US 3323098 A
Description (OCR text may contain errors)
May 30, 1967 M. F. O'KEEFE ET AL 3,323,098
SUB-MINIATURE COAXIAL CONNECTOR Filed March 22, 1965 5 Sheets-Sheet 1 INVENTORS 2? MICHAEL F'fiAucls O'KEEFE Rosier STANLEY sTLlLL N d y 1957 M. F. OKEEFE ET AL 3,323,098
SUBJ IIINIATURE COAXIAL CONNECTOR 3 Sheets-Sheet 2 Filed March 22, 1965 INVENTORS M \CHAEL FRAN OKssr=s 'Rwsew. BY
'r STANLEY 70m. W i W y 30, 1967 M. F. OKEEFE ET AL 3,323,098
SUBMINIATURE COAXIAL CONNECTOR Filed March 22, 1965 5 ShetsSh;eet 5 VENTORS MICHAEL Fa ens Q'KEBFE BY M, "M
United States Patent 3,323,098 SUB-MINIATURE COAXIAL CONNECTOR Michael Francis OKeefe and Robert Stanley Stull, Mechanicsburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.
Filed Mar. 22, 1965, Ser. No. 441,626 3 Claims. (Cl. 339-177) This invention relates to crimp type connectors of the type used with sub-miniature coaxial or shielded cable.
Sub-miniature coaxial or shielded cable is diflicult to terminate and connectors for such presently are expensive and require considerable installation time. Essentially, the problem is that in the sub-miniature range the cable is too small to be easily handled and too fragile to stand up under the handling called for by prior art techniques of termination. This problem extends to the connectors for such cable and manifests itself principally as an increase in cost attributable to the requirement of carefully machined components which must be carefully assembled.
As a related problem, the smallness of cable and connector parts involved makes it diificult to establish a sufficient contact area for providing a low resistant stable electrical interface; both permanent and disconnect.
As still another problem, the small sizes of components make it diflicult to provide a sufficiency of resiliency in the intermating parts of connectors and tend to preclude the use of drawn or stamped metal material for such parts.
It is one object of the present invention to provide a connector for sub-miniature cable which is inexpensive and easy to install. It is a further object to provide a novel connector construction for small cable which is pre-assem bled to constitute only two loose pieces per connector half. It is still another object to provide a connector having a construction which may be carried out in drawn or stamped metal. A further object is to provide a connector having an improved contact configuration for better resiliency and longer life. A still further object is to provide a coaxial or shielded connector which can be terminated to cable in a one-stroke crimp, simultaneously applied.
These and other objects which will be apparent to those skilled in the art are accomplished by the present invention through a composite tubular structure forming an outer conductive path having at one end characteristics to receive crimping forces and at the other end characteristics to provide contact surfaces intermatable under substantial spring pressure. Mounting springs are provided, captivated along the tubular structure, and apertured to permit the insertion of crimping dies. Within the tubular structure there is provided an assembly of insulating and conducting parts coaxially disposed to provide an inner conductive path, with the various parts adapted to be staked against relative movement. A ferrule member is provided which is adapted to be crimped to mechanically support the cable terminated and electrically terminate the cable braid to the tubular structure. In each connector half then there are but two loose pieces to be handled during installation on cable.
In the drawings:
FIGURE 1 is an exploded perspective view of the com- 3,323,098 Patented May 30, 1967 ponent parts of the pin half of the connector of the invention, enlarged several times actual size;
FIGURE 2 is a perspective view of the connector half of FIGURE 1 assembled and terminated on a cable;
FIGURE 3 is a longitudinal section of part of the outer shield of the connector half of FIGURE 1;
FIGURE 4 is an exploded perspective view of the component parts of the socket half of the connector of the invention;
FIGURE 5 is a perspective of the connector half of FIGURE 4 assembled and terminated to a cable;
FIGURE 6 is a longitudinal section of part of the outer shell of the connector half of FIGURE 5;
FIGURE 7 is a perspective view of the connector pin and socket halves of FIGURES 2 and 5 intermated to provide a cable connection; and
FIGURE 8 is a longitudinal section, enlarged, through lines 8-8 of FIGURE 7.
