U.S. patent number 3,609,463 [Application Number 04/859,748] was granted by the patent office on 1971-09-28 for connectors for printed-circuit cards.
This patent grant is currently assigned to Societe Industrielle Bull-General Electric, (Societe Anonyme). Invention is credited to Bernard Andre Laboue.
United States Patent |
3,609,463 |
Laboue |
September 28, 1971 |
CONNECTORS FOR PRINTED-CIRCUIT CARDS
Abstract
An arrangement for connecting circuits of printed-circuit cards
to circuits of a connection panel, comprising connectors fixed in
parallel relationship to one another on said connection panel, each
connector being provided with contact blades of which one end is
soldered to a conductive surface of the connection panel and each
of which is arranged to be pressed against a contact surface on a
card inserted between two connector elements, under the action of
an insulating push member pushed by a spring independent of the
contact blade.
Inventors: |
Laboue; Bernard Andre
(Goussainville, FR) |
Assignee: |
Societe Industrielle Bull-General
Electric, (Societe Anonyme) (Paris, FR)
|
Family
ID: |
8655144 |
Appl.
No.: |
04/859,748 |
Filed: |
September 22, 1969 |
Foreign Application Priority Data
Current U.S.
Class: |
361/787; 361/784;
439/55; 439/61; 439/65; 439/67 |
Current CPC
Class: |
H01R
12/79 (20130101); H01R 12/87 (20130101) |
Current International
Class: |
H01R
33/76 (20060101); H02b 001/02 (); H05k
001/04 () |
Field of
Search: |
;317/11DH,101,11CC
;339/176MP,17LM,17LC,17M |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Smith, Jr.; David
Claims
I claim:
1. A connecting system for detachably connecting conductive
surfaces aligned on the faces of a number N of printed-circuit
cards with a conductive surfaces on a printed-circuit panel, said
system comprising:
a number N+1 of connector elements fixed parallel to said panel in
order to permit the insertion of an edge of one of said cards
between two adjacent connector elements, each of said elements
comprising:
an elongated body of insulating material having two lateral walls,
each lateral wall being formed with a plurality of recesses
a push member slidably disposed in each of said recesses, said push
member consisting of insulating material and being provided with
bosses,
a spring element fixed in said body and provided with two sets of
spring blades, each of said spring blades being disposed to urge
one of said push members through the corresponding recess in order
that the bosses of said push member may project outside of the
associated lateral wall, and
two series of elongated contact blades, each of said blades having
one end thereof bonded to a conductive surface on said panel
between the latter and an opposed connector body and having a
central portion disposed opposite to an associated one of said push
members whereby said central portion is urged towards a conductive
surface on a printed-circuit card when the latter is inserted
between two adjacent connector elements.
2. A connecting system according to claim 1, wherein each of said
push members is provided with two bosses to transmit to two
separate points of a contact blade the force which is applied
thereto by the corresponding spring blade.
3. A connecting system according to claim 2, wherein for each of
said connector elements, said contact blades consist of thin strips
of conductive metal deposited upon a thin sheet of insulating
material, which sheet is gripped between said panel and the
corresponding connector body and has its two edges turned down one
upon the other and fixed on said connector body.
4. A connecting system according to claim 3, wherein each of said
sheets consists of a material resistant to the tin-soldering
temperature, such as polyethylene terephthalate.
5. A connecting arrangement for detachably connecting a plurality
of conductive surfaces, disposed on at least one face of a circuit
board and spaced apart along one edge of said face, to conductive
surfaces disposed on one face of a connection panel, said
connecting arrangement being provided with at least one connector
element comprising:
an elongated connector body of insulating material mounted on said
one face of said connection panel, the elongated dimension of said
body being oriented parallel to the plane of said one face of said
connection panel and a lateral wall of said body extending along
the length thereof being tangent to a plane perpendicular to the
plane of said one face of said connection panel, said wall being
provided with a plurality of apertures extending therethrough,
a push member slidably disposed in each of said apertures,
a spring member mounted in said body for each of said push members,
each of said spring members being disposed to urge the associated
push member through the corresponding aperture to project outwardly
from said lateral wall, and
a plurality of elongated contact strips spaced apart along the
length of said lateral wall and oriented transversely to the length
of said lateral wall, each of said strips having one end thereof
bonded to one of said conductive surfaces disposed on said one face
of said connection panel between said panel and said connector
body, having a central portion thereof disposed opposite to a
respective one of said push members to provide for said control
portion to be urged away from said wall by the corresponding push
member, and having the other end thereof affixed to said body near
the edge of said lateral wall remote from said panel.
