Patent Description:
The present disclosure relates to a connector and, more particularly, to an electrical connector for a flat flexible cable or a flat printed cable.

As understood by those skilled in the art, flat flexible cables (FFCs) or flat flexible circuits are electrical components consisting of at least one conductor (e.g., a metallic foil conductor) embedded within a thin, flexible strip of insulation. Flat flexible cables, as well as similarly-configured flat printed cables (FPCs) are gaining popularity across many industries due to advantages offered over their traditional "round wire" counter parts. Specifically, in addition to having a lower profile and lighter weight, FFCs enable the implementation of large circuit pathways with significantly greater ease compared to round wire-based architectures. As a result, FFCs are being considered for many complex and/or high-volume applications, including wiring harnesses, such as those used in automotive manufacturing.

The implementation or integration of FFCs into existing wiring environments is not without significant challenges. In an automotive application, by way of example only, an FFC-based wiring harness would be required to mate with perhaps hundreds of existing components, including sub-harnesses and various electronic devices (e.g., lights, sensors, etc.), each having established, and in some cases standardized, connector or interface types. Accordingly, a critical obstacle preventing the implementation of FFCs into these applications includes the need to develop quick, robust, and low resistance termination techniques which enable an FFC to be connectorized for mating with these existing connections.

A typical FFC may be realized by applying insulation material to either side of a pre-patterned thin foil conductor, and bonding the sides together via an adhesive to enclose the conductor therein. Current FFC terminals include piercing-style crimp terminals, wherein sharpened tines of a terminal are used to pierce the insulation and adhesive material of the FFC in order to attempt to establish a secure electrical connection with the embedded conductor.

Due in part to the fragile nature of the thin foil conductor material, these types of terminals have several drawbacks, including much higher electrical resistances than conventional round wire F-crimps, inconsistent electrical connectivity between the conductor and the terminal, and mechanical unreliability over time in harsh environments. Further, a connector to which an FFC is terminated includes a plurality of terminals that each must be crimped to establish the electrical connection with the embedded conductor. Current FFC terminal connectors require complex equipment to terminate the crimp and are inefficient by requiring individualized crimping of the terminals. A further prior art FFC connector (on which the preamble of claim <NUM> is based) is disclosed in patent <CIT>.

Accordingly, the problem to be solved is to provide improved electrical connector assemblies and accompanying termination techniques for adapting FFCs and/or FPCs to these environments.

According to the invention there is provided a connector for a FFC according to claim <NUM>. A plurality of conductors exposed in a window extending through an insulation material of the FFC are each clamped in the terminating portion of one of the plurality of terminals by a pressing or clamping force applied thereon by a cover or clamp housing selectively fixable to the housing.

The invention will now be described by way of example with reference to the accompanying Figures, of which:.

Embodiments of the present disclosure include electrical connectors or connector assemblies configured to be mated to an FFC or FPC without the use of soldering or traditional crimping-type terminal connections. According to embodiments, each terminal of the connector includes a clamping or terminating portion having a U-shaped cross-section or other similar profile configured to receive a pre-exposed conductor of an FFC. More specifically, each terminal is secured to a housing of the connector, and the FFC positioned relative to the terminal such that one or more conductors thereof is arrange in, or aligned with, a respective terminating portion (also referred to herein as a "wire barrel"). A cover or clamp housing, either formed integrally with the housing or separate therefrom, is selectively fixable in a clamping position on the housing. In the clamping position, the clamp housing is configured to press or clamp each conductor into electrical contact with a respective terminating portion of each terminal. In one embodiment, pressing or clamping elements or fingers (also referred to as "stuffing elements") of the clamp housing bear against the conductors of the FFC, simultaneously pressing them into the terminating portions of the terminals as the clamp housing is fixed into the clamping position. The cover or clamp housing is selectively fixable relative to the connector housing such that in the clamping or attached position, constant pressure is applied and maintained on the conductors for establishing and retaining electrical contact with the terminals.

