Feedthrough coaxial cable connector

• US 5,127,853 A
• Filed: 04/19/1990
• Issued: 07/07/1992
• Est. Priority Date: 11/08/1989
• Status: Expired due to Term

• Current Assignee: The Siemon Company Incorporated
• Original Assignee: Raychem Limited (TE Connectivity Limited)
• Inventors: Mattis, John, Sampson, Jeff, Ross, John A., McMills, Corey
• Primary Examiner(s): PIRLOT, DAVID
• Application Number:
  US07/509,669
• Time in Patent Office: 810 Days
• Field of Search: 29/861-863, 439/578-585, 439/675, 439/586, 439/587, 439/592, 439/593, 439/877, 439/879
• US Class Current: 439/578
• CPC Class Codes: H01R 9/053 using contact members penetrating insulation
• CPC Class Codes: Y10T 29/49181 by deforming

Abstract

A feedthrough coaxial cable connector includes a tubular mandrel body dimensioned to be pressed between a foil-bonded dielectric core and other elements of an outer conductor of the prepared end of the cable. The body has cable engagement surface which defines a knife edge projection therearound for engaging an outer conductor of the cable by creating shear stresses therein without actually shearing the outer conductor. A tubular shank portion extends from the cable engagement surface portion to a radial wall portion, and a jack engagement portion is coaxial about the exposed central conductor. The jack engagement portion achieves a tight friction fit upon a jack and may be formed as an inside compression collet. A radial copmression providing structure causes an inside surface region of the outer conductor to bear directly against and bend over the knife edge portion. Preferably, a slideable shell is slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of the connector to slide over the outer surface of the jack, and slideably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack to secure the connector thereto. A kit of parts including an expendable installation tool enables proper asembly of the cable connector without special skills or tools.

Claims

1. A feedthrough coaxial cable connector for connecting to a prepared end of a coaxial cable having an exposed solid-wire central conductor, the connector comprising:

a tubular mandrel body of conductive material dimensioned to be pressed between a dielectric core and an outer conductor of the prepared end of the cable, the mandrel body including a cable engagement surface portion defining a projecting knife edge extending therearound for engaging an outer conductor of the coaxial cable, said cable engagement surface comprises a tubular structure including a helix projecting upwardly from the structure, the helix defining an acute angle and providing the projecting knife edge, a tubular shank portion extending from the cable engagement surface portion of the radial wall portion, and a receptacle engagement portion coaxial extending forwardly from the radial wall portion and coaxially disposed about the exposed central conductor and dimensioned to slide into and contact in close fitting friction engagement an outer surface of a receptacle means with which the connector makes in use, and radial compression means for compressing the inside surface of the outer conductor of the coaxial cable over the knife edge of the cable engagement surface of the mandrel body in order to place the outer conductor into shear stress and without shearing the outer conductor, the compression means including a resiliently deformable elastomeric material.

2. The coaxial cable connector set forth in claim 1 wherein the projecting knife edge is formed with a flat at the apex thereof, the flat being approximately two to three mils in cross dimension.

3. The coaxial cable connector set forth in claim 2 wherein the radial compression means comprises a snap-ring dimensioned to fit tightly over the coaxial cable at the knife edge including a portion thereof comprised of the resiliently deformable elastomeric material which is radially extended by the frustoconical surface so as to snap lock the coaxial cable toward the annular edge portion thereby to cause the outer conductor to bend over and bear upon the annular knife-edge.

4. The coaxial cable connector set forth in claim 3 wherein the portion of the snap-ring forms a spline having teeth which bite into and thereby engage an outer insulation covering of the coaxial cable and thereby cause it to press the outer conductor against and cause it to bear upon the annular knife-edge.

