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EP 0 005 356 B1 |
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EUROPEAN PATENT SPECIFICATION |
(45) |
Mention of the grant of the patent: |
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02.12.1981 Bulletin 1981/48 |
(22) |
Date of filing: 27.04.1979 |
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International Patent Classification (IPC)3: H01R 23/70 |
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(54) |
An electrical terminal and an edgecard connector incorporating the same
Elektrisches Anschlusselement und Plattenrandverbinder mit einem solchen Element
Borne électrique et connecteur en bordure de carte comprenant une telle borne
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(84) |
Designated Contracting States: |
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DE FR GB NL SE |
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Priority: |
27.04.1978 US 900486
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Date of publication of application: |
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14.11.1979 Bulletin 1979/23 |
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Applicant: E.I. DU PONT DE NEMOURS AND COMPANY |
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Wilmington
Delaware 19898 (US) |
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Inventor: |
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- Keim, Kenneth John
Lewisberry
Pennsylvania 17339 (US)
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(74) |
Representative: Leale, Robin George et al |
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Frank B. Dehn & Co.,European Patent Attorneys,
179 Queen Victoria Street London EC4V 4EL London EC4V 4EL (GB) |
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] This invention relates to an electrical terminal, particularly for an edgecard connector
for use in the electrical connector industry, for example in microcircuits technology
involving multiple circuit board terminations. More particularly, this invention relates
to elongate terminals which are press fit into circuit board aperture and which have
spring arm contacts adapted for receiving and making electrical contact with circuit
boards.
[0002] In the use of terminals for microcircuit applications there is an ever-present need
for structures which are inexpensive to manufacture, yet which possess inherently
high degrees of reliability. In the manufacture of press-fit terminals for mounting
in circuit board apertures, care must be exercised to insure that tolerances between
the board apertures and the mounting portions of the terminals are within certain
preset limits. The limits must be adequate to insure sufficient retention force, and
yet avoid injury to metallization plating in the aperture. Many structures have been
proposed for achievement of this objective without substantial sacrifice in manufacturing
costs and reliability of the terminations effected thereby.
[0003] For example, U.S. 4,066,326, discloses a circuit board contact with an expanded mounting
portion which will maintain a desired retention force over a large circuit board aperture
tolerance. Circuit board terminals having similar deformed mounting portions are also
described in U.S. 3,827,004 issued to Vanden Heuvel et al. and U.S. 3,634,819 issued
to Evans. These structures, although quite sufficient for their intended purposes,
do not provide sufficient retention force without solder bonding when utilized in
conjunction with wire wrap tail contacts wherein the terminal may be subjected to
substantial torsional forces. Additionally, some of the prior art structures (e.g.,
U.S. 3,634,819) designed for high force retention do not sufficiently insure accurate
location of the central axis of the mounting portion within the circuit board aperture
upon termination.
[0004] US-A-4,057,315 discloses an elongate electrical terminal for press fitting in a circuit
board aperture, having a contact at each end and a mounting portion (16) therebetween,
said mounting portion comprising a generally cylindrical body having voids impressed
therein, the body having a generally bow-tie shaped cross-section with convex surfaces
at its ends and impressions formed in its sides by said voids to define reduced centre
portions in said cross-section.
[0005] Press-fit terminals with spring arm contacts are often used in edgecard connectors.
Unfortunately, such connectors built to provide high normal forces have been associated
with undesirably high insertion forces, as most of them utilize cantilever spring
arm systems. In order to provide satisfactory mating between the board and spring
arms, a sufficient normal force must be created to assure firm electrical contact,
but high board insertion forces must be avoided. The typical edgecard connector contains
parallel opposing rows of terminals having spring arm contacts biased toward each
other so as to define a convex contact engaging surface for a mating board. The spring
arms function as cantilever beams, so that when a board is slidably inserted therebetween,
the ends of the spring arms are forced laterally apart. Thus, the higher the normal
force provided, the greater the insertion force. Various structures have been proposed
for achieving a reduced insertion force per a given normal force, but many do so only
marginally, and most involve the technique of preloading the opposing spring arm contacts
as disclosed in U.S. 3,963,293 issued to McKee and U.S. 3,671,917 issued to Ammon
et al. Therefore, the spring arm contacts should have a high retention force when
mounted in the connector, without damaging the board.
