WO2004051808A9

WO2004051808A9 - Compression connector for coaxial cable and method of installation

Info

Publication number: WO2004051808A9
Application number: PCT/US2003/038424
Authority: WO
Inventors: Noah Montena; Stephen Malak
Original assignee: Mezzalingua John Ass
Priority date: 2002-12-04
Filing date: 2003-12-03
Publication date: 2004-07-22
Also published as: MXPA05005690A; CN100463292C; BR0307609A; US20050032422A1; AU2003298842A1; CN1720642A; WO2004051808A1; US6780052B2; US20050003706A1; US6887103B2; US6994588B2; US20040110416A1

Abstract

A connector body (18) for use with a coaxial cable connector includes a hollow, one-piece body with three axial sections. The first section has an inner diameter equal to an outer diameter of a hollow post stem (14) which fits inside the first section. The second section extends integrally from the first section with an inner diameter larger than the first section inner diameter. The third section extends integrally from the second section. The first and second sections have walls of predetermined thickness while the third section includes at least one peripheral wall area having a thickness substantially less than the predetermined thickness. The third section includes at least one portion movable between the inner surface of the second section and the cable outer surface in response to axial force, transmitting a radially compressive force to the cable, thereby effecting tight frictional engagement between the connector body and the cable.

Description

COMPRESSION CONNECTOR FOR COAXIAL CABLE AKD METHOD OF

INSTALLATION

FIELD OF THE INVENTION

[01] This invention relates generally to the field of coaxial cable connectors, and more particularly to a coaxial cable connector which attaches to the coaxial cable via axial deformation of a deformable portion of the connector body.

BACKGROUND OF THE INVENTION

[02] A common type of connector installed on a terminal end of a coaxial cable includes elements known as a post, a nut, a body, and a compression ring. The post includes a hollow stem integrally joined at one end to a flange. The nut is rotatably secured to the post, typically at or near the junction of the stem and flange, while the body suπounds the stem with a first portion near the nut, in frictional engagement therewith, and a second portion in outwardly spaced relation thereto. The compression ring, a hollow, substantially cylindrical member, is initially maintained in engagement with the body by one end of the ring encircling the end of the body remote from the nut. The end of the coaxial cable is prepared by stripping away certain layers thereof at specified distances from the end of the central conductor. After the cable is prepared, the connector is installed by inserting the cable axially into the connector with the stem of the connector post being forced between the outer layer of conducting material and the woven mesh metallic shielding layer. The shielding layer and the outer dielectric layer are in the initially open annular space between the stem and inner surface of the body. Installation is completed by axial movement of the compression ring over the body with tapered surfaces on one or both of these members causing radial compression of the body into tight, frictional engagement with the outer surface of the coaxial cable.

[03] The prior art includes a wide variety of styles and configurations of compression connectors of this general type. A feature common to radial compression connectors, however, is the separate fabrication of the body and compression ring which provide the means for frictionally engaging the connector with the cable. A variation of this design is disclosed in U.S. Patent No. 5,525,076 (Down) wherein the connector body includes one or more grooves extending into and around its outer surface. As the body is axially compressed, a portion of the body wall at the groove(s) is forced radially inward into the outer dielectric layer of the coaxial cable. This inward movement forms a moisture barrier around the surface of the cable and mechanically locks the connector and cable, but does not radially compress the body into tight frictional engagement with the cable in the manner of the prior art connectors alluded to above and the present invention.

[04] It is a principle object of the present invention to provide a novel and improved coaxial cable connector of the radial compression type which requires fewer parts than typical prior art connectors of the same general type, thereby offering advantages normally associated with a reduction in part count of multi-element devices.

[05] It is a further object to provide a connector which is mounted to an end portion of a coaxial cable by a novel method of operation.

[06] It is another object to provide novel and improved means for mounting a 'connector to the end of a, coaxial cable.