5. The coaxial cable connector set forth in claim 1 wherein the receptacle engagement portion is dimensioned to diverge radially from the radial wall portion and further comprising slideable shell means disposed over at least the receptacle engagement portion of the mandrel body, slideably positionable generally away from a connector end facing the outer surface of the receptacle to enable the receptacle engagement portion of the connector to slide freely over the outer surface of the receptacle, the slideable shell means being slidably positionable toward the connector end so as to radially compress the radially diverging receptacle engagement portion against the outer surface of the receptacle and thereby lock the connector thereto.

6. The coaxial cable connector means set forth in claim 5 wherein the slideable shell means further defines an inside frustoconical portion congruent with the frustoconical surface portion of the mandrel body for compressing a region of the coaxial cable outer conductor against the frustoconical surface portion of the mandrel body when the slideable shell means is slideably positioned over the mandrel body when the connector is locked onto the receptacle.

7. The coaxial cable connector set forth in claim 1 wherein the receptacle engagement portion is slotted longitudinally to form a slip ring for slideable engagement over the outer surface of the receptacle.

8. The coaxial cable connector set forth in claim 7 wherein the receptacle engagement portion includes plural slots and functions as a compression collet to lock onto the outer surface of the jack as a slideable shell means is positioned toward the connector end facing the receptacle.

9. The coaxial cable connector set forth in claim 3 wherein the snap ring includes a cap portion for fitting snugly over the receptacle engagement portion of the mandrel body thereby to provide additional hoop strength to the receptacle engagement portion.

10. The coaxial cable connector set forth in claim 9 wherein the receptacle engagement portion is dimensioned to diverge radially from the radial wall portion and further comprising slideable shell means disposed over at least the cap portion of the snap ring and the receptacle engagement portion of the mandrel body, the slideable shell means being slideably positionable generally away from a connector end facing the outer surface of the receptacle to enable the receptacle engagement portion of the connector to slide freely over the outer surface of the receptacle, the slideable shell means being slidably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the receptacle and thereby lock the connector thereto.

11. The coaxial cable connector set forth in claim 10 wherein the slideable shell means is adapted to guide the snap ring into position over the coaxial cable end and mandrel body during installation of the connector onto the prepared end.

12. The coaxial cable connector set forth in claim 1 wherein the cable engagement surface portion has an interior bore which is generally frustoconically convergent toward the cable end, and further comprising a plurality of spaced apart longitudinal slots extending through the shank portion, thereby to define the cable engagement surface portion as a variable diameter collet for engaging a prepared cable ends having a dielectric core within a predetermined size range of varying core diameters.

13. The coaxial cable connector set forth in claim 12 further comprising expendable ramping means slidably positionable over the exposed central conductor of the cable for expanding the variable diameter collet as the mandrel body is positioned onto the prepared cable end.

14. A tubular mandrel body for a feedthrough coaxial cable connector, the mandrel body being formed of conductive material dimensioned to be positioned by hand between a dielectric core and an outer conductor of the prepared and of a coaxial cable, the mandrel body including a cable engagement surface portion defining a projecting knife edge extending therearound for engaging and outer conductor of the coaxial cable, said cable engagement surface portion comprises a tubular structure including a helix projecting upwardly from the structure, the helix defining an acute angle and thereby providing the projecting knife edge, a tubular shank portion extending from the cable engagement surface portion to a radial wall portion, and a jack engagement portion extending forwardly from the radial wall portion and coaxially disposed about the exposed central conductor and dimensioned to slide onto the contact in close fitting friction engagement an outer surface of a jack with which the connector mates in use.

15. The tubular mandrel body set forth in claim 14 wherein the knife edge being adapted to cooperate with the retention means of the cable connector slidably positionable over the cable end on which the mandrel body is mounted to become seated at the vicinity of the tubular shank portion.

16. The tubular mandrel body set forth in claim 14 wherein the jack engagement portion defines a shallow helical thread having a pitch to match a threaded outer surface of a jack type with which the connector is to be used after the jack engagement portion is pushed into engagement with the jack.

17. The tubular mandrel body set forth in claim 14 wherein the jack engagement portion is slotted longitudinally to form a slip ring for slideable engagement over the outer surface of the jack.

