Coaxial cable F connector with improved RFI sealing

• US 6,716,062 B1
• Filed: 10/21/2002
• Issued: 04/06/2004
• Est. Priority Date: 10/21/2002
• Status: Expired due to Term

• Current Assignee: PPC Broadband Incorporated (Belden Inc.)
• Original Assignee: John Mezzalingua Associates Incorporated
• Inventors: Palinkas, Raymond, Fox, Michael T., Montena, Noah
• Primary Examiner(s): Luebke, Renee
• Assistant Examiner(s): Figueroa, Felix O.
• Application Number:
  US10/277,756
• Publication Number:
  US 20040077215A1
• Time in Patent Office: 533 Days
• Field of Search: 439/578, 439/320, 439/583-585, 439/322, 439/323, 439/700, 439/824, 439/607, 439/610
• US Class Current: 439/578
• CPC Class Codes: H01R 13/622 Screw-ring or screw-casing H01R13/623 takes precedence
• CPC Class Codes: H01R 9/0521 Connection to outer conductor by action of a nut

Abstract

An F-type connector for mounting to a prepared terminal end of a coaxial cable for threaded engagement of a nut on the connector to a threaded shaft at a port on video equipment to which the coaxial cable is to be electrically connected. In the connector of the present invention, the nut is mounted for limited axial movement with respect to the post, body and compression ring. A coil spring biases the nut toward a rest position with respect to the other elements wherein not more than three revolutions of the nut into engagement with the shaft are necessary in order to bring the post of the connector into contact with the shaft on the equipment, providing a satisfactory coupling. Upon further revolution of the nut, the post and shaft remain in contact as the nut moves axially away from the rest position with respect to the other elements.

Claims

1. An F-type connector for mounting upon a terminal end of a coaxial cable having a bare central conductor extending a predetermined length from the planar end surface of an inner dielectric layer, said connector comprising:

a) a post member having a hollow, substantially cylindrical stem portion with a central axis and first end surrounded by a metal flange having a planar annular surface perpendicular to said central axis;

b) means for securely maintaining said post in assembled relation with said terminal end of said cable;

c) a nut including an internally threaded bore sized for threaded engagement with a hollow, threaded shaft at a port on video equipment to which said cable is to be electrically coupled, said shaft having a metal, terminal end;

d) means for mounting said nut in encircling relation to at least a portion of said post including said flange for free rotation and limited axial movement between first and second positions relative to said post; and

e) a spring biasing said nut toward said first position wherein said nut may be placed in alignment with said shaft and rotated not more than three revolutions to bring said terminal end of said shaft into contact, and thus RFI shielding relation, with said annular surface of said post, continued rotation of said nut moving said nut axially with respect to said post toward said second position against the biasing force of said spring.

2. The connector of claim 1 wherein said means for maintaining said post in assembled relation with said terminal end of said cable comprise compression engagement means.

3. The connector of claim 2 wherein said compression engagement means include an elastomeric body and a compression ring axially movable with respect to said body to radially compress the latter into tightly gripping relation with said cable.

4. The connector of claim 1 wherein said spring is a coil spring having opposite ends captured between portions of said post and said nut.

5. The connector of claim 4 wherein said portion of said post is a surface of said flange on the side thereof opposite said annular surface.

6. The connector of claim 5 wherein said threaded bore has a diameter substantially equal to that of said flange.

7. The connector of claim 6 wherein said nut includes an internal flange and wherein said portion of said nut comprises said internal flange.

8. The connector of claim 5 wherein said threaded bore has a diameter less than that of said flange and wherein said nut includes a hollow skirt portion having an inside diameter slightly larger than said flange and a terminal, open end.

9. The connector of claim 8 wherein said skirt is deformed inwardly about its entire periphery to a diameter less than said inside diameter at said open end, and said portion of said nut comprises said periphery of said open end.

10. The connector of claim 9 and further including an elastomeric body encircling said stem portion of said post and a compression ring.

11. The connector of claim 10 wherein said spring encircles at least portions of said body and said ring, being positioned in an annular space between said inside diameter of said skirt and outside surfaces of said body and compression ring.

