An electrical coaxial connector and method for connecting a coaxial connector to a cable

Abstract

 An electrical connector (1) for attachment to a cable 201, comprising a main body 17. The electrical connector (1) has
- a first body end 3 for receiving an inner conductor 204 of the cable, - a post 5 coaxially mounted within the main body 17, a contact assembly 30 movably mounted within the post, and surrounded by an inner surface of the post. Said assembly comprises
- a receptacle guide 8 having a first receptacle guide end 20 for receiving the inner conductor 204 of the cable and a second opposing receptacle guide end 21 to which a pin 6 is fixedly mounted, and
- a clip 7 for receiving the inner conductor 204 of the cable.
Said contact assembly 30 has a start position, before the cable is inserted, and an end position, when the cable 201 is fully inserted for use, wherein the first receptacle guide end 20 comprises first stop means 22 engaging with second stop means 25 of the post, said first and second stop means interacting with each other in the end position.

Description

[0001] The present invention relates to a coaxial connector for attachment to a coaxial cable and a method for connecting a coaxial connector to a cable.

[0002] Connecting the inner conductor of a cable in the receiving part of a connector can be difficult and if the connector has a blind entry, a series of mistakes is possible. The inner conductor might be bent during installation or the inner conductor might be too long, whereby there is a risk of disturbance of the impedance if the inner conductor is left without a proper shielding in a certain area. The risk of bending the inner conductor of the coaxial cable might also take place as a consequence of the material of the inner conductor being quite soft. Further, when the inner conductor is pushed into its correct end position, it is not possible to carry out a visual inspection from this end position in order to see that the end position is in fact reached as the stop mechanism and construction as such will obstruct this visual inspection.

[0003] WO 2006/076440 discloses a coaxial connector with a movable pin. However, due to the construction of a stop mechanism, it is difficult - if not impossible - to inspect visually whether an end position has been reached when the pin is connected to the receiving part inside the connector and moved to its end position. Further, the interaction between the construction of the stop mechanism and the way the slidable movement from the start position to its end position takes place makes the suspension of the receiving part quite rigid. As the receiving part is not capable of being adjusted when the inner conductor is inserted inside the connector, the risk of bending the inner conductor is quite high.

[0004] A first aspect of the present invention is at least partly to overcome the disadvantages of the prior art mentioned above and to provide a coaxial connector, where the risk of bending the inner conductor is reduced by providing visible entry, and where it is possible to visually inspect that the cable is pushed fully to the desired position inside the connector. Hence, blind entry is avoided. It is possible to see that the end position has in fact been reached, i.e. that the pin has been pushed to its end position - its position where it is ready for use. These aspects and the advantages become evident from the description below and are obtained by an electrical coaxial connector for attachment to a coaxial cable, said connector comprising a main body having a central bore defining a longitudinal axis and having

• a first body end for receiving an inner conductor of the cable and a second body end opposite the first body end,
• a post coaxially mounted within the main body and having a first post end for receiving the dielectric of a cable and an opposite second post end,
• a contact assembly movably mounted within the post and surrounded by an inner surface of the post, said assembly comprising a receptacle guide coaxially placed within the connector, said guide having a first receptacle guide end for receiving the inner conductor of the cable and a second opposing receptacle guide end to which a pin is fixedly mounted, and
• a clip coaxially and fixedly placed within the receptacle guide and for receiving the center conductor of the cable,
  said contact assembly having a start position, before the cable is inserted, and an end position, when the cable is fully inserted for use, the end position being different from the start position, wherein the first receptacle guide end comprises a first stop means engaging with a second stop means of the post, said first and second stop means interacting with each other in the end position of the contact assembly.

[0005] As the first and second stop means for the stop position are only interacting with each other in the end position, and the first stop means is placed at the receptacle guide end near the connection of the inner conductor, certain flexibility is obtained in such way that a small inaccurate positioning of the inner conductor during insertion will not lead to it being bend. Further, as the stop mechanism of the receptacle guide is placed at this first end, and as no stop means is covering the position between the receptacle guide and the post, it is possible to visually inspect the connector when the pin has reached its end position.

