EP0028947B1

EP0028947B1 - Electrical connector insert for removably receiving elongated electrical contacts and means for molding same

Info

Publication number: EP0028947B1
Application number: EP80401381A
Authority: EP
Inventors: Richard Sanford; Norman Charles Bourdon
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1979-11-07
Filing date: 1980-09-30
Publication date: 1984-06-06
Also published as: EP0028947A1; CA1146646A; JPS5676178A; DE3068122D1

Description

This invention relates to an electrical connector insert for removably receiving elongated electrical contacts which are respectively provided with an enlarged section defining two shoulders that face in opposite directions, said insert being provided with an integral arrangement adapted to secure within the insert a retention device for each of the electrical contacts.
Electrical connectors generally include a plug and a receptacle, each of which has an insert of dielectric material within which electrical contacts are retained. The prior art under consideration addresses the insert means which were employed to secure electrical contact retention devices within a dielectric material and the means of molding these inserts.
Among the techniques often employed was the use of complex and intricate retaining mechanisms which were generally comprised of multiple pieces of dielectric material bonded together. When multiple pieces of dielectric are used, it is necessary to carefully seal the pieces together in order to eliminate the lower resistance paths and electrical breakdowns which occur between contacts along the interface of the pieces that form the retention device insert. Examples of this method are disclosed in U.S. Patents No. 3 727 172 and No. 3 638 165. The difficulties encountered with multiple pieces of dielectric bonded together to form an insert were partially overcome by minimizing the number of pieces of dielectric material required to fabricate an electrical connector insert. An example of this is given in U.S. Patent No. 3 721 943 where the dielectric material is formed in two parts, the contacts being inserted in one part and are thereafter enclosed by the addition of the other part. This technique is advanced in U.S. Patent No. 4082398. Perhaps one of the most significant developments prior to this disclosure in the field of electrical connector retention means is found in U.S. Patent No. 3 158 424. Among the teachings of this patent is the use of a flange, encompassing a full 360°, at the rearward edge of an insert passageway that is designed to hold an electrical connector retention clip within the bored section of an insert. This design, however, contains several drawbacks which become evident in the manufacture of the insert. It is taught that this insert can be molded with an annular member that is removable or dissolvable or otherwise disposable from the molded insert. Along the problems encountered in this method of manufacture is an inexactness in the length and positioning of the metal bushing being molded into the insert. After melting the bushing away from the insert, a standard length connector retention clip may not seat properly with the result that the entire insert must be scrapped. Another problem with this type of manufacturing method is that the metal bushings have to be cleaned thoroughly prior to molding the bushing into the insert. If any metal chips have not been cleaned from the bushings, they become molded into the insert and can cause electrical breakdowns within the insert. Another major problem with the use of metal bushings is that oxidation and static electricity are formed on the bushings. This results in obvious handling and molding difficulties.
An alternative approach is illustrated in U.S. Patent No. 4 114 976 where, in order to avoid the need for moulding a retention structure for a clip in the dielectric material, the clip was secured in the material by embedding it therein under the influence of pressure and heat. However, this had the disadvantage that the assembly process was relatively slow and complex and did not allow the subsequent removal of the clip.
The present invention eliminates the problems encountered with electrical failures within the inserts as well as those difficulties common to the manufacturing methods now employed by providing an electrical connector insert which is integrally molded from a dielectric material and which comprises a plurality of passages which extend therethrough from a rear face to a front face, at least two peripherally spaced retention shoulder housings for each passage near the rear face, and a rearwardly facing abutment for each passage which reduces the bore of the passage. The retention shoulder housings and abutment form the rear and frontal boundaries of a retention clip cavity. Each passage allows the close passing and securing of a contact resilient retention clip between the forward facing inward wall of the shoulder housings and the rearward facing wall of the abutment.
The contact resilient retention clip has at least two fingers which, when mounted within an individual passage, are positioned forwardly and radially inward to form a resilient cone. When an electrical contact forming a connector pin (or a connector socket) with an elongated body having, as an integral part of its structure, an enlarged section is entered into the passage through the rear face, and through the retention clip, this connector pin causes these fingers to be forced away from their rest position back against the walls of the passage. Once the enlarged section is clear of the fingers, the forward shoulder of the enlarged section is contiguous with the abutment and the fingers will return to their rest position against the rear shoulder of the enlarged section. Thus, the connector pin is removably secured between the abutment and the retention clip fingers.
Each -passage of insert can be integrally molded, to incorporate all the features for the mounting of a resilient retention clip and connector pin (or connector socket) described above, by means of a herein disclosed core pin and core bushing configuration. The core pin and core bushing are matable and, when mated, produce an insert passage mold which renders the shoulder housings, the retention clip cavity, the abutment, a contact sleeve and inspection openings. Once the material used to mold the insert is set, the core pin can be withdrawn from the rear face of the passage and the core bushing can be withdrawn through the contact sleeve and the inspection openings. No further tooling of the insert is required. These means for molding the insert can be mounted in different numbers and patterns to suit the type of connector shell within which an insert will be mounted.
According therefore to the present invention there is provided an electrical connector insert for removably receiving alongated electrical contacts which is simple and economical to manufacture since it minimizes the required number of pieces, which permits the removal of an individual electrical contact from a resilient retention clip while retaining said clip within it, and which is manufactured by a molding means which is immediately reusable and requires no tooling between uses.
The manner of carrying out the invention is described in detail below with reference to the drawings which illustrate several embodiments of this invention, in which:

