US3333229A - Strip cable connector - Google Patents

Description

July 25, 1967 w, DEAN ET AL STRIP CABLE CONNECTOR 2 Sheets-Sheet l Filed July 25, 1961 INVENTORS. Goeoou W DER/V HQQOLD Ross 3v July 25, 1967 G. w. DEAN ET AL 3,333,229

STRIP CABLE CONNECTOR I Filed July 25, 1961 2 Sheets-Sheet 2 INVENTORS. 00200 PV; DEfl/V Hflzou: Ross Ml/L d/ma/ flrramvsys.

United States Patent 3,333,229 STRIP CABLE CONNECTOR Gordon W. Dean, Alhambra, and Harold Rose, Whittier,

Calif, assignors, by mesne assignments, to International Telephone and Telegraph Corporation, New York,

N.Y., a corporation of Maryland Filed July 25, 1961, Ser. No. 126,666 4 Claims. (Cl. 339-99) This invention relates to electrical connectors and more particularly to strip cable connectors that may be used with other types of electrical devices to complete one or more electrical circuits.

A major object of this invention is to provide a strip cable connector that employs programmed electrical contact plates to selectively rupture and strip the insulation material of a strip cable from about conductor ribbons enclosed therein in order to provide an intimate and positive electrical contact between the exposed, damagefree, conductor ribbons and the respective contact plates.

Another object of this invention is to provide a strip cable connector having the aforementioned characteristics wherein the contact plates have a slot therein to receive the strip cable, the entrance of which is defined by beveled corners that provide obtuse angled corners which penetrate the insulation material of the strip cable and strip the insulation material therefrom to expose the conductor ribbons, free of damage, as the strip cable is forced into the slot.

A further object of this invention is to provide contact plates of a strip cable connector having the aforementioned characteristics and wherein the contact plates incorporate resilient portions therein that are flexed as the strip cable is forced into the slot to allow for the variation of strip cable thickness, to insure against damage to the conductor ribbons, and to provide pressure for good contact mating.

A more specific object of this invention is to provide a strip cable connector of the aforementioned characteristics wherein the strip cable is stabilized by a resilient wedge of material that may be deformed as the strip cable is forcibly inserted into the slots of the contact plates and which deforming allows for variation in the thickness of the strip cable and in combination with the flexing of the resilient portions of the contact plates, insures that damage to the conductor ribbons when exposed does not occur.

Another more specific object of this invention is to provide a strip cable connector of the aforementioned characteristics wherein the contact plates are selectively disposed within an insulator body that includes guiding structure which insures a properly oriented insertion of the strip cable into the slots of the contact plates whereby the strip cable is centrally disposed with respect to the rupturing corners thereof, and positive electrical contact will be made between the contact plates and the respective conductor strips in the strip cable.

An additional object of the invention is to provide a strip cable connector of the character described wherein a good contact wiping action occurs between the contact members and the conductor strips as the contact members peel the insulation off of the conductor strips, and wherein a large area of metal-to-metal surface engagement is 3,333,229 Patented July 25, 1967 provided between the contact members and the respective conductor strips.

A yet further object of this invention is to provide a strip cable connector that includes structure that retains the strip cable within the connector and provides a moisture-tight seal.

Further objects and advantages of the invention will become apparent from a consideration of the subsequent detailed description, taken in conjunction with the drawings.

FIGURE 1 is a perspective view illustrating and having embodied therein one form of the present invention in the assembled condition.

FIGURE 2 is a perspective view illustrating the strip cable and connector in a separated condition.

FIGURE 3 is an enlarged, cross-sectional view taken on line 33 of FIGURE 1 and including a terminal socket that mates with the terminal pins of the connector to complete an electrical circuit.

FIGURE 4 is an enlarged cross-sectional view taken on line 44 of FIGURE 1 looking in the direction indicated.

FIGURE 5 is also an enlarged view partly in section, taken on line 5-5 of FIGURE 1, looking in the direction indicated.

FIGURES 6a, b and c are exaggerated schematic illustrationsshowing the procedure that is followed for rupturing and stripping the material that encloses the ribbon conductors of the strip cable.

FIGURE 7 is a fragmentary, cross-sectional view taken on line 7-7 of FIGURE 5.

