Flat cable connector

[57] ABSTRACT

This invention provides a connector for flat multiconductor cable. Cables to be connected are inserted in slots on opposite sides of a housing, there being an upper and a lower contact adjacent the slot for each cable conductor to be mated. There is an eccentrically mounted cam for each upper contact which cams are commonly actuated to force the upper contacts into engagement with cable positioned in the slot. Each upper and lower contact has a pointed projection for each cable to be joined which projections pierce the insulation of the cable when the cams are actuated, pinching the conductor of the cable therebetween to assure good physical and electrical contact of the cable connector with the connector contacts. If there is a metalic ground shield on the cable, an extra pair of contacts' are provided adjacent the slot which contacts have teeth for engaging the shielding. A cam is provided for the Upper of the shield engaging contacts which cam is operated by the same means as the other cams of the connector.

Claims, 7 Drawing Figures

<img file="US3824529A_D0001.tif" />

PATENTED> 16 im

3,824,529

SHEET 1 OF 3

<img file="US3824529A_D0002.tif" />

<img file="US3824529A_D0003.tif" />

PATENTED Μ161974

SHEET 3 OF 3

3,824,529

<img file="US3824529A_D0004.tif" />

<img file="US3824529A_D0005.tif" />

3,824,529

2

FLAT CABLE CONNECTOR

This invention relates to a connector for flat multiconductor cable.

BACKGROUND OF THE INVENTION

Existing flat cable connectors are of two general types. Most of these connectors require that the cable insulation be removed from at least a portion of the cable to expose the cable conductors. Exposed conductors are then mounted in the connector in contact with exposed conductors of the cable to be connected to or with electrical contacts of the connector. While these connectors may be relatively simple and inexpensive in construction, they have the disadvantage of requiring prestripping of the cable. Since this prestripping must frequently be done with fairly high precision in order to prevent damage to the conductors and for the cable to fit properly into the connector, prestripping of the cable is a difficult, time consuming, and therefore, expensive operation.

In order to overcome the need for prestripping cable, insulation piercing flat cable connectors have been developed. These connectors, however, have generally been bulky, expensive and complicated to use, frequently requiring the use of specialized tools in order to secure the cable in the connector. Additional connection operations are also frequently required in order to electrically connect cable shielding, where this exists, to ground contacts of the connector.

From the above it is clear that a need exists for an insulation piercing flat cable connector which is (1) quick and simple to operate without requiring the use of any special tools, (2) relatively simple in design and thus inexpensive to manufacture, and (3) which permits electrical connection to be made to a ground shield of a cable as part of the same operation during which electrical connection is made to the conductors of the cable.

SUMMARY OF THE INVENTION

In accordance with the above, this invention provides a connector for flat cables which cables each have at least one insulation covered conductor. The connector includes a housing having .at least one cable receiving slot. A moveable contact is mounted in the housing adjacent the slot, a separate moveable Contact being provided for each conductor of the cable. There is a pointed projection on each contact for each of the cables to be joined, the projections being on the side of the contact adjacent the slot. A cam follower surface is provided on the opposite side of each contact. There is also a cam eccentrically mounted in the housing for each of the moveable contacts, wich each cam being rotatable between an inoperative and an operative position. When in its operative position, each cam Coacts with the cam follower surface of the corresponding moveable contact to drive the contact against cable positioned in the slot. When this occurs, the projections on the contacts pierce the cable insulation to make physical and electrical contact with the corresponding conductors of the cables.

For preferred embodiments, a second fixed contact is provided on the opposite side of the slot from each moveable contact, with the conductor of the cable being pinched between projections on the fixed and moveable contacts when the cam is in its operative po sition. The cams for all the contacts are joined together and are operated by a single means, such as, for example, a common shaft. An additional moveable contact may be provided having projections adapted to engage 5 the cable shield. This additional contact is operated by a cam mounted on the same shaft as the other cams.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodi10 merits of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a pair of stacked con15 nectors of this invention.

FIG. 2 is a partially broken away front view along line 2—2 of FIG. 1.

FIGS. 3, 4 and 5 are sectional views along the line 3—3 of FIG. 2 showing respectively the connector be20 fore cable is inserted therein; after cable is inserted therein but before the cam is operated, and with the cable in the connector and the cam operated.

FIG. 6 is a front sectional view of a slightly modified embodiment of the invention.

FIG. 7 is a sectional view along the line 7—7 of FIG. 6 showing the modified form of the invention with shielded cable in the connector and the cam operated.