In related embodiments, multiple parallel rows of terminals can be accommodated by using an inner and outer housing. Plastic retention features can be molded into the connector housing and/or clamp housing that will work with pre-cut openings in the FFC to provide strain relief, and/or function to lock or latch the cover to the housing. In further embodiments, surfaces of the terminating portion or wire barrel and/or the clamping elements may define non-planar, roughened or serrated surfaces, including the presence of bumps, ridges or slotting for improving electrical contact with the conductor by penetrating and breaking through any surface deposits present thereon.

Connector assemblies according to embodiments of the present disclosure are configured for use with an FFC, such as the exemplary portion of an FFC <NUM> shown in <FIG>. The FFC <NUM> generally includes a plurality of conductors <NUM> embedded within an insulation material <NUM>. The conductors <NUM> may comprise metallic foil, such as copper foil on the order of <NUM> in thickness, by way of example only, patterned in any desirable configuration. The insulation material <NUM>, such as a polymer insulation material, may be applied to either side of the conductors <NUM> via an adhesive material, resulting in an embedded conductor arrangement. The exemplary FFC <NUM> includes multiple segments <NUM>,<NUM>,<NUM>, each containing a plurality of conductors <NUM>. Respective windows or openings <NUM>,<NUM>,<NUM> are selectively formed or defined proximate respective ends of the segments <NUM>,<NUM>,<NUM> for exposing the conductors <NUM>, enabling connectorization thereof utilizing terminals and associated clamping or stuffing elements according to embodiments of the present disclosure. These and/or other windows or openings may be formed in the insulation material <NUM> in any desired location in order to expose portions of the conductors <NUM> for facilitating termination, improving mechanical connections and/or providing strain relief. For example, additional openings <NUM> may be provided and adapted to accept complementary features of associated connector or clamp housings, as will be described in further detail herein.

With reference to <FIG>, a connector assembly <NUM> or subassembly forming a part of a mechanical connector is shown with a portion of the FFC <NUM> of <FIG> partially connected thereto. The connector assembly or inner housing assembly <NUM> includes a first inner housing or body <NUM> defining a mating end <NUM> and a rear end <NUM> oriented opposite the mating end in a longitudinal direction of the connector assembly. A mating section <NUM> is provided, generally beginning at the mating end <NUM> and extending toward the rear end <NUM> to a terminating or clamping section <NUM>, which extends from the mating section to the rear end in the longitudinal direction. The mating section <NUM> may define a plurality of retention protrusions <NUM> for securing the inner housing <NUM> with an outer housing (e.g., outer housing <NUM> shown in <FIG>) and a plurality of locking recesses <NUM>. Each of the locking recesses <NUM> is aligned with one of a plurality of terminal receiving passageways <NUM> formed through the mating section <NUM>, and is configured to receive a corresponding locking feature of a conductive terminal <NUM> for securing the terminal in a longitudinal direction within the receiving passageway.

The terminating or clamping section <NUM> has a base <NUM> defining a plurality of slotted recesses <NUM> extending in the longitudinal direction, with each recess aligning with a respective one of the terminal receiving passageways <NUM>. The terminating section <NUM> has a plurality of locking or securing elements <NUM> extending from an exterior surface in the height direction. Each securing element <NUM> may comprise a latch, lever or hook-like protrusion defining a portion of a lock or latch assembly. In the illustrated embodiment, the securing elements <NUM> are positioned at the rear end <NUM>. In other embodiments, the securing elements <NUM> may be positioned elsewhere on the base <NUM> along the longitudinal direction. In any position, each securing element <NUM> may extend from the inner housing <NUM> and through the corresponding opening <NUM> formed in the insulation material <NUM> of the FFC <NUM>, thereby function as a form a strain relief for the FFC. A plurality of positioning features <NUM> are also provided or defined by the inner housing <NUM> and are configured to engage with corresponding features formed on a removable or moveable cover of the connector assembly <NUM>. More specifically, the securing elements <NUM> and the positioning features <NUM> are configured to selectively mate with corresponding features of a removable cover, clamp or clamp housing <NUM> as shown in <FIG> in order to align and secure the clamp housing to the first inner housing <NUM>. In the exemplary embodiment, the first inner housing <NUM> is monolithically formed in a single piece from an insulative material, such as plastic.