[0006] In a second embodiment of the invention, the receptacle guide and thereby the contact assembly may be slidably placed in the post.

[0007] In a third embodiment of the invention, the first receptacle guide end may be in contact with the inner surface of the post in the start position and in the end position and further during the movement from the start position to the end position. In this way, the contact assembly is moved in a secured manner by the dielectric of the cable.

[0008] In a fourth embodiment of the invention, in the start position of the contact assembly, the second receptacle guide end may not touch the inner surface of the post.

[0009] In a fifth embodiment of the invention, the second receptacle guide end may have a circular circumference and a diameter being smaller than the diameter of the inner surface of the post. In this way, the receptacle guide is flexibly related to the surface, e.g. with a play at the second receptacle guide end, so that when the cable is inserted, the risk of bending the inner conductor of the cable is reduced due to said flexibility.

[0010] In a sixth embodiment of the invention, in the end position the second receptacle guide end may be placed in a fixed receptacle guide formed with an annular wall, said fixed receptacle guide being placed inside the post. By this construction, the resistance and the signal between the inner conductor and the outer conductor are regulated.

[0011] In a seventh embodiment of the invention, the fixed receptacle guide may be formed with slots in the annular wall. In this way, the signal can be fine-adjusted.

[0012] In an eighth embodiment of the invention, the receptacle guide may be formed like a spool, the first end of the spool having a larger diameter than the second end of the spool.

[0013] In a ninth embodiment of the invention, the receptacle guide may comprise a hollow cylindrical part, and a substantially circular or cylindrical plate is arranged at each end of the hollow cylindrical part.

[0014] In a tenth embodiment of the invention, the first stop means may comprise a flange/collar placed at the first receptacle guide end and may interact in the end position with a protrusion being the second stop means, said second stop means protruding from the inner surface of the post.

[0015] In an eleventh embodiment of the invention, the first receptacle guide end may further comprise compressible outwardly directed protrusions. In this way, the same receptacle guide unit can be used for two different post diameters and thereby two different connectors and two different diameters of the dielectric part of the cable.

[0016] In a twelfth embodiment of the invention, the post, the pin and the clip may be made substantially of a conductive material, and the receptacle guide and the fixed receptacle guide may be made substantially of a non-conductive material.

[0017] In a thirteenth embodiment of the invention, the post may be manufactured in one piece. This is possible due to the construction of the receptacle guide according to the invention. Although it is a one-piece post, the post may still be manufactured on a simple manufacturing machine, e.g. a simple automatic bar machine (e.g. manufactured by Davenport) or similar non-CNC machine. The build-up of the post facilitates that it is possible to adjust the impedance in at least a section of the post by the fixed receptacle guide and still having the post in one piece.

[0018] In a fourteenth embodiment of the invention, the clip may be configured to grip the inner conductor of the cable and comprises a conical-formed hollow cylinder with a first clip end with a fixed diameter a and an opposing second clip end with a diameter b and flexible walls connecting the ends, said diameter b having in a start position a diameter smaller than a, and in a position where the cable is fully inserted having a diameter b1 that is substantially equal to a. By this construction, the inner conductor is held firmly.

[0019] In a fifteenth embodiment of the invention, the connector may further comprise a nut having a first nut end and a second nut end placed in such way that the first nut end abuts to the second end of the main body and that a part of the inner surface of the nut is in contact with a part of the outer surface of the post.

[0020] In a sixteenth embodiment of the invention, a compressible sealing ring (O-ring) may be placed between the nut and the post.

[0021] In a seventeenth embodiment of the invention, the connector may further comprise an annular sealing ring having a first sealing ring end and a second sealing ring end, said first sealing ring end having an annular inner engagement portion being in contact with the outer surface of the second nut end.

[0022] In an eighteenth embodiment of the invention, the connector may further comprise an annular grip ring with the inner surface of the annular grip ring covering and being in contact with a part of the outer surface of the nut and the outer surface of the seal ring. In a nineteenth embodiment of the invention, in its end position the second receptacle guide end may be placed inside the second post end in such way that an outer surface of the end portion of the second receptacle guide end is substantially aligned with an outer end surface of the second post end.