SUMMARY OF THE INVENTION

[07] Briefly stated, a connector body for use with a coaxial cable connector includes a hollow, one-piece body with three axial sections. The first section has an inner diameter equal to an outer diameter of a hollow post stem which fits inside the first section. The second section extends integrally from the first section with an inner diameter larger than the first section inner diameter. The third section extends integrally from the second section. The first and second sections have walls of a predetermined thickness while the third section includes at least one peripheral wall area having a thickness substantially less than the predetermined thickness. The third section includes at least one portion movable between the inner surface of the second section and the cable outer surface in response to axial force, transmitting a radially compressive force to the cable, thereby effecting tight frictional engagement between the connector body and the cable. [08] According to an embodiment of the invention, a connector body for use with a coaxial cable connector includes a hollow, one-piece body of predetermined material having opposite ends, a first axial section extending from one of the ends for a first distance and having a first inner diameter substantially equal to an outer diameter of a stem of a hollow post which fits inside at least a portion of the first axial section, a second axial section extending integrally from the first section for a second distance and having a second inner diameter larger than the first inner diameter over at least a portion of the second distance, and a third axial section extending integrally from the second section for a third axial distance to the other of the ends of the body; the first and second sections having walls not less than a predetermined thickness and the third section including at least one peripheral wall area having a thickness substantially less than the predetermined thickness; the third section including an inner surface defining a diameter substantially equal to an inner surface of the second section; and the third section including at least one portion axially movable in response to application of axial force to an end of the third section, wherein a radially compressive force is transmitted to the cable, thereby effecting tight frictional engagement of the connector body to the cable.

[09] According to an embodiment of the invention, a method of mounting a connector body to a prepared end of a coaxial cable having an inner conductor, an inner layer of dielectric material, a conducting layer, a layer of woven mesh shielding material and an outer layer of dielectric material includes the steps of (a) providing a post having a hollow, substantially cylindrical stem portion having a first, outer diameter, and a flange portion with a through, central opening integrally joined to and extending radially outwardly from one end of the stem portion; (b) providing an axially elongated, hollow body having first and second ends, a first section extending from the first end with a cylindrical internal surface of diameter substantially equal to the first diameter, a second section extending integrally from the first portion with a cylindrical internal surface of second diameter greater than the first diameter, and a third section extending integrally from the second section to the second end with a cylindrical internal surface of diameter substantially equal to the second diameter, the first and second sections having a wall thickness not less than a predetermined dimension and the third section including at least one peripheral area of reduced thickness: (c) inserrinp- the nrenared end of the coaxial cable into the connector bodv from the end of the body and advancing the cable to insert a portion of the stem between the conducting layer and the shielding layer with portions of the inner dielectric layer and the conducting layer positioned within the stem and portions of the shielding layer and the outer dielectric layer positioned in the space between the outside of the stem and the inner surface of the second and third sections; and (d) applying an axial force to the body causing movement of at least a portion of the third section in the direction of the second section between the inner surface of the second section and the shielding layer of the cable therein effecting tight frictional engagement of the connector and the cable.

[010] The invention contemplates a connector having an essentially conventional post and nut in combination with a novel body. The post has the usual, integral flange and stem portions and the nut is rotatably engaged with the post at the flanged end. The hollow body includes a first portion extending axially from a first end and having an inner diameter substantially coπesponding to the outer diameter of the post stem, a second portion extending axially from the first portion and having a larger inner diameter, and a third portion extending axially from the second portion to a second end. The three portions are integrally formed as a single, molded part. In a first disclosed embodiment, the third portion is connected to the second portion by a wall section of reduced thickness. The third portion is of the same inner diameter as the second portion and tapers to a larger outer diameter from the position of smallest wall thickness toward the second end of the body. When the connector is installed on the cable, the stem extends between the metal shielding layer of the cable and the outer conducting layer in the usual manner with these two layers positioned in the space between the outside of the stem and inside of the second body portion.. When an axial force is applied by an appropriate tool to the third body portion, tending to move it in the direction of the first portion, the wall fractures at the section of smallest thickness, allowing the third section to be forced between the second section and the outer surface of the coaxial cable. The tapered surface on the third section is wedged between the second section and the cable surface, thereby radially compressing the cable and causing tight frictional engagement of the connector and cable.

