Note: Descriptions are shown in the official language in which they were submitted.
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1 FIELD _F_THE INVENTION
The field of the invention includes electrolytic
treatment apparatus often found classified in the United
States Patent Office under Class 204; and a process of
exchanging metal on a workpiece often found classified in
Class 204 as well.
DESC~IPTION OF THE PRIOR ART:
________________________ _ ___
The prior art is exemplified in United States
Patents 936,472; 3,661,752; and 3,904,489; and also in
French Patent 331930 and Patents in Great Britain Numbers
760016 and 18643 (the latter published in 1899).
In the prior art type devices, rotary members for
light frictional engagement with the cathode are shown.
Moving contact is also shown for purposes of wiping away
bubbles, electrodeposition, and the like, so that the
electric plating action will proceed without contamination
or film barriers on the surface to be plated. The prior
art, however, fails to deal with the modern problems of
gold plating, particularly as applicable to the plating
of contact points on a curvilinear surface. In the
plating of such contact points, the prior art techniques
have involved dipping in the anode, and therefore plating
portions of the contact which do not require plating.
Where precious metals such as gold are employed in the
plating, this overplating even to the extent of 100
percent, doubles the cost of material which is a
significant cost in the gold plating of any product.
Also because the prior art involves dipping, there is no
way of discretely determining the specific area to be
plated, much less determining the exact thickness to be
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1 plated Gn the discrete area.
SUMMARY OF THE INVENTION
The present invention includes a method for
continuous plating of a discrete area on a convex
curvilinear surface of each of a plurality of aligned
electronic contact points comprising the steps of:
confining and orientating the contact points to allow
movement thereof along a fixed axis of travel, engaging
the same orientated contact points to move the thus
orientated contact points with their discrete area plated
firmly against a plating member; applying a predetermined
amount of plating solution on the plating member to
constantly wet the same in a controllable electro-
deposition quantity; electrically energizing the contact
points as a cathode and the plating solution as an anode;
rotating the plating member to pass the plating solution
on its surface onto the discrete area of the convex
curvilLnear surface of the contact points which are
passed against the plating member, whereby contact points
cen be plated with a metal on the discrete area of the
convex curvilinear surface intended for electrical
contact with another member, without plating the rear
portion or other portions of the contact points which
otherwise have no electrical relationship in a circuit.
The invention also includes a device for continuous
contact plating of a plurality of contact points having a
curvilinear portion comprising, in combination, a plating
member having an axis of rotation and a wettable surface,
a bath for electrolytic solution for supplying such
solution to said plating member, a transport means
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1 oriented to move such contact points across said plating
member and in contact therewith, means for positioning a
plurality of contact points along a bandolier for feeding
the same into said transport means, and means for
electrically energizing such contact points as a cathode
and electrically energizing said bath as an anode,
whereby the contact points may be passed against the
wettable surface of the roller for plating of a discrete
area of the curvilinear portion of such contact points.
Furthermore according to the present invention, an
electrical connector with a contact point for engaging a
further contact in electrical communication comprises a
metal underbody having an essentially uniform rectangular
cross section throughout a region and being
longitudinally curvilinear in the region, a conductive
metal overlay plated onto the external surface of said
region, and at least a portion of the periphery of said
metal overlay smoothly decreasing in thickne~s to define
at least a thin edge wheeein the conductive metal overlay
i~ substantially free of plated metal buildup common to
electrodeposition techniques using immersion plating.
According to an aspect of the invention, a method
for plating a discrete contact point on a carrier of
electronic contacts is disclosed.
According to another aspect of the invention is the
plating of a contact point at only the point where the
same will make electrical contact with a plated finger on
a printed circuit board, and to control the plated
dimensional portion of the contact as well as the
thickness of the plated metal.
Still another aspect of the present invention is the
continuous contact plating of a plurality of contacts
secured to a bandolier or carrier, the length of which may
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1 be effectively endless.
Still another aspect of the invention is an
apparatus for carrying out the above which is readily
adjustable in its basic respects, easy to service, and
economical to construct, operate and maintain.
DESCRIPTION OF THE DRAWINGS
________________________ _ _
Further objects and advantages of the present
inventon will become apparent as the following
description proceeds, taken in conjunction with the
accompanying drawings in which:
Figure 1 is a perspective partially broken rear view
of the subject continuous plate.
