US3665601A

US3665601A - Method of making a connector

Info

Publication number: US3665601A
Application number: US843459A
Authority: US
Inventors: John G Dunbabin
Original assignee: Connecting Devices Inc
Current assignee: Connecting Devices Inc
Priority date: 1969-07-22
Filing date: 1969-07-22
Publication date: 1972-05-30
Anticipated expiration: 1989-05-30

Abstract

A method of making a connector comprising bending a tube to form a bend portion and forcing a plurality of balls through the passage in the tube to appropriately shape the cross section of the passage. An insulator and inner conductor are forced into the bent tube with the tube forming a die for shaping of the insulator and inner conductor.

Description

United States Patent Dunbabin 1 51 May 30, 1972 54 METHOD OF MAKING A CONNECTOR 2,869,377 1 1959 Pieterse ..74/216.3 2,945,203 7/ 1960 Quackenbush. .....339/59 I Z [72] G El Cahf 3,183,472 5/1965 Pawl ..29/629 [73] Assignee: Connecting Devices, Inc., El Segundo, 3,335,485 8/1967 Russo ..29/455 Califi 3,457,540 7/1969 Rolfes ..339/89 [22] Filed: July 22 1969 1,095,265 5/1914 Brinkman ..72/370 2,914,839 12/1959 Schwenger ..29/148.4 [21] Appl. No.: 843,459

Primary Examiner-John F. Campbell 52 US. Cl ..29/629 339/59 339 97 455mm" 74 2 3 i9/ 4 4: 72/376 Attorney-Smyth, ROSIOII & Pavitt [51] Int. Cl. ..H02g 15/00 [58] Field of Search ..29/629, 626, 630 R, 630 A, ABSTRACT 29/630 148A; 339/97 59; 74/2163; A method of making a connector comprising bending a tube 72/370 to form a bend portion and forcing a plurality of balls through the passage in the tube to appropriately shape the cross sec- [56] References Cmd tion of the passage. An insulator and inner conductor are UNITED STATES PATENTS forced into the bent tube with the tube forming a die for shaping of the insulator and inner conductor. 2,747,059 5/1956 Cockerham ..29/630 2,856,674 10/1956 Hill .339/89 15 Claims, 7 Drawing Figures METHOD OF MAKING A CONNECTOR BACKGROUND OF THE INVENTION The present invention relates to a method of making an angle connector of the type including a tubular outer conductor, a central or inner conductor within the outer conductor and an insulator for mounting the inner conductor within the outer conductor and for spacing the two conductors. Suitable connector elements are provided at opposite ends of the connector to provide for electrically and mechanically joining the opposite ends of the connector to conductive elements such as coaxial cable. The connector is bent through a predetermined angle such as 90 so that the conductive elements connected thereby can be joined at the desired angle.

In making connectors of this type it is important that the passage through the tube or outer conductor have a perfectly circular cross sectional configuration. This is necessary to assure that the connector will have the desired electrical qualities such as good impedance matching characteristics. If the outer conductor is simply bent to the desired angle, the internal diameter of the bend portion takes on a generally elliptical configuration which is very undesirable electrically in that it produces poor impedance matching.

In an effort to solve these problems, it has been proposed to construct the tube in half sections and then join the half sections in a brazing operation. This process is difiicult because the mating faces of the half sections must be finished prior to brazing and because it is difficult to accurately align the half sections for the brazing operation so that no discontinuities of the type which would impair the electrical characteristics of the outer conductor would be formed. Due to the nature of the brazing and alignment operations it is virtually impossible to make a perfectly circular passage through the-ultimately formed tube.

Also, even if the brazing operation is carefully carried out, small pinholes may be formed in the ultimately formed outer conductor. These pinholes cause discontinuities which have an adverse effect on the electrical characteristics of the connector. Specifically, the pinholes may cause a frequency shift and/or a voltage drop. Furthermore, moisture may enter the pinholes and provide a conductive path between the inner conductor and the outer conductor.