FIGURE 1 is a partial cross-sectional diagrammatic view of an integrally molded dielectric insert designed to removably secure a contact resilient retention clip and a pin contact assembly;
FIGURE 2 is a partial cross-sectional diagrammatic view of the molded insert of Figure 1 with a contact resilient retention clip seated in the assembled position;
FIGURE 3 is a cross-sectional view of an electrical pin contact engaged by a contact resilient retention clip mounted within the molded insert;
FIGURE 4 is a partial cross-sectional diagrammatic view of an alternative embodiment of the invention which is molded to house an electrical socket contact;
FIGURE 5 is a schematic illustration of a separated core pin and bushing utilized in molding the clip retention insert used for a pin contact as in Figure 1;
FIGURE 6 is the mated view of the core and bushing of Figure 5;
FIGURE 7 is a schematic illustration of a separated core pin and bushing utilized in molding the clip retention insert used for a socket contact as in Figure 4;
FIGURE 8 is the mated view of the core and bushing of Figure 7;
FIGURE 9 is a molded dielectric insert, with retention clip and pin contact mounted, assembled in a typical electrical connector plug; and
FIGURE 10 is a molded dielectric insert with retention clip and socket contact mounted and assembled in a typical electrical connector plug such that the plugs in Figures 9 and 10 are matable.