FIGURE 8 is a cross-sectional view illustrating a modified form of assembling the strip cable to the connector.

FIGURE 9 is a cross-sectional view illustrating a modified form of connector for the strip cable.

FIGURE 10 is a fragmentary sectional view taken on the line 10-10 of FIGURE 3.

Referring particularly to FIGURES l-7 of the drawings for a more comprehensive understanding of the invention, an elongated insulator body broadly designated 10 removably receives one or more programmed electrical contact plates 12. One end of a fiat, relatively flexible strip cable 14 is rendered more rigid by being wrapped about a flat, elongated wedge of resilient material 16, and insertion of the stabilized strip cable into a slot, to be hereinafter described in greater detail, in the contact plate 12 results, as best shown in FIGURE 6a, b and c, in one sheet 13 of the material of the strip cable being ruptured and stripped to expose a conductor ribbon 15 therein. An intimate and positive electrical connection is formed between the exposed conductor ribbon and contact plate. An elastomer seal 18 in combination with an elongated pressure member 20 is secured to the body 10 to provide a moisture-tight seal and connection that secures the strip cable 14 in the body 10.

The strip cable 14 is generally fabricated of a pair of relatively soft sheets of plastic material 13 and 21, usually composed of polyester resin, that are bonded together and have enclosed therebetween a plurality of spaced, parallel conductor ribbons 15 usually composed of copper. Although the sheets of plastic material readily bond to each other, there is little or no adhesion between the plastic material and the conductor ribbon, and therefore when the material is ruptured by the electrical contact plates 12, stripping of the material from about the conductor ribbons is accomplished with relative ease and without damage to the ribbons.

It has been determined that the average thickness of strip cables presently in commercial use is about .009 inch, but that the thickness varies between about .008 and .0095 inch.

The insulator body 10, preferably molded of a non- .conducting, relatively rigid plastic material, has anelongated compartment 22 therein that is defined by a front wall 24, having a'plurality of spaced terminal-receiving openings 26 therein, a pair of parallel side walls 28, and .a pair of end walls 30, each of which has an opening 32 therethrough to receive a stud 34. The back of the compartment is open to receive the strip cable 14, wedge 16 and moisture seal 18. Each end wall 30 has a guide slot 36 formed therein that is midway between the side walls 28. Each slot, which extends in an axial direction from the backof the body 10 toward the front wall 24, receives one end of the wedge 16, to be hereinafter described in greater detail, which spans the distance between the slots. Each side wall has a series of spaced, parallel, elongated guides 38, see FIGURE 10, that define channels 39 which slidably receive the electrical contacts 12. The contacts 12 span the distance between the side walls, the side edges of contacts .12 being retained in channels 39 so that the contacts are held in a parallel, spaced relationship.

The electrical contact plates 12 each comprise a flat plate of electrically conducting material. Each contact plate, when fully inserted into the body 10, has a front edge 40 that engages against the interior of the front wall 24 of the insulator body. A straight back edge 42 of the contact plate is parallel to and spaced inwardly 'in the compartment 22 away from the open back of the body 10. :As a result of the spaced relationship of the back edge 42 of the contact to'the open back of the compartment 22, a lead-in portion for strip cable 14 and wedge 16 is provided in the guide slots 36 which assures that the wedge 16 is parallel to side walls 28 when the strip cable engages the contact plates 12. The contact also includes a pair of straight parallel side edges 43 which are received in the channels 39 defined by the guides 38.

Each contact platehas a terminal 44 secured to the front thereof, preferably by brazing or welding. The terminals 44 are illustrated as pin terminals, but it is to be understood that they may be socket terminals, hermaphrodite terminals, or any other desired electrically conducting structure. Each terminal 44 extends through a corresponding opening 26 in the front wall 24 and is adapted to mate with a suitable complementary terminal such as socket terminal 46 that is a component of another connector member.

Polarizing of the terminals 44 may be accomplished by 'oif setting some of the holes 26 in the front wall 24 of the insulator body toward one side wall 28 and others of the holes 26 toward the other side wall 28, and off setting the terminals 44 from the centers of the contact plates 12, so that one or more of the terminals 44 may be off set toward either side of the insulator, as shown in FIGURE 3.