Referring first to FIGURE 2 the pin half of the connector of the invention is shown as 20 terminated to a coaxial cable 10. The cable 10 may be seen in FIGURE 1 to include a center conductor 12 surrounded by an insulating and dielectric sheath 14, an outer conductor or braid 16 and an outer protective and flexible sheath 18. The cable is permanently terminated to 20 and 20 is utilized to provide a disconnect function with respect to the electrical paths 10 in connection with a further cable 10 terminated to a socket connector half as in FIGURE 5. The two connectors halves are adapted to be secured in a multiple insulating block (not shown) by means of locking springs to be described or utilized for individual connections in a single block. In use the halves are plugged together as in FIGURES 7 and 8 to interconnect the inner and outer conductors of the cable and may be separated to disconnect these conductors.
Examining now the details of the pin half 20 of the connector of the invention, FIGURE 1 shows separately the various components relative to alignment for assembly. There is included an outer shell 22 having a cylindrical rear portion 22a necked down as at 22b to a reduced diameter cylindrical portion 220 ending in a resilient contact portion 220.. The portion 22d includes a plurality of spring fingers bowed outwardly in their relaxed state to a diameter larger than the diameter of 22c. The fingers are given a substantial length to reduce the force required for deflection and to permit operation well within the range of elastic limit of the metal material employed. The length of the fingers can be calculated on the basis of a double cantilever spring and the material should be of spring stock such as /30 cartridge brass.
Fitted within the rear of shell 22 is a further tubular member 24 of relatively hard metal material including at the forward end a portion 24a permanently secured to portions 22a of 22 as by welding or soldering. At the other end is a cylindrical portion 2411 having serrations in the outer surface to provide an adequate gripping surface for cable braid fitted thereover. A bore 240 extends through 24 to accommodate the metal and insulating members of the assembly. A pair of rectangular apertures 24d are provided in 24 spaced apart to accommodate the insertion of dies as shown in FIGURE 8 to crimp the center contact member 30 of the assembly. These apertures are, in the small structure represented by 24, pref- 3 erably axially cut as by a fine saw prior to insertion of 24 within 22. Further provided on 24 is an outwardly directed flange 24a formed by collapsing the structure in an axial sense.
As described, both 22 and 24 can be manufactured by drawing thin metal stock or from thin tubular stock rather than by the more expensive screw machining required by prior art devices. The material characteristics of drawn or tubular stock are well suited for the staking procedures to be described as the preferred technique of anchoring the insulating and conductive components of the assembly within the shell structure.
FIGURE 1 shows further a first insulating insert 28 comprised of an elongated sleeve portion 28a headed at one end by a beveled portion 280 extending radially outward and bored out along its length as at 2%. The outer diameter of 28 is such as to slidingly fit with 22 with portion 280 proximate to the ends of the fingers of 22 and as shown in FIGURE 2. The forward outer surface of 28 operates to support the ends of the fingers under inward travel and compression during insertion of in socket 40.
A center contact member is provided including a tubular portion 30a adapted to fit with 28b and extend fully along 28 into the portion 280. The forward end of 30 is bifurcated as at 30b for resiliency and mating With the center contact of socket 40 and opposite thereto is a flange or annular barb 300 which operates to lock 30 against axial movement forwardly in 28 and thus in the assembly. Spaced from 30c is a similar barb 30d oppositely directed to engage an insulating insert 32 and lock 32 against axial movement forwardly relative thereto. The rear portion of 30 includes an opening which extends through the member as a bore 30a to receive the center conductor 12 of the cable terminated to the assembly. Between 300 and 30a is a tubular portion 30 adapted to be deformed inwardly to terminate 30 to 12 of the cable. This deformation is shown in FIGURE 8 to include two axially separated crimps which are preferably accomplished by integral dies simultaneously inserted through the shell apertures 24d from each side of the assembly.
The insert 32 is of an outer diameter to slidingly fit within 24 and is fitted over the rear end of 30. The insert includes a recess 32a sized to receive and support the sheath 14 of cable 10 and a bore 32b adapted to receive the cable center conductor 12. After installation of 32 on 30, the bore 3% thereof is flared outwardly to lock 32 against 30d and onto 30. This is shown in FIG- URE 8 relative to socket :4).
With the various components of FIGURE 1 assembled, the shell 22 is staked as indicated at 222 to lock the insert 28 thereto and thus lock the contact member 30 axially within 20. The member 30 is then supported axially and radially in 22-24, insulated therefrom and coaxial thereto.