Referring to <FIG> and <FIG>, the first inner housing <NUM> is pre-fitted with the plurality of the conductive terminals <NUM>. Each terminal <NUM> generally includes an electrical contact or mating end <NUM>, in this embodiment, a female mating end configured to receive a corresponding male terminal for establishing an electrical connection. However a male contact portion may be provided in another embodiment. A rear end <NUM> of the terminal <NUM> opposite the mating end <NUM> defines a terminating or clamping portion <NUM> defining a generally U-shaped receiving passage between opposing outwardly and vertically extending walls thereof. The mating ends <NUM> of the terminals <NUM> are received within a respective one of the plurality of terminal receiving passageways <NUM> in the longitudinal direction and into the illustrated installed position.

Likewise, each recess <NUM> of the terminating section <NUM> receives the terminating portion <NUM> of a respective terminal <NUM>. As can be seen in <FIG>, the terminating portions <NUM> are sized to at least partially extend through the openings <NUM> in the FFC <NUM>, and receive the conductors <NUM> of the FFC therein. The FFC <NUM> is shown in <FIG> in an installed, pre-clamping position on the first inner housing <NUM>, wherein the conductors <NUM> exposed in the opening <NUM> of the first segment <NUM> are positioned within the terminating portions <NUM> of the terminals <NUM> for subsequent clamping.

Referring now to <FIG>, embodiments of the present disclosure utilize clamp assemblies which work in conjunction with connector housings to secure the conductors of an FFC to their corresponding terminals. These arrangements avoid the time-consumption and reliability drawbacks associated with other terminating operations, such as soldering or crimping. With particular reference to <FIG>, an exemplary clamp housing or cover <NUM> according to an embodiment of the present disclosure is shown. The clamp housing <NUM> comprises a body defining an underside <NUM> in which a plurality of slot-like openings <NUM> are defined. Each opening <NUM> receives and retains a corresponding one of a plurality of clamping elements or fingers <NUM>, each configured to engage with an exposed surface of one of the conductors <NUM> of the FFC <NUM> (see <FIG>) in an installed state of the clamp housing <NUM>. In the exemplary embodiment, the clamping elements <NUM> comprise stamped, machined or otherwise formed metallic elements mechanically fixed to the clamp housing <NUM>. The clamping elements <NUM> may be attached to the clamp housing in a removable and replaceable manner (e.g., secured via a friction fit connection).

As shown in more detail in <FIG>, in the exemplary embodiment, each clamping element <NUM> comprises a body including a planar portion having a first free end <NUM> configured to be inserted into a corresponding one of the openings <NUM> defined in the clamp housing <NUM>, or molded therein during manufacturing of the housing. A conductor engaging portion <NUM> is defined between the first free end <NUM> and an opposite free end <NUM>. The engaging portion <NUM> includes a "U" shaped folded section of the body defining a rounded or arcuate outer exterior surface <NUM> configured for engaging with a conductor <NUM>. Preferable, the radius of curvature of the engaging portion <NUM> is sized so as to generally correspond with a rounded bottom clamping surface of the terminating portion <NUM> of the terminal <NUM>, and is defined about an axis of curvature extending generally in a longitudinal direction of the conductor. One or more outward-facing sides of the engaging portion <NUM> define one or more features, such as protrusions <NUM> for engaging with the conductor <NUM> in the installed position of the clamp housing <NUM>. The formation of the dome-shaped protrusions <NUM> on the clamping surface increases the pressure applied on the conductor <NUM> in these areas for ensuring sufficient electrical connectivity. These elements may also aid in breaking through any surface deposits present on the conductor, and/or increase the holding capacity of the conductor within the terminal <NUM>. In other embodiments, these features may comprise recesses, ridges, serrations or other roughened or irregular surfaces without departing from the scope of the present disclosure. It should also be noted that the folded or overlapped configuration of the engaging portion <NUM> results in a resilient or elastic clamping end. In this way, more consistent pressure on the conductor is realized. Residual spring or elastic forces generated by the deformed conductor and/or the terminal and clamping elements act to maintain sufficient clamping forces such that end of life resistance requirements are satisfied.