Figure 2 is an enlarged partially broken view
illustrating the feed guide for delivering a plurality of
bandolier secured contact points to the opposed driving
belts.
Figure 3 is a partially diagrammatic broken view of
a rear portion of the unit taken in perspective and
illustrating particularly the relationship between the
opposed jaws, the plating roller and the adjustment of
the plating holder.
Figure 4 is a rear elevation of the mechanism shown
in Figure 3 in substantially the same scale.
Figure ~ is a partially diagrammatic view
illustrating the drive mechanism for the carrier belts.
Figure 6 is an end view of the mechanism shown in
Figures 3 and 4 in slightly enlarged scale.
Figure 7 is a top view of the jaws, driving belt,
and anode roller broken at the midportion thereof.
Figure 8 is an enlarged, partially broken transverse
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1 sectional view of the relationship between the jaws,
driving belt and roller taken along section line 8-8 of
Figure 7.
Figure 9 is a plan view of a typical bandolier of a
pluarlity of contact points.
THE METHOD
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The method for continuous contact plating of a
curvilinear contact point presupposes contacts 51 in a
bandolier 50 as shown in Figure 9. The contact points
are positior.ed 80 that the bandolier is essentially
perpendicular to the contact point. Thereafter the
contact points and bandolier are oriented to pass the
same along a longitudinal axis. A roller having an
absorbent peripheral surface is po6itioned for driving
rotatably with its long axis in parallel relationship to
the bandolier, and its longitudinal axis. An electrolytic
bath is provided for fluid contact with an absorbent
surface on the roller. The bandolier and its contained
contact points are then moved along the axis parallel to
the axis of the roller with the contact points in
tangential contact with the absorbent surface. The
resultant action is to follow a helical path along the
absorbent surface of the roller with the contact points
energized as a cathode, and the electrolytic solution
electrically energized, particularly as to the absorbent
portion of the roller, as an anode. The method also
contemplates means in pressure relationship to the
absorbent surface of the roller to control the amount of
plating solution that is passed thereabout for purposes
of plating.
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1 THE_APPARATUS
The continuous plater 10 is shown in rear elevation,
and perspectively, in Figure 1. There it will be seen
that the continuous plater 10 includes a main frame 11,
and a plurality of carrier belts 12. The carrier belts
12 include an upper belt 18 and a lower belt 19, which
are positioned to tangentially engage each other and pass
through the jaws 14 which orient the same for tangential
helical trace contact with an anode roller 15. A plating
solution tray 16 is positioned beneath the anode roller
15, and provided with an electrolytic solution for
purposes of plating, usually plating gold to the contact
points. The entire continuous plater 10 presupposes a
treatment of the contact points prior to entering the
plater and treatment thereafter. It is therefore a
continuous plater 10, as a part of a total processing
apparatus for contact points.
To be noted in Figure 1 is the drive motor 20 for
the anode roller 15. A feed guide sprocket 21 is
provided immediately adjacent the feed point 60, the same
belng the point where the upper belt 18 and the lower
belt 19 first come into continuous contact for the
feeding of the contact points.
Turning now to Figure 8, it will be seen that the
jaws 14 include an upper jaw 42 and a lower jaw 44. The
same are secured to jaw bracket 41 which is permanently
affixed to the frame 11 of the continuous plater 10. The
bandolier 50 is grasped by the opposed upper belt 18 and
lower belt 19, and so positioned that the contact point
56 is in contact relationship with the absorbent sleeve 24
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1 of the roller 15. A meter roller 22 is provided for
adjustable pressure contact against the porous sleeve 24,
so that as the roller passes through the electrolyte 58,
the amount of retained fluid after passing the metering
roller 22 can be controlled by adjustment. The upper and
lower belts 18, 19 may be of a closed cell foam-like
material, or solid rubber, depending upon the contacts
being fed.
The roller 15 allows transfer of the electrolytic
solution from the plating solution tray 16 to roller 15
and subsequently to the contact points. This is
preferably accomplished by use of the absorbent sleeve
24; however, other alternative6 are possible. The
important feature i8 that the roller must transfer the
plating solution from the solution tray to the electrical
contact point or controllable electrodeposition quantity.