6. The arrangement of claim 5 provided with a plurality of said
connector elements, the respective connector bodies of said
connector elements being oriented mutually parallel and spaced
apart to admit the edge of one of said circuit boards between
adjacent pairs of said bodies.
7. The arrangement of claim 5 for detachably connecting a plurality
of said conductive surfaces disposed on both faces of a circuit
board to conductive surfaces on said panel and provided with a pair
of said connector elements, the respective connector bodies of said
connector elements being oriented mutually parallel and with the
respective lateral walls of said bodies facing each other, said
connector bodies being spaced apart to admit the edge of one of
said circuit boards between said facing lateral walls.
Description
The present invention relates to improvements in connectors for
printed-circuit cards and concerns an arrangement which is more
particularly adapted for electrically connecting the conductors of
printed-circuit cards to conductors of a connection panel also
comprising printed circuits. These electrical connections are made
by means of connectors, regarding which a major problem exists at
present, namely to minimize the length of the conductors introduced
by the said connector into the circuits in order not to insert into
the said circuits conductors having electrical characteristics
which are likely to modify substantially the electrical
characteristics of the connected circuits, sometimes with the
introduction of inductive couplings or stray capacitances between
the circuits.
The techniques at present employed for the production of compact
circuits make it possible to reduce considerably the overall
dimensions of the greater part of the electrical circuits present
in information-processing and other equipment. These compact
circuits are often made in the form of so-called "printed
circuits," which are sometimes assembled in a number of layers in
detachable cards and in connection panels designed to support
connectors and to make the connections between the circuits of
different cards. Connecting devices are necessarily employed for
establishing the electrical connections between the circuits of the
cards and the circuits of the panels. In these connectors, a very
large number of contact members are assembled within a very small
space. Many connector systems are known in which the contact
members by which the electrical connections are made are formed of
relatively long flexible conductive blades or rods which are often
bent over on themselves and which are adapted to supply by their
own resilience a sufficient bearing force on the contact surfaces.
When connectors are employed to connect together circuits through
which there pass electric pulses having components of very high
frequency, those parts of the connectors through which these pulses
pass often have the disadvantage that they introduce discontinuity
of impedance matching and the looped forms of some of the parts of
these circuits often give rise to stray inductive couplings between
circuits. The present invention has for its object to obviate these
disadvantages and relates to an arrangement in which electrical
connections are made by means of connectors in which the conductive
parts by which circuits are connected are of remarkably small
length and in which the conductive surfaces by which the said
contacts are made are each subjected at a number of points to a
mechanical pressure which is exerted on these surfaces by means of
mechanical members independent of the electrical circuits. In the
case envisaged in which the conductors of the printed circuits of
the detachable cards and of the connection panel are comparable to
portions of transmission lines whose characteristic impedance is
predetermined, another object of the invention is to provide a
connector, as defined above, in which the length of a conductive
member capable of locally exhibiting a different characteristic
impedance is so small that the resultant disadvantages are
negligible or zero.
The invention concerns an arrangement for connecting circuits of
printed-circuit cards to circuits of a printed-circuit connection
panel which supports a plurality of connectors disposed in parallel
relationship to one another at such a distance as to enable a card
to be inserted between two consecutive connectors and to enable it
to be maintained perpendicularly to the said panel, wherein each
connector is characterized in that it comprises at least on one
side corresponding to one face of a card provided with contact
surfaces, a row of conductive and flexible contact blades, one
portion of each of which is soldered to a conductive surface on the
connection panel, while another portion thereof is situated against
a contact surface on the card, a row of push members, each of which
is arranged to be slidable in a recess situated opposite a contact
blade, and a row of springs, each of which is arranged to urge a
push member against a contact blade and to urge the latter against
a corresponding contact surface on the card.