Referring again to <FIG>, as well as to <FIG>, the illustrated exemplary clamp housing <NUM> includes openings <NUM> corresponding in shape and location to the securing elements <NUM> of the first inner housing <NUM>. More specifically, the hook or latch-like ends of the securing elements <NUM> are configured to engage or abut with corresponding opposing locking or latching surfaces <NUM> defined within the openings <NUM> of the clamp housing <NUM> when installed on the first inner housing <NUM>, mechanically fixing the housings together and simultaneously clamping each of the exposed portions of the conductors <NUM> of the FFC <NUM> into electrical contact with a respective one of the terminating portions <NUM> of the terminals <NUM>. Likewise, positioning openings <NUM> are configured to receive the positioning features <NUM> of the first inner housing <NUM> therein for ensuring maintained alignment of the clamp housing <NUM> relative to the first inner housing <NUM> in the installed position. It should be noted that the positioning openings <NUM> and positioning features <NUM> comprise surfaces which oppose each other along multiple planes extending in multiple directions (e.g., along a plane extending transverse to the connector and along a plane extending longitudinally relative to the connector). In this way, motion of the clamp housing <NUM> relative to the first inner housing <NUM> is limited by these connections in multiple directions (e.g., transverse and longitudinal motion).

Referring particularly to <FIG>, in the clamped or installed position, the clamping elements <NUM> act to compress and deform the conductors <NUM> into the base or bottom surface of the terminating portions <NUM> of the terminals <NUM>. Moreover, as the conductors <NUM> are compressed, the sidewalls of each U-shaped engaging portion <NUM> are biased outwardly or horizontally in the illustrated orientation, further clamping the conductors <NUM> against the opposing sidewalls of the terminating portions <NUM>, thus establishing a reliable electrical connection therebetween without the use of soldering or crimping. Moreover, as no plastic deformation of the clamping element <NUM> or terminal <NUM> is required, this clamped connection is easily releasable or reversible, facilitating disassembly of the connector assembly for repair or replacement, by way of example. Further still, the fixation of the clamp housing <NUM> relative to the first inner housing <NUM> is operative to clamp and secure portions of the insulation material <NUM> of the FFC <NUM> therebetween, providing additional mechanical strain relief.

<FIG> illustrates another embodiment of the present disclosure including a clamping element <NUM> having features similar to those set forth above in the embodiment of <FIG>. The clamping element <NUM> further includes a generally planar end <NUM> section oriented perpendicularly from a vertically extending central portion <NUM> thereof, and extending in a longitudinal direction of an associated clamp housing <NUM>. The end section <NUM> comprises a width defined between free ends <NUM>,<NUM> thereof. As illustrated, the central portion <NUM> extends normally from the end section <NUM> at a position offset from a center thereof in the width direction, resulting in a first underside surface <NUM> of the free end <NUM> having a greater surface area compared to a second underside surface <NUM> of the free end <NUM>. In this way, the clamping element <NUM> defines a generally "L" or "T" shaped cross-section. In the illustrated embodiment, the clamping element <NUM> may be secured to the clamp housing <NUM> by, for example, sliding the clamping element <NUM> in the longitudinal direction and through a corresponding slotted aperture <NUM> (such as an "L" or "T" shaped slotted aperture) defined in the clamp housing. In other embodiments, the clamping element <NUM> may be molded or mechanical stitched to the housing <NUM>.

While each of the above embodiments includes a clamp housing or cover and a plurality of discrete clamping elements mechanically attached thereto, it should be understood that the clamp elements may be embodied as independently protruding portions of a single monolithic structure mechanically attached to the clamp housing. Likewise, the clamp elements may be formed integrally with the housing, as shown in the embodiment of <FIG>.

Referring now to <FIG>, an exemplary electrical connector according to an embodiment of the present disclosure includes a pair of second inner housings <NUM> separate from the first inner housing <NUM>. The second inner housings <NUM> may be configured to mate with, for example, the remaining segments <NUM>,<NUM> of the FFC <NUM> as shown in <FIG>. Each of the second inner housings <NUM> is structured similarly to the first inner housing <NUM>, and receives a corresponding plurality of terminals <NUM> in the above-described manner. Likewise, each second housing <NUM> is fitted with a clamping cover or clamp housing <NUM>, having features similar to those of the clamp housing <NUM>, for electrically connecting the conductors <NUM> of the FFC <NUM> to the terminals arranged therein via clamping. Accordingly, additional details of the second inner housings <NUM> and associated clamp housings <NUM> are omitted herein for the purposes of brevity.