Referring now to the drawings, Figure 1 illustrates a portion of an electrical connector insert that discloses one embodiment of the invention. The insert 10 consists of a body molded from a dielectric material. Generally, the dielectric insert is made from a thermoplastic resin, although other materials such as thermosetting materials may be used. Some examples of preferable materials are: polyester (Valox), polyarylsulfone (B 360 Astrel), polyethersulfone (Torlon), polymides (Nylon), acetates (Deldrin), and polycarbonates (Lexan). The polyester material sold under the trade name "Valox" is preferred along with polyaryisulfone and polyethersulfone. The foregoing materials have acceptable mechanical strength and electrical insulation characteristics which serve to increase the dielectric separation between adjacent contacts.
The insert 10 has a plurality of passages 15 therethrough from a front face 11 to a rear face 13. The front face 11 being defined as that section of insert 10 which faces toward an engaged connector assembly, and the rear face 13 as that side of the insert 10 opposite front face 11. The insert 10 has along the rear face of passage 15 and extending forwardly and inwardly along the wall of passage 15 at least two retention clip shoulder housings 17 spaced about the periphery of passage 15. As Figure 1 is a cross-sectional view it only shows half of the internal surface of passage 1 5. Thus only one shoulder housing 17 is shown. The other, unseen half of the passage 15 is a mirror image of that shown in the figure. Consequently the whole passage will be understood to contain two shoulder housings 17 equally spaced about the inner surface of passage 15. Figure 4 which is also a cross-sectional view should be regarded in a similar manner. The shoulder housings 17 have a vertical inward edge 19 which faces an abutment 21. The section of passage 15 defined by the vertical inward edge 19 of shoulder housings 17 and abutment 21 forms a cavity 23 within which a retention clip 29 is removably secured. The horizontal surface of shoulder housings 17 may be either flat, or plate-like surfaces angled away from a central line as shown in the drawings or semicircular in shape. The vertical inward edge 19 of shoulder housings 17 can be angled rearwardly from the foregoing horizontal edge of the shoulder housings 17 to the wall of the passage 15. This configuration will provide a lip in the shoulder housing that will engage the rear edge of clip 29. The abutment 21 contains a contact sleeve 25 which completes the passage 15 within the integrally molded dielectric insert. Alternatively, abutment 21, rather than presenting a surface perpendicular to the wall of passage 15, could be angled forward from the contact sleeve 25 to the wall of passage 15. This would provide a recessed lip that engages the forward edge of the retention clip.
Also shown in Figure 1 are a plurality of openings 27 which are created during the molding process herein disclosed. These openings 27 provide a means through which the visual inspection of the forward seating and alignment of contact retention clips 29 is possible.
The shoulder housings 17 do not form a complete 360° lip at the rear face 13 of insert 10. Rather, the shoulder housings 17 are in axial alignment with openings 27 and form a partial lip along the rear face 13 of insert 10. An additional benefit of this design is the capability of examining the insert vertical edge 19 of shoulder housings 17 through the openings 27.
Figure 2, which is another partial view of the electrical connector insert 10, shows a contact retention clip 29 installed within the cavity 23 of the passage 15. It will be noted that clip 29 is not a completely enclosed cylinder, but rather has an opening along one full side. This opening permits a clip of resilient material to be slightly compressed in order to slide the clip between the shoulder housings 17 (only one shown in drawings) into the clip cavity 23. Once in place, the retention clip 29 returns to its rest condition and is restricted in its lateral movement within the insert 10 by means of vertical edge 19 and the sleeve abutment 21. The fingers 31 of retention clip 29 are sections of the clip's 29 wall which point downwardly and forwardly forming a cone like configuration within the cavity 23.