An arrangement comprising such connectors makes it possible to
produce an assembly of extremely compact circuits in which the
contacts between circuits are made with maximum reliability, with
the introduction of minimum disturbance into the electrical
characteristics of the circuits.
Further advantages and features of the invention will become more
readily apparent in the course of the following description, with
reference to the accompanying drawings, in which:
FIG. 1 is a sectional view of a part of an arrangement of
connectors according to a first embodiment of the invention, this
section being taken along the line 1--1 of FIG. 2,
FIG. 2 is a plan view of a part of the same arrangement as seen
along the line 2--2 of FIG. 1,
FIG. 3 is a plan view of a portion of a connection panel as seen
along the line 3--3 of FIG. 1,
FIG. 4 illustrates a second form of construction of an arrangement
of connectors as seen along the line 4--4 of FIG. 5,
FIG. 5 is a view in section along the line 5--5 of FIG. 4,
FIG. 6 is an external view of a portion of a printed-circuit card
as seen in the direction 6 of FIG. 1, showing an arrangement of the
contact surfaces on the card,
FIG. 7 is a fragmentary sectional view constituting a variant of
FIG. 4, and
FIG. 8 is a view in perspective of various parts of a connector of
the type illustrated in FIGS. 4 and 5.
FIG. 1 shows a portion of an arrangement in which three connectors
A, B and C respectively are mounted on a printed-circuit connection
panel 11, the said three connectors being shown in section along
the line 1--1 of FIG. 2. The connectors of one assembly are
identical in principle and the connectors A and C of FIG. 1 are
only partly shown. A printed-circuit card CA1 is shown inserted
between the connectors A and B and a second card CA2 is shown in
the preparatory position for insertion, in which it is only engaged
in guide means 12 arranged in known manner at the ends of the
connectors (see also FIG. 8) in order to ensure correct engagement
of the cards between the connectors. The connectors A, B and C are
fixedly mounted on the connection panel 11, for example by means of
pins 14 situated at intervals along each connector so as to secure
the latter on the connection panel in parallel relationship to
other connectors and to maintain them at a distance X (FIGS. 1 and
4) which is determined in accordance with the thickness of the
cards which are to be inserted between the said connectors. A
connector of like form may be employed in assemblies designed to
receive cards of different thicknesses, in accordance with the
distance X between the points at which the connectors are secured
to the connection panel. In the arrangement illustrated in
fragmentary form in FIGS. 1 and 2, each connector comprises an
insulating body 15 provided with a base 16, a central partition 17
and left-hand and right-hand lateral walls 18 and 19 respectively,
which are connected to a central partition by ribs 20 disposed on
either side of the said partition. The lateral walls are formed
with left-hand and right-hand recesses 22 and 21 respectively,
which are each situated between two ribs and each adapted to
receive a push member 23 consisting of insulating material, which
is freely slidable in a recess. Each push member is provided,
towards the exterior of the connector, with two bosses 24 and 25
and provided within the connector with two shoulders 26 and 27
arranged to prevent the push member from leaving the connector. The
push members disposed on one side of a connector may be connected
together by means of a flexible strip 28 adapted to permit relative
independence of the displacements of each push member in its
recess. These strips, which merely have the object of facilitating
the positioning of the push members on one side of a connector, are
not absolutely necessary for the correct operation of the device. A
spring element comprises a metal strip 29, which bears against the
central partition 17 and is provided, on each side, with flexible
blades 30 and 31 on the left-hand and right-hand sides
respectively, which are adapted to form leaf springs and are each
engaged between two ribs on the insulating body of the connector,
that is to say, opposite a corresponding push member, in order to
push the latter towards the outside of the connector. The metal
strip 29 is maintained in position between the central partition of
the connector and a cover 32 of flexible plastics. The said cover
is maintained in position on the body of the connector by means of
two longitudinal strips 33 and 34 adapted to engage in grooves 35
and 36 extending along the lateral walls 18 and 19 of the body of
the connector. The connection panel 11 may, like the
printed-circuit cards, comprise a number of layers of printed
circuits assembled in the thickness of one panel, which is provided
(FIG. 3) on its upper face with conductive surfaces situated in
rows 37 and 38 to the left and to the right respectively, for each
connector and connected to electrical circuits of the panel. These
conductive surfaces are positioned so that they may each receive by
soldering, by an appropriate method, the lower end of a conductive
blade 40 to the left or 41 to the right, of which the other end is
engaged in a slot 42 or 43 in the upper part of each of the lateral
walls and in which it is retained by a barlike portion 44 adapted
to engage in the said slot. Provided on each side of the slots are
bosses 45-46 which are arranged to center the cover 32 on the
connector. Each contact blade extends past the bosses 24-25 of a
push member.