[0006] U.S. 3,864,014 discloses an edgecard connector which comprises a plurality of elongate
terminals each having a contact at both ends and a deformable mounting portion therebetween,
said mounting portions being a press fit into apertures in a supporting circuit board,
one of said contacts of each terminal being a spring arm having a free end, the second
of said contacts being a wire wrap tail, and an insulative housing mated with said
supporting circuit board, said housing having means to removably receive, edgewise,
a mating circuit board, and being adapted to fit over the spring arm contacts of said
plurality of terminals, the terminals being positioned in opposing rows in said apertures
of the supporting circuit board, the housing having a well therein substantially parallel
to the axes of the wire wrap tails of inserted terminals, the wall being adapted to
restrict the free ends of the spring arms to movement only along a plane parallel
to the axes of said tails when a mating circuit board is inserted into the connector.
[0007] Viewed from one aspect the present invention provides an elongate electrical terminal
for press fitting in a circuit board aperture, having a contact at each end and a
mounting portion therebetween, said mounting portion comprising a generally cylindrical
body having voids impressed therein, the body having a generally bow-tie shaped cross-section
with convex surfaces at its ends and impressions formed in its sides by said voids
to define reduced centre portions in said cross-section, characterised in that the
voids are generally oval-shaped, that the major axes of said voids extend parallel
to the longitudinal axis of said body, that the impressions are symmetrically opposed
and dish-shaped and in that said mounting portion as a result of the impressions therein,
is deformable upon press fitting into a round circuit board aperture so as to have
the convex surfaces at each end of the bow-tie shaped cross-section in intimate contact
with the inside surface of said round aperture whereby said reduced centre portion
plastically deforms and/or shears.
[0008] Viewed from another aspect the invention provides an edgecard connector which constitutes
an improvement over that disclosed in U.S. 3,864,014 in that the said mounting portion
of each terminal has a generally cylindrical body with symmetrically opposed generally
oval-shaped voids impressed therein, the major axes of said voids extending parallel
to the longitudinal axis of said body, the body having a generally bow-tie shaped
cross-section with symmetrically opposed dish-shaped impressions formed therein by
said voids to define a reduced centre portion in said cross-section, the reduced portion
of said cross-section of said mounting portion being adapted to be plastically deformed
and/or sheared upon the press fitting of said mounting portion into a circuit board
aperture.
[0009] The elongate press-fit terminal of this invention has a mounting portion which provides
a high retention force under torsional stress without solder bonding. The mounting
portion also provides accurate central axis location in a circuit board aperture.
The edgecard connector of this invention provides a high normal force.
[0010] Some embodiments of the invention will now be described by way of example and with
reference to the accompanying drawings, in which:
Figure 1 is a side elevation view of a press-fit terminal of this invention attached
to a carrier strip;
Figure 2 is a front elevation view of the press-fit terminal of Figure 1, including
two such terminals attached to a carrier strip;
Figure 3 is a front elevation view of the deformed mounting portion of the terminal;
Figure 4 is a cross-section view of the deformed mounting portion of the terminal;
Figure 5 is a cross-section view of the deformed mounting portion after being press
fitted into a circuit board aperture;
Figure 6 is a broken perspective view of an alternate embodiment of the mounting portion
of the terminal;
Figure 7 is an exploded perspective view of an edgecard connector of this invention
which utilizes the terminal of Figures 1 and 2;
Figure 8 is a side elevation sectional view of the edgecard connector which shows
a pair of opposed terminals positioned therein; and
Figure 9 is a side elevation sectional view of the connector which depicts flexure
positions of the spring arm contact of the terminal.
[0011] An elongate terminal 10 according to this invention is shown in Figures 1 and 2.