In Figure 3 the manner according to which a pin contact is removably secured within the body of insert 10 is illustrated. Additionally illustrated is a contact retention clip 29 mounted within the cavity 23 of passage 15, being restricted from rotational movement within the cavity 23 by means of a key 32 which extends axially along the wall of cavity 23 and engages the retention clip 29. More precisely, a connector pin 33 enters through the rear face 13 of insert 10 and passes between the opposed shoulder housings 17. As connector pin 33 passes between the fingers 31 of retention clip 29, an enlarged section 37 of connector pin 33 pushes the fingers 31 out away from the center of the cavity, permitting the enlarged section 37 complete entry. When the forward wall 39 of enlarged section 37 is contiguous with the abutment 21, the fingers 31 will return to their rest position, engaging the rear wall 41 of the enlarged section 37. This will restrict longitudinal movement of the connector pin 33 within the insert 10. The terminal element 35 of connector pin 33 passes into and through the contact sleeve 25 in a close fitting relationship and extends beyond the front face 11 of insert 10 a sufficient distance to properly engage a socket contact. As can be seen from the drawing the close fit between the terminal element 35 and the interior surface of the contact sleeve 25 will serve to restrict lateral movement of the terminal element. The shoulder housings 17 are in a spaced relationship to connector pin 33 and a tool can enter into the passage 15 therebetween. This tool will release connector pin 33 by forcing the fingers 31 away from their rest position, that is to say away from the rear wall 41 of enlarged section 37 and against the walls of clip 29. When this is accomplished, the connector pin 33 can be easily withdrawn from the insert 10.
Figure 4 is an alternative embodiment of the invention which relates to an insert 10' which is designed to receive and removably secure a socket contact 43. The principal difference lies in a contact sleeve 45 which rests between the front face of an aperture 25' and the abutment 21'. A contact retention clip 29' removably mounted within the cavity 23' of insert 10' and restricted from longitudinal movement within the cavity 23' by abutment 21' and the vertical insert edge 19' of shoulder housings 17'. Whereas abutment 21' would be the same surface as the rearward face 47' of the aperture 25' in the assembly employed for a contact pin 33' as displayed in Figures 1 through 3, the abutment 21' is now a separate entity. The rear face 47' of aperture 25' can be sloped rearwardly from the walls of contact sleeve 45 to serve as a guide for a penetrating connector pin terminal element 35. A socket contact is removably secured by the retention clip 29' within the insert 10' with the same technique as depicted in Figure 3. The insert 10' with retention clip 29' and a connector socket 43 can be seen in this configuration in Figure 10. As with the embodiment shown in Figure 3 there will be a close fit between a socket contact 43 and the interior surface of contact sleeve 45 to restrict lateral movement of the terminal element.
Figure 5 illustrates a core pin 53 and a core bushing 61. The core pin 53 includes, at its forward edge, axial projection 55, at least two indented flat sides 57 and two shoulder forms 59 protruding from the rearward portion of the flat sides 57 and contiguous with the rear base section 51 of core pin 53. Core bushing 61 includes an axial bore 63, which is matable with the axial projection 55 and side fins 65 which have flat internal walls and curved exterior walls and are matable with the flat sides 57 of the core pin 53. In the mated condition of Figure 6, the rearwardly facing edges of the side fins 65 will abut the forward edge of shoulder forms 59. The combination of the side fins 65 with the flat sides 57 will form a shaft like section of the mold which forms the contact retention clip cavity 23 in insert 10. In this alignment there will be an open area 69 around the axial projection 55 which has only partially penetrated bore 63. This open area 69 forms the front face 11 and the abutment 21 of the passage 15. The axial projection 55 forms the contact sleeve 25 of insert 10. The shoulder forms 59 form a shoulder housing mold area 67. This corresponds to the shoulder housings 17. The rearward edges of side fins 65 control the angle, if any, of the shoulder housings' vertical inward edge 19. Those sections of the side fins 65 which are in a spaced relationship adjacent to axial projection 55 form the openings 27 seen in the inserts front face 11. Upon completion of the molding process the core pin 53 and core bushing 61 can be separated and withdrawn from the insert 10. Core pin 53 is drawn out through the rear face 13 of insert 10. Core bushing 61 is drawn from the front face 11 of insert 10 and leaves the opening 27.