[011] In a second embodiment, the third section of the body has two annular areas of reduced cross section, axially spaced from one another. The thickness of these sections is such, relative to the type and characteristics of the material from which the body is fabricated, that as axial force is applied to the third section, tending to move it in the direction of the second section, that the wall folds at both areas of reduced cross section. Thus, rather than fracturing the body wall, as in the first embodiment, the body remains in a single part, but with folded layers of the third body portion between the inner surface of the second body portion and the outer surface of the cable, producing tight frictional engagement of the connector and the cable.

[012] The features of the invention generally described above will be more readily apparent and fully appreciated from the following detailed description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[013] Fig. 1 shows an exploded perspective view of the first embodiment of the cable connector of the invention.

[014] Fig. 2 shows a front elevation view of one of the elements of Fig. 1 in full section.

[015] Fig. 3 shows a front elevation view of the connector of Fig. 1 mounted to a conventional coaxial cable with portions of both the connector and cable broken away to be seen in section.

[016] Fig. 4 shows an exploded perspective view of the second embodiment of the cable connector of the invention.

[017] Fig. 5 shows a front elevation view of one of the elements of Fig. 4 in full section.

[018] Fig. 6 shows a front elevation view of the connector of Fig. 4 mounted to a conventional coaxial cable with portions of both the connector and cable broken away to be seen in section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[019] Referring to Figs. 1-3, the three components of the first embodiment of the connector are shown, post 10, including integrally formed flange 12 and stem 14 sections, nut 16, and body 18. Post 10 and nut 16 are of conventional construction for use in this type of coaxial cable connector, with body 18 being of unique construction. Body 18 is shown in cross section in Fig. 2 where it should be noted that body 18 includes three sections integrally formed as a single piece. A first section 20 extends axially from one end 22 of body 18 for a portion of its axial length having inner diameter Dl . A second section 24 includes a tapered portion 26, connecting inner diameter Dl with larger inner diameter D2 of a constant diameter portion 28 of second section 24. A third section 30 extends integrally from second section 24 with the same inner diameter, but with a wall portion 32 of reduced thickness. The smallest thickness of wall portion 32 is at its juncture with second section 24, denoted by reference numeral 34, from which the outer surface of third section 30 tapers outwardly at a relatively small angle to wall portion 36 which has the same outer diameter as second section 24 and extends to the other end 38 of body 18. The three parts of the connector are mutually assembled by passing stem 14 through the opening defined by internal flange 17 (see Fig. 3) of nut 16, followed by passing the stem through first section 20 of body 18 until end 22 abuts a larger diameter portion 15 of stem 14. Flange 17 is thus axially engaged between flange 12 of post 10 and end 22 of body 18 with nut 16 being freely rotatable with respect to post 10 and body 18.

[020] The connector is shown in Fig. 3 in assembled relation with an end portion of a conventional coaxial cable, denoted generally by reference numeral 40 and having an inner conductor 42 suπounded by an inner layer 44 of dielectric material, a layer 46 of conducting material, a shielding layer 48 in woven mesh form, and an outer layer 50 of dielectric material. After the end of the cable has been prepped in the specified conventional manner, it is inserted axially into end 38 of body 18 and advanced until the exposed end surfaces of layers 44 and 46 are substantially flush with the end surface of flange 12. During this relative movement of the cable and connector, stem 14 is forcibly inserted between cable layers 46 and 48, as is also conventional in the mounting of F-connectors upon coaxial cables. The connector is then engaged by a compression tool (not shown) in order to apply an axial force tending to move second and third sections 24 and 30 in opposite directions, i.e., toward one another. Upon application of sufficient force in this manner, body 18 fractures about its periphery at the smallest thickness of wall section 32, i.e., at juncture 34 of second and third sections 24 and 30 (Fig. 2). After fracturing, body 18 is in two pieces and continued application of axial force moves wall portion 32 between the inner surface of second section 24 and the outer surface of cable dielectric layer 50. The outward taper of the outer surface of wall portion 32 results in radial compression of cable 40 and tight frictional engagement of the connector and cable, as shown in Fig. 3.