Although outwardly projecting terminals 44 have been shown in the drawings, it is to be understood that the terminals could be recessed, if desired, and that the connector of the present invention may be adapted for mating with any other type of connector member, or with a printed circuit card or board, or any other type of electrical device, to complete one ormore electrical :Circuits.

In addition,.each contact plate 12 has a wedge and strip cable receiving slot 48 therein which may best be seen in FIGURE 6. Each slot 48 extends from the back edge 42 toward the front edge 40 and is located substantially mid- 4 way between the side edges 43. The slot 48 is defined by conductor ribbon engaging side edges 50 and a bottom 49 which is preferably arcuate.

Formation of thetslot 48 in the contact plates results in producing a pair of relatively resilient legs 51 that will be urged away from each other when the strip cable 14 and wedge 16 are forced into the slot. This resilience allows, in part, for variations in the thickness of the strip cable 14. V

A plane parallel to and passing through the guide slots 36 of insulator body 10 also passes through the center line of the slots 48 in contact plates 12. As a result of this relationship, when the strip cable 14 and Wedge 16 are urged into the slots they are parallel to the side edges 50 of the slots 48.

Each side of the mouth or entrance of each slot 48 is beveled as at 52 to produce a corner 54 having an obtuse angle, these corners 54 engaging the plastic material 13 of the strip cable 14 to cause the aforementioned rupture and stripping thereof and to expose the conductor ribbon 15. It has been found that the obtuse angle should be between about 105 and 165 for best results, and preferably about 135.

The spacing of the contact plates 12 in the body 10 corresponds to the spacing of the ribbon conductors 15 in the strip cable 14. Therefore, when the strip cable is forced into engagement with the corners 54, only a localized rupture and stripping of the plastic material 13 is achieved to expose the ribbon conductors 15, and the remainder of the plastic material remains undamaged.

The electrical contacts 12 may be inserted into the body 10 to achieve a desired programming of electrical As few as one and as many as twelve contact plates may be inserted into the body 10, and the contact plates 12 can be placed in various pairs of opposed channels 39 for the desired programming.

In order to compensate, inpart, for variations in the thickness of the strip cable .14, the wedge 16 is preferably, but not necessarily, made of a material having some resilence. For example, the wedge 16 may be molded of Lexan, a polycarbonate resin. However, nylon and other somewhat resilient resins and plastics are also applicable.

The wedge 16 has an elongated straight front edge 56, about which the end of the strip cable 14 is folded or wrapped with the sheet 13 of the strip cable 14 being outermost. The wedge 16 also includes a pair of parallel ends 58, each of which is slidably received in a corresponding guide slot 36, and a straight back'edge 60 which is parallel to the front edge. Extending from the front edge 55, adjacent each end is a projection 62 that has the function of orienting the strip cable 14 on the wedge 16 in order that the material 13 will be ruptured and stripped inthe localized areas to expose the ribbon conductors 15. However, the strip cable 14 wrapped about the front edge 56 generally bottoms against the arcuate bottoms 49 of the slots 48 before the projections 62 bottom against the bottom of the polarizing slots 36, as may be determined by referring to FIGURE 5 of the drawings.

FIGURES 6a, b and 0 illustrate, in sequence, the manner in which the plastic material 13 of the strip cable 14 is ruptured and stripped to expose the ribbon conductors 15 and to produce an intimate and positive electrical contact between the ribbon conductors 15 and the edges 50 of slot 48. One end of the strip cable is wrapped about the front-edge56 of the wedge 16 in the manner illustrated in FIGURE 6a. The wedge and strip cable are then forced into the slot 48, where the corners -54 engage the material 13 and cause a rupture thereof. I

In order that the corners 54 can engage the-material 13 the combined dimensions of the slots 48, wedge 16 and strip cable 14 must be considered. It has been found that the slots and the wedge are to be made so that the difference in their size is approximately twice the ribbon conductor thickness plus twice the thickness of one sheet of the plastic material of the strip cable; i.e., approximately twice the ribbon conductor thickness plus the thickness of the plastic material of the strip cable. This relationship is established for the minimum thickness of the strip cable likely to be found in the tolerance range for the strip cable thickness, any additional thickness of the strip cable within its tolerance range being accommodated by the resilience of the contacts 12 or by the resilience of wedge 16, or by the resilience of both of them.

