[0001] The invention relates to a method for manufacturing contact pins from a strip of
conductive material according to the preamble of claim 1.
[0002] In applying this known method the contact faces are formed on the contact pin parts
at opposite sides of the strip, so that the contact faces of the contact pins obtained
extend in the plane of the material strip. The faces of the contact pin parts extending
transverse to these contact faces are not suitable for contacting a complementary
contact element due to the step of cutting away the portions of the strip lying between
subsequent contact pins.
[0003] The invention aims to provide a method of the above-mentioned type whereby contact
pins are obtained with a contact pin part with contact faces extending transverse
to the plane of the material strip.
[0004] To this end the method of the invention is characterized by the characterizing features
of claim 1.
[0005] By means of the method of the invention contact pins can be manufactured which are
particularly suitable for applications wherein the contact pins must be closely spaced.
Further, contact pins can be manufactured for application in connector assemblies
for connecting printed circuit boards at both sides of a central printed circuit board,
wherein the printed circuit boards cross each other perpendicularly. Such contact
pins are made with two contact pin parts with contact faces for contacting complementary
contact elements, wherein in this case one contact pin part is twisted along 90° with
respect to the other contact pin part.
[0006] The invention will be further explained by reference to the drawings in which Figs.
a, b, c and d show successive steps of an embodiment of the method according to the
invention.
[0007] Fig. a shows two adjacent contact pins 1 formed out of a strip of conductive material,
such as for example a suitable copper alloy, of which only a narrow band 2 is present
connecting the successive contact pins with each other. The parts of the material
strip lying between the successive contact pins 1 are cut away. As shown in Fig. a
the intermediate parts are cut away in such a manner at the top side of the narrow
band 2 that the contact pins have a shoulder portion 3 lying in the plane of the strip.
Above this shoulder portion 3 each contact pin 1 has a contact pin part 4 with opposite
contact faces 5 lying in the respective main planes of the strip and are therefore
extending substantially parallel to the shoulder portions 3. These contact faces 5
are formed in a usual manner for contacting a complementary element. The faces of
the contact pin parts 1 directed towards each other are not suitable for contacting
a complementary contact element due to the cutting away of the intermediate parts
of the strip.
[0008] In the embodiment shown the contact pins 1 are provided at their lower side with
a press fit portion 6 known per se, wherein a contact pin is adapted to be inserted
into a hole of a printed circuit board with this press fit portion 6. This press fit
portion 6 guarantees a good contacting of the wall of the hole plated with a conductive
material, and holds the contact pin 1 in the hole. The shoulder portion 3 is provided
to press the contact pin 1 in a suitable manner into the hole of the printed circuit
board.
[0009] The contact pin part 7 of each contact pin 1 opposite of the contact pin part 4 can
also be provided with opposite contact faces 5 extending in the main planes of the
material strip. Such contact pins 1 with two contact pin parts 4, 7 are suitable for
applications wherein the contact pins should be contacted at both sides of a printed
circuit board.
[0010] In Fig. b it is indicated that in the embodiment shown the contact faces 5 of the
contact pin parts 4 are advantageously plated with a noble metal, such as for example
gold, when the contact pins 1 are still in the material strip. The coating layer 8
obtained is shown in the drawing by shading. Thereby a good contact with complementary
contact elements can be guaranteed.
[0011] Fig. c shows that the contact pin parts 4 are twisted along 90° with respect to the
plane of the material strip when the contact pins 1 are still in the material strip.
In this manner the contact pin parts 4 each include a twisted portion 9. Thereby it
is obtained that the contact faces 5 extend transverse to the direction of the shoulder
portions 3. Finally, the contact pins 1 are cut loose from the material strip as shown
in Fig. d. A coating layer 8 of the contact faces of the contact pin parts 7 is schematically
shown by shading in Figs. c and d.
[0012] By means of the method described contact pins 1 are obtained wherein the contact
faces 5 of the contact pin part 4 extend transverse to the shoulder portions 3. The
contact pins 1 are thereby particularly suitable for application in connector assemblies
in systems with a central printed circuit board, wherein printed circuit boards mutually
crossing each other perpendicularly are connected to the central printed circuit board
at both sides. Further, the contact pins 1 are very suitable for applications, wherein
the contact pins must be closely spaced.
[0013] The invention is not restricted to the above described embodiment which can be varied
in a number of ways within the scope of the claims. It will be understood that the
described embodiment of the contact pins 1 is only an example and that the method
of the invention can also be applied at other types of contact pins.
1. Method for manufacturing contact elements from a strip of conductive material, wherein
successive contact elements are formed in the strip by cutting away parts between
the successive contact elements, wherein each contact element is made with a contact
means with opposite contact faces for contacting a complementary contact element,
characterized in that the contact means of each contact element includes a twisted portion in such a manner
that the contact means is twisted along an angle of substantially 90° with respect
to the plane of the material strip.
2. Method according to claim 1, wherein the surfaces of said contact means lying in the
plane of the strip are plated as contact faces with a noble metal before twisting
the contact means.
3. Method according to claim 1 or 2, wherein the contact elements are cut loose from
the strip after the twisting step.