SUMMARY OF THE INVENTION The present invention solves these problems by providing integral outer conductor with a bend portion having a passage therethrough which is of circular cross section. Brazing of half sections and the consequent disadvantages thereof are eliminated.

According to the present invention, the tube for the outer conductor is first bent to the desired angle. This inherently causes the tube to distort with the result that the passage at the bend portion assumes a noncircular configuration such as a generally elliptical configuration. To make the passage of circular cross section at the bend portion, the present invention provides for the forcing of one or more balls through the passage. The ball should have a larger diameter than the minor axis of the elliptical passage so that the ball can deform the material of the tube and reshape the passage to the desired circular configuration.

In a preferred form of the invention, the passage is progressively shaped through the use of a plurality of balls each having a larger diameter than the previously used ball. In this fashion, the elliptical passage at the bend portion is progressively converted into a circular passage of the desired diameter.

In addition to accurately shaping the passage, the movement of the balls through the passage burnishes the wall of the passage. This further improves the electrical characteristics of the outer conductor.

Although this feature of passage shaping is particularly adapted for converting a noncircular passage into a passage having a circular cross section, it may be applied to make the passage of other cross sectional configurations. Similarly, this principle of the invention may be applied to shaping of the intemal surface of a tube which is ultimately used for purposes other than an outer conductor for an angle connector such as wave guides.

It is preferred to fill the tube with a bendable filler material prior to bending of the tube. This tends to reduce, but does not eliminate, the extent to which the passage becomes noncircular as a result of the bending operation. Following the bending of the tube, the bendable material therein can be removed as by melting of the filler material.

After the outer conductor has been formed, the insulator and inner conductor are inserted as a unit into the passage of the outer conductor. The outer conductor serves as a die for shaping of the insulator and inner conductor as the latter are forced into the passage. A region of the inner conductor is preferably annealed to facilitate the bending thereof. The resultant structure has excellent electrical properties.

The invention, both as to its organization and method of operation together with further features and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view taken on an axial plane of an illustrative connector which has been constructed in accordance with the method of this invention.

FIG. 2 is a side elevational view of a tube which is to be formed into the outer conductor of the connector.

FIG. 3 is an elevational view showing the tube after it has been bent.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3 and illustrating the general configuration of the bend portion of the tube following the bending thereof.

FIG. 5 is a sectional view on an axial plane through the bent tube illustrating the process of forcing a series of balls through the tube to appropriately shape the passage at the bend portion of the tube.

FIG. 6 is a sectional view taken along line 6--6 of FIG. 5 illustrating a typical general configuration of the tube after it has been subjected to the action illustrated in FIG. 5.

FIG. 7 is a sectional view on an axial plane illustrating the insertion of the insulator and inner conductor into the outer conductor.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and in particular to FIG. 1 thereof, reference numeral 11 designates an electrical connector constructed in accordance with the method of this invention. The connector 11 generally comprises an outer conductor 13, an inner conductor 15 and an insulator 17 separating the conductors. In the embodiment illustrated, the connector 1 1 has been bent through an angle of 90 although the particular angle which is formed by the connector can be varied to suit external conditions.

The outer conductor 13 is constructed of a deformable conductive metal. Preferably the metal for the outer conductor 13 is nonmagnetic as magnetic materials could adversely affect I the electrical characteristics of the connector. The outer conductor 13 may be constructed, for example, of brass, aluminum, or stainless steel with 304 stainless steel being preferred.

The outer conductor 13 has an axial passage 19 extending completely therethrough. The passage is formed by a wall 21 of the tube 13. The passage 19 is of circular cross section throughout the full length thereof so as to provide excellent electrical characteristics for the connector 1 1.

The inner or central conductor 15, in the embodiment illustrated, is in the form of an elongated rod which is coaxial with the passage 19 and with the outer conductor 13. The inner conductor 15 is mounted within the outer conductor 13 by the insulator 17. The inner conductor has a male end 23 and a female end which is defined by a plurality of axially extending spring fingers which provide a socket 27. The female end of the connector 11 is adapted to receive the male end of an external member (not shown) such as the male end 23 and the male end 23 is adapted to be received within the female portion of an external member (not shown) such as the socket 27.

