglng sldes
40 evenly. Slnce the surfaces of the converging sldes 40 are
plated wlth electroless nickel 44 whlch ls wet easily by solder,
and the rest o~ the lron ls plated wlth hard chrome platlng
whlch ls not wet easily by solder, the solder adheres to the
slanted sldes evenly and well.
When the converging sides 40 make contact with the
edges 42 of the metal llners 24 as lndlcated ln Figure 6 by
means of broken llnes alternatlng wlth double dashes, the metal
liners 24 which have small heat capacity compared to the con-
20 ductors of the strlpped wlres 22 are heated rapldly. As thetemperature of the metal liners rises, the solder adhering to
the converging sldes 40 slldes down along the converglng sldes
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40 and runs lnto each metal llner 24 ln even quantities. Thu~
the conductors of strlpped wires 22 become surrounded by the
solder and by appllcation of heat the soldering is accomplished.
On the other hand, in the case o~ the iron 30 wlth
rectangular pro~ections 33, the lron 30 makes contact with the
solder mainly at the termlnal planes 56 o~ the rectangular
pro~ectlons 33 as shown in Figure 7. Moreover, the vertical
~ 30 8ides 58 of the rectangular pro~ections cut into the solder
,;; perpendicular to its alignment, so that only a vertlcal cross-
.~.$ section o~ the solder comes lnto contact with the iron. There-
.;l fore, the solder is heated only locally and not throughout lts
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total length as is the ca~e with the iron 32 wlth triangular
proJections 38. Such local heating result~ in small amounts
Or solder adhering to the proJectlons 33 and therefore only
small amounts of solder flows around the wires 22. Accordingly,
wasted solder 18 left on the metal liners after solderlng.
Although quantities of solder adhere to the termlnal planes 56
Or the iron 30 with rectangular pro~ectlons 33, the flow of this
solder onto the wires 22 is not good because Or the horizontal
posltlons of the termlnal plane.
In addltion, the flow Or solder onto the wires 22 is
greatly lnfluenced by the surface conditions of the termlnal
planes 56 and of the wlres 22 thus resultlng ln uneven quantl-
tles Or solder rlow. Therefore, even and rellable soldering i~
dlfflcult. A1BO~ the solder accumulates on the iron wlth re-
peated soldering and thls accumulated solder flow~ suddenly
onto the wlres when the accumulatlon has exceeded a certaln
amount. Thls makes the solderlng Or uniform quallty dlfflcult.
In addltlon to pro~ectlons 38 having converging sldes
40 formlng a trlangle, other embodlments wlthln the scope Or
20 the lnventlon can utilize converglng sides which are curved
as shown ln Figure 8 (A and B).
Also, ln a case ln whiah the intervals between the -
,' metal liners are large, planar ~paces 60 can be provlded between
the pro3ectlons as shown lnFigure 9(C). In thls case, however,
lt 1B deslred that solder not adhere to the rlat sectlons. A
structure wlth gutters 62 at the base Or the pro~ections as in
Figure 9(D) 18 al~o posslble.
Although ln the experlmental example (outllned ln de.tall previously) only the converglng sides of the pro~ectlons
3 were plated wlth electrole~s nlckel, lf solder ls not llkely
~ to adhere to the iron except on the con~erging sldes because
; o~ the shape Oe the iron (for example, when the iron is much
thlcker than the ætrip of solder læ wlde), then the entlre
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1046861
proJectlon 38 can be plated wlth electrole3s nlckel 44 as shown
in Figure 1~. The rest of the lron should be plated wlth hard
chrome 46 to make the platlng process easler.
From the foregoing, it can be readily re~llzed that -
thls lnventlon can assume varlous embodiments. Thus, it is to
be understood that the lnventlon ls not limited to the speclfic
embodlments descrlbed hereln, but is to be limited only by the
appended clalms.
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