Abstract:
An improved method for molding an elongated insulative housing having an extended height insulative housing which reduces the tendency of the housing to warp or bow during molding is disclosed. The improved combined steps of this invention comprise injecting a molding compound in a mold cavity having opposed, inwardly directed, tapered fingers providing a transverse flow restriction in the mold cavity, allowing the molding compound to cure and then removing the housing from the mold cavity.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to application Ser. No. 09/224,142 entitled “ELECTRICAL CONNECTOR WITH TERMINAL LOCATION CONTROL FEATURE” and to application Ser. No. 09/224,140 entitled “PRESS FIT SCA CONNECTOR” both filed on Dec. 31, 1998 and which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present application relates to electrical connectors and more particularly to methods for manufacturing electrical connectors. 
     2. Brief Description of Prior Developments 
     In various electrical connectors particular needs require the use of relatively long beams. The physical relationship of the cross sectional area of the beam and its length will make it difficult to manage more critical dimensional tolerances. The critical dimensional tolerances in question control the inner relationship between the terminal tail, the retention feature and the contact area of the terminal. An example of such an electrical connector is a receptacle used on a single connect attach (SCA) disk drive interface. 
     There is, therefore, a need for means for managing critical tolerances in connectors having such cross sectional area to length relationships. 
     It is also known that the use of a relatively long beam will generally require the use of a relatively high insulative housing. It is found, however, that such extended height insulative housings or other atypical height to width ratio housings may have a tendency to bow or warp during molding. 
     There is, therefore, a need for a method of molding extended height insulative housings. 
     SUMMARY OF THE INVENTION 
     The present invention is a receptacle for an electrical connector which comprises an elongated insulative housing having parallel lateral walls, parallel end walls and base wall. An interior cavity is formed by those walls, and a longitudinal groove extends between the longitudinal walls from adjacent one of said end walls to the other end wall. At least one conductive contact having a base end and a distal end extends upwardly in the interior cavity. It is fixed to the housing adjacent the base end and is attached at a medial guide means and then extends upwardly such that the distal end of the contact is adjacent the longitudinal groove. 
     Also encompassed by the present invention is a method for molding an insulative housing for an extended height housings in which a transverse flow restriction means is provided to eliminate or reduce bow and warp in the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The connector of the present invention is further described with reference to the accompanying drawings in which: 
     FIG. 1 is a top plan view of a preferred embodiment of the connector of the present invention; 
     FIG. 2 is a side elevational view of the connector shown in FIG. 1; 
     FIG. 3 is a bottom plan view of the connector shown in FIG. 1; 
     FIG. 4 is an end view of the connector shown in FIG. 1; 
     FIG. 5 is a cross sectional view through  5 — 5  in FIG. 2; 
     FIG. 6 is a detailed view of the area in circle  6  in FIG. 3; 
     FIG. 7 is a side view of the terminal used in the connector shown in FIG. 1; 
     FIG. 8 is a front view of the terminal shown in FIG. 7; and 
     FIG. 9 is the bottom section of a mold used in the manufacture of the insulative housing used in the connector shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1-6, the receptacle of the present invention includes an insulative housing shown generally at numeral  10 . This housing has a first end wall  12  and a second end wall  14  which are connected by a first lateral wall  16  and a second lateral wall  18 . The housing also includes an upper plug receiving structure shown generally at numeral  20 . This upper receiving structure is made up of a first end wall extension  22  and a second end wall extension  24  which are connected by a first lateral wall extension  25  and a second lateral wall extension  26  that form a medial plug receiving channel  28 . The housing also includes a base wall  30  with attachment brackets  32  and  34  and a positioning peg  36 . Adjacent the first and second end walls  12  an  14  there are respectively ground springs  38  and  40 . 
     Referring particularly to FIGS. 5-8, an interior cavity  42  is formed between the first lateral wall  16  and the lateral wall  18  and beneath the plug receiving channel  28 . Inside this cavity and between the exterior lateral walls there is a medial interior longitudinal wall  44  which separates the interior cavity  42  into a first terminal containing section  45  and a second terminal containing section  46 . 
     Extending into the first terminal containing section  45  from the medial interior longitudinal wall  44  there is an outward longitudinal wall protrusion  47 . Extending into the second terminal containing section  46  from the medial interior longitudinal wall  44  there is a second outward longitudinal wall protrusion  48 . Extending from the second lateral wall into the first terminal containing section  45  there is an inward longitudinal protrusion  49 . Terminal conveying openings are formed respectively in terminal containing section  45  between wall  18  and protrusion  49  and protrusion  47 . In terminal retaining section  46  a similar space is formed between longitudinal protrusion  48  and wall  16 . In this terminal conveying space there are respectively in retaining sections  45  and  46  widened upper sections  50  and  51 , widened and lower sections  52  and  53 , and narrow medial terminal retaining sections  54  and  55 . In the first and second terminal retaining sections  45  and  46  there are respectively a first terminal  56  and a second terminal  57 . These terminals extend through the base wall respectively in a first base wall aperture  58  and a second base wall aperture  59 . The first and second terminals  56  and  57  also have respectively a first lower terminal section  60  and a second lower terminal section  61 . The first and second terminals  56  and  57  also have respectively a first attachment section  62  and a second attachment section  63  which are connected at the housing at lower connection point  64  and lower connection point  65  by means of barbs as at barb  66  (FIG. 8) which cut into the plastic of the housing. The first and second terminals  56  and  57  also have lateral bends  67  and  68  from where they extend respectively from the widened lower sections  52  and  53  to the narrow medial retaining sections  54  and  55 . 