12. An F-type connector for permanent mounting upon a terminal end of a conventional coaxial cable having a central conductor, an inner dielectric layer, a conductive layer, a shielding layer and an outer dielectric layer, said cable being prepared for mounting of said connector by stripping away all of said layers from a first, predetermined length of said central conductor and stripping away said shielding and outer dielectric layers from a second, predetermined length of said conductive layer in order to electrically connect said central conductor to contacts at a video equipment port surrounded by a threaded, metal shaft having an annular terminal end, said connector comprising:

a) a metal post having a hollow, substantially cylindrical stem and a flange extending radially outwardly from one end of said stem, said flange having first and second, opposite, annular surfaces;

b) a body portion of elastomeric material having an outer surface and a through bore with;

i) a first portion having a diameter substantially equal to the outside diameter of said stem, said stem extending through and contacting said first portion of said bore over a first axial portion of said stem adjoining said second surface of said flange, and

ii) a second portion having a cross section larger than said outside diameter of said stem, said second portion of said bore surrounding said stem in outwardly spaced relation thereto over a second axial portion thereof to form a first annular cavity between said second axial portion of said stem and said second portion of said bore;

c) a compression ring surrounding a portion of said body outer surface, said ring being axially movable upon said body to radially compress the latter into firm engagement with portions of said cable positioned within said annular cavity;

d) a nut having a threaded bore at one end and a cylindrical skirt extending integrally from said one end to an open end, said skirt having an inside diameter substantially equal to the diameter of said flange, said skirt surrounding said flange and portions of said body and ring inwardly spaced from said skirt to form a second annular cavity between said skirt and said inwardly spaced portions, said nut including an annular lip surrounding said open end and extending inwardly to a diameter less than said inside diameter of said skirt; and

e) a coil spring disposed within said second annular cavity and having a first end contacting said second surface of said flange and a second end contacting said annular lip, said nut being axially movable with respect to said post, body and ring between a first position, toward which said nut is biased by said spring and wherein a first abutment portion of said nut engages a second abutment portion of said post, and a second position, wherein said spring is compressed to a length less than in said first position of said nut.

13. The connector of claim 12 wherein said first abutment surface is an internal surface of said nut surrounding said threaded bore.

14. The connector of claim 13 wherein said second abutment surface is said first surface of said flange.

15. The connector of claim 12 wherein said first and second ends of said spring lie in parallel planes.

16. The connector of claim 12 wherein said first and second surfaces of said flange lie in parallel planes.

17. The connector of claim 12 wherein said first and second predetermined lengths correspond to industry-standard lengths for preparation of coaxial cable to be mounted to industry-standard F-type connectors.

18. The method of fabricating and assembling an F-type connector for mounting upon an end portion of a coaxial cable, said method comprising:

a) providing a post having a substantially cylindrical, hollow, post with first and second ends and an annular flange extending radially outwardly from said first end of said post to a first diameter, said flange having a first surface adjoining said second end of said post and a second surface, parallel to and facing oppositely from said first surface;

b) providing a coil spring having opposite ends in parallel planes, and predetermined inner and outer diameters and undeformed axial length;

c) providing a nut having an end portion with inner and outer surfaces surrounding a threaded bore and a skirt extending integrally from said end portion for a predetermined axial distance to an open end, said skirt having a substantially cylindrical inner surface with a diameter not less than and substantially equal to said first diameter;

d) providing a body portion having a through bore with a first portion of diameter substantially equal to the outer diameter of said post, and a second portion of diameter larger than that of said first portion, said body portion further having an outer surface of predetermined configuration;

e) providing, a substantially cylindrical, hollow compression ring having an interior surface configured to surround and compress said body portion radially inwardly in response to relative axial movement of said body portion and ring;

f) inserting said post through said first portion of said body portion bore until said body portion abuts said first surface of said flange;

g) placing said ring in frictional engagement with said body portion outer surface;

h) passing said ring and body portion through said spring to place one of said opposite ends of said spring in contact with said first surface of said flange;

i) passing said skirt over said flange to place said inner surface of said nut end portion in contact with said second surface of said flange and forming an annular cavity between said inner surface of said skirt and portions of said ring and body portion outer surface, said spring being disposed entirely within said cavity, said undeformed axial length of said spring being so related to said axial distance of extent of said skirt that said open end of said skirt extends post said other of said opposite ends of said spring; and

j) bending said open end of said skirt radially inwardly to form an annular lip of diameter less than said outer diameter of said spring, whereby said spring is axially captured between said first surface of said flange and said annular lip of said skirt, permitting axial compression of said spring by relative axial movement of said nut and said post, body portion and ring.

