EP0000434B1

EP0000434B1 - Connecting block for interconnecting wires and with two matable connector parts and slotted beam contacts

Info

Publication number: EP0000434B1
Application number: EP78300122A
Authority: EP
Inventors: Richard Newman Berglund; John Paul Pasternak
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1977-07-06
Filing date: 1978-07-06
Publication date: 1983-05-11
Also published as: ES471510A1; US4118095A; IT7853481V0; JPS5415187A; JPS58158B2; IT7868579A0; DE2862245D1; IT1108534B; EP0000434A1

Description

This invention relates to devices for making electrical cross-connections between two sets of conductors and, in particular, to apparatus for electrically interconnecting first conductors with associated second conductors, the apparatus comprising a first connector of insulative material, provided with individual receiving and indexing means for the first conductors, and a second connector for mating with the first connector, comprising a body member of insulative material and a plurality of slotted beam contacts, each in a cavity in the body, one end of the slotted beam contacts for contacting the first conductors when the first and second connectors are mated, the other end of the slotted beam contacts for contacting the second conductors.
In the prior art, wire connecting blocks of the type including an indexing strip and a connecting block are known wherein the connecting block carries a plurality of slotted beam contacts, such as disclosed in U.S. Patent No. 3,611,264. The indexing strip has a plurality of uniform height, spaced-apart teeth along its length. These teeth aid in indexing a first set of conductors. A corresponding plurality of uniform height, spaced-apart teeth carried by the connecting block serve to index a second set of conductors to be cross-connected through the slotted beam contacts to the first set of conductors.
A number of improvements to this basic connecting block are disclosed in U.S. Patent No. 3,798,587. In order to facilitate mass assembly of the contacts in the connecting block, this improved connecting block is a two- piece structure, the parts of which are secured together following insertion of the slotted beam contacts. While this connecting block arrangement has proved to be satisfactory in some applications, it was found that when the connecting block is placed over the indexing strip in cold temperatures, certain stresses are applied to the bond between two connector parts. These stresses often rupture the bond causing failure of the entire unit.
U.S. Patent No. 3,778,750 describes another connecting block which is a two piece structure the parts of which are secured together following insertion of the contacts. One part of the block is formed with integral pins which extend through holes in the contacts into holes in the other part of the block. The connecting block is used without an indexing strip.
The problems of the prior art are solved by the invention in accordance with which the second connector includes separate contact holding means which project into the cavity through a hole in the wall thereof, which physically engage in said hole, which coact with the contacts so as to hold the contacts in the body member, and which physically engage in a recess in the opposite wall of the cavity, whereby insertion forces produced during engagement of said slotted beam contacts with said indexed conductors tend toward shearing of said holding means rather than splitting of the body member.
In the claimed apparatus, the body member in which the contacts are held can be manufactured as one piece, so avoiding rupture of a bond between parts thereof. On the other hand, assembly of the slotted beam contacts in the connector is facilitated by the use of the contact holding means which enables the contacts to be inserted easily in the body member and then secured by the contact holding means.
In other applications, such as outdoor environments, moisture collects across the exposed conductor ends. This moisture often times results in short circuits between some of the conductors. In an attempt to alleviate this problem, an insulative, greaselike compound is placed in the cavity of the connector disclosed in the said U.S. Patent No. 3,798,587. While this greaselike compound aids in the reduction of electrical short circuits, unfortunately, it further increases the mechanical stresses applied to the joint between the two connector parts as the connector is brought into engagement with the indexing strip.
A preferred embodiment of the invention has a L-shaped skirt integral with and projecting away from the second connector for encasing the end of the first conductors.
One way of carrying out the invention will now be described, by way of example, with reference to the attached drawings which illustrate one specific embodiment and in which:

Fig. 1 is a side view of a first connector;
Fig. 2 is an end view of the first connector;
Fig. 3 is a top view of the first connector;
Fig. 4 is an exploded partial perspective view of the second connector;
Fig. 5 is a partial perspective view of a comb- like slotted beam contact retainer;
Fig. 6 is a side view of the second connector;
Fig. 7 is an end view of the second connector;
Fig. 8 is a top view of the second connector;
Fig. 9 is a composite end view of the first and second connectors aligned for mating connection with one another and further illustrating encasement of the exposed wire ends of the first set of conductors.