The contacts, while generally secured to a
bandolier, may take varying forms. As shown in Figure 9,
the Bandolier 50 has a plurality of contacts 51 secured
thereto by means of a fastener 52, in this instance
opposed jaws. The band 54 is provided with a pluarlity
of drive holes 55 which permit it to be sprocket fed for
movement.
The electrical contacts 51 shown in the enlargement
of Figure 8 have the metal-plated area 100 which form the
electrical contact point. The thickness of the contact
point decreases radially outward from the center thereof
along the axis of the contact and each contact point
joins with the body of the contact 51 at the thin edge
102. Thus, it can be appreciated that the thickness of
the contact point decreases to provide an
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1 essentially flush junction wi~h the underlying support
portion of the contact. Furthermore, the interaction o-f
the rotating roller and the movement of the contacts
reduce the possibility of bubbles thereby causing the
density to be more uniform.
Turning now to Figure 3, it will be seen that the
roller 15 is secured to a roller frame 25 which includes
a pa~r of roller frame legs 26, a rollee frame base 28,
and opposed roller frame posts 29 to which the roller 15
is mounted. The roller frame legs 26 are mounted at a
pivot 30 to the main frame 11. A horizontal adjusting
member 31 is provided at each end of the lower frame 25,
immediately adjacent the pivot 30. Vertical adjustment
means 32 are provided beneath the base 28 of the roller
frame 25, as noted in Figure 4, by rotating the knob 34,
the pads 59 bear upon the lower face of the base 28, and
raise and lower the same.
Turning now to Figure 5, it will be seen that the
upper and lower belts 18, 19 are driven by a belt motor
35 through a given sprocket mechanism to a plurality of
belt pulleys 36. The upper belt and lower belt 18, 19
are reeved around the pulleys to insure a firm flow and
continuous drive. The motor bracket 38 permits some
adjustment of the belt motor 35, and cooperates with the
idler adjustment 40 ~see Figure 1) to adju6tably secure
, . . . _ , . .. .
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1 the tension and frictional engagement of the belts 18, 19
with the pulleys 36.
In Figure 6 the bracket 45 for the metering rollers
is disclosed, the same being urged by the spring 46 into
compressive relationship with the roller 15. An
adjustment nut 48 i8 provided to further adjust the
yieldable relationship between the metering roll 22 and
the anode roller 15, the bracket 45 pivoting around pivot
point 49.
It is highly desirable to lead the bandolier 50 into
the feed point 60 defined by the position where the upper
belt 18 and lower belt 19 come together, the alignment to
be as close as possible. It will be appreciated that to
accomplish this purpose, a feed guide sprocket assembly
21 may be usefully employed ~see Figure 2). The assembly
comprises an upper inner toothed wheel 61 and an upper
outer toothed wheel 62. The teeth 66 are positioned
circumferentially to penetrate the drive holes 55 of the
bandolier 50. The driving effort of the upper and lower
belts 18, 19, will rotate the toothed wheels 61, 62, and
pull the bandolier 50 between the teeth 66 and the lower
inner guide wheel 64 and the outer lower guide wheel 65.
Other alternatives are available for the feed guide
sprocket assembly 21, such as a pair of opposed plates.
The principal result to be achieved is one of presenting
the bandolier 50 in a path substantially coincident with
the feed point 60, and the trace of the upper and lower
belts 18, 19 as they pass through the opposed jaws 42, 44.
For purposes of cleaning, an eccentric tray mount
assembly 70 (see Figure 1) in which a single crank 71 may
be rotated to the end that the four contact rollers 72
; ~
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1 supporting the tray 16 lower their contact points, and
the tray 16 may be removed from its fluid bath relation-
ship with the roller 15 for cleaning, replenishing the
electrolytic solution, or otherwise engaging in the
maintenance and operation of the subject continuous
plater 10.
Although particular embodiments of the invention
have been shown and described in full here, there is no
intention to thereby limit the invention to the details
of such embodiments. On the contrary, the intention is
to cover all modifications, alternatives, embodiments,
usages and equivalents of a continuous contact plater and
method as fall within the spirit and scope of the
invention, specification and the appended claims.