The terminal has a bifurcated spring arm contact 12 at one end and a wire wrap tail
contact 14 at the other. Intermediate the contacts is a deformed mounting portion
16 adapted for press fitting into an aperture in a printed circuit board. Intermediate
the spring arm contact and the mounting portion is a first shoulder 18, a neck 20,
and a second shoulder 22. The terminal 10 is integrally attached to a carrier strip
24 from which it is severed at reduced section 26 for press fitting into a circuit
board aperture. The spring arm contact 12 when severed from a carrier strip has a
free end 15 parallel to and offset from the axis 17 of the wire wrap tail 14 as may
be observed in Figure 1. The offset feature, however, is not essential to the operability
of this invention.
[0012] Figure 3 is an enlarged view of the mounting portion 16 of the terminal 10. The body
of the mounting portion 16 is generally cylindrical with symmetrically opposed oval-shaped
voids 28 impressed therein by a die. The major axes 30 of the oval voids extend parallel
to. the longitudinal axis 32 of the mounting portion 16. The cross-section 34 of the
mounting portion 16 is shown in Figure 4. It is generally bow-tie shaped with symmetrically
opposed dish-shaped sections 36 formed by the voids 28 to form a reduced centre portion
38. The reduced center portion 38 is designed to plastically deform upon the press
fitting of the mounting portion 16 into a circuit board aperture 40 as shown in Figure
5. Deformation of the center portion 38 occurs prior to the realization of injurious
pressure fitting forces. Thus, referring to Figure 5, the pressure exerted by the
contact surface 42 of the mounting portion 16 against the metallization plating 44
in the aperture is thereby controlled to avoid (1) injury to the plating 44, and (2)
extreme deformation of the aperture 40. At the same time, the contact surface 42 is
large enough to afford high rates of retention force without solder bonding in terminations
subjected to substantial torsional forces as, for example those encountered in the
use of wire wrap tails.
[0013] Although the mounting portion of this invention provides a high retention force without
solder bonding, the application of solder may be utilized for an even higher retention
force. Thus, Figure 6 is a broken perspective view of an alternate embodiment of the
mounting portion 16 in a cross section of the aperture 40. A mass of solder 46, shown
as a globule, is contained within a support hole 48 formed within the shoulder 22
of the terminal. As the shoulder 22 is contiguous with the mounting portion 16, the
mass of solder is positioned so as to flow into interspaces 50 (Fig. 5) between inserted
mounting portion 16 and the aperture 40 upon exposure to an external heat source,
such as infrared heater.
[0014] The elongate terminal 10 of this invention is adapted for use in an edgecard connector
60 as shown in Figures 7 and 8.
[0015] Figure 7 is an exploded perspective view of the connector 60 which contains a plurality
of the terminals 10. The terminals are press fit into apertures 40 in a supporting
circuit board 52 in opposing parallel rows as shown. An insulative housing 70 fits
over the spring arm contacts 12 of the terminals 10 and is mated with the supporting
board 52 by mechanical fasteners not shown. The housing 70 has an opening 72 adapted
for removably receiving a mating circuit board 80 in edgewise fashion as depicted.
[0016] The circuit board 80 has metallization pads 82 printed thereon by conventional screen
printing techniques. The pads 82 are electrically connected to other electrical elements,
not shown. The edgecard connector 60 provides a mechanism by which mechanical and
electrical contact may be achieved between the metallization pads 82 and the spring
arm contacts 12 contained within the housing 70.
[0017] Figure 8 is an elevation sectional view of the assembled edgecard connector 60 which
shows a pair of opposed terminals 10 positioned within the housing 70 for receiving
mating circuit board 80. The housing 70 has an internal wall 74 parallel to the axes
17 of the wire wrap tails 14 of inserted terminals 10.
[0018] In Figure 9, one of the spring arms 12 is shown in both unflexed and flexed positions
(the latter in phantom). The free end 15 of the spring arm 12 maintains contact with
the wall 74 in both positions shown as well as between positions. The wall restricts
the free end 15 to slidable movement along a plane parallel to the axis 17 of the
wire wrap tail 14 of an inserted terminal 10. The spring arm 12 functions therefore
as a leaf spring instead of the typical cantilever spring used in most edgecard connectors.