DETAILED DESCRIPTION

Referring now to FIGS. 1,2, and 3, it is seen that the connector 10 consists of a housing of dielectric material which is divided into an upper housing section 12A • and a lower housing section 12B. Sections 12A and ³⁵ 12B may be snap-fitted together with projections 14 on section 12B fitting into grooves 16 on section 12A. In the alternative, the sections may be bolted together, glued together, fused together by che application of heat and pressure after assembly, or held together by ⁰ any other suitable means. Grooves formed in each of the sections form a cable receiving slots 18 which extend into the center of the connector housing from each end. Flat cables 20 having conductors 22 surrounded by insulation 24 are inserted into the slots 18, with the two cables to be connected being inserted into the slots on opposite sides of the housing.

As may be best seen in FIGS. 2 and 3, there is a cavity 26 formed in housing 12B adjacent slot 18 for each ₅₀ conductor 22 of the cable. A lower contact 28 having at each of its ends an angled leading surface 31 terminating in pointed projection 30 is positioned in each of the cavities 26. There is also a cavity 32 formed in upper housing 12A for each conductor 22. An upper ₅₅ contact 34 is positioned in each cavity 32 and is free to move laterally therein. Referring to FIG. 3 it is seen that each contact 34 has an upper cam surface 36, the function of which will be described shortly, and angled leading surfaces 38 at each of its ends, each of which ₆₀ angled surfaces terminates in a pointed projection 40. Projections 40 normally extend through a slot 18 into partial engagement with the corresponding projections 30 of contact 28.

Extending through upper housing section 12A is a ₆₅ channel 41 having enlarged portions 43 adjacent each of the slots 32. Channel 41 extends above and perpendicular to slot 18. A shaft 46 is positioned in channel 41. Cams 42, eccentrically mounted on shaft 46, are

3,824,529 positioned in each extended portion 43. Cams 42 and shaft 46 are preferably of a metalic material with a dielectric coating 44, the metalic material providing strength and the dielectric coating electrical insulation. However, cams of a hard dielectric material may also be utilized. Attached to one end of shaft 46 is a squareshaped knob 48 having affixed thereto a circular flange 50. Grooves 52 spaced 180° apart are formed in flange 50. Attached to housing 12A is a spring 54 having resilient detenting projections 56 at either end and an opening at its center through which shaft 46 projects. At least one wall of slot 52 is chamferred or angled so as to provide a camming surface to remove projection 56 from slot 52 when knob 48 is turned to rotate shaft 46. Slots 52 and spring 54 thus provide two stable, easily recognized positions, 180° apart, in which cams 42, shaft 46 and knob 48 may be positioned and held.

To assemble the connector shown in the figures, contacts 28 are first placed into cavities 26 of lower housing 12B. Contacts 34 are then positioned and nested on top of contacts 28. Next, upper housing 12A is placed over the projecting surfaces of contacts 28, projections 14 fitting into openings 16 to assure proper orientation between the two housing sections. As indicated previously, the two housings are secured together by snap-fitting, bonding, fusing, or other suitable means.

When the housings have been secured together, eccentric shaft 46 with cams 42 positioned thereon arid coating 44 deposited thereon, is inserted into channel 41 with the cams each resting in an enlarged portion 43 of the channel. The ends of shaft 46 rest on curved surfaces 47 formed in housing 12A at each end of channel 41. Cap 61 is then placed into an opening formed in the top of housing 12A over channel 41 and bonded or fused to the top surface of housing 12A. Cap 61 has end portions 49 with curved surfaces 51 that engage shaft 46 entrapping the entire camming assembly in the connector. Finally, detent spring 54 is mounted on the shaft and secured to housing 12A and knob 48 is secured to shaft 46.

In operation, knob 48 and shaft 46 are initially positioned so that cams 42 are as shown in FIG. 3 with their low dwells adjacent cam follower surfaces 36 of contacts 34. Since contacts 34 are not initially biased, they rest, under the influence of gravity, on the corresponding contacts 28 as shown in FIG. 3. When cable 20 is inserted into slot 18 of the connector, the leading edge of the cable bears against angled surface 38 at the end of contact 34 and rides along this surface and the angled leading surface of pointed projection 40 to cam contact 34 in an upward direction. Once contact 34 has been cammed out of the way, the cable may be fully inserted into the slot 18 as shown in FIG. 4. The exact amount of cable which is inserted into the connector at each end is not critical. However, sufficient cable should be inserted into the slot so that projections 40 engage the cable well behind its leading edge. The amount of cable inserted cannot, however, cause the cable to extend beyond the end of the slot which is substantially even with projection 60 on contact 34. The cables may both be inserted at the same time as shown in FIG. 3, or the two cables to be connected may be inserted in the slot 18 separately.