[0023] In a twentieth embodiment of the invention, the first stop means of the receptacle guide may also position and guide the receptacle guide inside the post when moving the contact assembly from the start position to its end position.

[0024] The invention also relates to a method for connecting a coaxial connector to a cable comprising an inner conductor and an outer conductor. Said inner conductor may be mounted inside the receptacle guide where the contact assembly is in its start position, and the contact assembly may be moved to the end position by pushing the cable towards the second body end, and in which position the pin is protruding at least with a part outside the post.

[0025] The invention is explained in details below with reference to the drawings in which

Fig. 1 shows a side view of an embodiment of a coaxial connector according to the invention,

Fig. 2 shows an exploded view of the coaxial connector of Fig. 1,

Fig. 3 shows a coaxial connector according to the invention in a sectional view and in the start position for the contact assembly, and

Fig. 4 is a sectional view of the coaxial connector according to the invention and where the contact assembly and thereby the movable pin have reached their end position.

[0026] Fig. 1 is a side view of a coaxial connector 1 in accordance with a preferred embodiment of the invention. It shows a connector 1 before the connector 1 and a coaxial cable have been attached to each other. The connector 1 comprises a main body 17 having a central bore 2. The main body 17 is cylindrical and has a front end - a first body end 3 - around which a compression ring 18 is arranged. A nut 15 is attached to the main body 17 at the other end - the second body end 4. An annular sealing ring 14 is attached to the nut 15, and a grip ring 16 partly surrounds the outer surface of the nut and the annular sealing ring 14, whereby it is achieved that the annular sealing ring 14 is compressed and secured to the nut.

[0027] Fig. 2, Fig. 3 and Fig. 4 show an embodiment of a coaxial connector 1 according to the invention. The coaxial connector 1 comprises a tubular post 5, which is formed in one piece and in a conductive material. Further, the coaxial connector 1 comprises the annular sealing ring 14 and the nut 15, said nut 15 having an internal threaded region 19 at the end where the annular sealing ring 14 is placed. The nut 15 further comprises an outer recessed region in engagement with an inner part of the annular sealing ring 14.

[0028] Further, a tubular, fixed receptacle guide 9 is placed inside the main body 17 and the post 5 and also abuts to the internal surfaces of the post 5. Said fixed receptacle guide 9 is tubular-shaped and open in both ends in such way that a pin 6 can be put through the guide. Moreover, the connector 1 comprises a receptacle guide 8, this guide as well as the fixed receptacle guide 9 being made of non-conductive material. Said receptacle guide 8 has substantially the shape of a spool. This guide 8 is movably placed inside the post 5 and is able to slide from a first position to a second position. The first position is different from the second position, wherein in the first position, the pin 6 will at least partly be placed inside the main body 17, and in the second position, the pin 6 will be positioned in the region where the nut is placed, i.e. the region of the second end of the body. Further, the connector comprises a clip 7 (e.g. a receptacle from Mill-max), said clip 7 being fixedly and immovably placed inside the pin 6. The pin 6 is fixedly and immovably positioned inside the receptacle guide 8.The clip 7 comprises flexible walls so that it is possible to insert an inner conductor of a cable into this clip 7, where the compressing and flexible walls will grip around the conductor and thereby achieve that a firm electrical contact is achieved and generally that the inner conductor is retained in the pin 6. A sealing ring 13, e.g. an O-ring, is placed between the nut 15, the post 5 and the body 17, whereby it is achieved that a tight joint is obtained. Finally, the connector 1 comprises the compression ring 18, said compression ring 18 also being tubular-formed. All the parts, which are substantially cylindrical, are placed coaxially in relation to each other, said coaxial axis being a longitudinal axis 39 of the bore 2.

