US2981918A - Connector with strain relief for flat cable - Google Patents

Description

April 25, 1961 w, uc EI'AL CONNECTOR WITH STRAIN RELIEF FOR FLAT CABLE Filed Sept. 26, 1958 m4 mo m //2 m BY T1311. 1: 1E. W

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INVENTORS. au/cz I nections to the connector.

, which the'connector is used;

enlarged scale;

CONNECTOR WITH STRAIN RELIEF FOR r FLAT (IIABLE William Gluck, Yonkers, and Seymour ()lferman, New York, N.Y., assignors to Industrial Electronic Hardware Corp., a corporation of New York Filed Sept. 26, 1958, Ser. No. 763,498 19 Claims. (Cl. 339-103) This invention relates to connectors, especially for fiat cable, and more particularly to the prevention of strain between the cable and the connector.

The primary object of the present inventionis to generally improve connectors designed for use with thin, flat, flexible cable. A more particular object is to improve the connector shown in a copending application of William Gluck, a joint inventor herein, Serial No.

755,797, filed August 18,1958, and entitled Connector, Particularly for Flat Cable.

Another object is to provide a connector which affords strain relief as between the cable and its soldered con- Still another object is to provide a connector with strain relief means which is short, compact and sturdy. Speaking generally, this oh- I ject is fulfilled by providing a strain relief means which is superposed directly over the body of the connector, in-

' stead of being disposed behind the connector.

To accomplish the foregoing general objects, other more specific objects which will hereinafter appear, our invention resides in the interrelated connector, and strain United tates P w -t O 28 ,are deposited in parallel spaced relation. Thereafter the conductors are coated with another layer of insulation 30 to finish the cable. The particular cable here shown relief elements as hereinafter more particularly described in the following specification. The specification is accompanied by a drawing, in which: I I 37 a Fig. 1 is a plan view of a connector embodying features of the invention, prior to the addition ofthe cables and strain relief plates;

Fig. 2 is a similar View subsequent to the addition of the cables and strain relief plates; 1

Fig. 3 is a side elevation of the assembly shown in Fig. 2, drawnto larger scale; I

Fig. 4 is a transverse section taken approximatelyon I the plane of theline 44 of Fig. 2, and drawn to the scale'of Fig. 3; I I

Fig. 5 is a perspective exploded view showing the connector and strain relief elements;

-. block and adapted 'sure for good electrical contact. contact (Fig. 9),v the head H comprises a. sh'ank66 Fig. 6 is an end view of one form of flat cable with Fig.7 showsthe 'r'ighthand end of ig.5 as... to

Fig. 8 is a fragmentary view showing a female-contact "in the connectorblock; I I I I I I Fig. '9 is a similar fragmentary viewshowing a male contact in the connector block; I I

Fig. 10 is explanatory of the soldering of the cable to the connector; v

Fig. '11 is an elevation of another form of the inven-. tion usinga special moldedblock; and l Fig. 12 shows still another form of the invention using a differently molded block. 1 7

Referring to thedrawing; and more particularly to 12, and another such cable 14, arranged for detachable [connection by means of a connector comprising a female portion 16 and a male portion 18. The male portion '18 "has projecting tongues 20 which are adapted to be reportion 16.

foregoing will suflice for the present purpose.

Figs. 2 and 3, we there show a thin, flat, flexible cable ce ved with a frictional spring contact lit in the female center to center.

2,981,918 Patented Apr. 25, 1961 ice The thin, flat cable may be described with reference to Figs. 6 and 7 of the drawing. Fig. 6 is an end view, and shows the insulation body 22 of the cable, in which there are embedded thin, ribbon-like metal conductors 24. In the example here shown the cable has nine conductors, but it will be understood that the cable may be obtained in other widths with different numbers of conductors. I

Referring now to Fig. 7, the cable may consist of a lower ribbon 26 of insulatiomon which lines of copper is manufactured and sold commercially under the name Tape Cable by the Tape Cable Corporation of Rochester, New York. This cable comprises thin printed copper conductors embedded in a transparentpolyester, specifically Mylar manufactured by Du Pont. Tape Oable Corporation supplies the cable in different widths ranging from nine to fifty conductors. The conductors are 0.030 inch in width, and are spaced apart 0.100 inch The tape is only 0.008 inch thick, and is very flexible, light in weight, and easily handled in complex wiring operations.