18. The tubular mandrel body set forth in claim 14 wherein the projecting knife edge is formed with a flat at the apex thereof, the flat being approximately two to three mils in cross dimension.

19. The tubular mandrel body set forth in claim 14 wherein the cable engagement surface portion has an interior bore which is generally frustoconically convergent toward the cable end, and further comprising a plurality of spaced apart longitudinal slots extending through the cable engagement surface portion and the tubular shank portion, thereby to define the cable engagement surface portion as a variable diameter collet for engaging a prepared cable ends having a dielectric core within a predetermined size range of varying core diameters.

20. The tubular mandrel body set forth in claim 14 formed by the process of die casting.

21. The tubular mandrel body set forth in claim 14 wherein the mandrel body is provided with a plating to improve lubricity characteristics.

22. The tubular mandrel body set forth in claim 14 wherein the jack engagement portion which i coaxial with the exposed central conductor includes a plurality of fingers which cooperatively define an inside collet structure for cooperation with a collet closure means of the connector which is slidably positionable over the collet structure toward the jack thereby to lock the collet structure onto a jack of a type intended for engagement with the connector.

23. The tubular mandrel body set forth in claim 22 wherein the plurality of fingers are formed by plural spaced apart radial slots extending longitudinally along the collet structure.

24. The tubular mandrel body set forth in claim 22 wherein the plurality of fingers are formed by plural slots formed by parallel cutting means operating upon the collet structure in a single pass.

25. The tubular mandrel body set forth in claim 22 wherein a cross-section of each finger defines a wall which is thicker at the opening of the collet structure than it is at the radial wall portion.

26. The tubular mandrel body set forth in claim 14 formed of a metal alloy selected from the group comprising copper, zinc and tin.

27. The tubular mandrel body set forth in claim 26 wherein the mandrel body is provided with a plating of material including tin to improve lubricity characteristics.

28. A kit of part for assembly into a feedthrough coaxial cable connector at a prepared end of a coaxial cable having an exposed solid-wire central conductor, the unassembled kit of parts comprising:

a tubular mandrel body of conductive material dimensioned to be pressed between a dielectric core and an outer conductor of the prepared end of the cable, the mandrel body including a cable engagement surface portion defining a projecting knife edge extending therearound, said cable engagement surface portion comprises a tubular structure including a helix projecting upwardly from the structure, the helix defining an acute angle and providing the projecting knife edge, a tubular shank portion extending from the cable engagement surface portion to a radial wall portion, and a jack engagement portion coaxial extending forwardly from the radial wall portion and coaxially disposed about the exposed central conductor and dimensioned to slide onto and contact in close fitting friction engagement an outer surface of a jack with which the connector makes in use, and

radial compression means for compressing the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body, the compression means including a resiliently deformable elastomeric material.

29. The kit of parts set forth in claim 28 wherein the jack engagement portion is slotted longitudinally to form a slip ring for slideable engagement over the outer surface of the jack.

30. The kit of parts set forth in claim 28 wherein the jack engagement portion defines a shallow helical thread having a pitch to match a threaded outer surface of a jack type with which the assembled connector is to be used after it is pushed onto the jack.

31. The kit of parts set forth in claim 28 wherein the projecting knife edge is formed with a flat at the apex thereof, the flat being approximately two to three mils in cross dimension.

32. The kit of parts set forth in claim 28 wherein the mandrel body is formed by the process of die casting.

33. The kit of parts set forth in claim 28 wherein the tubular mandrel body is provided with a plating to improve lubricity characteristics.

34. The kit of parts set forth in claim 28 wherein the radial compression means comprises a snap-ring dimensioned to fit tightly over the coaxial cable at the annular knife edge including a portion thereof comprised of the resiliently deformable elastomeric material which is radially extended by the frustoconical surface so as to snap lock the coaxial cable toward the annular wall portion thereby to cause the outer conductor to bend over and bear upon the knife edge in order to be subjected to shear stress without shearing of the outer conductor.