[0029] Fig. 3 shows the coaxial connector 1 in a cross sectional view along the longitudinal axis and where the receptacle guide 8 is in its first position - starting position, i.e. before an inner conductor is pushed into the connector, i.e. into the aperture of the first body end 3 and partly into the post 5 (the inner conductor and the dielectric) through the aperture of the compression ring 18. The construction is as follows: The cylindrical main body 17 surrounds a part of the post 5. The main body 17 comprises the first body end 3 at which end the compression ring 18 is placed in tight relation to the outside of the first body end 3. The second body end 4 is placed in the other end of the main body 17 opposite the first body end 3, said second body end 4 surrounding a part of the post 5. The main body 17 is substantially circular in cross section perpendicular to its longitudinal axis. The receptacle guide 8 is placed inside the main body 17, this being inside the post 5 in the region of the first body end 3. The receptacle guide 8 comprises a first receptacle guide end 20 pointing in the same direction as the first body end of 17. The first receptacle guide end 20 is formed as a substantially circular or cylindrical plate, and the outer surface/edge of the plate - or protrusions from said surface/edge - is in contact with the inner surface 31 of the post 5, said post being placed inside the main body 17. A flange/collar part 22 of the plate being the first stop means is engaging with an annular ledge 25 of the post 5, said ledge 25 protruding inwardly in the post, the ledge being the second stop means 25. The flange/collar part 22 and the ledge 25 are forming the stop means. The first receptacle guide end 20 is pressed into contact with the inner surface of the post in such way that it can withstand the force applied when the inner conductor of the cable is inserted in the receptacle guide 8, i.e. in the clip 7. A second receptacle guide end 21 is placed in the opposite end of the receptacle guide 8, said receptacle guide end 21 also being a substantially circular or cylindrical plate. However, as opposed to the plate of the first receptacle guide end 20, the edge of the plate of the second receptacle guide end 21 does not touch the inside of the post. The receptacle guide 8 comprises a hollow cylindrical part. The first and the second receptacle guide ends are arranged in each end of the hollow cylindrical part.

[0030] The pin 6 is attached to the second receptacle guide end 21, said pin being made of a conductive, cylindrical-shaped material. The pin 6 is slid along with the receptacle guide 8 and pressed into its second position. Hence, in use the pin 6 engages with another object such as a junction or an appliance.

[0031] Inside the hollow part of the pin 6, the clip 7 is fixedly placed, said clip 7 having flexible walls so that when an inner conductor of a cable is pressed inside the clip 7, the clip 7 is able to grip around said inner conductor. In this embodiment, the clip 7 grips the inner/centre conductor of the cable with a spring action caused by these flexible walls (e.g. a mill-max). The central longitudinal axis of the clip 7, the post 5, the pin 6, the bore 2 and the receptacle guide 8 have coaxial axes, and the pin 6, the receptacle guide 8 and the clip 7 form a contact assembly 30.

[0032] The entire contact assembly 30 is moved from a start position to an end position when the dielectric of a cable moves the receptacle guide 8 from the first position to the second position.

[0033] The clip 7 has a first clip end 23 and an opposite second clip end 24, said second clip end 24 being the part that performs the spring action. The clip is configured to grip the inner conductor of the cable and comprises a conical-formed hollow cylinder with the first clip end 23 having a fixed diameter and the opposing second clip end 24 having a diameter b as well as slotted, flexible walls 32 connected at the first clip end. Prior to inserting the inner conductor of a cable into the clip 7, the diameter b (second clip end 24, i.e. the exit end of the clip) is smaller than the diameter a (first clip end 23, i.e. the entry end of the clip) and in the situation where the cable is fully inserted, the diameter b1 may be substantially equal to a.

[0034] The inner surface 31 of the post 5 is annular and has a substantially circular cross-section. The inner surface 31 of the post touches the outer diameter/edge of the first receptacle guide end 20. The first receptacle guide end 20 is in contact with the inner surface 31 of the post 5 in the start position and also in the end position and further during the movement from the start to the end position. It should be mentioned that this guide end might also have protrusions 11, which are compressible. In this way, it is possible to use a receptacle guide 8 for at least two sizes of posts and thus at least two sizes of cables, which will lower the costs for producing such coaxial connectors. In the present embodiment, there are four protrusions 11, but other numbers of protrusions may be provided. By these protrusions 11, it is achieved that the receptacle guide 8 is centered correctly when sliding forward to its end position. In a certain distance from the first post end 28, the inner surface of the post 5 will comprise the second stop means 25. The second stop means 25 may be formed like a protruding ledge. The aperture defined by the ledge has a diameter rendering it possible for the second receptacle guide end 21 to pass through, but the first receptacle guide end 20 will be caught by the protruding part of the inner surface of the post 5, whereby the receptacle guide 8 will have a well-defined second position/end position when it has been pushed fully forward.