In order to facilitate the fitting of the contact blades on one
side of a connector, these blades may be connected together, before
fitting, at their upper end by means of a strip of insulating
plastics (not shown). In FIG. 1, a contact blade 41A belonging to
the right-hand row of the connector B is soldered at its lower end
to a conductive surface 38A of the row 38 (FIG. 3) of the
connection panel. The said blade extends past the bosses 24 and 25
of a push member 23 and the upper end of this blade is retained in
one of the slots 43 in the partition 19. When no card has been
inserted between two connectors (for example B and C in FIG. 1),
the contact blades of one row and the blades which are in the
connector disposed opposite thereto are tensioned under the action
of the springs 30 and 31 of each connector, acting on the push
members, this tension being limited by virtue of the fact that the
shoulders 26 and 27 of the push members abut (FIG. 1) the inside
face of a lateral wall of the connector. In addition, the contact
blades 40 to the left of the connector B (FIGS. 1 and 2) are urged
towards the connector by the card CA1 which has been inserted
between the connectors A and B. In this case, each contact blade of
the same row is urged by its push member against a corresponding
contact surface of the card CA1. Thus, all the contact blades 41
situated in the right-hand row of the connector A are also applied
under the same conditions against the contact surfaces of the card
CA1. FIG. 6 shows the form and the relative arrangement of the
contact surfaces 51 on a portion of the printed-circuit card CA2 as
seen in the direction of the arrow 6 of FIG. 1. When the
printed-circuit card CA1 is introduced between the connectors A and
B, the contact blades and the corresponding push members are pushed
towards the inside of the bodies of the connectors and the contact
blades may be carried slightly downwards by the friction of the
introduced card, but the said blades are retained in the upper part
of each connector by the blade portion which is engaged in a slot.
Each push member receives the thrust of its corresponding spring at
a point situated substantially on the axis of the said push member.
This thrust is transmitted by the two bosses of the push member at
two points of the contact blade, which are situated symmetrically
about the said axis. Consequently, the thrust exerted by the spring
is substantially equally distributed among the bosses of the push
member at two points of the contact blade bearing on a contact
surface of a card, whereby perfect electrical contact is ensured at
least at these two points. It is known that the friction of the
contact surfaces on the contact blades of the connectors when a
card is introduced contributes to cleaning the contact surfaces and
to improving the electrical contacts.