The inner conductor 15 is preferably constructed of a nonmagnetic conductive metal having spring qualities such as beryllium copper. The spring qualities are necessary for the spring fingers 25. The entire inner conductor 15 except for the spring fingers 25 may be annealed to facilitate bending thereof.

The insulator 17 fits snugly within the passage 19 and is coaxial therewith. The inner conductor 15 fits snugly within an axial passage which extends through the insulator 17. The female end of the inner conductor 15 is flush with one end of the insulator 17 and the male end 23 projects outwardly beyond the other end of the insulator. The insulator may be of various materials having electrical insulating qualities with polytetrafluoroethylene being preferred.

At the female end of the connector 1 1, the outer conductor 13 has been machined to form an end portion 29 of reduced wall thickness. A boss 31 having external threads 33 telescopically receives the end portion 29 and is rigidly affixed thereto as by brazing. The boss 31 forms, in effect, an extension of the outer conductor 13 and houses a portion of the insulator l7.

Adjacent the male end of the connector 11, the outer conductor 13 has been machined to form an annular groove 35 and an end portion 37 of reduced wall thickness. A retaining ring 39 is received with groove 35 and within an internal groove 41 of a nut 43 to rotatably mount the latter on the outer conductor 13. The nut 43 has internal threads 45 for connection to an external member (not shown). An annular seal 47 is mounted on the end portion 37 and provides a seal between such end portion and the internal surface of the nut 43.

The outer conductor 13 is formed from a cylindrical tube 49 (FIG. 2) having a cylindrical passage 51 extending therethrough. The tube 49 is filled with a low melting point bendable material such as the material sold the trademark Ceriban. The tube 49 is then bent through the desired angle utilizing appropriate tooling for accomplishing this purpose to form the bend portion 53 (FIG. 3). The Ceriban is then heated to a temperature above its melting point but below the melting point of the material of the tube 49 to allow the former to flow out of the passage 51.

The result of bending of the tube 49 is that the passage 51 assumes an elliptical configuration at the bend portion 53 as shown in FIG. 4. The wall thickness of the tube 49 at the bend portion 53 will be different at different circumferential locations. Generally, however, the wall thickness of the tube 49 will be greater along the inside 55 of the bend portion than along the outside 57 of the bend portion. The use of the Ceriban within the tube 49 prior to bending of the tube reduces the amount to which the passage 55 becomes noncircular as a result of the bending operation.

Next, the tube 49 is placed in a suitable fixture 59 which may be of conventional construction and for this reason is shown diagrammatically in FIG. 5. The fixture 59 retains the tube 49 while a first hard spherical ball 61 is positioned in the upper end of the passage 51. The portion of the passage 51 which is not at the bend portion will remain circular and will be unaffected by the bending operation. Accordingly, the ball 61 will fall through such circular portion of the passage until further movement thereof is prevented by the elliptical portion of the passage 51. The ball 61 is sized so as to have a diameter which is larger than the minor axis of the elliptical portion of the passage so that it can exert a reshaping effect on such portion of the passage. Next, balls 63, 65, and 67 of progressively increasing diameters are positioned in the passage 51 and driven therethrough utilizing a ram such as a hydraulically operated ram 69. Although any suitable number of the balls may be utilized, depending upon the results desired, it will usually be desirable to utilize three or four of the balls with each of the balls being of progressively increas ing diameter.

The balls must be sufficiently hard so that they can deform the tube 49 sufficiently to form the passage 51 into a circular configuration as shown in FIG. 6. Because of the inherent springback of the material of the tube 49, the last of the forming balls utilized should be of slightly larger diameter than the desired diameter of the passage 51 at the bend portion 53. The last forming ball 67 is forced through the passage 51 using one or more balls 68 of smaller diameter than the ball 67 and the passage 51. Preferably, at the completion of the operation shown in FIG. 5, the diameter of the passage 51 will be constant throughout the full length thereof. Although the bending of the tube 49 and the forcing of the balls therethrough may affect the wall thickness of the tube 49, this will not affect the electrical characteristics of such tube when the latter is utilized as an outer conductor for a connector.