19. The method of claim 18 wherein said annular lip lies in closely encircling relation to said compression ring.

20. The method of claim 18 and further including mounting said connector upon a prepared terminal end of a coaxial cable and moving said ring axially upon said body portion outer surface to radially compress said body portion into tight frictional engagement with said cable.

21. The method of fabricating and assembling an F-type connector for mounting upon a prepared terminal end of a coaxial cable, said method comprising:

a) forming a post having a hollow stem portion extending linearly between first and second ends, and a first flange extending radially outwardly from said first end of said stem to a first diameter;

b) forming an elastomeric body member with a through bore and an external surface of predetermined configuration;

c) forming a compression ring cooperatively formed with said body member to compress said body member radially inwardly in response to relative axial movement of said body member and ring;

d) forming a nut having a through bore with third and fourth, open ends, a stop member extending radially inwardly of said bore to define a passageway of cross-dimension greater than the maximum outer cross-dimension of said stem and less than said first diameter, and an internally threaded portion having a second diameter at least as great as said first diameter between said stop member and said third end;

e) forming a coil spring having an inner diameter at least as large as said maximum outer cross-dimension of said stem, an outer diameter not greater than said first diameter, and a predetermined, undistorted axial length;

f) placing said spring into said third end of said nut to rest upon said stop member;

g) passing said second end of said stem through said third end of said nut and through said spring and stp member to extend from said fourth end of said nut and said first flange positioned within said internally threaded portion and said spring captured between said stop member and said first flange;

h) passing said stem at least partially through said body member bore to bring an abutment portion of said body external surface into contact with said fourth end of said nut, whereby said body portion limits axial movement of said nut in a first direction past a predetermined position relative to said stem and body member; and

i) moving said compression ring axially into radially compressive engagement with a portion of said body member external surface, thereby fixing the relative positions of said stem, body portion and ring, and permitting axial movement of said nut away from said predetermined position in a second direction, opposite to said first direction, as said spring is compressed between said stop portion and said first flange.

22. The method of claim 21 and including the further step of mounting said connector to a prepared terminal end of a coaxial cable prior to axially moving said compression ring.

23. The method of claim 22 wherein said stop portion comprises a second flange defining a circular opening having a diameter less than the largest cross-dimension of said stem and less than said first diameter.

24. The method of claim 22 wherein said second diameter is substantially equal to said first diameter.

25. The method of claim 22 including the further step of engaging the threads of said internally threaded portion with the external threads of a metal shaft at a port of video equipment to which said coaxial cable is electrically connected.

26. The method of claim 25 wherein said predetermined position of said nut is such that not more than three revolutions of said nut are required to bring said shaft into contact with said first flange, thereby establishing RFI shielding of said coaxial cable.

27. An F-type connector for mounting upon a prepared terminal end of a coaxial cable to permit electrical connection of said cable to a port on video equipment by threaded engagement of said connector and a metal shaft surrounding said port, said connector comprising:

a) a plurality of cable engagement members secured to said terminal end, one of said engagement members having a planar surface in perpendicular, surrounding relation to said terminal end;

b) a nut having internal threads matable with external threads on said shaft, said nut being mounted to said engagement members for free rotation and limited axial movement from a rest position in a first direction with respect to said engagement members; and

c) spring means biasing said nut toward said rest position.

28. The connector of claim 27 wherein said spring means comprise a coil spring compressible between portions of said nut and said one of said engagement members.

29. The connector of claim 28 wherein the relative position of said nut and said planar surface, when said nut is in said rest position, is such that the end of said shaft is brought into contact with said planar surface by not more than three revolutions of said nut into threaded engagement with said shaft, further revolutions of said nut after contact of said shaft with said planar surface resulting in relative axial movement of said nut and said engagement members away from said rest position of said nut.

30. The connector of claim 29 wherein said engagement members comprise a post, an elastomeric body member and a compression ring.

31. The connector of claim 30 wherein said planar surface has an outer, circular periphery of first diameter and a inner, circular periphery defining an opening of second diameter.

32. The connector of claim 31 wherein the diameter of said internal threads is less than said first diameter and greater than said second diameter.

33. The connector of claim 31 wherein the diameter of said internal threads is substantially equal to said first diameter.