Referring now to Figs. 5, 8 and 9 of the drawing, each connector portion comprises a generally flat insulation block 32 having a series of open sided channels 34, each receiving a metal contact. Each contact comprises a head generally designated H, an offset 36, and a tail 38. The channel 34 has a part 40 to receive the flattened inner end of tail 38, an offset part 42 to receive the offset 36, and a part 44 to receive the head H. Referring to Fig. 5, a generally flat cover 46 closes the channels and thereby holds the metal contacts in the block.

j The face of the block preferably has a plurality, in

'thiscase four rectangular projections, which are received in four mating rectangular aperturesin the cover ;plate 46. *These apertures are shown at 54 in FigsLl 40.

and 5. There are passages through these. projections which receive rather wide metal staples, there being four I passages for two such staples shown at 60.

Reverting to Fig. 8, in the case of the female contact the head H is a concavo-convex spring 50 disposed perpendicular or edgewise relative to the plane of the to provide the desired spring pres- In the caseof the male which is received in the channel portion 44;.of the block,

and a pin 20 which projects beyond the block, the pin being a flattened straight strip disposed edgewise and I adapted to cooperate with the female contact previously I described.

I The connector itself is described in further detail in the copending application previously referred to, but the The soldering of the flat cable to the connector is preferably performed by a pot soldering operation, "whether or not strain relief means are used. The end of the cable is first stripped by a commercially available device comprising opposed grinding wheels which have a glass fibre base. In Fig. 10 a cable 70 which has been so treated is held on a connector, with the projecting stripped conductors 72 lying against the contact tails 'has a slot 82 dimensioned to receive the fiatcable. The

arrangement is such that the cable may be folded about the plate 80 and passed through the slot 82 for strain relief. More specifically, the cable preferably passes forwardly beneath the plate 80, as shown at 84 in Fig. 4, and is then folded reversely about the forward edge of the plate, as shown at 86 and is then passed downwardly through the slot 82 and outwardly in desired direction beneath the plate 80, as shown at 88. It is important to note that the strain relief plate 80 is no larger than the connector in the direction of the cable, so that the resulting connector and strain relief assembly is short, compact, sturdy, and does not interfere with the desired flexibility of the cable.

Considering the arrangement in greater detail, the cover 46 (Fig. of the present form of the improved connector differs from that previously used in that it is longer than the block 32 in a direction transverse to the contacts and cables. This provides overhanging ends 90. The strain relief plate 80 has a length commensurate with that of the cover 46, thereby providing ends through which fastener means may be passed to secure the plate 80 to the cover 46. In this case the ends 90 have holes, and the cover 80 has mating holes, any of which may receive small eyelets. In Fig. 2 there are two eyelets 92 at each end, while the third hole 94 may be used to secure or support the connector, should that be desired. If it be known that the extra attaching holes 94 are not needed, the cover plate and the strain relief plate may be shortened somewhat to provide room merely for the eyelets 92,

Reverting to Fig. 5, spacers 96 are preferably provided,

and these conform to the end portions, and have registering holes. They are held in position by the eyelets 92 previously mentioned. They insure adequate clearance to slidably receive the two thicknesses of the flatcable.

The strain relief plate may be made of thin insulation laminate, and the same applies to the spacers 96. However, either or both might be made of metal. The cover plate 46, however, is necessarily made of insulation because it bears against the contacts of the connector.

The usual practice is for the manufacturer to sell the connector completed, with the strain relief plate already eyeletted in position as shown in Fig. 2, but without the cable. The user strips the end of the cable, passes it through the space beneath the strain relief plate, and solders the conductors as shown in Fig. 10. He then guides the free end of the cable around the strain relief plate and through the slot, as shown in Figs. 2 and 4. It is primarily for this reason that adequate clearance is desired beneath the strain relief plate.

The form of the invention so far described presupposes that the molded block 32 of the connector is to be unchanged. However, with suflicient demand to warrant a special mold, the block itself may be lengthened, instead ,of the cover plate 46. Also, the block itself may be thickened to replace the separate spacers 96 previously shown. Such an arrangement is illustrated in Fig. 11,

in which the block 100 is molded with outwardly projecting ends 102, affording room to receive eyelets 104. In addition, the block may be raised or thickened .as shown at 106, to sufficiently raise the strain relief plate 108. The cover 110 may be the short standard cover previously used, and having a length no greaterthan that of the original block 32 shown in Fig. 5. The cover 110 is secured by the regular staples 60, while the strain relief plate 108 is secured by one or more eyelets 104 at each end.

The method of addition of the cable to the connector is the same as previously described. I

While it is preferred to locate the strain relief plate on top of the connector, it may instead be located beneath the connector, and such a variation is shown in Fig. 12 in which the block 112 is molded with additional end por- -tions 114 to receive eyelets 116. The end portions are thickened as shown at 118 to act as spacers. The strain relief plate 120 is held by the eyelets 116. The cover 122 may be short, as shown, and is held by the staples 60.