It may be seen in FIGURE 617 that further forcing of the strip cable 14 and wedge 16 into the slot 48 strips the material 13 and exposes the ribbon conductor 15 which is wiped against the side edges 50 of the contact plate. Any metal oxidation that has accumulated thereon is wiped therefrom to expose clean metal.

FIGURE 60 shows the strip cable substantially fully inserted into the slot 48, with a substantial amount of insulation material 13 locally stripped away to expose the conductor ribbon 15. It may be seen that a sutficient amount of the plastic material 13 has been stripped away whereby the side edges 50 are in full engagement with the ribbon conductor 15.

Prior to insertion of the strip cable 14 and wedge 16 into the slot 48 the pressure member 20 and elastomer seal 18 are placed thereabout in the manner illustrated in FIGURE 2. The moisture seal 18 may be made of any resilient material, but the material preferred is an elastomer such as rubber.

The moisture seal 18 has a portion 63 that is inserted into the compartment 22 and the free end 64 of the strip cable is disposed and held captive therein.

A portion 66 of the moisture seal projects through an elongated opening 68 in the pressure member 20, and this portion embraces the portion of the strip cable 14 that is exterior of the body 10.

The pressure member 20, in addition to having the elongated opening 68 therein, includes an endless base 70 that bears against the portion 63 of the moisture seal disposed in the compartment 22. Integral with the base is an endless flange 72 that circumscribes and embraces portion 66 of the moisture seal. Ends 74 which are a part at the base each have an opening 76 therein that registers with the corresponding openings 32 in the end walls 30 of the body and receives threaded end 78 of the stud 34 that projects therethrough.

The threaded end 78 of each stud 34 receives a nut 80. When the nut is tightened to secure the pressure member 20 to the body 10 the base 70 bears against portion 63 of the moisture seal to cause deformation thereof in the compartment 22 to prevent the entrance of moisture thereinto. The deformation of portion 63 is also reflected in portion 66 which is also deformed to provide a seal that prevents the passage of moisture through the opening 68.

Each opening 32 in the ends 30 of body 10 has a hexagonal recess therein to receive a hexagonal collar 81 that is integral with each stud 34. Projecting from the collar 81 of each stud in the same direction as terminals 44 is a polarizing pin 82.

FIGURE 8 illustrates that it is not necessary to restrict the use of the strip cable 14 by Wrapping one end about the wedge 16. The wedge 16 may be positioned anywhere along the strip cable 14 between the ends, and as a result of this versatility of the strip cable connector a series of T or branch connections of strip cable and connectors may be employed if desired. By proper programming of the contacts in the strip cable connectors in such branch connections, different conductors or groups of conductors can be tapped at different points along the length of the strip cable. Such branch connectors can be adapted for engagement with other strip cable connectors, with printed circuit boards, or any other suitable electrical device.

Another form of a strip cable connector is illustrated in FIGURE 9, which is adapted for mating with two other connector members. The body 84 illustrated in FIGURE 9 is similar to body 10 except that the parallel side walls 86 have the terminal receiving openings therein instead of the front wall 88.

Additionally, the electrical contact plates 90 are similar to electrical contact plates 12 except that the terminals 92, secured to the contact plates, project from the side edges 94 and extend through the openings in the side walls 86. Thus the terminals may extend from only one side wall 86 or, as illustrated, the terminals may extend from both side walls. With the illustrated arrangement, a pair of mating connector members may be engaged to both sides of the body 84 to complete electrical circuits.

The body 84 may be constructed in two identical halves in order that the contact plates 90 may be disposed therein.

As with the other forms of the invention hereinabove described, the embodiment of FIGURE 9 can be adapted to receive various types of electrical devices, such as other strip cable connectors, printed circuit boards, or the like.

While the instant invention has been shown and described herein in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims.