A first mating connector, hereinafter denoted as indexing strip 11 and shown in Figs. 1 through 3, includes a longitudinally extending body member 12. Integral with body member 12 and extending generally perpendicular to an axis thereof are a plurality of spaced-apart teeth 13. Teeth 13 alternate in height to facilitate indexing of a first set of conductors 14 shown in Fig. 9. To further facilitate wire indexing, teeth 13, as shown in Fig. 1, have tapered tip regions 15 on adjacent sidewalls 16. These tapered tip regions 15 form generally funnel-shaped wire entry ways for directing conductors 14 into wire retaining slots 17 formed by spaced-apart teeth 13.
Adjacent sidewalls 16 of spaced-apart teeth 13 have integral therewith a pair of opposed depressions 18 for capturing and holding an indexed conductor 14 between the teeth in a wire retaining slot 17. Opposed depressions 18 are located at an intermediate point along the height of teeth 13 above wire retaining slot 17.
Extending along a length of body member 12 are outwardly projecting edges 20 and 21, as shown in Fig. 2. Edges 20 and 21 are at different elevations along body member 12 with edge 20 being at a lower elevation than edge 21 when viewed from tapered tip regions 15 of spaced-apart teeth 13. This difference in elevation of edges 20 and 21 enables only one way engagement of indexing strip 11 with a second mating connector 40, as shown in Fig. 9. Edge 21 has a width nearly twice the width of edge 20. This difference in width facilitates cutoff of first conductors 14 by a tool (not shown).
Also shown in Fig. 2 is a generally funnel-shaped channel 22 which is integral with sidewall 16 of spaced apart teeth 13. A similar channel 22 is integral with an opposed sidewall 16 of teeth 13. These funnel-shaped channels 22 have widths of greater extent at tip regions 15 of teeth 13 to facilitate directing slotted beam contacts 30, carried by second mating connector 40 and shown in Fig. 4, into engagement with indexed conductors 14, as shown in Fig. 9.
Indexing strip 11 is affixed to a support carrier (not shown), similar to that illustrated as element 36 in Fig. 2 of U.S. Patent No. 3,798,587, by cylindrical posts 23. Posts 23 are inserted into apertures in the support carrier and heated to produce an expanded head similar to that of a rivet.
In order to securely couple indexing strip 11 to second mating connector 40, a plurality of truncated cylindrical projections 24 are integrally provided on outer walls of spaced-apart teeth 13. Projections 24, as shown in Figs. 2 and 3, have a greater thickness near an edge opposite tip regions 15 of spaced-apart teeth 13. This coupling arrangement will be considered in further detail following the description of second mating connector 40.
Once conductors 14 are indexed, cross-connections among these conductors and conductors 39 of a second set, as shown in Fig. 9, are effected through a plurality of slotted beam contacts 30, shown in Fig. 4. Each of contacts 30 includes a central portion 31 which has first and second pairs of oppositely directed cantilever beams 32 and 33 extending therefrom. Each of the beams in the pairs of beams 32 and 33 are spaced apart from one another by elongated generally rectangular apertures 34 and 35, respectively. Apertures 34 and 35 extend from central portion 31 to a point near a pair of oppositely directed insulation-penetrating edges 36 and 37, respectively, at the ends of beams 32 and 33. It should be noted that beams 33 are of shorter length than beams 32 to increase the force provided by edges 37 during engagement with conductor insulation. Also included in central portion 31 is a generally oval-shaped aperture 25 used in mounting contact 30 in mating connector 40.
The second mating connector 40, shown in Fig. 4, comprises a body member 41 which has a plurality of elongate generally rectangular cavities 42 therein for slidably engaging slotted beam contacts 30. Extending partially along planar inner sidewalls 43 of cavities 42 are channel cavities 44. A corresponding plurality of spaced-apart apertures 45 are included in an outer sidewall 46 of body member 41. Spaced-apart apertures 45 are aligned in one-to-one correspondence with rectangular cavities 42 and channel cavities 44.