When both cables are properly positioned in the connector as shown in FIG. 4, knob 48 is rotated, for example counterclockwise, causing spring projections 56 to be cammed out of slot 52. When knob 48 has been rotated a full 180°, causing cams 42 to be positioned as shown in FIG. 5, with their high dwells adjacent cam follower surfaces 36 of contacts 34, slots 52 are again adjacent projections 56, permitting the projections to spring back into the slots to lock the knob 48, shaft 46 and cams 42 in their new position. As each cam 42 is rotated, its high dwell coacts with the corresponding cam follower surface 36 of contact 34, forcing the contact downward against cables 20. As this is done, pointed projections 40 pierce insulation 24 adjacent the corresponding conductor 22 and make electrical contact with the conductors. The cable is distorted in the area of projections 30 and 40 with the conductor being pushed through the bottom insulation and effectively pinched between the two projections to assure good physical and electrical contact between the conductor 22 and both contacts. Contacts 28 and 34 provide a low resistance electrical path between the cable conductors.

When a cable 20 is to be removed from connector 10, know 48 is again rotated 180° until slots 52 are again adjacent projections 56 of spring 54. With shaft 46 in this position, a low dwell of each cam 42 is adjacent cam follower surface 36 of the corresponding contact 34. The contacts are thus free to move away from engagement with cables 20, but remain in the position shown in FIG. 5 under the influence of gravity. However, with the holding force removed from contacts 34, cable 20 may be pulled out of the connector by exerting pressure thereon. The force applied to the cable causes the conductor of the cable to exert force on the inclined trailing surface of projection 40 effectively camming the contact out of the way to permit the conductor to be removed.

It should be noted that, while in the discussion above the force of the cable on inclined leading surface 38 and on the inclined leading and trailing surfaces of projection 40 have been considered adequate to raise contact 34 out of the way of the cable when the cable is inserted or removed from the connector, a bias spring or other biasing means may, if desired, be provided to normally hold contacts 34 in a raised position. With such a biasing means, the contacts would always return to this position when cams 42 are in a position with the low dwell of the cam adjacent surface 36. While such a biasing means does simplify cable insertion and withdrawal, it also increases the cost of and the force required to actuate the connector.

A connector for flat multiconductor cable has thus been provided which permits connection to be made to the cable by easily hand-inserting the cable therein without any prestripping of the cable or the requirement of any special tools. Insulation piercing and electrical connection to all conductors of the cable is effected through the 180° rotation of a single knob. A simple, easily fabricated, easily utilized connector for flat coaxial cable is thus provided.

Referring in particular to FIGS. 1 and 3, it is seen that a cap 61, which covers the channel 41 and enlarged channel portions 43 in which cams 42 and shaft 46 are positioned projects above the surface of housing section 12A. There is a mating groove 62 in the bottom of housing section 12B for the projecting portion of cap 61 which permits the connectors 10 to be easily stacked as shown in FIG. 1. Suitable flanges may also

3,824,529 be provided on housings 12 for wall mounting or otherwise mounting one or more of the connectors.

FIGS. 6 and 7 illustrate an embodiment of the invention which differs from that shown in FIGS. 1-5 only in that cable 20 has a metalic ground shield 70 around it and in the provision of a pair of ground shield contacts 72 and 74 in place of the contacts 28 and 34 respectively for the right-most conductor position. Contact 72 has an angled leading surface 76 at each end which terminates in a row of shield-engaging teeth 78. Upper contact 74 has an angled leading surface 80 at each end which terminates in a row of shield-engaging teeth 82. Upper contact 74 also has a cam follower surface 84 along its upper edge.

In operation, shield 70 is cut-back slightly before the cable is inserted in slot 18. Then, when knob 48 is rotated to move the high dwells of cams 42 into engagement with cam follower surfaces 36 of upper contacts 34, the rotation of shaft 46 also brings the high dwell of the cam 42 adjacent contact 74 into engagement with cam follower surface 84, forcing contact 74 into engagement with the cut-back shielding 70 on each of the cables 20. With the cam in a fully operated position as shown in FIG. 7, the shielding is pinched between contacts 72 and 74 with the teeth 78 and 82 of the contacts digging into the shielding to assure good physical and electrical contact with the shielding. Thus, electrical contact is established and connection effected with both the conductors 22 of cables 20 and the shielding 70 of the cable as a result of a single 180° rotation of a knob. It should be noted that, while the shield engaging contacts are shown in FIG. 6 as being in the right-most conductor position, this is by way of example only, and these contacts may, in fact be in any of the conductor positions.

While the invention has been particularly shown and described above with reference to preferred embodiments thereof, it would be apparent to one ordinarily skilled in the art that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.