US3541495A - Connector for termination of coaxial cable - Google Patents

Description

H. ELLIS E AL CONNECTOR F'OR TERMINATION OF COAXIAL CABLE Filed m. 12, 1968 Nov. 17, 1970 2 Sheets-Sheet 1 WN mm QM j \m mm QM & /N-m 7x v m mm R Q m w v, mm w Wax/6 v E m 7 Hm A Rm M D GE mmf M/ Nov. 17, 1970 ELLls EI'AL 3,541,495

CONNECTOR FOR TERMINATION 0F COAXIAL CABLE Filed Aug. 12, 1968 2 Sheets-Sheet 2 NVENTOPS ROGER H. ELLIS FREDERICK M. GRAFTON BY A7700VV5 sfi gm 3. mm QR m Q 1% 1 ymmwg Sm xli my, 5 w m v .li; gm x g g sfi mg United States Patent US. Cl. 339-177 16 Claims ABSTRACT OF THE DISCLOSURE A coaxial contact for terminating both the center conductor and the braid shield of a coaxial cable with soldered connections. The contact is provided with an internal sleeve of heat recoverable material having a solder insert. This sleeve receives the central conductor of the cable and the solder insert serves, when melted, to make a soldered connection between the conductor and the inner contact while the sleeve provides a continuous insulation between the inner and outer contacts. The outer contact is provided with a window to permit radiant heat energy to be directed onto the internal sleeve and solder insert. A second heat recoverable sleeve and solder insert are positioned around the outside of the outer contact, the solder insert being located over a second window. When the cable is inserted into the contact, the conductor is located under the first window and the braid beneath the second window. Recovery of the external sleeve causes solder to be forced through the second window to make a soldered connection between the braid and the inside of the outer contact which is insulated from the inner contact.

BACKGROUND OF THE INVENTION Numerous contacts have in the past been provided for terminating coaxial cables. Generally, these contacts are in the form of a contact pin assembly or a contact socket assembly which are interconnectable and which are adapted to be releasably held in a terminal block. The contact assemblies are made up of two conducting portions which are insulated from each other, the inner contact being connected in some fashion to the center conductor and the outer contact being connected to the braid of the coaxial cable. Originally, the connections between the body portions and the conductors were soldered connections. However, because of the expense and operators skill required to make soldered connections and the impracticality of making such soldered connections in large volume and by automatic equipment, the art has more recently turned to crimped connections. Crimped connec tions are, however, less desirable than soldered connections because they are not as reliable electrically and the use of any crimping mechanism increases the. probability of mechanical damage being done to the parts.

SUMMARY OF THE INVENTION According to the present invention, a contact is provided which permits the making of soldered connections between the conductors of a coaxial cable and the body portions of the contact in a reliable and expeditious manner and permits the cable to be terminated automatically and by unskilled operators. This is accomplished by incorporating in the contact body a pair of heatrecoverable sleeves having solder inserts positioned therein. The construction of such sleeves is disclosed in Wetmore Pat. No. 3,243,211, the disclosure of which is incorporated herein by reference. The first of the solder sleeves is positioned between the inner and outer contact body portions of the contact and serves to properly space these portions and to electrically insulate them. A window is provided in the outer body portion so that heat energy can be applied to the first solder sleeve to cause the recovery of the sleeve which forces the solder to make a connection between the inner contact and the central conductor of the coaxial cable. The second solder sleeve is positioned around the outer body portion with the solder insert being located over a second window in this portion. When heat is applied to this second sleeve, it recovers, forcing the solder through the window to form a soldered connection between the braid portion of the coaxial cable and the interior of the outer body portion. Both sleeves can be recovered simultaneously and by automatic equipment with the result that a coaxial cable can be terminated with the desired soldered connections but without the disadvantages previously associated with soldered terminations.

It is therefore an object of the present invention to provide a soldered termination for a coaxial cable.

Other objects and advantages of the present invention will become more apparent upon reference to the accompanying description and drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation in cross-section showing a contact pin assembly according to the present invention before it has been recovered over a coaxial cable but with the cable in place;

FIG. 2 is a cross-sectional view taken along lines 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along lines 3-3 of FIG. 1; I

FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 1;

FIG. 5 is a side elevation in cross-section of a contact socket assembly according to the present invention before it has been recovered over a coaxial cable but with the cable in place.

FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 5;

FIG. 7 is a cross-sectional view taken along lines 77 of FIG. 5;

FIG. 8 is a cross-sectional view taken along lines 8-8 of FIG. 5;

FIG. 9 is a cross-sectional view of the contact pin assembly of FIG. 1 after installation;

FIG. 10 is a cross-sectional view of the contact socket assembly of FIG. 5 after installation;

FIG. 11 is a side elevation in cros-section showing a modification of the present invention used for terminating a pair of twisted wires; and

FIG. 12 is a cross-sectional view taken along lines 12-l2 of FIG. 11.

DESCRIPTION OF THE INVENTION Turning now to FIG. 1 through 4 there is shown a contact pin assembly according to the present invention. A generally tubular outer pin contact body 10 has an interior passageway 11 and first and second openings or windows 12 and 13 in the wall of the body 10 to provide access to the passageway 11. The exterior of the body 10 is provided with a collar 14 in which is mounted a spring tension clip 15 of conventional design for cooperating with conventional terminal blocks for releasably holding the contact pin assembly in the block. A heat recoverable sleeve 16 is positioned over the rear portion of the body 10, the latter preferably being provided with a shoulder 17 to properly locate the sleeve 16 and to radially locate the assembly in the terminal block. Positioned within the sleeve 16 is a ring of fluxed solder 18, the solder 18 being located over the window 13. When the sleeve 16 is initially positioned over the rear portion of the body 10, its internal diameter is slightly larger than the external diameter of the body 10. It is then partially recovered down around the body so that it grips end of the inner socket contact is provided with a pair of tines 24 and 25 which form a tapered slot 23 to receive the inner conductor of a coaxial cable. A groove 26 is provided in the straight portion of the inner socket 20 that will be positioned under the shoulder 14 of the outer pin contact body 10.

A solder ring 27 is positioned over the tines 24 and 25 and a second heat recoverable sleeve 28 is positioned over the inner socket contact 20 and the ring 27. When initially installed, the inner diameter of the sleeve 28 was greater than the outer diameter of the inner socket contact 20 but it was partially recovered to firmly grip the inner socket contact 20, the partial recovery causing the sleeve 28 to enter the groove 26 and to shrink down to a predetermined diameter around but not quite engaging the tines 21 in their position on one end of the inner socket contact 20 and the tines 24 and 25 on the other end. During this partial recovery, mandrels (not shown) were inserted in both ends of the sleeve 28 to shape this sleeve so that it could perform various functions. At the forward end of the inner socket contact 20 the sleeve 28 has been shrunk to form a reduced diameter portion 29 which serves as a closed entry for the tines 21 so as to protect the inner socket contact. Next to the reduced diameter portion 29 the sleeve 28 has been restrained from shrinking past a predetermined diameter to form an annular spacer portion 30 which accurately and concentrically positions the inner socket contact 20 within the outer pin contact body 10. The other end of the sleeve 28 has been formed so as to receive the dielectric portion of a coaxial cable. For this purpose, the end 31 of the sleeve has been provided with a slight taper.

After the sleeves 28 and 16 have been partially recovered around the inner socket contact 20 and the outer pin contact body 10 respectively, the inner socket contact 20 is inserted into the passageway 11 of the outer pin contact body 10. As stated, the sleeve 28 serves to properly locate the inner socket contact 20 within the outer pin contact body 10 so that these two elements are concentric. The use of a sleeve for this alignment purpose is a considerable advantage over conventional means of accomplishing this purpose which usually require machining of the various elements with a consequent increase in cost. After the inner socket contact 20 is in place, dimples 32 are formed in the shoulder portion 14 of the outer pin contact body 10 to extend into the groove 26 of the inner socket contact 20 and hold this contact in place. The spring tension clip 15 is then positioned on the shoulder 14.