[021] Referring now to Figs. 4-6, the connector is shown with a second embodiment of a body 52 in combination with a conventional post 10' and nut 16'. Body 52, as best seen in the sectional view of Fig. 5, again includes a first section 54, extending from one end 56 of body 52 for the axial length thereof having an inner diameter Dl, a second section 58, having a tapered inner surface portion 60 connecting diameter Dl with a larger inner diameter D2 of a constant diameter portion 62 of second section 58. In this embodiment, a third section 64 includes first, second and third wall portions 66, 68, and 70, respectively. First portion 66 extends from a first area 72 of reduced thickness at a junction of second and third sections 58 and 64, tapering outwardly to its juncture with second portion 68 at a second area 74 of reduced thickness. Second portion 68 tapers outwardly to its junction with third portion 70 which extends to the other end 76 of body 52. Third section 64 is of constant inner diameter D2 throughout its length and is of smaller outer diameter over both portions 66 and 68 than second section 58, the outer diameter of third wall portion 70 being equal to that of second section 58.

[022] Body 52 differs from body 18 not only in the use of an additional wall portion in the third section, but also in the material used and the manner of operation. Body 18 is preferably of a quite rigid plastic which also exhibits a degree of brittleness, whereby the material fractures at the peripheral line of smallest thickness and axial movement of the tapered portion between the second body portion and the cable radially compresses the cable with little if any outward radial movement of the body. Body 52, on the other hand, is made of a more flexible, elastic material. When axial force is applied with a compression tool, rather than fracturing, first wall portion 66 folds inwardly about the periphery of reduced thickness area 72., causing the periphery at reduced thickness area 74 to move in the direction of arrows 78. After movement of portion 66 substantially 180 degrees, into contact with the inner surface of second section 58, wall section 68 has moved into surface-to-surface contact with wall section 66, as shown in Fig. 6 which also includes the coaxial cable with common reference numerals denoting the same parts thereof as in Fig. 3. The axial force producing the folding action of wall portions 66 and 68 is applied, of course, after the cable has bee inserted into the connector. Consequently, the outer surface of the cable stands in the way of the inner movement of wall section 66, as indicated by aπows 78 in Fig. 5. The flexible nature of body 52 permits outward, flexing movement of second section 58 as inward movement of section 66 begins and inward contraction thereof as the folding is completed. The combined thickness of wall sections 66 and 68 ensure a tight frictional fit against cable layer 50. The thicknesses in areas 72 and 74 are established as a function of the properties of the material of body 52 to provide the desired folding action upon application of axial force tending to move third section 64 toward second section 58.

[023] While the present invention has been described with reference to a particular prefeπed embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the prefeπed embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims.

Claims

What is claimed is:

1. A connector body for use with a coaxial cable connector, comprising: a hollow, one-piece body of predetermined material having opposite ends, a first axial section extending from one of said ends for a first distance and having a first inner diameter substantially equal to an outer diameter of a stem of a hollow post which fits inside at least a portion of said first axial section, a second axial section extending integrally from said first section for a second distance and having a second inner diameter larger than said first inner diameter over at least a portion of said second distance, and a third axial section extending integrally from said second section for a third axial distance to the other of said ends of said body; said first and second sections having walls not less than a predetermined thickness and said third section including at least one peripheral wall area having a thickness substantially less than said predetermined thickness; said third section including an inner surface defining a diameter substantially equal to an inner surface of said second section; and said third section including at least one portion axially movable in response to application of axial force to an end of said third section, wherein a radially compressive force is transmitted to said cable, thereby effecting tight frictional engagement of said connector body to said cable.