Once slotted beam contacts 30 are inserted into rectangular cavities 42 and aligned such that aperture 25 is beneath a corresponding aperture 26, shown in Fig. 6, anchoring member 50 is brought into engagement with body member 41. Anchoring member 50, shown in Fig. 5 is comprised of a generally flat rectangular member 51. Integral with member 51 and extending outwardly therefrom are a plurality of spaced-apart generally triangular projections 52. Extending from tops of triangular projections 52 are projections 53 and 54. Interposed between projections 53 and 54 is a notch 55 the width of which is approximately equal to a width of central portion 31 between apertures 25 and 34 of contact 30. The projections 52, 53, 54 extend through and physically engage in the apertures 45 in the wall 46 of respective cavities 42, to hold the contacts in the cavities.
Triangular projections 52, in conjunction with projections 53 and 54 and the depth of notch 55, limit the extent of engagement of slotted beam contact 30 with rectangular member 51. It should be noted that projection 53 extends through slot 34 in the contact to physically engage in channel cavities 44 and projection 54 extends through aperture 25 in the contact to physically engage in aperture 26. This mounting arrangement for slotted beam contacts 30 couples insertion forces produced during engagement of second mating connector 40 with indexing strip 11 into projections 53 and 54. Consequently, the insertion forces tend toward the shearing of projections 53 and 54 rather than the splitting of body member 41.
To ensure proper alignment of anchoring member 50 with body member 41, the former includes a projecting lip 56 along a lengthwise edge 57. Outer sidewall 46 has a mating groove 48 extending along its length. This lip and groove arrangement provides a polarized mating of anchoring member 50 with body member 41. The two members 50 and 41 are secured to one another, for example, by ultrasonic welding.
As shown most clearly in Figs. 7 and 9, body member 41 has integral therewith and extending outwardly away therefrom a generally L-shaped skirt 61. A plurality of scallops 62, as shown in Fig. 4, along the base leg of the "L" and along opposite edge 63, engage conductors 14, as shown in Fig. 9, and hold them in place between indexing strip 11 and mating connector 40. Skirt 61 encases exposed ends 19 of first conductors 14 to electrically isolate them from one another. Not only does the insulative material of which both indexing strip 11 and mating connector 40 are made provide electrical isolation, but skirt 61 in conjunction with sealing compound (not shown) shields exposed ends 19 to prevent any accumulation of moisture which could cause electrical short circuits.
After first conductors 14 are individually received and indexed in indexing strip 11 and conductor ends 19 are trimmed to the proper length, mating connector 40 with the plurality of slotted beam contacts 30 therein is brought into engagement with indexing strip 11. Mating connector 40 is coupled securely to indexing strip 11 by projections 24 which engage a corresponding plurality of circular apertures 49 in sidewall 46 and skirt 61. Circular apertures 49 are aligned in correspondence with truncated cylindrical projections 24 so that apertures 49 surround projections 24 with the greater thickness inhibiting separation of mating connector 40 from indexing strip 11 once the two are mated.
It should be noted that mating connector 40 holds the slotted beam contacts 30 in a spatial relationship so that an individual contact 30 is engageable with an individual conductor 14. Opposite ends of contacts 30 are now available for engagement with second conductors 39, as shown in Fig. 9.
To facilitate alignment and indexing of second conductors 39, mating connector 40, as shown in Figs. 6 through 8, has a plurality of spaced-apart, alternating height teeth 65 integral with body member 41. Teeth 65 have a configuration somewhat similar to that of teeth 13 on indexing strip 11 insofar as teeth 65 have tapered tip regions 66 forming funnel-shaped wire entry ways 67. Near the bottom of wire retaining slots 68 formed by adjacent sidewalls 69 of teeth 65 there are oppositely directed interference projections 71. Projections 71 have a thickness of greater extent at a central point therein which is removed from taper tip regions 66. Projections 71 facilitate capture and inhibit conductors 39 from separating from mating connector 40 after being seated in contacts 30.
Electrical isolation is provided among exposed ends of conductors 39 by extended lateral projections 72 on teeth 65 as shown in Fig. 8. These extended projections 72 increase the electrical path length between adjacent exposed conductor ends. On outer edges of alternate ones of projections 72 are projecting lips 73 for facilitating engagement of a test cord (not shown) with mating connector 40.

Claims

1. Apparatus for electrically interconnecting first conductors with associated second conductors, the apparatus comprising a first connector (11) of insulative material, provided with individual receiving and indexing means for the first conductors, and a second connector (40) for mating with the first connector, comprising a body member (41) of insulative material and a plurality of slotted beam contacts (30), each in a cavity in the body, one end of the slotted beam contacts for contacting the first conductors when the first (11) and second (40) connectors are mated, the other end of the slotted beam contacts for contacting the second conductors, characterised in that the second connector (40) includes separate contact holding means (52-54) which project into the cavity (42) through a hole (45) in the wall (46) thereof, which physically engage in said hole (45), which coact with the contacts (30) so as to hold the contacts (30) in the body member (41), and which physically engage in a recess (26, 44) in the opposite wall of the cavity, whereby insertion forces produced during engagement of said slotted beam contacts with said indexed conductors tend toward shearing of said holding means (52-54) rather than splitting of the body member (41).

2. Apparatus in accordance with claim 1, wherein said contact holding means comprises a holding member (50) which is provided with projections (52-54) which penetrate wall (46) of the second connector as well as the beam contacts (30) and which extend into recesses (26, 44) in the opposite wall so as to hold the contacts in the second connector.

3. Apparatus in accordance with claim 2, wherein capturing and holding means are provided integral with adjacent sidewalls of spaced-apart teeth (13) of the first connector and comprise first and second opposed depressions (18) in adjacent sidewalls of the teeth, the opposed depressions located at an intermediate point along the height of the teeth above wire retaining slots (17).

4. The apparatus in accordance with claim 2 or 3, wherein directing means (22) are included in the first connector (11), integral with opposed sidewalls (16) of each of the spaced-apart teeth (13), for directing a plurality of slotted beam contacts (30) held by the second connector (40) into engagement with the indexed first conductors (14).

5. Apparatus in accordance with claim 4 wherein the directing means comprise generally funnel-shaped channels (22) on adjacent sidewalls of the spaced-apart teeth, the channels having a width of greater extent at the tips of the teeth.

6. Apparatus in accordance with one or more of claims 2 to 5, wherein each of the slotted beam contacts includes: a central portion having a generally oval-shaped aperture (25) therein; first and second pairs of oppositely directed cantilever beams (33), wherein the first pair of beams (33) is shorter in length than the second pair of beams (32).

7. Apparatus in accordance with any of claims 2 to 6, wherein the second connector (40) comprises a body member (41) having a plurality of elongated generally rectangular cavities (42) therein for slidably engaging slotted beam contacts (30); channel cavities (44) extending partially along planar inner sidewalls (43) of cavities (42); and an outer sidewall (46) extending along a length of the body member, said outer sidewall having a plurality of spaced-apart apertures (45) therein aligned in one-to-one correspondence with said plurality of rectangular cavities (42) and the channel cavities (44).

8. Apparatus in accordance with claim 7, wherein the contact holding member (50) is engaged with the aligned plurality of apertures (45), one of the elongated generally rectangular apertures (34, 35) in each of the slotted beam contacts (30) the generally oval-shaped aperture (25) in the contacts, and the channel cavities (44).

9. Apparatus in accordance with claim 8, wherein the contact holding member (50) comprises: a generally flat rectangular member (51); a plurality of spaced-apart generally triangular projections (52) integral with said rectangular member; and a plurality of projections (53, 54) integral with tops of the triangular projections 52, the triangular projections limiting the extent of engagement of the slotted beam contacts with the rectangular member (51).

10. Apparatus in accordance with claim 9, wherein each of the projections (53, 54) has a notch (55) therein the width of which is approximately equal to a width of a central portion (31) between the generally oval-shaped aperture (25) and one of the generally rectangular apertures (34, 35) in one of the slotted beam contacts (30).

11. Apparatus in accordance with claims 9 or 10, wherein the contact holding member (50) includes a projecting lip (56) along an edge (57) of said rectangular member (51).

12. Apparatus in accordance with claim 11, wherein the outer sidewall (46) of the second mating connector (40) includes a groove (48) therein engaging the projecting lip (56) and providing mating of the contact holding member with the second mating connector (40).

13. Apparatus in accordance with any of claims 2 to 12, wherein a shielding means (61) forms an integral part of the second connector (40) and encases exposed ends (19) of the first conductors (14) and comprises: a generally L-shaped skirt (61) projecting away from the second connector (40).

14. Apparatus in accordance with claim 13, wherein the integral skirt (61) is scalloped along the base of the L-shape, the scallops (62) engaging the first conductors (14) and holding them in place between the first and second connectors (11, 40).

15. Apparatus in accordance with any of claims 4 to 14, wherein coupling members (24) are provided integral with each of the spaced-apart teeth (13) securely coupling the second connector to the first connector.

16. Apparatus in accordance with claim 15, wherein the coupling members (24) comprise a plurality of truncated cylindrical projections (24) each projection having a greater thickness near its edge opposite a tip of said spaced-apart teeth; and that the second mating connector (40) comprises a plurality of generally circular apertures (49) aligned in correspondence with the truncated cylindrical projections (24), said apertures surrounding the projections and the greater thickness inhibiting separation of the first and second connectors after the connectors are mated.

17. Apparatus in accordance with any of claims 2 to 16 wherein the first connector includes: a longitudinally extending body member (12); first and second projecting side edges (20, 21) extending along a length of the body member, the first and second side edges being at different elevations along the body member such that the first side edge is at a higher elevation than the second side edge to enable one way engagement of the first and second connectors.

18. Apparatus in accordance with claim 17, wherein the first side edge (21) has a width nearly twice the width of the second side edge (20) to facilitate cutoff of the first conductors (14).