Thus, as seen in Figure 8, since the free ends 15 of the spring arms 12 cannot move
laterally, they will not be forced apart upon insertion of a mating board so as to
produce the high rates of inserstion forces associated with cantilever systems. Rather,
a much lower insertion force is realized for a given normal force value in the leaf
spring system.
[0019] The press-fit terminal and edgecard connector of this invention have wide applicability
in micro-circuits applications involving electrical terminations between circuit boards.
For example, such devices are mounted in electronic backplanes of computers telephonic
switching gear, and many other low voltage signal systems.
[0020] It should be noted that the reduced centre portion 38 of the mounting portion 16
of the terminal may be adapted to shear upon press fitting in a circuit board aperture,
rather than only plastically deforming as described above, with little or no reduction
in the advantages already set forth.
1. An elongate electrical terminal (10) for press fitting in a circuit board aperture
(40), having a contact (12, 14) at each end and a mounting portion (16) therebetween,
said mounting portion comprising a generally cylindrical body having voids (28) impressed
therein, the body having a generally bow-tie shaped cross-section with convex surfaces
(42) at its ends and impressions (36) formed in its sides by said voids to define
reduced centre portions (38) in said cross-section, characterised in that the voids
(28) are generally oval-shaped, that the major axes (30) of said voids extend parallel
to the longitudinal axis (32) of said body, that the impressions (36) are symmetrically
opposed and dish-shaped and in that said mounting portion (16) as a result of the
impressions (36) therein, is deformable upon press fitting into a round circuit board
aperture (40) so as to have the convex surfaces (42) at each end of the bow-tie shaped
cross-section in intimate contact with the inside surface of said round aperture (40)
whereby said reduced centre portion (38) plastically deforms and/or shears.
2. A terminal as claimed in claim 1, which has a mass of solder (46) adjacent said
mounting portion (16), said mass of solder being positioned so as to flow, upon exposure
to an external heat source, into interspaces (50) between an inserted mounting portion
(16) and a corresponding circuit board aperture (40).
3. A terminal as claimed in claim 1 or 2, wherein one of said contacts is a spring
arm (12) in line with the axis of the terminal (32).
4. A terminal as claimed in claim 1 or 2, wherein one of said contacts is a wire wrap
tail (14), the other being a spring arm (12) having a free end (15) parallel to and
offset from the axis (17) of the wire wrap tail.
5. A terminal as claimed in claim 4, wherein said spring arm contact (12) is bifurcated,
said terminal (10) having a first shoulder (18), a neck portion (20), and a second
shoulder (22) all positioned intermediate said spring arm contact (12) and said mounting
portion (16).
6. An edgecard connector (60) which comprises:
(a) a plurality of elongate terminal (10) each having a contact (12, 14) at both ends
and a deformable mounting portion (16) therebetween, said mounting portions being
a press fit into apertures (40) in a supporting circuit board (52), one of said contacts
of each terminal being a spring arm (12) having a free end (15), the second of said
contacts being a wire wrap tail (14),
(b) an insulative housing (70) mated with said supporting circuit board (52), said
housing having means to removably receive, edgewise, a mating circuit board (80),
and being adapted to fit over the spring arm contacts (12) of said plurality of terminals
(10), the terminals being positioned in opposing rows in said apertures of the supporting
circuit board, the housing having a wall (74) therein substantially parallel to the
axes (17) of the wire wrap tails of inserted terminals, the wall being adapted to
restrict the free ends of the spring arms to movement only along a plane parallel
to the axes of said tails when a mating circuit board (80) is inserted into the connector
(60), characterised in that the said mounting portion (16) of each terminal (10) has
a generally cylindrical body with symmetrically opposed generally oval-shaped voids
(28) impressed therein, the major axes (30) of said voids extending parallel to the
longitudinal axis (32) of said body, the body having a generally bow-tie shaped cross-section
with symmetrically opposed dish-shaped impressions (36) formed therein by said voids
to define a reduced centre portion (28) in said cross-section, the reduced portion
(38) of said cross-section of said mounting portion being adapted to be plastically
deformed and/or sheared upon the press fitting of said mounting portion into a circuit
board aperture (40).