2. A connector body according to claim 1, wherein said third section has a wall thickness which increases from said reduced thickness toward said second end.

3. A connector body according to claim 1, wherein said axial force is so related to the properties of said predetermined material and said thickness of said peripheral wall area that said axial force completely fractures said body in an area of said peripheral wall area.

4. A connector body according to claim 1 wherein said reduced thickness is so related to the properties of the material from which said body is foπrted that said axial force causes said body to fracture at said reduced thickness of said wall.

5. A connector body according to claim 1, wherein said peripheral wall area is at the iuncture of said second and third sections.

6. A connector body according to claim 1, wherein said third section includes two of said peripheral wall areas.

7. A connector body according to claim 6, wherein portions of said third section adjacent to said peripheral wall areas are folded to a position between said inner surface of said second section and an outer surface of an outer dielectric layer of said cable in response to said axial force, thereby applying a radially compressive force to said cable and effecting said tight frictional engagement of said connector and said cable.

8. A connector body according to claim 1 wherein said third section includes an inner surface defining a diameter substantially equal to said second inner diameter.

9. A connector body according to claim 1 wherein application of said axial force to an end of said third section moves at least a portion of said third section in the direction of said second section between said inner surface of said second section and said shielding layer of said cable therein effecting tight frictional engagement of said connector and said cable.

10. A method of mounting a connector body to a prepared end of a coaxial cable having an inner conductor, an inner layer of dielectric material, a conducting layer, a layer of woven mesh shielding material and an outer layer of dielectric material, said method comprising the steps of: providing a post having a hollow, substantially cylindrical stem portion having a first, outer diameter, and a flange portion with a through, central opening integrally joined to and extending radially outwardly from one end of said stem portion; providing an axially elongated, hollow body having first and second ends, a first section extending from said first end with a cylindrical internal surface of diameter substantially equal to said first diameter, a second section extending integrally from said first portion with a cylindrical internal surface of second diameter greater than said first diameter, and a third section extending integrally from said second section to said second end with a cylindrical internal surface of diameter substantially equal to said second diameter, said first and second sections having a wall thickness not less than a predetermined dimension and said third section including at least one peripheral area of reduced thickness; inserting said prepared end of said coaxial cable into said connector body from said end of said body and advancing said cable to insert a portion of said stem between said conducting layer and said shielding layer with portions of said inner dielectric layer and said conducting layer positioned within said stem and portions of said shielding layer and said outer dielectric layer positioned in the space between the outside of said stem and the inner surface of said second and third sections; and applying an axial force to said body causing movement of at least a portion of said third section in the direction of said second section between said inner surface of said second section and said shielding layer of said cable therein effecting tight frictional engagement of said connector and said cable.

11. A method according to claim 10 wherein said axial force fractures said body at said peripheral area of reduced thickness.

12. A method according to claim 11 wherein said peripheral area of reduced thickness is at the juncture of said second and third sections.

13. A method according to claim 10, wherein: said axial force fractures said body at said peripheral area of reduced thickness; said peripheral area of reduced thickness is at the juncture of said second and third sections; and an outer surface of said third section tapers outwardly from said area of reduced thickness toward said second end, and said axial force moves of a portion of said third section between said inner surface of said second section and the outer surface of said outer dielectric layer of said cable, thereby applying a radially compressive force to said cable and effecting said tight frictional engagement of said connector and cable..

14. A method according to claim 10 wherein said third section includes two, axially spaced peripheral areas of reduced thickness.

15. A method according to claim 14 wherein portions of said third section adjacent said areas of reduced thickness are folded to a position between said inner surface of said second section and the outer surface of said outer dielectric layer of said cable in response to said axial force, thereby applying a radially compressive force to said cable and effecting said tight frictional engagement of said connector and said cable.