35. The kit of parts set forth in claim 34 wherein the portion of the snap-ring forms a spline having teeth which bite into and thereby engage an outer insulation covering of the coaxial cable when the connector is assembled and thereby press the outer conductor against and cause it to bear upon the knife edge.

36. The coaxial cable connector set forth in claim 35 wherein the snap ring includes a cap portion for fitting snugly over the jack engagement portion of the mandrel body upon assembly of the connector thereby to provide hoop strength to the jack engagement portion.

37. The kit of parts set forth in claim 28 wherein the jack engagement portion is dimensioned to diverge radially from the radial wall portion and further comprising slideable shell means for clamping engagement over at least the jack engagement portion of the mandrel body, the slidable shell means being slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of a connector assembled from the kit to slide freely over the outer surface of the jack, the slideable shell means being slidably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack and thereby lock the assembled connector thereto.

38. The kit of parts set forth in claim 37 wherein the cable engagement surface portion of the tubular mandrel body comprises a rearwardly converging, generally frustoconical surface portion defining a shallow angle with respect to a longitudinal axis of the cable, a radially extending annular wall portion extending outwardly to the frustoconical surface portion for defining the knife edge generally as an annulus, and wherein the slideable shell means further defines an inside frustoconical portion congruent with the frustoconical surface portion of the mandrel body for compressing a region of the coaxial cable outer conductor against the frustoconical surface portion of the mandrel body when the slideable shell means is slideably positioned over the mandrel body.

39. The kit of parts set forth in claim 37 wherein the jack engagement portion includes plural slots and functions as a compression collet to lock onto the outer surface of the jack as the slideable shell means is positioned toward the connector end facing the jack.

40. The kit of parts set forth in claim 28 wherein the jack engagement portion i dimensioned to diverge radially from the second radial wall portion and further comprising slideable shell means disposed over at least the cap portion of the snap ring and the jack engagement portion of the mandrel body, the slideable shell means being slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of the assembled connector to slide freely over the outer surface of the jack, the slideable shell mean being slidably positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack and thereby lock the connector thereto.

41. The kit of parts set forth in claim 40 wherein the slideable shell means is adapted to guide the snap ring into position over the coaxial cable end and mandrel body during assembly of the connector and installation thereof onto the prepared end.

42. The kit of parts set forth in claim 41 further comprising an installation tool carrying in nested relation the mandrel body, snap ring and slideable shell means, so that the prepared cable end may be pressed into position against the mandrel body as the cable is pressed against the installation tool.

43. The kit of parts set forth in claim 42 wherein the installation tool enables visual inspection of the cable end relative to the mandrel position after the cable end has been pressed into position.

44. The kit of parts set forth in claim 28 wherein the tubular mandrel body is formed of a metal alloy selected from the group comprising copper, zinc and tin.

45. The kit of parts set forth in claim 44 wherein the tubular mandrel body is provided with a plating of material including tin to improve lubricity characteristics.

46. The kit of parts set forth in claim 28 wherein the jack engagement portion includes plural slots and functions as a compression collet to lock onto the outer surface of the jack as the slideable shell means is positioned toward the connector end facing the jack and further comprising an installation tool carrying in nested relation the mandrel body, snap ring and slideable shell means, the installation tool having keying means for keying to the plural slots so that the installation tool and mandrel body may be rotated onto the prepared cable end as the cable is pressed against the installation tool.

47. The kit of parts set forth in claim 46 wherein the installation tool includes a central plug portion defining an inner wall, and an opening defined through the inner wall, the opening being sized to admit the center conductor of the prepared cable end and not admit a dielectric wall formed by a dielectric core of the prepared cable end, the dielectric wall adapted to come into contact with the inner wall of the installation tool central plug portion and thereby disengage the keying means from the plural slots thereby to disengage the installation tool when the mandrel body has been rotated onto the prepared cable end for a predetermined distance.