7. An edgecard connector as claimed in claim 6, including mechanical fastener means
for mating said insulative housing (70) with said supporting circuit board (52).
8. An edgecard connector as claimed in claim 6 or 7, wherein the spring arm contact
(12) of each said terminal (10) is bifurcated, the terminal having a first shoulder
(18), a neck (20), and a second shoulder (22) all positioned intermediate said spring
arm contact (12) and said mounting portion (16).
9. An edgecard connector as claimed in any of claims 6-8 wherein the free end (15)
of the spring arm (12) of each terminal (10) is parallel to and offset from the axis
(17) of said wire wrap tail (14).
1. Ein länglicher elektrischer Anschluß (10) zum Preßsitz in einer Schaltplattenöffnung
(40) mit einem Kontakt (12, 14) an jedem Ende und einem Halteteil (16) dazwischen,
welcher Halteteil einen im wesentlichen zylindrischen Körper aufweist, in den Aushöhlungen
(28) eingepreßt sind und der einen im wesentlichen wulsttellerförmigen Querschnitt
mit konvexen Flächen (42) an seinen Enden und Eintiefungen (36) hat, die an seinen
Seiten durch die erwähnten Aushöhlungen geformt sind, um verengte Mittelteile (38)
in dem erwähnten Querschnitt zu bilden, dadurch gekennzeichnet, daß die Aushöhlungen
(28) eine im wesentlichen ovale Form haben, die Hauptachsen (30) der Aushöhlungen
sich parallel zur Längsachse (32) des Körpers erstrecken, die Eintiefungen (36) symmetrisch
entgegengesetzt und schalenförmig sind und daß der Halteteil (16) infolge der Eintiefungen
(36) in diesem beim Einpressen in eine runde Schaltplattenöffnung (40) so verformbar
ist, daß er konvexe Flächen (42) an iedem Ende des wulsttellerförmigen Querschnitts
in innigem Kontakt mit der Innenfläche der erwähnten runden Öffnung (40) aufweist,
wodurch der verengte Teil (38) plastisch verformt wird und/oder abschert.
2. Ein Anschluß nach Anspruch 1, der eine Lötmittelmasse (46) benachbart dem Halteteil
(16) besitzt, welche Lötmittelmasse so angeordnet ist, daß sie, wenn sie einer äußeren
Wärmequelle ausgesetzt wird, in die Zwischenräume (50) zwischen einem eingesetzten
Halteteil (16) und einer entsprechenden Schaltplattenöffnung (40) fließt.
3. Ein Anschluß nach Anspruch 1 oder 2, bei welchem einer der erwähnten Kontakte ein
Federarm (12) in Ausfluchtung mit der Achse des Anschlusses (32) ist.
4. Ein Anschluß nach Anspruch 1 oder 2, bei welchem einer der erwähnten Kontakte ein
Wire-Wrap-Anschluß (14) ist, der andere ein Federarm (12) mit einem freien Ende (15)
parallel zu und versetzt von der Achse (17) des Wire-Wrap-Anschlusses ist.
5. Ein Anschluß nach Anspruch 4, bei welchem der Federarmköntakt (12) gegabelt ist,
der erste Anschluß (10) eine erste Schulter (18), einen Halsteil (20) und eine zweite
Schulter (22) aufweist, die alle zwischen dem Federarmkontakt (12) und dem Halteteil
(16) angeordnet sind.