As can be seen, the tines 24 and 25 of the inner socket contact 20, together with the solder ring 27, are located under the window 12 in the outer pin contact body -10 so that radiant energy may be directed onto the ring 27 and the portion of a sleeve 28 that is exposed. A coaxial cable 33 having an inner conductor 34, a cable dielectric 35, a braid 36 and a cable jacket 37 is now inserted into the end of the contact pin assembly. Preferably, the braid 36 has been folded back over the cable jacket 37 to expose significant area of the cable dielectric 35. As can be seen, the conductor 34 extends between the tines 24 and 25, the cable dielectric 35 abutting against these tines. The braid 36 is located under the solder ring 18 and is exposed to radiant energy passing through the window 13. The unit is now ready for final installation.

Installation is accomplished by directing a beam of radiant heat energy onto at least that portion of the assembly to the rear of the window 12. The heat causes the solder ring 27 to fuse and the sleeve 28 to recover, forcing the solder between the tines 24 and 25 and the conductor 34 of the cable 33 to make a soldered connection between these elements. The solder ring 18 is also fused and the sleeve 16 recovered. Recovery of the sleeve 16 causes the solder of the insert 18 to be forced through the window 13 and onto the braid 36 to form a soldered connection between the braid 36 and the interior of the outer pin contact body 10. The end 31 of the sleeve 28 also recovers to firmly grip the cable dielectric 35 and prevent shorting between the braid and the conductor. The tapered end 19 of the sleeve recovers around the cable jacket 37 to form a mechanically strong sealed connection between the sleeve 16 and the jacket 37. The assembly after installation is shown in FIG. 9, the same elements being identified by the same reference numerals.

The socket half of the contact of the present invention is shown in FIGS. 5 through 8. The contact socket assembly shown in these figures is in many respects identical to that of the contact pin assembly of FIGS. 1 through 4. These similar features will. be designated by the same reference numerals with the subscript a and for the sake of simplicity will not be described again. The only significant difference between the contact socket assembly of FIGS. 5-8 and the contact pin assembly of FIGS. l-4 is in the configuration of the forward end of the assembly. The contact socket assembly has an outer socket contact body 40 which has an internal diameter sufficient to receive the outer pin contact body 10 of the contact pin assembly. The forward end of the outer socket contact body 40 is slotted to form a plurality of tines 41 for making good mechanical and electrical contact with the end of the outer pin contact body 10. The tines 41 are provided with a groove 42 which receives a spring tension clip 43 which releasibly engages the contact socket assembly in a conventional terminal block.

An inner pin contact 45 which corresponds with the inner socket contact 20 of FIG. 1 is provided with an elongated pin 46 which is adapted to be received between the tines 21 of the inner socket contact 20. The inner pin contact is provided with a groove 47 which cooperates with dimples 48 formed in the outer socket contact body 40 to hold the inner pin contact in place. As stated, all of the other elements of the contact socket assembly are essentially identical to those of the contact pin assembly.

When the contact socket assembly is irradiated by radiant heat energy, the solder ring 27a is caused to fuse and form a soldered connection between the inner pin contact 45 and the conductor 34a of a coaxial cable 33a, recovery of the sleeve 28a causing movement of the solder through the tapered slots 23a. Similarly, recovery of the sleeve 16a causes movement of the fused solder from the ring 18a through the window 13a to form a soldered connection between the braid 36a and the outer socket contact body 40. The tapered portion 19a of the sleeve 16a recovers to firmly engage the cable jacket 37 of the cable 330. The contact socket assembly after installation is shown in FIG. 10.

Turning now to FIGS. 11 and 12, there is shown a modification of the present invention which permits it to be used with a twisted pair of wires rather than a coaxial cable. In this embodiment, the forward end of the contact can take either of the forms shown in FIGS. 1 or 5 and thus no particular front end structure is illustrated. The inner contact 50 may thus be provided with either a pin or socket at its forward end and at its other end is provided with tines 51 and 52 over which is positioned a solder ring 53. The inner contact 50 and solder ring 53 are covered by a heat recoverable sleeve 54 which is partially heat recovered around the body 50. The sleeve 54 extends for the entire length of the axial passageway 55 of the outer contact body 56. The outer contact body 56 is provided with a window 57 which overlies the tines 51 and 52 and solder ring 53 so that the solder ring 53 can be fused and the sleeve 54 recovered in this area.