[0035] A second post end 29 is arranged for receiving and embracing the fixed receptacle guide 9, said fixed receptacle guide being a tubular, non-conductive part. This fixed receptacle guide 9 is formed with slits 27 in the annular wall, thus creating tongues 26. In this way, it is possible to regulate the impedance between the inner conductor and the outer conductor. The nut 15 is in engagement with the outer surface of the second post end 29. A second nut end 34 opposing a first nut end 33 is surrounded at least partly by a first seal end 35 of the annular seal ring 14. The outer surface of this annular seal ring 14 and a part of the outer surface of the second nut end 34 are surrounded by the cylindrical-formed grip ring 16.

[0036] A second seal end 36 of the annular seal ring 14 is placed opposite the first seal end 35 of the annular seal ring 14.

[0037] Fig. 4 shows a sectional view of the coaxial connector 1 according to the invention having a cable inserted, where the contact assembly 30 and thereby the movable pin 6 have reached their end positions. In the end position, the first receptacle guide end 20 is engaged with the second stop means 25 at the inner surface 31 of the post 5, this stop means 25 being formed like a protruding shelf or a protruding annular ledge. The second receptacle guide end 21 of the receptacle guide 8 is now placed so that an outer surface 37 of the second receptacle guide end 21 is facing towards the annular seal ring 14, i.e. away from the second body end, and the outer surface 37 will be substantially aligned with an outer end surface 38 of the post. By this construction, it is possible by visual control to check that the pin 6 is in its correct position. The second receptacle guide end 21 is formed like a circular plate and the diameter of this plate is smaller than or equal to the diameter of the bore of the the fixed receptacle guide 9 in which the second receptacle guide end 21 is sliding towards its end position. When the second receptacle guide end 21 is moving inside the fixed receptacle guide 9, it slides against at least a part of the said inner surfaces provided by the tongues. The inner walls of the fixed receptacle guide 9 may guide the contact assembly 30.

[0038] In Fig. 4, a cable 201 is placed and an inner conductor 204 is pressed into the inside of the receptacle guide 8 and caught by the clip 7, where the walls of the clip are pressing around the inner conductor 204 and ensuring that the cable will not disconnect from the connector. The inner conductor 204 is surrounded by a non-conductive material - a dielectric 205. This is surrounded by an outer conductor 202, which is surrounded by a jacket 203 formed in a non-conductive material. A front outer surface of the dielectric 205 is pushing the contact assembly 30 forward when the cable is pressed forward.

[0039] The outer conductor 202 is placed with its inside surrounding the outside of the post 5 when the cable is in its end position.

Reference numbers

[0040] 

1	Coaxial connector
2	Central bore
3	First body end of 17
4	Second body end of 17
5	Post
6	Pin
7	Clip
8	Receptacle guide
9	Fixed receptacle guide
11	Compressed protrusions of 20
13	Sealing ring/O-ring
14	Annular sealing ring
15	Nuts
16	Grip ring
17	Main body
18	Compression ring
19	Threaded region
20	First receptacle guide end
21	Second receptacle guide end
22	First stop means/first plate part
23	First clip end
24	Second clip end
25	Second stop means/shoulder/protrusions/ledge
26	Tongue
27	Slits
28	First post end
29	Second post end
30	Contact assembly
31	Inner surface of the post
32	Clip wall
33	First nut end
34	Second nut end
35	First seal end of annular seal ring (14)
36	Second seal end of annular seal ring (14)
37	Outer surface of 21
38	Outer end surface of the post
39	Longitudinal axis
201	Cable
202	Outer conductor
203	Jacket
204	Inner conductor
205	Dielectric