Several modifications can be incorporated within the core pin 53 and core bushing 61 in order to fabricate an insert with features that will enhance the retention clip mounting and securing capabilities of the insert 10. For example, the vertical inward edge 19 of shoulder housings 17, if angled rearwardly towards the passage walls, would provide a lip like structure which would act to positively engage the contact retention clip 29. This result can be obtained by beveling the edges of the side fins 65 which abut the shoulder forms 59. The beveled section would extend above and behind the shoulder forms 59 when the core pin and bushing are mated. Another method of increasing the contact retention clip 29 mounting capability of insert 10 could be achieved by forming a groove in one of the sections of the core pin 53 or bushing 61 which form the clip retention cavity 23. This groove would extend along the length of the member on which it was cut, axially from a point corresponding with the forward edge of core pin 53 to a point corresponding with the forward edge of the shoulder forms 59. This will leave a protruding key within the cavity 23 integral with insert 10 which would align with the contact retention clip 29 when assembled. Such a design would allow a fixed location of the retention clip fingers 31 relative to the enlarged section 37 of the pin contact 33. These features can similarly be incorporated in the core pin and core bushing presented in Figures 7 and 8 which are employed in molding an insert 10' used with socket contact 43. These core pin 53 and core bushing 61 can be multiply mounted in an endless variety of configurations as dictated by the number of contacts required and the dimensions of the plug in which the inserts are mounted.
Figure 7 illustrates a core pin 53' and a core bushing 61' which are utilized in the molding of an integral dielectric insert 10'. The core pin 53' includes a base portion 51' from which extends a shaft like portion which terminates in its forward end with axial projection 55'. At least two sides 57' of the shaft like portion are indented and flat. In addition, a portion of this shaft has a reduced diameter which results in stepped sides 73. Also protruding from the flat sides 57' and in a contiguous relationship with the base 51' are shoulder forms 59'. The core bushing 61' includes at least two extending side fins 65' which are flat along their inside walls and curved along their outside walls, an axial bore 63' and a protruding cone 71. The core pin 53' and core bushing 61' mate with the axial projection 55' penetrating the cone 71 through axial bore 63'. Side fins 65' will abut the shoulder forms 59' and be aligned with and contiguous to the flat sides 57' of core pin 53'. This will provide a cavity 23' in the completed insert 10'. With this mated alignment there will be an open area 69' around the axial projection 55' which will form the front face 11' and the rearward face 47' of aperture 25'. The axial projection 55' results in the aperture 25'. The cone 71 creates a tapering extension with a cone-shaped mouth on the rearward face 47'. The cone shaped mouth can serve as a guide for the introduction of a pin contact terminal element 35. The steps 73 of core pin 51' form within the insert 10' a contact sleeve 45' which closely receives a socket contact. The vertical wall created by the different dimensions of step 73 and core pin 53' provides an abutment 21' within insert 10'. The section of the flat sides 57' contiguous with side fins 65' forms cavity 23' designed to receive a retention clip 29'. The shoulder forms 59', along with the portions of side fins 65' contiguous with the shoulder forms 59', form the shoulder housings 17' and vertical inward edge 19' of insert 10'. It should be noted that the modifications which can be introduced to core pin 53 and core bushing 61 are among the modifications which can be effected on core pin 53' and core bushing 61'.
Figure 9 illustrates an insert 10 that contains a plurality of connector pins 33 secured by retention clips 29. The insert 10 is mounted in a typical electrical connector plug assembly 77. Also shown are a rear moisture sealing grommet 79, an interfacial seal 91, a sealing gasket 93, a connector shell 18, a retaining nut 83 and a retaining ring 95.
Figure 10 illustrates an integral dielectric insert 10' with connector socket 43 and contact retention clip 29' in a conventional socket assembly 77' which is matable with the conventional pin connector assembly of Figure 9. Also shown are a rear moisture sealing grommet 79', a connector shell 81', a retaining nut 83', a retaining ring 95', a coupling nut 85, a wave washer 87 and a snap ring 89.