6. Ein Hochkant-Steckverbinder (60), mit
(a) eine Vielzahl von länglichen Anschlüssen (10) je mit einem Kontakt (12, 14) an
beiden Enden mit einem verformbaren Halteteil (16) dazwischen, welche Halteteile einen
Preßsitz in Öffnungen (40) in einer tragenden Schaltplatte (52) haben, einer der erwähnten
Kontakte jedes Anschlusses ein Federarm (12) mit einem freien Ende (15) ist, der zweite
der erwähnten Kontakte ein Wire-Wrap-Anschluß (14) ist,
(b) ein Isoliergehäuse (70) passend zu der erwähnten tragenden Schaltplatte (52),
welches Gehäuse Mittel besitzt zur kantenweisen Aufnahme einer passenden Schaltplatte
(80) und über die Federarmkontakte (12) der erwähnten Vielzahl von Anschlüssen (10)
geschoben werden kann, welche Anschlüsse in gegenüberliegenden Reihen in den erwähnten
Öffnungen der tragenden Schaltplatte angeordnet sind, in welchem Gehäuse eine Wand
(74) vorgesehen ist, die im wesentlichen parallel zu den Achsen (17) der Wire-Wrap-Anschlüsse
der eingesetzten Anschlüsse ist, welche Wand dazu dient, die freien Enden der Federarme
auf eine Bewegung nur längs einer Ebene zu beschränken, die parallel zu den Achsen
der Wire-Wrap-Anschlüsse ist, wenn eine passende Schaltplatte (80) in den Steckverbinder
(60) eingesetzt wird, dadurch gekennzeichnet, daß der Halteteil (16) jedes Anschlusses
(10) einen im wesentlichen zylindrischen Körper mit symmetrisch entgegengesetzten,
in diesen eingepreßten im wesentlichen ovalen Aushöhlungen (28) hat, deren Hauptachsen
(30) sich parallel zu der Längsachse (32) des Körpers erstrecken, welcher Körper einen
im wesentlichen wulsttellerförmigen Querschnitt mit im wesentlichen symmetrisch entgegengesetzten schalenförmigen
Eintiefungen (36) hat, die in diesem durch die erwähnten Aushöhlungen geformt sind,
um einen verengten Mittelteil in dem erwähnten Querschnitt zu bilden, welcher verengte
Teil (38) des Querschnitts beim Einpressen des erwähnten Halteteils in eine Schaltplattenöffnung
(40) plastisch verformt und/oder abgeschert werden kann.
7. Ein Hochkant-Steckverbinder nach Anspruch 6, mit mechanischen Befestigungsmitteln
zum Zusammenfügen des lsoliergehäuses (70) mit der tragenden Schaltplatte (52).
8. Ein Hochkant-Steckverbinder nach Anspruch 6 oder 7, bei welchem der Federarmkontakt
(12) von jedem erwähnten Anschluß (10) gegabelt ist, welcher Anschluß eine erste Schulter
(18), einen Hals (20) und eine zweite Schulter (22) aufweist, die alle zwischen dem
erwähnten Federarmkontakt (12) und dem erwähnten Halteteil (16) angeordnet sind.
9. Ein Hochkant-Steckverbinder nach einem oder mehreren der Ansprüche 6 bis 8, bei
welchem das freie Ende (15) des Federarmes (12) jedes Anschlusses (10) parallel zur
Achse (17) des erwähnten Wire-Wrap-Anschlusses (14) und von dieser versetzt ist.
1. Borne électrique allongée (10) destinée à s'ajuster à pression dans une ouverture
(40) de plaquette de circuit, présentant un contact (12, 14) à chaque extrémité et
une partie de montage (16) entre les contacts, cette partie de montage comprenant
un corps généralement cylindrique dans lequel des cavités (28) sont empreintes, le
corps ayant une section généralement en forme de noeud papillon présentant des surfaces
convexes (42) à ses extrémités et des empreintes (36) formées dans ses côtés par lesdites
cavités pour définir des parties centrales réduites (38) dans la section mentionnée,
caractérisée en ce que les cavités (28) ont une forme généralement ovale, que les
grands axes (30) des cavités sont dirigés parallèlement à l'axe longitudinal (32)
du corps, que les empreintes (36) sont opposées symétriquement et en forme de cuvette
et que la partie de montage (16) par suite des empreintes (36) qu'elle présente, est
déformable lors de l'ajustement à pression dans une ouverture circulaire (40) de plaquette
de circuit de façon que les surfaces convexes (42) de chaque extrémité de la section
en forme de noeud papillon soient en contact intime avec la surface intérieure de
l'ouverture circulaire (40) et qu'ainsi la partie centrale réduite (38) se déforme
plastiquement et/ou se cisaille.
