Insulated and shielded connector

Abstract: A connector comprises conductive contact means (14) for connection to a corresponding signal conductor (3) of an electrical cable (2), a drawn conductive shell (16), insulator means (15) for separating the contact means (14) and the conductive shell (3), an insulative housing (8) with a key, for orienting and covering the conductive shell (16) and the insulator means (15), and insulative coupling means (9) for disconnectable coupling to a complementary connector and adapted for movement along a portion of the insulative housing (8) with an interference fit therewith to a position for rotation with said insulative housing (8) while interlocked with a second portion of said insulative housing (8).

Description: The invention relates to a shielded electrical connector providing EMI and RF shielding. A connector disclosed in U.S. Patent 3,281,756 includes electrical contacts connected to corresponding signal carrying conductors of a cable, and a conductive shell connected to a conductive, outer braid or tubing providing a shield for EMI, electromagnetic interference and RF, radio frequency interference. The conductive shell is uncovered, and can transmit high voltage that is induced or conducted along the shield of the cable. Such high voltage can cause electrical shock to a person that grasps the conductive shell. In a connector that has two electrical contacts, a keying feature is required to orient the contacts during mated connection of the connector to another, complementary connector. Heretofore, the keying feature was accomplished by machining a key unitary with the shell, or by assembling a separate key and the shell. A further assembly operation is required for mounting a coupling mechanism to the connector, such that the coupling mechanism can be coupled to a complementary connector. Heretofore a coupling mechanism was retained on the connector by a ring assembled on an exterior of the connector as a separate component part. The present invention consists in a connector as defined in claim 1. EP-A-0 249 250 discloses a connector according to the preamble of claim 1. Further according to an embodiment of the invention, a connector comprises, an insulative coupling means and an insulative housing having been molded with an integral key, and the coupling means is assembled by movement along a portion of the housing with an interference fit to a position for rotation with respect to the housing while interlocked with a second portion of the housing. As disclosed herein a connector comprises, conductive contact means for connection to corresponding signal conductor means of an electrical cable, a conductive shell, insulator means for separating the contact means and the conductive shell, an insulative housing having a unitary key, respective keyways of the conductive shell and the insulator means receiving the unitary key, and the conductive shell is fabricated by having been drawn into the shape of a cylinder with the keyway extending longitudinally of the cylinder and opening into a front end of the cylinder. Also as disclosed herein a connector is fabricated by a process comprising the steps of: assembling an insulative coupling means and a unitary insulative housing having been molded with a key, assembling a conductive shell into an opening of the housing with a keyway of the shell receiving the key, assembling into the opening insulator means and at least one electrical contact having been joined to a corresponding conductor of an electrical cable and a conductive clamp having been joined to a conductive shield of the cable, and covering the opening in the housing with an insulative cover. An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings. Figure 1 is a perspective view of a connector assembled with an electrical cable. Figure 2 is a perspective view of the connector shown in Figure 1 with parts exploded apart. Figure 3 is a side elevation view in section of a shell as shown in Figure 10. Figure 4 is an end elevation view of a conductive shell of the connector shown in Figure 3. Figure 5 is an elevation view of the housing shown in Figure 10. Figure 6 is an elevation view in section of a nut shown in Figure 8. Figure 7 is an elevation view partially in section of the housing and nut assembled. Figure 8 is a side elevation view of the nut shown in Figure 9. Figure 9 is a partial end elevation view of an insulative nut of the connector shown in Figure 1. Figure 10 is a side elevation view of an insulative housing of the connector shown in Figure 1. Figure 11 is an end elevation view of the housing of the connector shown in Figure 1. Figure 12 is a side elevation of an assembly of the connector shown in Figure 1. Figure 13 is a side elevation view in section of an insulative nut of the connector shown in Figure 1. Figure 14 is an end elevation view of the nut shown in Figure 13. Figure 15 is a side elevation view of the nut shown in Figure 13. Figure 16 is a section view of a