We claim:

1. A strip cable connector comprising a strip cable composed of a plurality of parallel, spaced electrical connector ribbons enclosed between sheets of rupturable material that are bonded together; an elongated wedge of material about which said strip cable is folded for stabilizing and positioning the strip cable; an insulator body having a compartment therein, said body having a pair of spaced, parallel guide slots therein that slidably receive opposite sides of said wedge; and a plurality of spaced, aligned electrical contact members disposed within said body and having electrical terminal means thereon; said contact members each having a slot therein the entrance of which has corners thereon that locally rupture and strip one sheet of said material of said strip cable to expose the conductor ribbons to an intimate electrical contact with said contact member when the stabilized strip cable is inserted into said slot; said contact members each having resilient portions thereon on each side of said slot that are capable of being flexed away from each other when the strip cable is inserted into said slot and in cooperation with said guide slots insures, at least in part, that said conductor ribbons are not damaged when the enclosing material is ruptured and stripped therefrom.

2. A strip cable connector according to claim 1 wherein said wedge is fabricated of a resilient material and in cooperation with said resilient portions allows for variation in thickness of said strip cable and in cooperation with said resilient portions and guide slots insures that said conductor ribbons are not damaged.

'3. Astrip cable connector as defined in claim 1 which includes resilient sealing means secured to said body for rendering said compartment moisture-tight.

4. A strip cable connector member comprising a strip cable having a plurality of spaced, fiat, parallel conductor ribbons lying in a common plane and enclosed within rupturable insulation material, a support member having a generally flat surface terminating at a generally straight edge, the strip cable extending over said surface and being bent over said edge with said edge extending transversely relative to said conductor ribbons, and a connector memher body having a plurality of spaced, parallel contact members supported therein, said contact members each having a corner thereon, said support member and strip cable being slidable in said body so that individual condoctor ribbons of the strip cable slide longitudinally in alignment with respective contact members, said corners on the contact members engaging the strip cable proximate said edge of the support member and locally rupturing and stripping the insulation material of the strip cable to expose the conductor ribbons to intimate electrical contact with respective contact members, said contact members each having a substantially straight contacting edge thereon which terminates at one end at said corner, said contacting edges of the contact members being substantially parallel to said generally flat surface of the support member.

References Cited UNITED STATES PATENTS Gibson 339-98 Novak 339--17 Thomas et al 33917'X 3 Valach 339+176 MARVIN A. CHAMPION, Primary Examin'er.

10 ALFRED S. TRASK, Examiner.

J. H. MCGLYNN, Assistant Examiner.

Claims (1)

1. A STRIP CABLE CONNECTOR COMPRISING A STRIP CABLE COMPOSED OF A PLURALITY OF PARALLEL, SPACED ELECTRICAL CONNECTOR RIBBONS ENCLOSED BETWEEN SHEETS OF RUPTURABLE MATERIAL THAT ARE BONDED TOGETHER; AN ELONGATED WEDGE OF MATERIAL ABOUT WHICH SAID STRIP CABLE IS FOLDED FOR STABILIZING AND POSITIONING THE STRIP CABLE; AN INSULATOR BODY HAVING A COMPARTMENT THEREIN, SAID BODY HAVING A PAIR OF SPACED, PARALLEL GUIDE SLOTS THEREIN THAT SLIDABLY RECEIVE OPPOSITE SIDES OF SAID WEDGE; AND A PLURALITY OF SPACED, ALIGNED ELECTRICAL CONTACT MEMBERS DISPOSED WITHIN SAID BODY AND HAVING ELECTRICAL TERMINAL MEANS THEREON; SAID CONTACT MEMBERS EACH HAVING A SLOT THEREIN THE ENTRANCE OF WHICH HAS CORNERS THEREON THAT LOCALLY RUPTURE AND STRIP ONE SHEET OF SAID MATERIAL OF SAID STRIP CABLE TO EXPOSE THE CONDUCTOR RIBBONS TO AN INTIMATE ELECTRICAL CONTACT WITH SAID CONTACT MEMBER WHEN THE STABILIZED STRIP CABLE IS INSERTED INTO SAID SLOT; SAID CONTACT MEMBERS EACH HAVING RESILIENT PORTIONS THEREON ON EACH SIDE OF SAID SLOT THAT ARE CAPABLE OF BEING FLEXED AWAY FROM EACH OTHER WHEN THE STRIP CABLE IS INSERTED INTO SAID SLOT AND IN COOPERATION WITH SAID GUIDE SLOTS INSURES, AT LEAST IN PART, THAT SAID CONDUCTOR RIBBONS ARE NOT DAMAGED WHEN THE ENCLOSING MATERIAL IS RUPTURED AND STRIPPED THEREFROM.

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