FR2798228A1 - ELECTRICAL CONTACT AND CONNECTOR FOR FLEXIBLE CIRCUIT - Google Patents

Abstract

Connection device for a flexible printed circuit comprising a contact equipped with a termination (20) for connection to a supplementary contact, a central elongated part (21) which forms the floor and an insulation-piercing connection part (22) destined to come into contact with a track of a flexible printed circuit and comprising a housing to receive the contact, for which the contact and the housing possess, more particularly, supplementary means of retention in the pre-insertion position.

Description

I

  ELECTRICAL CONTACT AND CONNECTOR FOR FLEXIBLE CIRCUIT

  The present invention relates to a flexible circuit connection device comprising a contact and a

associated connector.

  The flexible circuits (or flexible circuits) generally consist of a first sheet of flexible insulating material on which are arranged conductive tracks, for example made of copper, these tracks themselves being covered either by a second

  sheet of insulating material either by an insulating varnish.

  These circuits are widely used in the electrical industry and several connection methods exist to connect them to electrical contacts or

electronic components.

  Document US 3,713,072 relates in this context to a device for connecting pins, arranged perpendicular to the flexible circuit, produced by staples piercing the flexible circuit, these staples having in their center a hole for passage of the spindle, these staples then being crimped on the flexible circuit. Document US Pat. No. 4,749,368 relates to a device for connecting a component to one or more tracks of a flexible circuit by staples provided with crowns of piercing teeth inserted in the flexible circuit and

  then crimped onto the flexible circuit.

  Document US 4,082,402 relates to the production of a connector for a flexible circuit for which electrical contacts comprise on the one hand piercing wings of the flexible circuit and on the other hand a contact termination with a complementary contact. These contacts connected to the flexible circuit are received in an insulating box intended to receive an additional box.

  including additional contacts.

  The connection of flexible circuits to connectors imposes constraints on the connection with contacts and, in the case of flexible circuits with multiple tracks connected by device with piercing of insulation, imposes to realize the simultaneous connection of the tracks with the contacts and maintain a good alignment of the contacts as much along an axis parallel to the contacts as

  in an axis perpendicular to the flexible circuit.

  Patent application FR99 02519 filed on February 24, 1999 in the name of the applicant relates to a connection device for flexible circuit comprising a housing provided with receptacles for receiving contacts terminating the flexible circuit, this connection device comprising means for holding the contacts in the pre-insertion position, this position allowing the simultaneous connection of all the contacts provided with piercing means to be crimped with the flexible circuit, these holding means being crushed during the crimping operation of the piercing means in order to allow complete insertion of the contacts into the housing, a cover then closing the housing and effecting the complete locking of the contacts in the

housing cells.

  Still for this purpose, the present invention provides a flexible circuit connection device simplifying the connection process while ensuring maintenance

improved flexible circuit.

  For this, the invention mainly proposes a connection contact for flexible circuit provided with a connection termination to a complementary contact, an elongated central part forming a floor and a connection part with insulation piercing intended to come in contact with a track of a flexible circuit, the contact being intended to be positioned in a cell of a housing, contact for which the elongated central part is provided with an elastic tab, this tab comprising a lug bent under the part elongated central. Advantageously, the connection part with insulation piercing can be raised relative to the part

  elongated central unit forming a floor.

  In a particular embodiment of the contact according to the invention, the insulating piercing part may comprise at least one ring of teeth intended to pierce the flexible circuit and be crimped in the flexible circuit. More particularly, the contact may include two

aligned crimping rings.

  The contact may also include in its part

  central elongated side flanks of reinforcement.

  Still according to the invention, the lateral flanks of the contact may include a pinching zone forming

  stiffener substantially arranged opposite the lug.

  The invention also relates to a connector for a flexible circuit comprising a contact according to the invention, and a housing, provided with at least one socket for receiving said contact, for which the lug of the contact comes, in the pre-insertion position, in abutment against the edge of a lower wall of the housing and is capable of bending and disappearing under the action of a push in the direction

inserting contacts.

  Advantageously, the housing and the contact may include complementary means for hooking and

  contact retention in the direction of contact insertion.

  In a particular embodiment of the connector according to the invention, this may include a cover element which can be maneuvered in a direction perpendicular to the cells between a position of pre-insertion of the contacts and a position of complete insertion and locking of the contacts, the cover comprising at least one pin per contact, this pin coming into the locking position press on the connection part of the contact with the

flexible circuit.