gasket. Figure 17 is an elevation view in section of a clamp element. Figure 18 is an elevation view in section of a sleeve element. Figure 19 is a plan view of a bottom of an insulator means of the connector shown in Figure 1. Figure 20 is an end view of the insulator means shown in Figure 19. Figure 21 is a section view of the insulator means shown in Figure 19. With reference to Figures 1 and 2, a connector 1 is assembled to an electrical cable 2. The cable 2 includes first and second elongated conductor means or conductors 3, 3 each encircled by insulation 4 known as the dielectric, a conductive shield 5, for example, braided wires encircling the dielectric 4, and an outer insulative jacket 6 of polymeric material. Insulation 7 may encircle a corresponding conductor 3. The connector 1 and its component parts will now be explained. An insulative housing 8 and an insulative coupling means 9, for example, a tubular collar, provides outer insulative surfaces that prevent electrical shock from voltage transmitted along the shield 5 of the cable 2. Also shown is an insulative nut 10, a gasket 11, a conductive clamp element 12, a conductive sleeve element 13, conductive contact means, for example, electrical contacts 14, 14 of tubular form for receipt of and connection to the respective conductors 3 of the cable 2, insulator means 15, and a conductive shell 16, Figures 3 and 4. With reference to Figures 13 through 15, the nut 10 is of unitary molded plastics construction, and includes a central bore 17 receiving the cable 2, an exterior end cap 18 provided with exterior flats 19 to receive a wrench, not shown, and exterior threads 20. With reference to Figures 5 through 11, the housing 8 is of unitary molded plastics construction with a stepped axial bore 21, a rear end 22 with an internal threaded section 23, for threadably receiving the threads 20 of the nut 10 , an internal rear facing interior shoulder 24, and axial slits 25 spaced circumferentially of a front end 26 and communicating with the bore 21. The slits 25 permit inward radial deflection of the lip 27 and the front end 26. A thickened cylindrical lip 27 with an exterior, frusto conical surface 27′ tapers to the front end 26. A cylindrical groove 28 is in the exterior immediately to the rear of the lip 27. Exterior flat recesses 29 in a thickened cylindrical wall 30 to the rear of the groove 28 provides a tool rest for receiving a wrench tool, not shown, used to tighten the nut 10 threadable to the housing 8. At the front end 26, an interior, projecting key 31 is constructed for fabrication unitary with the housing 8, and has a construction suited for fabrication by a straight draw mold apparatus, not shown, with a one piece, molding core pin, not shown. The key 31 is unitary with the lip 27, and projects into the interior of the housing 8. The key 31 has a rear facing end 32 projecting into the interior of the housing 8, to facilitate molding by a one piece core pin having a first step reduced diameter to form the shoulder 24, and a second step of reduced dimension to form the key 31 unitary with the housing 8. After formation of the housing 8 around such a core pin, the core pin is readily withdrawn from front to rear of the housing 8. Accordingly, the construction of the housing 8 is suitable for mass production by repeated molding operations using such a core pin to form duplicate housings 8. With reference to Figures 6 through 9, the coupling means 9 is of unitary molded plastics construction, and includes a cylindrical exterior provided with a series of recessed flutes 33 communicating with a front end 34, an internally threaded front section 35 for establishing a threaded connection to another, complementary connector, not shown, and an interior, projecting, circular lip 36. The lip 36 has an interference, or force, fit with the lip 27 of the housing 8, and is slidable over the lip 27 of the housing 8, as the lip 27 of the housing 8 deflects radially inward to permit passage of the coupling means 9 to a second position where the lip 36 enters the groove 28 and becomes interlocked against further movement front to rear. While the coupling means 9 is interlocked in the groove 28, it is also rotatable with respect to the housing 8 while interlocked in the groove 28, such that a threaded coupling can be established with a complementary connector, not shown, without rotation of the housing 8. The gasket 11, figure 16, is fabricated of resilient rubber, and includes a circular groove 37, facing forward. The clamp element 12, Figure 17, is fabricated of metal and includes an axial bore 38 to receive the cable 2, a rear facing ridge 39 for receipt in the groove 37 of the gasket 11 , and a front facing cup 40. The sleeve element 13, figure 18, is fabricated of metal with an axial bore 41 receiving the cable 2, and a rear facing cup 42 that overlaps the cup 40 of the clamp element 12, as illustrated in Figure 12. The insulator means 15, figures 19 through 21, for example, is a unitary