The tube 49 is then removed from the fixture 59 and the reduced

thickness end portions

29 and 37 and the groove 35 are formed as by machining. Next the end faces of the tube 49 are made perfectly square with the axis of the passage. With the completion of these operations, the tube 49 is converted into the outer conductor 13.

The boss 31 is then pressed on the end portion 29 and brazed to the outer conductor 13 as shown in FIG. 1. The resultant construction is then plated, first with nickle and then with gold, in order to give it better conductive properties.

Assuming that the center conductor 15 and the insulator 17 have been preformed, the center conductor 15 may be inserted within the axial passage through the insulator 17 as shown in FIG. 7. When in this condition, the inner conductor 15 and the insulator 17 are both straight cylindrical members. Prior to the insertion of the inner conductor 15, the entire inner conductor 15 except for the spring fingers 25 should be annealed to facilitate bending thereof and the spring fingers 25 should be heat treated to impart substantial resilience thereto. The outer conductor 13 and the boss 31 can be retained in a suitable fixture 71 having a tubular extension 72 for slidably retaining the insulator 17. Utilizing an appropriate ram 73 the insulator l7 and the inner conductor 15 can be forced into the passage 51 as shown in FIG. 7. As downward movement of the ram 73 progresses, the inner conductor 15 and the insulator 17 are gradually subjected to the progressive curving of the passage 51. This results in distortion of the inner conductor 15 and of the insulator 17. Thus, the outer conductor 13 serves as a die for forming of the inner conductor 15 and the insulator 17. The insulator fits snugly within the outer conductor 13. Next, the insulator 17 at the end thereof adjacent the male end 23 is trimmed as necessary and the retaining ring 39 and the nut 43 are mounted on the outer conductor 13.

The method described herein can be applied to connectors of many designs and to many other devices and is not restricted to the making of the particular connector 11 illustrated in FIG. 1. Although an exemplary embodiment of the invention has been shown and described, many changes, modifications, and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

We claim:

1. A method of forming a tube having a curved portion with a passage of a predetermined cross sectional configuration extending therethrough, said method comprising:

providing a tube having a curved portion and a curved passage extending through said curved portion, said passage having a cross sectional configuration other than said predetermined cross sectional configuration, said tube being constructed of deformable material;

forcing at least one member of approximately said predetermined cross sectional configuration through said curved passage to deform said tube to thereby form said passage providing an insulator and an inner conductor with the with said predetermined cross sectional configuration at said curved portion; and

said predetermined cross sectional configuration being circular and said member being a substantially spherical ball, said step of forcing including forcing a plurality of 5 said balls of progressively increasing diameter through said curved passage with the last of said balls being of substantially said predetermined cross sectional configuration.

2. A method of making an electrical connector comprising:

providing a tube of conductive material having a bend portion and a passage extending through said bend portion with said passage being of circular cross sectional con figuration;

inner conductor extending through the insulator and sized to snugly fit within said passage, at least a portion of said inner conductor being annealed to facilitate subsequent bending thereof;

retaining said tube;

forcing said insulator and inner conductor into said passage of said tube with the tube deforming said insulator and inner conductor as the insulator and inner conductor are forced through said bend portion of the tube; and

said first mentioned step of providing including providing a tube of deformable material having a substantially cylindrical passage extending generally axially therethrough, bending said tube about an axis generally transverse to the axis of said passage to form the bend portion with the passage extending through said bend portion and with the bending of said tube distorting the passage through said bend portion to a generally elliptical cross sectional configuration, and forcing a plurality of balls of progressively increasing diameter through the passage through said bend portion to deform the material of the tube at the bend portion to provide the passageway through the bend portion with a circular cross sectional configuration.