48. The kit of parts set forth in claim 46 wherein the installation tool enables visual inspection of the cable end relative to the mandrel position after the mandrel has been rotated into position relative to the cable end.

49. The kit of parts set forth in claim 28 wherein the cable engagement surface portion of the mandrel body has an interior bore which is generally frustoconically convergent toward the cable end, and further comprising a plurality of spaced apart longitudinal slots extending through the cable engagement surface portion and the tubular shank portion, thereby to define the cable engagement surface portion as a variable diameter collet for engaging a prepared cable ends having a dielectric core within a predetermined size range of varying core diameters.

50. The kit of parts set forth in claim 49 further comprising expendable ramping means slidably positionable over the exposed central conductor of the cable for expanding the variable diameter collet as the mandrel body is positioned onto the prepared cable end.

51. A method for assembling a feedthrough coaxial cable connector from a kit of parts at an end of a coaxial cable, the method comprising the steps of:

preparing an end of the cable by peeling back a first cylindrical portion of outer insulator covering for a first length to expose an outer conductor braid/foil layer, and peeling back the outer conductor brad/foil layer and coaxially underlying dielectric insulator for a second length shorter than the first length thereby to expose a center solid conductor wire end portion,

providing a kit of parts by the steps of preforming a tubular mandrel body of conductive material dimensioned to be pressed between a dielectric core and an outer conductor of the prepared end of the coaxial cable, the mandrel body as preformed including a cable engagement surface portion defining a projecting knife edge extending therearound, said cable engagement surface portion comprises the steps of forming a projecting knife edge extending therearound as a helix projecting upwardly form the engagement surface, the helix defining an acute angle and providing the projecting knife edge, a tubular shank portion extending from the cable engagement surface portion to a radial wall portion, and a jack engagement portion coaxially extending forwardly from the radial wall portion and coaxially disposed about the exposed central conductor and dimensioned to slide onto and contact in close fitting friction engagement an outer surface of a jack with which the assembled connector mates, and preforming a radial compression means for compressing the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body installation,

sliding the radial compression means over the prepared cable end in one direction of movement away from the prepared end,

installing the mandrel body onto the prepared end of the cable, and

sliding the radial compression means over the prepared end of the cable installed on the mandrel body so as to compress the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body.

52. The method set forth in claim 51 wherein the step of forming the radial compression means is carried out by forming a snap-ring dimensioned to fit tightly over the coaxial cable at the knife edge including a portion thereof comprised of the resiliently deformable elastomeric material, and wherein the step of sliding the snap-ring over the prepared end of the cable installed on the mandrel body causes the resiliently deformable portion of elastomeric material to be radially extended by the frustoconical surface so as to snap lock the coaxial cable toward the radial wall portion and thereby cause the outer conductor to bear against the knife edge.

53. The method set forth in claim 52 wherein the step of forming the snap-ring comprises the step of forming the elastomeric portion as a spline having teeth, and wherein the step of sliding the snap-ring over the prepared end of the cable causes pointed spline ends to bite into and thereby engage an outer insulation covering of the coaxial cable thereby press the outer conductor against and cause it to bear upon the knife edge.

54. The method set forth in claim 51 wherein the step of forming the kit of parts includes the steps of forming the jack engagement portion of the mandrel body by dimensioning the portion to diverge radially from the radial wall portion, and additionally forming slideable shell means for clamping engagement over at least the jack engagement portion of the mandrel body, and comprising the further steps of installing the slidable shell means by sliding it over the cable away from the prepared cable end thereof immediately before the step of sliding the radial compression means over the prepared cable end, and then sliding the slidable shell means toward the prepared cable end thereby to carry the radial compression means over the prepared end of the cable installed on the mandrel body.