  In the case where the contacts have two aligned crimping rings, these pins can come to bear

between these crowns.

  The present invention will be better understood on reading

  the description of a particular embodiment not

  limitation of the invention in correspondence with the drawings which represent: - in Figure 1, a perspective view of a connection device according to the invention; - In Figure 2, a perspective view of a contact according to the invention; - In Figure 3, a detail of the connection device of Figure 1; - In Figure 4, a perspective bottom view of the cover of Figure 1; - In Figure 5 A, B and C, sectional views showing the kinematics of insertion and locking of the device of Figure 1; - In Figure 5 D, a detail of a variant of Figure 5; - In Figure 6 a partial section of the device of Figure 1 in the locked position; - in Figure 7, a connector according to the invention

completely locked.

  FIG. 2 represents a contact (general reference 6) for connection to a flexible circuit provided with a termination (20) for connection to a complementary contact, with an elongated central part (21) forming a floor and with a connection part with insulation piercing (22). The connection termination can in particular be, as shown, of the female type and consists of a cage provided with one or more elastic contact blades (50). The connection termination according to the invention is extended on one of its faces by an elongated central part (21) itself extending by a flat area.

  (22) forming connection part with insulation piercing.

  The elongated central part is provided with an elastic tab (26), this tab comprising a lug (27) curved under the elongated central part. This tab is intended to cooperate with the flange (32) of the lower wall (35) of a housing (1) for receiving the contact.

  (6) as will be explained later.

  Still according to FIG. 2, the connection part with insulation piercing (22) is raised relative to the elongated central part (21) forming the floor. This arrangement makes it possible, as seen in FIGS. 5 B and 5 C, to separate the piercing part of the insulation from the wall.

  bottom (35) of the housing receiving the contact.

  The elongated central part of the contact may have lateral flanks (24, 25). These flanks which extend the underside of the contact termination serve as reinforcement for the contact and as lateral guide for the contact in its receiving socket (2) in the housing (1). These flanks may include a pinching zone (28) located around the zone of the elastic tab (26) comprising the lug (27) so as to reinforce by stress of the metal this part weakened by the cut necessary for carrying out the tab (26). This pinching zone also makes it possible to continuously change the level so that the insulating piercing connection part (22) is raised relative to the

elongated central part.

  In known manner, the termination (20) for connection to a complementary contact can constitute a cage formed by successive folds in a direction parallel to the contact and comprise a flap (30) folded down at the level of

  the transition with the elongated central part.

  The insulating piercing part is, in the example shown in the figures, of the type comprising at least one ring of teeth (23) intended to pierce the flexible circuit and to be crimped in the flexible circuit to make contact with a track 100 of the flexible circuit 10. Other configurations such as piercing blades can be envisaged without departing from the scope of the invention, such configurations being well known in the art.

  field of flexible circuit connection.

  By way of simplification, a single track 100 is shown in FIG. 1, it being understood that there are

  several tracks on the flexible circuit.

  Advantageously, two aligned crimping rings (23, 23 ′) are made to improve the connection. It should be noted that, although FIG. 2 does not show the flexible circuit for reasons of clarity, the piercing rings are shown in their state after crimping. Crowns in their prior state

  crimping are visible in Figure 3.

  FIG. 1 gives a general view of a connector for a flexible circuit according to the invention comprising a contact (6) as described above, a housing (1), provided with at least one cell (2) for receiving said contact ( 6), for which the lug (27) of the contact comes, in the pre-insertion position, to bear against a flange (32) of the wall

  bottom (35) of the housing. This pre-

  insertion makes it possible to deliver connectors provided with their contacts and allows, in a suitable tool, to position the flexible circuit and to crimp in one operation all of the piercing and crimping elements

(23, 23 ') on the slopes (100).

  Once the crimping has been carried out, a push on the flexible circuit in the direction of insertion of the contacts causes the pins (27) to bend and disappear and allows the contacts to enter entirely into the insulation (1). The kinematics of insertion of the contacts is shown diagrammatically in FIGS. 5A, 5B, 5C where we see respectively in section the phases pre-inserted contact, contact crimped on the flexible circuit in pre-inserted position and connector locked. The housing (1) and the contact (6) may include complementary means for hooking and retaining the contact in the direction of insertion of the contact. These means may consist of a harpoon lug (51) on the contact, a first stop (52) for retaining the harpoon to prevent the contact from coming out when it is in the pre-inserted position and a second stop. (53) retaining the harpoon to maintain the contact in position

full insertion.