Claims

1. Electrical connector insert for removably receiving elongated electrical contacts (33; 43) which are respectively provided with an enlarged section (37) defining two shoulders (39; 41) that face in opposite directions and a longitudinally extending terminal portion (35; 43), said insert (10; 10') being formed of a unitary body of molded dielectric material having a plurality of passages (15) extending from a front face (11; 11') to a rear face (13; 13') thereof and being each adapted to receive and axially retain a resilient clip (29; 29') provided to removably secure an individual electrical contact (33; 43) within the insert (10; 10'), the sidewall of the resilient clip (29; 29') being completely interrupted by a longitudinal opening to permit by compression diametrical reduction of said clip (29; 29') and sections of said sidewall being tapered forwardly and radially inwardly to form a resilient conical arrangement (31) adapted to engage one of the shoulders (39; 41) of the enlarged section (37) of an individual electrical contact (33; 43) characterized in that each of the passages (15) in the insert (10; 10') has integrally formed therewith: at least two retention shoulder housings (17; 17') spaced about the periphery of passage (15) for retaining the resilient clip (29; 29') each housing (17; 17') extending inwardly into the passage (15) from the rear face (13; 13') towards the front face (11; 11') of the insert (10; 10'), coaxially with the passage (15) and forming an inward wall (19; 19') in said passage (15); an abutment (21; 21'), spaced from the retention shoulder housings (17; 17'), extending inwardly into the passage (15) to form a cavity (23; 23') within which the resilient clip (29; 29') is retained; and a contact sleeve (25; 45) extending from the abutment (21; 21') to the front face (11; 11') of the insert (10; 10') in axial alignment with and as a part of the passage (15), said contact sleeve (25; 45) being adapted to receive said terminal portion (35; 43) and to restrict lateral movement thereof.

2. Electrical connector insert as claimed in claim 1, characterized in that the inward wall (19; 19') of the retention shoulder housing (17; 17') is angled rearwardly from the horizontal edge of said shoulder housings (17; 17') to the wall of the passage (15) so as to form a lip to restrain axial movement of the resilient clip (29; 29').

3. Electrical connector insert as claimed in claim 1, characterized in that the abutment (21; 21') is angled forwardly from the contact sleeve (25; 45) to the wall of the passage (15) to form a recessed lip adapted to engage the forward edge of the resilient clip (29; 29').

4. Electrical connector insert as claimed in claim 1, characterized in that there is provided a protruding key (32) within each of the passages (15) which extends from the retention shoulder housings (17; 17') axially to the abutment (21; 21') so as to align with and engage the resilient clip (29; 29').

5. Means for molding the electrical connector insert of claim 1, characterized in that it comprises: a plurality of core pins (53; 53') respectively including a base section (51; 51') and a forward face, having at least two indented flat sides (57; 57') extending from the base section (51; 51') to the forward face, and at least two shoulder forms (59; 59') connecting the flat sides (57; 57') and the base section (51; 51'), and an axial projection (55; 55') extending from the forward face thereof; and a plurality of core bushings (61; 61') respectively including a base, terminating as a forward face, and at least two side fins (65; 65') extending from the base, the forward face having a bore (63; 63') therein cooperable with the axial projection (55; 55') of an individual core pin (53; 53'), whereby upon mating of an individual core pin (53; 53') and an individual core bushing (61; 61'), with the projection (55; 55') of the core pin (53; 53') mated, with the bore (63; 63') of the bushing (61; 61') and the side fins (65; 65') of said bushing flush with the flat sides (57; 57') of the core pin (53; 53'), dielectric material is moldable thereabout to form said electric connector insert (10; 10').

6. Means as claimed in claim 5, characterized in that the flat sides (57) of an individual core pin (53) extend a distance no less than the length of a resilient clip (29) to be retained within an individual passage (15) and the axial projection (55) extending from the forward face of the core pin (53) forms a contact sleeve (25) of a diameter no less than the diameter of the terminal element of an electrical contact (33) forming a connector pin to be retained within the resilient clip (29).

7. Means as claimed in claim 5, characterized in that an individual core pin (53') includes a forward facing shaft carrying the two indented flat sides (57') and a reduced diameter portion forming stepped flat sides (73), the rearward section of the stepped flat sides (73) having a length no less than the length of a resilient clip (29') to be retained within an individual passage (15) and the forward portion of the stepped flat sides (73) having a diameter and length no less than the terminal element of an electrical contact (43) forming a connector socket to be retained within the resilient clip (29').