2. Borne selon la revendication 1, présentant une masse de soudure (46) adjacente
à la partie de montage (16), cette masse de soudure étant placée de manière à couler,
lors de l'exposition à une source extérieure de chaleur, dans des interstices (50)
entre une partie de montage (16) insérée et une ouverture correspondante (40) de plaquette
de circuit.
3. Borne selon l'une des revendications 1 et 2, dans laquelle l'un des contacts est
une branche de ressort (12) alignée sur l'axe de la borne (32).
4. Borne selon l'une des revendications 1 et 2, dans laquelle l'un des contacts est
une queue à câblage enroulé (14), l'autre étant une branche de ressort (12) présentant
une extrémité libre (15) parallèle à l'axe (17) de la queue à câblage enroulé.
5. Borne selon la revendication 4, dans laquelle le contact à branche de ressort (12)
est fourchu, la borne (10) présentant un premier épaulement (18), une partie de col
(20) et un deuxième épaulement (22), tous placés entre le contact à branche de ressort
(12) et la partie de montage (16).
6. Connecteur plat (60) comprenant:
(a) de multiples bornes allongées (10) présentant un contact (12, 14) aux deux extrémités
et une partie de montage déformable (16) entre les contacts, ces parties de montage
étant ajustées à pression dans des ouvertures (40) d'une plaquette de circuit (52)
servant de support, l'un des contacts de chaque borne étant une branche de ressort
(12) présentant une extrémité libre (15) le deuxième de ces contacts étant une queue
à câblage enroulé (14);
(b) un boîtier isolant (7) adapté à la plaquette de circuit (52) servant de support,
ce boîtier présentant des moyens pour recevoir de chant et de façon amovible une plaquette
de circuit complémentaire (80) et étant conçu pour s'adapter par dessus les contacts
à branche de ressort (12) des multiples bornes (10), les bornes étant placées en rangées
opposées dans les ouvertures de la plaquette de circuit servant de support, le boîtier
contenant une paroi (74) pratiquement parallèle aux axes (17) des queues à câblage
enroulé des bornes insérées, la paroi étant conçue pour limiter le mouvement des extrémités
libres des branches de ressort uniquement à un mouvement suivant un plan parallèle
aux axes des queues lorsqu'on insère dans le connecteur (60) une plaquette de circuit
complémentaire (80), caractérisé en ce que la partie de montage (16) de chaque borne
(10) présente un corps généralement cylindrique dans lequel sont empreintes des cavités
(28) généralement ovales, opposées symétriquement, les grands axes (30) de ces cavités
étant dirigés parallèlement à l'axe longitudinal (32) du corps, le corps présentant
une section généralement en forme de noeud papillon dans lequel des empreintes en
forme de cuvette (36) opposées symétriquement sont formées par les cavités mentionnées,
pour définir dans la section une partie centrale réduite (38), la partie réduite (38)
de la section de la partie de montage étant conçue pour se déformer plastiquement
et/ou se cisailler lorsqu'on ajuste à pression ladite partie de montage dans une ouverture
(40) de plaquette de circuit.
7. Connecteur plat selon la revendication 6, comprenant des attaches mécaniques pour
accoupler le boîtier isolant (70) à la plaquette de circuit (52) servant de support.
8. Connecteur plat selon l'une des revendications 6 et 7, dans lequel le contact à
branche de ressort (12) de chacune des bornes (10) est fourchu, la borne présentant
un premier épaulement (18), un col (20) et un deuxième épaulement (22), tous placés
entre le contact à branche de ressort (12) et la partie de montage (16).
9. Connecteur plat selon l'une quelconque des revendications 6 à 8, dans lequel l'extrémité
libre (15) de la branche de ressort (12) de chaque borne (10) est parallèle à l'axe
(17) de la queue à câblage enroulé (14) et décalée relativement à cet axe.