  In the case where the connector includes a complementary locking cover, the lowered cover can also carry out a possible locking function of the contacts by pressing a finger (4) against a flap (30) disposed at the rear of the part of connection of the contact, a function for maintaining the flexible circuit and the contacts by pins (31) coming to bear on the

crimping area (22).

  The cover (5) visible in FIG. 4 can be maneuvered in a direction perpendicular to the cells between a position of pre-insertion of the contacts and a position of complete insertion and locking of the contacts. It comprises for example a window (60) receiving a lug

(61) of the shoemaker (1).

  When the contacts are fully inserted, the cover can be pushed vertically into the locking position. The hood is locked by snapping the window (60) onto a second lug (62). In the locked position, the pins (31) press on the connection part (22) of the contact with the flexible circuit. This support stresses and bends the crimping part which in its natural position is raised relative to the

bottom wall of the housing.

  Referring to Figure 3 we see that the bottom wall (35) of the housing (1) has ribs (40) separating the cells (2). Also, the bending of the crimping part (22) brings the flexible circuit into contact with the ribs framing the contacts and, advantageously causes the flexible circuit to undulate under this effect of offset offset supports. These constraints stiffen the connection area of the flexible circuit (10) making it more capable of withstanding the vibrations encountered in particular in automotive applications. In the case where the crimping zone comprises two aligned crimping rings (23, 23 '), the pins (31) come to rest between these reinforcing rings

again the connection area.

  To perform a secondary locking function of the contact in the cell, the contact may include a stop (30) for example constituted by a flap folded over the termination (20) or by the cage of the termination itself, the cover comprising a finger 4 for complementary retention of the contact cooperating with the stop (30) in order to lock the contact (6) in the cell, the cover being in the closed position. This constitution also makes it possible to prohibit the closing and locking of the cover when the contacts are not fully inserted, the fingers (4) abutting in this case

against termination (20).

  In applications where the cover is not necessary, for example to reduce the cost of the connector, it is possible as seen in the detail of FIG. 5 D taken at the level of FIG. 5C to make a hole (36) opening out or non reception of the lug (27) when the contact is in the fully inserted position. The ergot in

this case locks the contact.

  Of course, the invention is not limited to the example described in the figures and in particular is adaptable to any type of termination of connection to a contact.

  complementary for example a male termination.

Claims (7)

  1 - Contact (6) for connection to flexible circuit provided with a termination (20) for connection to a complementary contact, an elongated central part (21) forming a floor and a connection part with insulation piercing ( 22) intended to come into contact with a track (100) of a flexible circuit (10), the contact (6) being intended to be positioned in a cell (2) of a housing (1), characterized in that the elongated central part is provided with an elastic tab (26), this tab comprising a lug (27) curved under the part elongated central.   2 - Contact according to claim 1 characterized in that the insulating piercing connection part (22) is raised relative to the elongated central part (21) forming floor.   3 - Contact according to one of claims 1 or 2   characterized in that it comprises in its central part   elongated lateral reinforcement sides (24, 25).   4 - Contact according to one of the preceding claims   characterized in that the insulating piercing part comprises at least one ring of teeth (23) intended to pierce the flexible circuit and be crimped in the flexible circuit. - Contact according to claim 4 characterized in that it comprises two rings (23, 23 ') of crimping aligned.   6 - Contact according to one of the preceding claims   characterized in that the lateral flanks have a pinching zone (28) forming a substantially stiffener   arranged opposite the lug (27).   7 - Connector for flexible circuit comprising a contact   according to one of claims 1 to 6 characterized in that   that it comprises a housing (1), provided with at least one socket (2) for receiving said contact (6), for which the lug (27) of the contact comes, in the pre-insertion position, to bear against the rim (32) of a lower wall (35) of the housing and is capable of bending and disappearing under the action of a push in the direction of insertion of the contacts. 8 - Connector according to claim 7 characterized in that the housing (1) and the contact (6) comprise complementary means (51, 52, 53) for attachment and   contact retention in the direction of contact insertion.   9 - Connector according to one of claims 7 or 8   characterized in that it comprises a cover (5) which can be maneuvered between a position for pre-insertion of the contacts and a position for complete insertion and locking of the contacts, the cover comprising at least one pin (31) per contact, this pin (31) coming into the locking position press on the part of   connection (22) of the contact with the flexible circuit.   - Connector according to claim 9 characterized in that the contacts comprising two crimping rings (23, 23 ') aligned, the pins (31) come lean between these crowns.