3. A method of forming a tube comprising:

providing a tube having a curved portion and a curved passage extending through said curved portion, said curved passage having a noncircular cross sectional configuration said tube being constructed of deformable material; and

forcing at least one ball through said curved passage to deform said tube to thereby form said curved passage with a circular cross sectional configuration, said step of forcing being carried out subsequent to said step of providing.

4. A method of forming a tube having a bend portion with a passage of circular cross section extending through and along said bend portion, said method comprising:

providing a unitary tube of deformable material having a substantially cylindrical passage extending generally axially therethrough;

bending said unitary tube about an axis generally transverse to the axis of said passage to form a bend portion with the passage extending through said bend portion and with the bending of said tube distoring the passage through said bend portion to a noncircular cross sectional configuration;

retaining the unitary tube; and

following the step of bending forcing at least one ball through the passage through the bend portion to deform the material of the unitary tube at the bend portion to provide the passage through the bend portion with a circular cross sectional configuration.

5. A method as defined in claim 4 wherein said step of forcing includes forcing a plurality of balls of progressively increasing diameter through said passage at said bend portion.

6. A method as defined in claim 4 including filling the unbent tube with a deformable filler material and subsequently bending said tube about said axis, said method including the step of removing said deformable filler material from said passage of said tube prior to said step of forcing.

7. A method of making an electrical connector comprising:

providing a tube of deformable conductive material having a bend portion and a curved passage of noncircular cross sectional configuration extending through said bend portion; retaining said tube; forcing at least one ball through the passage through the bend portion to deform the material of the tube at the bend portion to provide the passage through the bend portion with a circular cross sectional configuration;

inserting an inner conductor into said passage; and

providing an insulator within said passage with the insulator spacing the inner conductor from the tube and with the insulator and inner conductor extending at least partially through the bend portion, said step of inserting being carried out subsequent to said step of forcing.

8. A method as defined in claim 7 wherein said step of forcing includes forcing a plurality of balls of progressively increasing diameter through said passage at said bend portion with the last of said balls being slightly larger than the desired cross sectional configuration of said passage at said bend portion to thereby allow for springback of the tube.

9. A method as defined in claim 7 wherein said step of inserting includes providing an insulator of deformable material and an inner conductor of deformable material with the insulator and inner conductor being substantially straight and with the inner conductor extending through said insulator, retaining said tube and forcing said insulator and inner conductor into said passage of said tube with the tube deforming said insulator and inner conductor to the desire configuration at said bend portion.

10. A method as defined in claim 2 wherein said step of providing an insulator and inner conductor includes providing the inner conductor with female connector means having resilient spring qualities, said portion of said center conductor which is annealed being a portion other than said female connector means.

11. A method as defined in claim 4 including the step of providing electrically conductive terminals adjacent the opposite end portions of said tube.

12. A method as defined in claim 7 wherein the first mentioned step of providing includes providing an axially unsplit tube and bending said tube to form said passage thereof into said noncircular cross sectional configuration, said step of forcing being carried out subsequent to said step of bending.

13. A method as defined in claim 3 wherein said step of forcing includes forcing a plurality of balls of progressively increasing diameter through said curved passage.

14. A method of forming a tube comprising:

providing a unitary tube of deformable material having a passage of predetermined cross sectional configuration extending generally axially therethrough;

bending said unitary tube about an axis generally transverse to the axis of said passage to form a bend portion with the passage extending through said bend portion and with the bending of said tube distorting the passage through said bend portion to a cross sectional configuration other than said predetermined cross sectional configuration; retaining the unitary tube; and

following the stp of bending forcing at least one member of substantially said predetermined cross sectional configuration through the passage through the bend portion to deform the material of the unitary tube at the bend portion to provide the passage through the bend portion with substantially said predetermined cross sectional configuration.