A second heat recoverable sleeve 58 is positioned on top of the outer contact body 56 and abuts against a solder ring 59 which surrounds the body 56 but which is not concentric therewith so that a space 60 is formed adjacent to the end of the sleeve 58. The body 56 is preferably provided with a shoulder 61 for locating the solder ring 59. A third heat recoverable sleeve 62 is positioned over the body 56, sleeve 58 and solder ring 59 and, like the sleeves 54 and 58 extends beyond the end of the body 56. The body 56 is preferably provided with a shoulder '63 against which the forward end of the sleeve 62 can be located and which locates the assembly radially in the terminal block. The sleeve 62 is partially recovered around the body :56, sleeve 58 and solder ring 59 to hold them all in place.

A twisted pair of wires 64 and 65 are inserted within the sleeve 58 and sleeve 54 respectively, the wire 65 being longer so that its conductor 66, which typically serves as the signal conductor, extends under the solder ring 53. The conductor 67 of the wire 64, which typically serves as the ground conductor, extends into the space 60 under the solder ring 59 and bottoms on the step of the sleeve 62. When heat is applied, the solder rings 53 and -9 fuse and the sleeves 54, 58 and 62 recover to cause a soldered connection to be formed between the conductor 66 and the inner contact 50 and the conductor 67 and the outer contact body 56. The heating is preferably done by the use of radiant heat such as infrared energy but can also be done by hot air if desired. The same, of course, is true of the previous embodiments.

The sleeves 54, 58 and 62 are extended beyond the outer contact body 56 to provide strain relief for the conductors. The sleeve 58 is not necessary but is added to cover the ground conductor 64 to maximize strain relief and protect the insulation of this wire during the heating cycle. The tapered portions 19 and 19a of the previous embodiments also provide strain relief for the cable by extending the strain relief point away from the contact bodies. The various windows provided in the contact bodies not only permit the making of soldered connections but also provide a way of making visual inspection of these connections after they have been completed. The sleeve 28 of FIG. 1 in addition to its other functions may, if desired, also serve to compress the tines 21 so that they firmly grasp the contact pin 46 of the contact socket assembly.

From the foregoing description it can be seen that a novel contact has been provided which permits the terminating of coaxial cables or twisted pairs of cables with a soldered connection. Although the termination is of the desired soldered variety, it can be made quickly and automatically by unskilled operators. Since the amount of solder and flux present in the solder ring are metered amounts, good reliable connections can be assured.

The invention may be embodied in other specific forms not departing from the spirit or central characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A contact for terminating an electrical conductor comprising:

an outer contact body having a wall forming a passageway therein, said wall having an opening therethrough communicating with said passageway;

an inner contact body positioned within said passageway, a portion of said inner contact body being located under said opening;

a sleeve of heat recoverable material positioned over said inner contact body and between said inner and said outer contact bodies; and

a solder insert positioned within said sleeve around said portion of said inner body contact.

2. A contact for terminating an electrical conductor comprising: (1) an outer contact body having a wall forming a passageway therein, said wall having an opening therethrough communicating with said passageway; (2) an inner contact body positioned within said passageway, a portion of said inner contact body being located under said opening; (3) a sleeve of heat recoverable material positioned over said inner contact body; (4) a solder insert positioned within said sleeve around said portion of said inner body contact; (5) a second sleeve of heat recoverable material positioned over said outer contact body; and (6) a second solder insert positioned within said second sleeve.

3. The contact of claim 2 further comprising a third sleeve of heat recoverable material positioned between said outer contact body and said second sleeve.

4. The contact of claim 2 wherein said wall is provided with a second opening communicating with said passageway and wherein at least a portion of said second solder insert overlies said second opening in said wall.

5. The contact of claim 4 wherein said second sleeve extends beyond one end of said outer contact body and is tapered to guide a coaxial cable into said passageway of said outer contact body.

6. The contact of claim 5 wherein said first sleeve extends beyond one end of said inner contact body and serves to guide a portion of a coaxial cable into said inner contact body.