Next, there is provided a locking spring member 34 which is C-shaped in cross-section to be fitted over 24 as indicated in FIGURE 2. The member 34 is made to be snapped on 24 with its edges well around the circumference of the shell surface to retain the member thereon. The length of 34 is such as to cause the member to nest between the radial flanges represented by the ends of 22a and 242 and there is provided in alignment with 24d an aperture 34a and small flanges 34b folded to project into 24d and hold 34 against being rotated to a point out of registry with 24d. Locking spring fingers 340 are pro- 'vided extending outwardly and rearwardly from 34 to engage portions of an insulating block into which 20 is fitted and to hold 20 against outward displacement therefrom. a
A ferrule 38 is provided which is of malleable material adapted to be deformed inwardly from the cylindrical shape of FIGURE 1 to the configuration of FIGURE 2. The deformation of the rear part of 38 grips the sheath 18 of the cable and the deformation of the forward part terminates the cable braid 16 to 24 as shown in FIGURE 8 relative to socket 40.
As assembled the pin 20 represents only two pieces which may be shipped, handled and installed as such. Installation is accompanied by first preparing the cable It as indicated in FIGURE 1, inserting the conductor 12 within 30d and the braid 16 over 24b, sliding ferrule 36 thereover and crimping the ferrule and 30 inwardly. This may be accomplished in one stroke with individual dies driven simultaneously in the same tool.
Turning now to a description of the socket half 44) of the connector of the invention, reference is made to FIG- URES 46 and 7 and 8. As will be discerned, the components of 40 are similar and identical to the components of 20 with changes only to effect an intermating of the conductive shells and center contact members. For this reason no descriptive detail is thought necessary as to those parts which are the same.
The socket 40 includes a forward conductive shell 42 which is cylindrical along its length and is adapted to be fitted over 22 in the manner represented in FIGURES 7 and 8. The inner bore 421; of the shell is of a diameter slightly greater than that of 220 and slightly less than that of 22d. This provides an acceptance of 22 with some variation in tolerances and alignment and, at the same time, a contact around the circumference of 22d of substantial area under spring force. At the inner end of 42 there is provided an inwardly directed flange 4212 which engages the end of a conductive shell 44 secured thereto as by soldering or Welding. Forward of 42b are dimples 420 as shown in FIGURES 5, 7 and 8 which stake the forward insulating insert thereto. The rear shell 44 and locking spring member 46 are identical to the parts 24 and 34 previously described.
Fitted within the shells 42 and 44 is an assembly including a center contact 48 having a forward portion 48a adatped to fit within contact portion 30b of the pin half 20. The remainder of 48, rearwardly of 480, is identical to the corresponding portions of 30. The rear insulating insert 52 is also identical to 32 of 20 but the forward insert 50 is substantially shorter in length. Insert 50 includes a portion 50a adapted to fit within 44 and a portion 50b adapted to fit within 42 as shown in FIGURE 8. With the ferrule 54 which is identical to 36, the socket represents a two piece assembly ready for termination to cable It) and use with pin 20.
Upon engagement of the pin and socket members, the forward end of 20 is guided into 42 by reason of the bevel at 28c and centered by the compression of the fingers on 22 to permit an engagement of 480 within 30b. The circular engagement permits this centering atcion and permits some degree of misalignment of 20 and 40 in the block housing the members which is of considerable advantage.
Having thus described our invention, we now define it.
What is claimed is:
1. In a coaxial connector for interconnecting cable having an inner conductor surrounded by an insulating sheath and an outer conductor, the combination including intermating connector halves each including an outer shell terminated to the cable outer conductor and an inner contact terminated to the cable inner conductor, the inner contact of each shell being supported within the shell by insulating inserts afiixed to the shell, one of the shells having an end adapted to be fitted within the other shell and including on said end a plurality of resilient fingers extending outwardly and curverd inwardly to bear against one of said inserts and form a cantilever spring action, each said shell including a pair of outward projections axially spaced apart with a pair of rectangular apertures disposed in opposing relationship between said projections, a locking spring secured to each shell between said projections said spring having an aperture aligned with one aperture of said shell to permit the entry of dies within said shell for crimping the inner contact thereof to terminate said contact to the cable inner conductor.
2. The connector of claim 1 wherein the insert of said one shell has a forward portion of a diameter approximating the inner diameter of the other shell and adjacent said forward portion a further portion of reduced diameter adapted to receive the ends of said fingers and to protect said fingers against accidental damage in handling and use of said connector.
3. The connector of claim 1 wherein the inner contact of the one shell extends axially outward of the ends of the spring fingers of the one shell whereby to be engaged by the male contact member of the other shell before the one shell is fully inserted within the other shell and the spring fingers thereof are fully compressed against said insert.
References Cited UNITED 0 MARVIN A. CHAMPION, Primary Examiner.
W. DONALD MILLER, EDWARD C. ALLEN,
J. R. MOSES, Assistant Examiner.