molded dielectric body having a cylindrical exterior provided with a recessed keyway 43 communicating with a front end 44, contact receiving cavities 45, 45 communicating with a rear end 46 and extending to the front end 44, and an axial recess 47 communicating with the rear end 46. An indentation 48 in the rear end 46 is adjacent to one of the cavities 45 to distinguish the same from the other cavity 45. The shell 16, figures 3 and 4, is a unitary metal sleeve, formed by drawing. In the prior art, as represented by U. S. Patent 4,804,339, it has been a common practice to have a conductive shell provided with a conductive key. The key was assembled to the shell, or was fabricated integral with the shell. A disadvantage of this construction was that the shell had to be fabricated by a relatively costly operation, such as machining, and by press fitting the key to the shell, or by machining the key integral with the shell. According to the invention, the key 31 is unitary with the insulative housing 8, permitting the shell 16 to be fabricated without a key, by a less costly operation, for example, metal drawing. The shell 16 has a construction suitable for fabrication by drawing. For example, the shell 16 has a constant cylindrical thickness, except for an external, projecting, cylindrical flange 49 at a rear end 50, formed during the drawing operation by subjecting only the front portion of the shell 16 to complete drawing into a cylindrical shape. A series of longitudinal slits 51 are circumferentially spaced about a cylindrical front end 52, and communicate with the front end 52. The slits 51 permit the front end 52 to deflect resiliently and radially during coupling with a complementary connector, not shown. A keyway 53 extends longitudinally and communicates with the front end 52. The keyway 53 and the slits 51 are recessed in the thickness of the shell 16, and thereby do not interfere with formation of the shell 16 during the drawing operation. Assembly of the connector 1 and the cable 2, Figures 2 and 12, involves passing the cable 2 successively through the nut 10, the gasket 11 and the clamp element 12, then doubling back the shield 5 over the cup 40 of the clamp element 12, then passing the cable 2 through the sleeve element 13, with the cups 40 and 42 overlapping each other and clamping the shield 5 to establish an electrical connection, assembling each contact 14 to a corresponding conductor 3, assembling each contact 14 along a corresponding cavity 45 of the insulator means 15 until the insulator means 15 engages the front of the sleeve element 13, and the contact 14 projects outward of the insulator means 15, and while the corresponding conductor 3 extends unimpeded across the recess 47. The shell 16 is assembled in the housing 8, with the keyway 53 receiving the key 31 and the front facing shoulder 54 of the flange 49 faces and engages the rear facing shoulder 24 of the housing 8. The shell 16 will project forward outward of the housing 8 for connection to a complementary connector, not shown. The coupling means 9 will at all times cover the projecting portion of the shell 16.

Claims: A connector comprising, a conductive contact (14), a conductive shell (16), and an insulator (15) separating the contact (14) and the shell (16), the connector being characterised by an insulative housing (8) having an internal, unitary key (31), respective keyways (53,43) of the shell (16) and the insulator (15) receiving the unitary key (31), and the shell (16) being fabricated by having been drawn into the shape of a cylinder with the keyway (53) extending axially of the cylinder and opening into a front of the cylinder. A connector as recited in claim 1, characterised by an insulative coupling (9) adapted for movement along a portion of the housing (8) with an interference fit therewith to a position for rotation while interlocked with a second portion of the housing (8). A connector as recited in claim 2, further characterised by: the first portion (27) being deflectable inward during said movement of the coupling (9) A connector as recited in claim 2, further characterised in that: the housing (8) covers a rear portion of the shell (16), and the coupling (9) covers a forward portion of the shell (16). A connector as recited in claim 1 or 2, further characterised in that; a conductive sleeve (13) secured to a conductive shield of the cable engages a rear portion of the shell (16), and a forward facing shoulder (54) on the shell (16) faces a rear facing shoulder (24) of the housing (8). A connector as recited in claim 1 or 2, further characterised in that; an insulative end cap (10) receiving the cable is secured to the housing (8) and covers a rear of a conductive clamp (12) secured to a conductive shield of the cable.

Inventors: HENRY RANDALL ROBERT, SMITH TRACY LEE, HENRY, RANDALL ROBERT, SMITH, TRACY LEE
Applicants: WHITAKER CORP, THE WHITAKER CORPORATION
Application year: 1991
Main classification: H01R13
IPC codes: H01R13, H01R24