7. The contact of claim 6 wherein the other end of said outer contact body terminates in a socket contact.

8. The contact of claim 6 wherein the other end of said outer contact body terminates in a pin socket.

9. The contact of claim 7 wherein the other end of said inner contact body terminates in a pin contact.

10. The contact of claim 8 wherein the other end of said inner contact body terminates in a socket contact.

11. A contact for terminating an electrical conductor comprising: 1) an outer contact body having a wall forming a passageway therein, said wall having an opening therethrough communicating with said passageway; (2) an inner contact body positioned within said passageway, a portion of said inner contact body being located under said opening; (3) a sleeve of heat recoverable material positioned over said inner contact body; (4) a solder insert positioned within said sleeve around said portion of said inner body contact; and (5) said sleeve spatially locating said inner contact body within said passageway.

12. An article comprising: (1) a first member having a wall forming a passageway therein; (2) a second member positioned within said passageway; and (3) means spatially locating said second member relative to said wall of said first member, said means comprising a sleeve of heat recoverable material recovered about said second member and having extending portions engaging said wall of said first member, the remaining portions of said heat recovered sleeve being spaced from said wall of said first member.

13. A contact or terminating a coaxial cable having an inner conductor and an outer conductor separated by a dielectric comprising:

an outer contact body having a wall forming a passageway therein, said wall having'first and second openings therein communicating with said passageway;

an inner contact body positioned within said passageway, one end of said inner contact body terminating in a plurality of tines, said tines being located under said first opening;

a solder ring positioned over said tines;

a first sleeve of heat recoverable material positioned over said inner contact body and extending beyond said tines, said sleeve having a reduced diameter portion engaging said tines and a tapered end portion for guiding the dielectric of a coaxial cable into said sleeve;

a second solder ring positioned around said outer contact body and over said second opening; and

a second sleeve of heat recoverable material positioned over said outer contact body and said second solder ring and extending beyond one end of said outer contact body, said sleeve having a tapered end portion for guiding a coaxial cable into said passageway of said outer contact body.

14. The contact of claim 13 wherein the other end of said outer contact body terminates in a pin contact, the other end of said inner contact body terminates in a socket contact, and said first sleeve extends beyond said other end of said inner contact body to form a closed entry for said socket contact and concentrically align said socket contact with said passageway.

15. The contact of claim 13 wherein the other end of said outer contact body terminates in a socket contact and the other end of said inner contact body terminates in a pin contact.

16. A contact for terminating a pair of wires comprismg:

an outer contact body having a wall forming a passageway therein, said wall having an opening therein communicating with said passageway;

an inner contact body positioned within said passageway, one end of said inner contact body terminating in a plurality of tines, said tines being located under said first opening;

a solder ring positioned over said tines;

a first sleeve of heat recoverable material positioned over said inner contact body and extending beyond said tines, said sleeve having a reduced diameter por- 8 tion engaging said tines and an extending portion for receiving one of said wires;

a second solder ring positioned around said outer contact body, said second solder ring being shaped so as to leave a space between a portion thereof and said outer contact body;

a second sleeve of heat recoverable material positioned over said outer contact body and said second solder ring, said second sleeve holding said second solder ring in position and being shaped so as to form a passageway communicating with said space; and

a third sleeve of heat recoverable material positioned in said passageway formed by said second sleeve and terminating adjacent said second solder ring, said third sleeve adapted to receive the other of said wires.

References Cited UNITED STATES PATENTS 2,936,440 5/1960 Mack et al. 339-177 2,992,457 7/1961 Harrison 1859 3,143,595 8/1964 Martin 174-84 3,305,625 2/1967 Ellis 17484 3,326,442 6/1967 Fattor 22856 3,474,385 10/ 1969 Cefarelli et a1. 339-47 OTHER REFERENCES Evans, Coaxial Cable Connector, IBM Tech. Disclosure Bulletin, vol. 9, No. 10, March 1967, p. 1299.

MARVIN A. CHAMPION, Primary Examiner L. J. STAAB, Assistant Examiner U.S. Cl. X.R.

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