It could be long and could receive the eyelets 116, but there is no present reason to lengthen the cover.

In using this connector, the cable is stripped and the stripped end is slid downwardly inside the strain relief plate, and is then soldered by pot soldering, just as previously described in connection with Fig. 10 except that the cable is on the opposite side of the connector. The cable is then reversely folded and passed inwardly through the slot in the strain relief plate (slot 82 in Fig. 5), much as previously described, except for the change of orientation.

It is believed that the method of constructing and using our improved connector with strain relief for fiat cable, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while we have shown and described our invention in a preferred form, changes may be made without departing from the scope of the invention as sought to be defined in the following claims.

We claim:

1. A connector for use with a flexible flat cable comprising a generally flat insulation base having spaced collateral metal contacts, each contact having a head and an outwardly projecting tail for soldering to the stripped conductors of a flat cable, and a strain relief plate disposed directly over and secured to said connector, with a space therebetween corresponding to twice the thickness of the cable or more, said plate having a slot dimensioned to receive the flat cable, the arrangement being such that a flat cable may be soldered to the tails, and may be folded about the plate and through the slot thereof, said plate being localized directly over said connector.

2. A connector for use with a flexible flat cable comprising a generally flat insulation base having spaced collateral metal contacts, each contact having a head and an outwardly projecting tail for soldering to the stripped conductors of a flat cable, and a. strain relief plate disposed directly over and secured to said connector, with a space therebetween corresponding to twice the thickness of the cable or more, said plate having a slot dimensioned extending in reverse direction, following which the cable may be folded about the forward edge of and over the plate and passed downwardly through the slot and outwardly in desired direction between the plate and the connector.

, 3. A connector for use with a flexible fiat cable comprising a generally flat insulation base having spaced collateral metal contacts, each contact having a head and an outwardly projecting tail for soldering to the stripped conductors of a flat cable, and a strain relief plate disposeddirectly over and secured to said connector, with a space therebetween corresponding to twice the thickness of the cable or more, said plate having a slot dimensioned to receive the flat cable, the arrangement being such that a flat cable may be soldered to the tails with the cable extending in reverse direction, following which the cable may befolded about the forward edge of and over the plate and passed downwardly through the slot and outwardly in desired direction between the plate and the connector, said plate being no larger than said connector in the direction of the cable.

4. A connector for use with a flexible flat cable comprising a flat insulation block having a plurality of collateral open channels each receiving a metal contact, said contacts each having a head and a tail projecting outwardly for soldering to the stripped ends of a fiat cable, an insulation cover secured to said block to hold the contacts in position, a strain relief plate secured directly over said cover with a space therebetween corresponding to twice the thickness of the cable or more, and having a dimension approximately commensurate with the cover in the direction of the contacts, a slot through said plate dimensioned to receive the flat cable, the arrangement being such that the stripped ends of a flat cable may be soldered to thetails with the cable extending in a direction from tail: to head between the cover and plate, and

then may be reversely folded over the top of the plate and downwardly through the slot and rearwardly betweenthe plate and cover; j

5. A connector for'hsewith a flexible flat cable comprising'a flat insulationblock having a plurality of collateral open channels 'each' receiving a metal contact, said contacts each having a head and a tail projecting outwardly for soldering to the stripped ends of a flat cable, an insulation cover secured to said block to hold the contacts in position, a strain relief plate secured directly over said cover with a space therebetween corresponding to twice the thickness of the cable or more, ,and having a dimension approximately commensurate with the cover in the direction of the contacts, means to space the plate away from the cover, a slot through said plate dimensioned to receive the flat cable, the arrangement being such that the stripped ends of a flat cable may be soldered to the tails with the cable extending in a direction from tail to head between the cover and plate, and then may be reversely folded over the top of the plate and downwardly through the slot and rearwardly between the plate and cover.

6. A connector for use with a flexible flat cable comprising a flat insulation block having a plurality of collateral open channels each receiving a metal contact, said ,contacts each having a head and a tail projecting outwardly for soldering to the stripped ends of a flat cable, an insulation cover secured to said block to hold the contacts in position, fastener means passing through said cover and block to secure them together, said cover being longer than the block in a direction transverse to the contacts and cable, a strain relief plate disposed directly over said cover with a space therebetween corresponding to twice the thickness of the cable or more, and having alength commensurate with the cover, fastener means passing through the projecting ends of the cover and plate to secure them together, a slot through said plate dimensioned to receive the flat cable, the arrangement being such that the stripped ends of a flat cable may be soldered to the tails and the cable may be folded about the plate and through the slot thereof.