     In these sections there are respectively a first terminal  56  and a second terminal  57 . In the base wall  30  there is a first base wall terminal aperture  58  and a second base wall aperture  59 . Extending outwardly from these apertures there are respectively a lower terminal section  60  of the first terminal  56  and a lower terminal section  60  of the second terminal  57 . The first terminal  56  and the second terminal  57  also have respectively lower attachment sections  62  and  63 , which are fixed to the housing at lower connection points  64  and  65  respectively. The attachment sections  64  and  65  have barbs as at barb  66  (FIG. 8) which cut into the plastic in the housing at the connection points  64  and  65 . The first and second terminals also include lateral bend sections  67  and  68  and interior vertical sections  70  and  72 . The first and second terminals also include, respectively, upper wing sections  74  and  76  to where they are movably retained on the housing, respectively, at the first and second medial guide sections  54  and  55 . Adjacent their distal ends, the first and second terminals  56  and  57  have respectively first and second contacts  78  and  80 . From the medial guide section  54  and  55  the first terminal  56  and second terminal  57  extend inwardly to the contacts  78  and  80  in sections  82  and  84  respectively. These inward sections  82  and  84  have distal outward bend sections  86  and  88  respectively. The housing also includes a plurality of side cores as at cores  90  and  91  for advantages in molding the receptacle. 
     It will be appreciated that control of critical dimensional tolerances in the terminals, such as distances between the contact points  78  and  80 , will be improved by virtue of the fact that they are movably retained in the medial guide positions  54  and  55 . 
     The receptacle described herein may be advantageously used on a single connect attach (SCA) disk drive interface. 
     It will be appreciated that the housing of the connector described above is of an extended height. Encompassed by this invention is a way of avoiding bow and warp in the molding of the insulative housing which has been a problem experienced in molding of prior art extended height housing. It has been found that such bow and warp may be eliminated or reduced by positioning one or more medial transverse restrictions in the mold during the molding process. Referring particularly to FIG. 2, it will be seen that on a second lateral wall  18  there is a row of vertically elongated apertures shown generally at numeral  92 . This row includes, for example, apertures  94 ,  96 ,  98 ,  100  and  102 . Although not shown, it will be understood that there is a similar row of apertures on the first lateral wall  16 . 
     Referring to FIG. 9, the lower section of the mold used in the manufacture of the insulative housing described above is shown generally at numeral  104 . As is conventional, this section of the mold includes a main chase body  106  and a main core body  108 . On the opposed longitudinal sides there are finger supports  110  and  112  from which there are respectively opposed rows of inwardly projecting tapered core fingers shown generally at numerals  114  and  116 . These rows  114  and  116  include a plurality of tapered core fingers as, for example, fingers  118  and  120  in row  114  and fingers  122  and  124  in row  116 . Outwardly from supports  114  and  116  there are respectively cams  126  and  128 . These cams rotate to move supports  114  and  116  inwardly until the fingers on support  114  contacts an opposed finger on support  116 . Each of these fingers forms a traverse restriction in the mold cavity. These transverse restrictions act as flow diverters for the molding compound to decrease the potential for bow and warp in the completed insulative housing. These opposed fingers also form the apertures in the lateral walls of the insulative housing. For example, finger  118  on support  114  and finger  122  on support  116  form aperture  94  on lateral wall  18  and an opposed aperture (not shown) on lateral wall  16 . As a further example, finger  120  on support  114  and finger  124  on support  116  form aperture  96  on lateral wall  18  and an opposed aperture (not shown) on lateral wall  16 . The other apertures as at apertures  98 ,  100  and  102  on lateral wall  18  and the aperture (not shown) on lateral wall  16  are formed in the same way. 
     EXAMPLE 
     In the way described above, an extended height insulative housing for a connector was molded from DUPONT polymer HTN FR5G35L which is a 35% by weight fiberglass glass filled nylon. The furnished housing had a length of 69 mm and a height of 15.85 mm. The finished part was inspected for part warpage and was found to be within generally accepted product specifications. 
     From the above example, it will be appreciated that the height to length ratio of the completed insulative housing was about 0.23:1.0. it is believed that this method may be advantageously employed in height to length ratios of at least about 0.20:1.0 to about 0.25:1.0. it is also believed that the method may be advantageously employed when fiberglass reinforcement is used in a range of at least about 30% to about 40% by weight. 
     It will be appreciated that the above described method for molding an insulative housing is applicable not only to the specific housing described herein but to any extended height insulative housing or any insulative housing having a high height to length ratio. 
     It will be appreciated that a long beam connector has been described that allows for critical dimension tolerances, particularly relative to the positioning of the terminal contacts either relative to each other or relative to some other feature. It will also be appreciated that a method has been described which decreases the potential for bow and warp in an extended height housing for an electrical connector or for any such insulative housing having a high height to length ratio. 
     While the present invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the present invention without deviating therefrom. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims.