Contact assembly

Abstract: A contact assembly (34) for a modular receptacle (20) includes an array (28) of substantially coplanar contacts (30, 32) which are held in position by first and second insulators (36, 38). The contacts are exposed (42) between the two insulators, and a latch mechanism (50, 54) holds the two insulators (36, 38) in the desired transversely oriented relationship with respect to one another. This contact assembly (34) can be formed by insert molding the insulators (36, 38) around the contacts (30, 32) in a substantially coplanar configuration, and then bending the exposed central portions (42) of the contacts to latch the two insulators into the final transverse orientation.

Description: This invention relates to an electrical connector according to the generi clause of claim 1. This invention is concerned with an improved contact assembly of the type having an array of contacts which are held in position by at least one contact retaining element for insertion into a housing. Though not limited thereto, this invention has been applied successfully to contact assemblies for modular receptacles. Modular receptacles are in widespread use, and there is an ongoing effort to provide lower cost, more reliable receptacles which can be assembled in a high speed, efficient manner. One approach of the prior art illustrated in document US-A-4,337,574 is to insert mold the housing for a modular receptacle around an array of contacts. This approach requires relatively complex insert molding equipment. Another approach which eliminates the need for insert molding equipment is illustrated in document US-A-4,292,736. In this approach, individual contacts are inserted into a premolded receptacle, as shown in Figures 7-9 of the document US-A-4,292,736. Another approach involves the use of a contact assembly which holds the preformed contacts in the desired alignment prior to assembly into a separate housing. For example, document US-A-4,202,593 discloses one such contact assembly in which the contacts are wrapped around a generally U-shaped molded insulator. Documents US-A-4,786,259, US-A-4,807,358, US-A-4,699,595 and US-A-4,274,691 disclose other types of contact assemblies for modular receptacles. In each of these four patents, the contact assemblies include contact retaining elements which are one piece devices. Document US-A-4,817,283 discloses another contact assembly for a modular receptacle. In this assembly the contacts are held in position by a insulating element 74 which is molded in place across the contacts, and by two insulating plates 60, 62 which are assembled with the contacts to hold them in position. Document WO-A1-81/02703 discloses an electrical contact assembly made as a socket for an electrical component. Said known socket comprises two plastic body members that are outsert molded to conductor straps which grip lead members of electrical components and also provide hinge elements connecting the two members. The conductor straps also provide clip elements for holding the body members in relation to one another. The present invention is directed to an improved contact assembly which is reliable and inexpensive, which provides excellent true position for both ends of the contact, which is insertable with high speed, low cost assembly equipment at a very low reject level, and which can be formed with relatively simple insert molding equipment. The present invention provides an electrical contact assembly as defined in claim 1. Embodiments of the invention are defined in the dependent claims. An electrical connector contact assembly includes a plurality of contacts and first and second insulating contact retaining elements. The contact retaining elements are engaged with the contacts to maintain the contacts in selected positions. Each of the contacts defines two exposed end portions and a central portion, and the end portions are each adapted to make contact with a respective external conductor. The central portions are disposed between the contact retaining elements and are bent such that the contact retaining elements are positioned at an angle with respect to one another. In the preferred embodiment described below, a latch on one of the contact retaining elements is configured to engage the other of the contact retaining elements to hold the contact retaining elements at the selected angle. First and second contact retaining elements are molded at respective positions around a plurality of substantially parallel contacts. Each of the contacts defines first and second end portions, each positioned adjacent to a respective one of the contact retaining elements and each adapted to make contact with a respective external conductor. Each of the contacts also defines a central portion located between the contact retaining elements. The central portions are then bent while moving the first and second contact retaining elements to a selected angle with respect to one another. Preferably, the first and second contact retaining elements are then latched together at the selected angle. The contact assembly described below provides a stable assembly that holds both ends of the contacts in the desired positions in a stand alone device, and that does not require further bending or deformation when it is inserted into the housing. The contacts and the contact retaining elements cooperate to hold the array of contacts in a stable, preformed configuration prior to insertion into the housing. The method described below can be practiced with relatively simple insert molding and bending equipment, and this method provides a reliable and inexpensive fabrication method for contact arrays having excellent true positions of both ends of the contacts. An electrical contact assembly comprises electrical contacts secured in a dielectric member, the said contact assembly being mountable in a cavity of a receptacle housing, the dielectric member comprises a first dielectric member and a second dielectric member secured onto the electrical contacts with exposed portions of the electrical contacts between the first and second dielectric members, the dielectric members being bent substantially normal with respect to one another, and latching members on the first and second dielectric members latching the first and second dielectric members in the substantially normal position. The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a front perspective view of a modular receptacle in which is mounted a preferred embodiment of the contact assembly of this invention; Figure 2 is a front view of the receptacle of Figure 1; Figure 3 is a side view of the preferred embodiment of the contact assembly of this invention; Figure 4 is a plan view of a stamped contact array used in the fabrication of the contact assembly of Figure 3; Figure 5 is a top view taken at a first stage in the fabrication of the contact assembly of Figure 3; Figure 6 is a bottom view of the elements of Figure 5; Figure 7 is a longitudinal sectional view taken along line 7-7 of Figure 6; Figure 8 is a cross-sectional view taken along line 8-8 of Figure 6; Figure 9 is a cross-sectional view taken along line 9-9 of Figure 6; Figure 10 is a side view taken along line 10-10 of Figure 6; Figure 11 is a top perspective view of the elements of Figure 6; Figure 12 is a bottom perspective view of the elements of Figure 6; Figure 13 is a side view in partial section of a first stage in the assembly of the contact assembly of Figure 3 with a housing; Figure 14 is a view corresponding to Figure 13 of a second, subsequent stage in the insertion of the contact assembly into the housing of Figure 13; and Figure 15 is a cross-sectional view of the contact assembly of Figure 3 fully inserted in the housing of Figures 13 and 14. Turning now the drawings, Figures 1 and 2 show two views of an electrical connector 20 which in this embodiment is a modular receptacle for two telephone type plugs. Though illustrated as a two port receptacle, it will of course be understood that the preferred embodiment described below can readily be used in a housing having any number of ports. The receptacle 20 includes a housing 22 that defines sidewalls 24. Each pair of sidewalls 24 in turn defines a plug receiving cavity 26 that is shaped to receive a mating plug (not shown). Contacts 28 are mounted within the housing 22, and these contacts 28 each define first end portions 30 positioned to make contact with the mating plug (not shown) and second end portions 32 configured as solder tails and adapted to make contact with conductive traces on a printed circuit board (not shown). As shown in Figures 1 and 2, the housing 22 is provided with a two part shield that can be made of a suitable sheet metal. The shield includes a front shield 23 that overlies the top, sides and front of the housing 22 and a rear shield 25 that overlaps the rear edge of the front shield 23 and overlies the rear of the housing 22. The front shield 23 defines spring fingers 27 shaped to make electrical contact with a mating plug (not shown). The front shield 23 may have a panel ground (not shown) as is known in the art, as disclosed for example in document US-A-5,083,945. The contacts 28 are arranged in a contact assembly or insert 34 that includes first and second insulators 36, 38 that operate as contact retaining elements (Figure 3). The following discussion will explain with Figures 4-12 the manner in which the insert 34 is formed, and then with Figures 13-15 the manner in which the insert 34 is assembled in the housing 22. Turning now to Figures 4-12, the first step in the formation of the insert 34 is to stamp an array of contacts 28 such that they are held in position by opposed paralleled carrier strips 40 (Figure 4). As shown in Figure 4 the contacts 28 define first ends 30 and second ends 32, and the spacing of the first ends 30 differs from that of the second ends 32. As shown in Figures 5-12, in the next step in the fabrication of the insert 34 first and second insulators 36, 38 are insert molded around the contacts 28. Prior to this insert molding operation half of the second end portions 32 are severed from the adjacent carrier strip 40 and bent to an offset configuration as shown in Figure 7. A number of features of the insulators 36, 38 are important in the subsequent discussion. First, it should be noted that the insulators 36, 38 are separated from one another, and that a central portion 42 of the contacts 28 is exposed between the insulators 36, 38. This central portion 42 of each of the contacts 28 lies exposed but closely adjacent to an external surface 44 defined by the second insulator 38 (Figure 8). As best shown in Figures 6 and 8, three ribs 46 are formed adjacent to the external surface 44, and each of these ribs 46 defines an arcuate bearing surface 48. In addition, the second insulator 38 defines a pair of flanges 50 at either end of the external surface 44. These flanges 50 are best shown in Figures 10 and 12. The second insulator 38 also defines a pair of wedges 51 on opposed side surfaces, as best shown in Figures 8, 11 and 12. Turning now to the first insulator 36, this element defines a follower surface 52 (Figures 7, 9 and 12) which is designed to bear against the bearing surface 48 as described below. Also, the first insulator 36 defines a pair of latches 54, a pair of tabs 56, and a rounded edge 58 (Figures 5, 6 and 12). The tabs 56 provide a locating and a protecting function as described below. As best shown for example in Figures 7, 11 and 12, the first and second insulators 36, 38 as initially formed are positioned in a substantially coplanar arrangement, as are the contacts 28. For this reason, the insulators 36, 38 can be formed using relatively small, inexpensive dies. In order to facilitate the bending operation described below the central portions 42 are preferably substantially coplanar (Figures 7-9) and completely exposed between the insulators 36, 38. After the elements of Figures 4-12 have been formed as shown, the carrier strips 40 are then severed, and the first end portions 30 are bent around the rounded edge 58 to the position shown in Figure 3. Then the first insulator 36 is rotated with respect to the second insulator 38 about a hinge axis defined by the central portions 42. This causes the central portions 42 to bend and to pull away from the external surface 44. During at least part of this bending operation the follower surface 52 rides along the arcuate bearing surface 48, thereby facilitating precisely repeatable bending of the central portions 42. As this bending operation nears completion, the latches 54 move into the region between the flanges 50 (see Figure 12). Once the insulators 36, 38 have been moved to a position in which they are substantially normal to each other, the latches 54 emerge below the flanges 50, thereby latching the first and second insulators 36, 38 at the desired 90° angle with respect to one another. This completes the formation of the insert or contact assembly 34 of Figure 3. Note that the first insulator 36 precisely positions the first end portions 30 immediately adjacent the rounded edge 58, and the second insulator 38 precisely positions the second end portions 32. The central portions 42 are bent to a selected angle of about 90°, and the bent central portions 42 provide a holding force that opposes the latches 54 and provides a stable assembly. In order to facilitate bending of the central portions 42, the central portions 42 are substantially coplanar adjacent their entry into both the first and second insulators 36, 38. The first end portions 30 are bent back toward the second insulator 38 to an acute angle as shown in Figure 3. As shown in Figures 13-15, the insert 34 is assembled into the housing 22 by initially positioning the two elements as shown in Figure 13. Note that the housing 22 defines a top wall 60, a bottom wall 62 and a comb-shaped cross bar 64 that extends between the sidewalls 24. The cross bar defines a sloped cam surface 66, and the top wall 60 defines a stop surface 68. In the next stage of insertion shown in Figure 14, the insert 34 is moved into the cavity 26 between the sidewalls 24. As shown in Figure 15, when the insert 34 is fully inserted within the housing 22, the stop surface 68 contacts the tabs 56 to define a fully inserted position for the insert 34, and to protect the first end portions 30 from undesired contact with the housing 22. The cam surface 66 moves the first end portions 30 toward the first insulator 36 in order to ensure that the first end portions 30 are in a predetermined position within the housing 22. The insert 34 is held in its final position within the housing 22 by the wedges 51, which snap into mating engagement with shoulders 24a in recesses in the sidewalls 24. Adhesives, ultrasonic welding and other types of mechanical latches may be substituted for the wedges 51. Simply by way of example and without intending to limit the scope of the following claims, it has been found that the following materials are suitable for use in this invention. The first and second insulators 36, 38 can be molded of a suitable thermoplastic material such as a polysulfone molding compound selected to provide low shrinkage and a suitable high degradation temperature to survive wave soldering. Contacts 28 can be formed of a suitable conducting material such as a spring tempered, cold rolled phosphor bronze. The insert 34 can be used with a wide variety of housings, and thus it should be clear that this invention is not limited to housings with any specified number of plug receiving cavities 26. Furthermore, this invention is not limited to use with modular receptacles of the type illustrated, and it is not essential that the first and second insulators 36, 38 be formed as the physically separate pieces. If desired, they can be interconnected by a web, as long as this web is sufficiently thin and flexible to allow the insulators 36, 38 to be bent to the desired end position in which they are held by the latch 54. From the foregoing, it should be apparent that a reliable and inexpensive method has been described for fabricating contact assemblies. These assemblies are completely preformed prior to insertion into the housing, and they therefore can be inserted at high speed using low cost assembly equipment with low reject levels. Because the contacts are fully retained in the insulators 36, 38, no bending or plastic deformation is required to hold the contacts in the housing. The insulators 36, 38 cooperate to provide excellent true position for both ends of the contacts. The low cost of the contact assembly 34 is enhanced by the fact that the contacts themselves are stamped in a relatively flat array and straight draw molds can be used to produce the insulators 36, 38. The foregoing detailed description has been intended to illustrate one preferred form of this invention and not to limit its scope. The scope of the invention is defined by the following claims, including all equivalents. An advantage of the present invention is an electrical contact assembly that is latchably secured in a housing cavity with contact sections being secured in first and second dielectric members. Another advantage of the present invention is the latching of the first and second dielectric members in a substantially normal position. A further advantage of the present invention is the contact sections secured in the first dielectric member extend therealong at an acute angle with respect thereto. An additional advantage of the present invention is a comb-shaped cross bar within a cavity of the housing for positioning the first dielectric member contact sections.

Claims: An electrical contact assembly (34) mounted in a cavity (26) of a receptacle housing (22), a) comprising electrical contacts (30, 32) secured in a dielectric member (36, 38), b) the dielectric member (36, 38) comprising ba) a first dielectric member (36) and bb) a second dielectric member (38) secured onto the electrical contacts (30, 32) with exposed portions (42) of the electrical contacts between the first and second dielectric members (36, 38), bc) the dielectric members (36, 38) being bent substantially normal with respect to one another, and bd) latching members (50, 54) on the first and second dielectric members (36, 38) latching the first and second dielectric members in the substantially normal position. An electrical contact assembly as claimed in claim 1, characterized in that said contacts (30) have contact sections extending along said first dielectric member (36) at an acute angle relative thereto. An electrical contact assembly as claimed in claim 1 or 2, characterized in that said contacts (32) have contact sections extending outwardly from a bottom surface of said second dielectric member (38). An electrical contact assembly as claimed in claims 1, 2 or 3, characterized in that some of the contacts (32) are offset with respect to the others. An electrical contact assemblv as claimed in any of claims 1 to 4, characterized in that said contact assembly (34) and said housing (22) have further latching members (51, 24a) for latching said contact assembly in said housing cavity (26). An electrical contact assembly as claimed in any of claims 1 to 5, characterized in that said housing (22) has a comb-shaped cross bar (64) in which contacts (30) are disposed.

Inventors: REED CARL GENE, REED, CARL GENE
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1993
Main classification: H01R13
IPC codes: H01R13