7. A connector for use with a flexible flat cable comprising a flat insulation block having a plurality of collateral open channels each receiving a metal contact, said contacts each having a head and a tail projecting outwardly for soldering to the stripped ends of a flat cable, an insulation cover secured to said block to hold the contacts in position, fastener means passing through said cover and block to secure them together, said cover being longer than the block in a direction transverse to the contacts and cable, a strain relief plate disposed directly over said cover with a space therebetween corresponding to twice the thickness of the cable or more, and having a length commensurate with the cover, fastener means passing through the projecting ends of the cover and plate to secure them together, a slot through said plate dimensioned to receive the flat cable, the arrangement being such that the stripped, ends of a flat cable may be soldered to the tails with the cable extending in a direction from tail to head between the cover and plate, and then may be reversely folded over the top of the plate and downwardly through the slot and rearwardly between the plate and cover.

8. A connector as defined in claim 1 in which the base is molded with ends projecting beyond the contacts to receive fastener means for securing the strain relief plate to the base.

9. A connector as defined in claim 3 in which the base is molded with ends projecting beyond the contacts to receive fastener means for securing the strain relief plate to the base.

10. A connector as defined in claim 1 in which the base is molded with ends projecting beyond the contacts 6 to receive fastener means for securing the strain relief plate to the base, and in which said ends are thickened to space the plate from the base. 11. A connector as defined in claim 3 in which the base is molded with ends projecting beyond the contacts to receive fastener'means for securing the strain relief plate to the base, and in which said ends are thickened to space the plate from the base.

12. A connector as defined in claim 4 in which the block is molded with ends projecting beyond the channels and contacts to receive fastener means for securing the strain relief plate tothe block, and in which the projecting ends are thickened in order to spacethe plate from the portion of the connector between said thickened ends.

113. A connector as defined in claim 4 in which the block is molded with ends projecting beyond the channels and contacts to receive fastener means for securing the strain relief plate to the block, and in which the projecting portion of the connector between said thickened ends, and in which the insulation cover is shorter than the block and plate and is secured to the block between the aforesaid projecting and thickened ends.

14. A two-part detachable connector comprising a male portion and a female portion, each portion being made in accordance with and having the features of claim 1, said male portion having contacts the heads of which include projecting pins, and said female portion having,

contacts the heads of which include springs for receiving said pins with a frictional fit.

15. A twopart detachable connector comprising a male portion and a female portion, each portion being made in accordance with and having the features of claim 5, said male portion having contacts the heads of which include projecting pins, and said female portion having contacts the heads of which include springs for receiving said pins with a frictional fit.

16. In combination, a flexible flat cable and a connector secured thereto, said connector comprising a flat insulation base having collateral metal contacts, each contact having a head and a tail projecting outwardly beneath the flat cable, and a strain relief plate disposed over and secured to said connector, with a space therebetween corresponding to twice the thickness of the cable or more, said plate having a slot extending transversely of the cable, said cable having its conductors soldered to said tails and being folded about the plate 50 and through the slot thereof, and said plate being localized directly over said connector.

17. In combination, aflexible flat cable and a connector secured to the same, said connector comprising a flat insulation block having a plurality of collateral open channels each receiving a metal contact, said contacts each having a head and a tail projecting outwardly, an insulation cover secured to said block to hold the contacts in position, a strain relief plate disposed directly over said cover with a space therebetween corresponding 7 to twice the thickness of the cable or more, and having a dimension commensurate with the cover in the direction of the contacts, a slot through said plate, the stripped ends of said cable being soldered to the tails with the cable extending between the cover and the plate in a direction from tail to head, and said cable being reversely folded over the top of the plate and then passing downwardly through the slot and rearwardly between the plate and the cover.

1 8. A two-part detachable connector and flat cable combination comprising a male portion and a female portion, each portion being made in accordance with and having the features of claim 16, said male portion having contacts the heads of which include projecting pins, and 75 said female portion having contacts the heads of which ends are thickened in order to space the plate from the v include springs for receiving said pins with a frictional fit, and said reversely folded cables extending away from one another. 7

'19. A two-part detachable connector and. flat cable combination comprising a male portion and a female portion, each portion being made in accordance with and having the features of claim 17, said male portion having contacts the heads of which include projecting pins, and said female portion having contacts the heads of which include springs for receiving said pins with a frictional fit, and said reversely folded cables extending away from one another.

OTHER REFERENCES Electronics, published August 10, 1957 (page 28); Electronic Design, published August 15, 1957 (pages 48 and 49).

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