Claims

1. An electrical coaxial connector (1) for attachment to a coaxial cable (201), said connector 1 comprising a main body 17 having a central bore 2 defining a longitudinal axis and having

- a first body end 3 for receiving an inner conductor 204 of the cable and a second body end 4 opposite the first body end 3,

- a post 5 coaxially mounted within the main body 17 and having a first post end 28 for receiving the dielectric of a cable and an opposite second post end 29,

- a contact assembly 30 movably mounted within the post and surrounded by an inner surface of the post, said assembly comprising

- a receptacle guide 8 coaxially placed within the connector 1, said guide 8 having a first receptacle guide end 20 for receiving the inner conductor 204 of the cable and a second opposing receptacle guide end 21 to which a pin 6 is fixedly mounted, and

- a clip 7 coaxially and fixedly placed within the receptacle guide 8 and for receiving the inner conductor 204 of the cable,
said contact assembly 30 having a start position, before the cable is inserted, and an end position, when the cable 201 is fully inserted for use, the end position being different from the start position,
characterised in that the first receptacle guide end 20 comprises a first stop means 22 engaging with a second stop means 25 of the post, said first and second stop means 22,25 interacting with each other in the end position of the contact assembly 30.

2. An electrical coaxial connector (1) according to claim 1, characterised in that the receptacle guide 8 and thereby the contact assembly 30 are slidably placed in the post.

3. An electrical coaxial connector (1) according to claim 1 or 2, characterised in that the first receptacle guide end 20 is in contact with an inner surface 31 of the post 5 in the start position and also in the end position and further during the movement from the start position to the end position.

4. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that in the start position of the contact assembly, the second receptacle guide end 21 does not touch the inner surface 31 of the post.

5. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the second receptacle guide end 21 has a circular circumference and a diameter being smaller than the diameter of the inner surface of the post 5.

6. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that in the end position, the second receptacle guide end 21 is positioned in a fixed receptacle guide 9 formed with an annular wall, said fixed receptacle guide 9 being placed inside the post 5.

7. An electrical coaxial connector (1) according to claim 6, characterised in that the fixed receptacle guide 9 is formed with slots in the annular wall.

8. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the receptacle guide (8) is formed like a spool, the first end of the spool having a larger diameter than the second end of the spool.

9. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the receptacle guide (8) comprises a hollow cylindrical part, and in that a substantially circular or cylindrical plate is arranged at each end of the cylindrical part.

10. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the first stop means (22) comprises a flange/collar placed at the first receptacle guide end (20) and interacts in the end position with a protrusion (25) being the second stop means and protruding from the inner surface of the post (5).

11. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the first receptacle guide end (20) further comprises compressible outwardly directed protrusions (11).

12. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the clip (7) is configured to grip the inner conductor (204) of the cable (201) and comprises a conical-formed hollow cylinder having a first clip end (23) with a fixed diameter a and an opposing second clip end (24) with a diameter b and flexible walls connected at the first end (23), said diameter b having in a start position a diameter smaller than a, and in a position where the cable (201) is fully inserted having a diameter b1 that is substantially equal to a.

13. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that in end position, the second receptacle guide end (21) is placed inside the second post end so that an outer surface (37) of the end portion of the second receptacle guide end (21) is substantially aligned with an outer end surface (38) of the second post end.

14. An electrical coaxial connector (1) according to any of the preceding claims, characterised in that the first stop means (22) of the receptacle guide (8) also positions and guides the receptacle guide (8) inside the post 5 when moving the contact assembly (30) from the start position to its end position.

15. Method for connecting a coaxial connector (1) to a cable comprising an inner conductor (204) and an outer conductor and according to any of the preceding claims, characterised in that the inner conductor (204) is positioned inside the receptacle guide (8) where the contact assembly (30) is in its start position, and in that the contact assembly (30) is moved to the end position by pressing the cable (201) towards the second body end and in which position the pin (6) is protruding at least with a part outside the post (5).

Drawing