Referring generally to <FIG>, the use of separate first and second inner housings <NUM>,<NUM> facilitates ease of assembly of the electrical connector. Specifically, with the FFC <NUM> shown in <FIG>, each of the segments <NUM>,<NUM>,<NUM> thereof may be fitted with a respective one of the first and second inner housings <NUM>,<NUM>. Once connected therewith, the segments <NUM>,<NUM> and associated inner housings <NUM> may be folded over the first inner housing <NUM> and associated FFC segment <NUM>, for forming the electrical connector profile illustrated in <FIG>. With the first inner housing <NUM> and the second inner housings <NUM> aligned in an installation orientation shown, they may be inserted into an outer housing <NUM> as shown in <FIG>. In the exemplary embodiment, the outer housing <NUM> comprises one half of an electrical connector configured to mate with a corresponding other half for establishing electrical connections between the FFC <NUM> and other components.

<FIG> provides a cross-sectional view of the assembled connector <NUM>, wherein the conductors <NUM> of respective FFC segments <NUM>,<NUM>,<NUM> are clamped to respective terminals <NUM> via the clamp housings <NUM>,<NUM> and their associated clamping elements. As shown, an insertion opening <NUM> of the outer housing <NUM> may be sized such that opposing inner walls <NUM>,<NUM> thereof place an opposing compressive force C on each of the clamp housings <NUM>,<NUM> in a direction generally towards a center of inner housing assembly <NUM>. In this way, the outer housing <NUM> is configured to generate and maintain a compressive force on the conductors <NUM> by continuously bearing on the clamp housings and associated clamping elements in the installed state or position.

Referring generally to <FIG>, in an alternate embodiment of the present disclosure, a single clamping connector or connector housing <NUM> is provide which may replace the separate first and second inner housings <NUM>,<NUM>, as well as the clamp housings <NUM>,<NUM> in the above embodiments. In particular, the detachable clamp housings may be replaced with respective covers <NUM>,<NUM> moveably attached to respective sides of the housing <NUM>. In one embodiment, the cover <NUM> is movably attached to the housing <NUM>, such as by a hinge or other pivoting connection <NUM> (e.g., a living hinge as shown), such that it is moveable between an unclamped or open position as shown, and a clamped position. The cover <NUM> may be a separate, discrete element pivotally or otherwise moveably attached to the housing <NUM>, or may be formed integrally therewith as shown. The additional details of the housing <NUM> are sufficiently described above, with features corresponding to those of the inner housings, the clamp housings, and the FFC, and are not repeated herein for the purpose of brevity.

Claim 1:
A connector (<NUM>) for a flat flexible cable (<NUM>), comprising:
a housing (<NUM>) having a plurality of terminal receiving passageways (<NUM>);
a plurality of terminals (<NUM>) each having a contact portion (<NUM>) held in one of the plurality of terminal receiving passageways (<NUM>) and an exposed terminating portion (<NUM>); and
a cover (<NUM>) selectively fixable to the housing (<NUM>) in a clamping position, the cover including a plurality of clamping elements (<NUM>) extending therefrom and configured to simultaneously clamp each of a plurality of conductors (<NUM>) of the flat flexible cable (<NUM>) within a respective one of the plurality of terminating portions (<NUM>) when the cover (<NUM>) is fixed to the housing (<NUM>) in the clamping position, wherein each of the plurality of clamping elements (<NUM>) defines a clamping surface (<NUM>) positioned to engage with one of the plurality of conductors (<NUM>) arranged within the terminating portion (<NUM>) of the terminal (<NUM>), wherein the conductor (<NUM>) is clamped between the clamping surface (<NUM>) and an opposing surface of the terminating portion (<NUM>) with the cover (<NUM>) in the clamping position, and wherein the clamping surface (<NUM>) comprises a rounded surface for engaging with the conductor (<NUM>), characterised in that the rounded surface defines an axis of curvature extending in a longitudinal direction of the conductor (<NUM>).