55. The method set forth in claim 54 wherein the step of forming the slideable shell means includes the step of defining an inside frustoconical portion congruent with the frustoconical surface portion of the mandrel body and wherein the step of sliding the slidable shell means toward the prepared cable end includes the step of causing the inside frustoconical surface portion to compress a region of the coaxial cable outer conductor against the frustoconical surface portion of the mandrel body.

56. The method set forth in claim 54 wherein the step of forming the jack engagement portion is carried out by forming slots longitudinally and the step of sliding the outer shell means over the mandrel body causes the jack engagement portion to compress against a jack with which the connector so formed is to be mated.

57. The method set forth in claim 51 comprising the further step of providing an installation tool for aiding the steps of sliding the radial compression means over the prepared cable end in one direction of movement away from the prepared end, installing the mandrel body onto the prepared end of the cable, and sliding the radial compression means over the prepared end of the cable installed on the mandrel body so as to compress the inside surface of the outer conductor of the coaxial cable over the knife edge of the tubular mandrel body.

58. The method set forth in claim 57 wherein the step of providing the installation tool includes the step of nesting the mandrel body and radial compression means within the tool and using the tool as a finger grip to contain, align and support the mandrel body and radial compression means as the prepared cable end is engaged by the mandrel body.

59. The method set forth in claim 57 wherein the step of providing the installation tool includes the steps of preassembling the mandrel body and the radial compression means within the installation tool for distribution to the installer/user.

60. The method set forth in claim 51 wherein the step of forming the jack engagement portion includes forming plural slots so that the jack engagement portion functions as a compression collet to lock onto the outer surface of the jack as the slideable shell means is positioned toward the connector end facing the jack and further comprising the steps of forming an expendable installation tool including keying means for keying to the plural slots so that the installation tool and mandrel body may be rotated together onto the prepared cable end as the cable is pressed against the installation tool, and arranging the mandrel body, snap ring and slideable shell means in nested relation within the installation tool, and wherein the step of installing the mandrel body onto the prepared end of the cable comprises the step of rotating the installation tool and the mandrel body onto the prepared cable end.

61. The method set forth in claim 60 wherein the step of forming the installation tool includes the step of forming a central plug portion defining an inner wall, and an opening through the inner wall, the opening being sized to admit the center conductor of the prepared cable end and not admit a dielectric wall formed by a dielectric core of the prepared cable end, and wherein the step of rotating the installation tool causes the dielectric wall to come into contact with the inner wall of the installation tool central plug portion and thereby disengage the keying means from the plural slots thereby to disengage the installation tool when the mandrel body has been rotated onto the prepared cable end for a predetermined distance.

62. The method set forth in claim 60 wherein the step of forming the installation tool comprises the step of forming the installation tool of a transparent material enabling visual inspection of the cable end relative to the mandrel position after the mandrel has been rotated into position relative to the cable end.

63. The method set forth in claim 51 wherein the step of forming the cable engagement surface portion of the mandrel body comprises the step of forming an an interior bore which is generally frustoconically convergent toward the cable end, and further comprising the step of forming a plurality of spaced apart longitudinal slots extending through the cable engagement surface portion and the tubular shank portion, thereby to define the cable engagement surface portion as a variable diameter collet for engaging a prepared cable ends having a dielectric core within a predetermined size range of varying core diameters.

64. The method set forth in claim 63 further comprising the steps of forming expendable ramping means, slidably positioning the ramping means over the exposed central conductor of the cable, passing the variable diameter collet over the ramping means to expand the diameter thereof as the mandrel body is installed onto the prepared cable end and thereupon removing the ramping means from the assembled cable connector.

65. The method set forth in claim 51 wherein the step of forming the mandrel body is carried out by the process of die casting the mandrel body from a suitable metal material.

66. The method set forth in claim 65 wherein the suitable metal material is selected from the group comprising copper, zinc and tin.

67. The method set forth in claim 51 wherein the step of forming the tubular mandrel body includes the step of plating the formed mandrel body with a plating to improve lubricity characteristics.

68. The method set forth in claim 67 where the plating step is carried out with a material including tin.