FIGS. 4, 5 and 8 show another embodiment of the invention in an
arrangement illustrated in section in FIGS. 4 and 5, which show
three connectors D, E and F mounted on a connection panel 11
similar to that of FIG. 1 by means of pins 60 fitted on the one
hand into the connectors and on the other hand into the said
connection panel. Each connector comprises an insulating body
having a central partition 62 extending along the length of the
connector, an upper partition 63 and lateral walls 64 and 65 to the
left and to the right respectively, which are connected to the
central partition by ribs 66 and 67 and formed with recesses 68 and
69 to the left and to the right respectively for push members 70
similar to the push members 23 of FIGS. 1 and 2. The push members
are subject to the action of springs 72 and 73, which are also
connected to a central strip 74. It will be noted that in this case
the arrangement of the insulating body of the connectors D, E and F
corresponds to an inverted arrangement of the connectors A, B and
C. In the connectors D, E and F, the contact blades are either
formed of thin metal strips 75 and 76 disposed in parallel
relationship and adhesively bonded by an appropriate method to the
outside face of a thin insulating support sheet 77, or formed by
deposition of conductive metal layers in the form of parallel
bands. The insulating strip provided with conductive bands is
appropriately positioned on the upper face of the connection panel,
whereafter the horizontal portions of the contact blades are welded
by any appropriate method to the corresponding conductive surfaces
of the connection panel. Thereafter, the body of the connector
provided with its push members and springs is positioned on the
said panel and held in position thereon by pins 60. The two edges
of the support sheet 77 are thereafter raised and bent down on to
the body of the connector, on which they are maintained when a
plate 78 is thereafter secured by pins 79 extending through holes
appropriately positioned in the plate 78, in the two edges of the
insulating sheet 77 and in the body of the connector. By reason of
the depression formed in the partition 63, a slight tension is
obtained in the insulating sheet, this tension being sufficient to
cause the latter to adapt itself to the bosses of the push members,
without the latter being moved into their recesses. In FIG. 4, a
printed-circuit card CA3 is provided on its two faces with
components 54-55 which may form functional units such as amplifier
devices, switching circuit or the like, of which the maximum
overall dimensions are indicated by a dash-dotted line 58. A
similar arrangement may be provided on the cards CA1-CA2 which are
employed with connectors A, B and C, in FIGS. 1 and 2. In most
cases, the connectors are provided at their ends with plates 80-81
formed with guide grooves 12 and 13 (FIGS. 1, 4 and 8) which are
adapted to guide the cards on their insertion into the
connectors.
In the examples illustrated in FIG. 1 to 5, the distance X between
the axes of two neighboring connectors is about 18 millimeters in
the cases described. On the other hand, the spacing between the
contact blades may be equal to or less than 2.54 mm. Assuming, in
the least favorable case, that a correct electrical contact is
ensured, between a contact blade and the corresponding contact
surface of a card, only at the level of the upper boss of the push
member acting on this blade, the contact blade length which will be
comprised between this contact point and the soldering point of the
said contact blade on a conductive surface of the connection panel,
i.e. the contact blade length constituting a discontinuity in the
impedance matching, will not exceed 8 mm., which is a remarkably
short length as compared with the length introduced by the majority
of known connectors.
FIG. 7 illustrates a cutoff portion of a connector G similar to
those shown in FIGS. 4, 5 and 8, but specially designed to
introduce no interruption of impedance matching between the
connected printed circuits. The construction is generally similar
to the preceding one, but in this embodiment a flexible insulating
sheet 90 is provided on its outside face with contact blades 91
adhesively secured or formed as already stated by a thin conductive
metallic deposit, but in addition the insulating sheet is provided
on its inside face with a conductive deposit 49 forming an earth
surface and connected to an earth conductor of the connection panel
11. This connection may be obtained by means of one or more pins 94
also serving to secure the connector to the connection panel.
With due regard to the dielectric constant of the material of the
insulating sheet, to its thickness and to the dimensions of the
contact blades, it is possible to arrange that the characteristic
impedance of the transmission line formed by each contact blade is
equal to the characteristic impedance adopted for the printed
circuits of the detachable cards and of the connection panel. There
is therefore no longer any mismatch caused by the members of the
connector.
It will be noted that in FIG. 6 the contact surfaces on the
opposite faces of one and the same card are alternately arranged,
that is to say, the contact surfaces of one face are offset by
one-half spacing in relation to the contact areas of the opposite
face of the card. Consequently, those contact blades of the faces
of two connectors which are provided for the two faces of one and
the same card are necessarily (FIGS. 2 and 5) arranged alternately
for these two faces. In the examples described in the foregoing,
the contact blades are alternately arranged on either side of the
axis of each connector and the contact surfaces 37 and 38 are
alternately positioned on the connection panel 11 to receive the
contact blades of one connector. This staggering of the contact
blades of the opposite rows of a connector is not the only possible
arrangement, because a similar result can be obtained with
connectors of symmetrical construction by longitudinally staggering
by a half-pitch in relation to one another the neighboring
connectors on the connection panel.
It is obvious that the embodiments and adaptations which have been
described to illustrate the invention have no limiting character
and that any modifications and adaptations may be made to the
arrangements described in accordance with the circumstances and the
applications without departing from the invention.
* * * * *