15. A method as defined in claim 14 wherein said one member is a first member and including a second member having a cross sectional configuration geometrically similar to and smaller than said first member, said step of forcing includes forcing said second member through the passage through the bend portion to deform the material of the tube at the bend portion prior to forcing said first member through the passage through the bend portion.

Claims

1. A method of forming a tube having a curved portion with a passage of a predetermined cross sectional configuration extending therethrough, said method comprising: providing a tube having a curved portion and a curved passage extending through said curved portion, said passage having a cross sectional configuration other than said predetermined cross sectional configuration, said tube being constructed of deformable material; forcing at least one member of approximately said predetermined cross sectional configuration through said curved passage to deform said tube to thereby form said passage with said predetermined cross sectional configuration at said curved portion; and said predetermined cross sectional configuration being circular and said member being a substantially spherical ball, said step of forcing including forcing a plurality of said balls of progressively increasing diameter through said curved passage with the last of said balls being of substantially said predetermined cross sectional configuration.

2. A method of making an electrical connector comprising: providing a tube of conductive material having a bend portion and a passage extending through said bend portion with said passage being of circular cross sectional configuration; providing an insulator and an inner conductor with the inner conductor extending through the insulator and sized to snugly fit within said passage, at least a portion of said inner conductor being annealed to facilitate subsequent bending thereof; retaining said tube; forcing said insulator and inner conductor into said passage of said tube with the tube deforming said insulator and inner conductor as the insulator and inner conductor are forced through said bend portion of the tube; and said first mentioned step of providing including providing a tube of deformable material having a substantially cylindrical passage extending generally axially therethrough, bending said tube about an axis generally transverse to the axis of said passage to form the bend portion with the passage extending through said bend portion and with the bending of said tube distorting the passage through said bend portion to a generally elliptical cross sectional configuration, and forcing a plurality of balls of progressively increasing diameter through the passage through said bend portion to deform the material of the tube at the bend portion to provide the passageway through the bend portion with a circular cross sectional configuration.

3. A method of forming a tube comprising: providing a tube having a curved portion and a curved passage extending through said curved portion, said curved passage having a noncircular cross sectional configuration said tube being constructed of deformable material; and forcing at least one ball through said curved passage to deform said tube to thereby form said curved passage with a circular cross sectional configuration, said step of forcing being carried out subsequent to said step of providing.

4. A method of forming a tube having a bend portion with a passage of circular cross section extending through and along said bend portion, said method comprising: providing a unitary tube of deformable material having a substantially cylindrical passage extending generally axially therethrough; bending said unitary tube about an axis generally transverse to the axis of said passage to form a bend portion with the passage extending through said bend portion and with the bending of said tube distoring the passage through said bend portion to a noncircular cross sectional configuration; retaining the unitary tube; and following the step of bending forcing at least one ball through the passage through the bend portion to deform the material of the unitary tube at the bend portion to provide the passage through the bend portion with a circular cross sectional configuration.

7. A method of making an electrical connector comprising: providing a tube of deformable conductive material having a bend portion and a curved passage of noncircular cross sectional configuration extending through said bend portion; retaining said tube; forcing at least one ball through the passage through the bend portion to deform the material of the tube at the bend portion to provide the passage through the bend portion with a circular cross sectional configuration; inserting an inner conductor into said passage; and providing an insulator within said passage with the insulator spacing the inner conductor from the tube and with the insulator and inner conductor extending at least partially through the bend portion, said step of inserting being carried out subsequent to said step of forcing.

14. A method of forming a tube comprising: providing a unitary tube of deformable material having a passage of predetermined cross sectional configuration extending genErally axially therethrough; bending said unitary tube about an axis generally transverse to the axis of said passage to form a bend portion with the passage extending through said bend portion and with the bending of said tube distorting the passage through said bend portion to a cross sectional configuration other than said predetermined cross sectional configuration; retaining the unitary tube; and following the stp of bending forcing at least one member of substantially said predetermined cross sectional configuration through the passage through the bend portion to deform the material of the unitary tube at the bend portion to provide the passage through the bend portion with substantially said predetermined cross sectional configuration.