Abstract:
A connector assembly with front and rear bodies ( 50, 40 ) and a surrounding shell ( 12 ), has a potting material ( 72 ) that is molded around the cable ( 20 ) and within a rear body passageway ( 70 ) in a manner that avoids leakage of the potting material. The shell outside surface has outwardly-projecting ridges ( 124, 141-144 ) for effectively grasping the connector, and the front body is latchable to the shell with robust latch arms ( 174 ). An O-ring ( 80 ) lying forward of the threading connections ( 52, 54 ) of the bodies limits leakage of the potting material flowed under pressure into the passageway. The outer shell is molded with ridges ( 124, 141-144 ) extending in loops that facilitate correct gripping and avoid slipping of the thumb on the connector. The front body has slots ( 170, 172 ) forming latch arms that latch to openings in the shell, the arms being formed by slots with enlarged ends ( 190, 192 ).

Description:
BACKGROUND OF THE INVENTION 
     A common type of connector includes a front body with contact-holding passages, a rear body, and a shell that surrounds the bodies. A cable whose wire front ends are terminated to the rear ends of the contacts, extends through a passageway in the rear body and trails from the connector. The rear body can be filled with potting material around the cable to seal the connections to the contacts. However, when the potting material is injected from the rear of the rear body under pressure, the potting material tends to leak from the front of the rear body. Avoiding such leakage would be desirable. 
     A molded shell has a largely cylindrical surface that is grasped in a person&#39;s hand to push the shell forwardly and pull it rearwardly during mating and unmating. It would be desirable if the shell indicated to a person where he should grasp the shell, and provide high friction against slippage of the person&#39;s thumb with respect to the shell. 
     After the front and rear bodies are assembled around the cable, the body assembly is inserted forwardly into the shell and is latched therein by a pair of arms formed in a snap lock sleeve of the front body. The arms tend to break, and a construction that avoided such breakage would be of value. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment of the present invention, a connector assembly is provided with pressure sealed potting material around the cable, with a grip around the shell that indicates how the shell should be held and which avoids slippage, and with rugged latch arms that latch the body assembly to the shell. The body assembly includes front and rear bodies that are joined together by a threaded connection, and with potting material injected under pressure into the passageway along which the cable extends through and out the rear of the connector. An O-ring lying immediately forward of the threaded connection, provides a seal against leakage of pressured potting material when the potting material is still flowable. 
     The shell is molded or cast and has an outside surface that avoids slippage. The outside surface has at least one ridge on one side of the axis, the ridge extending in a loop and including opposite sides that extend largely parallel to the axis of the shell and a rear rib portion that connects the sides and that projects further radially outward than most of the area of the shell outside surface. Additional ridges extending in smaller loops preferably lie within the larger loop. The opposite side of the shell is devoid of ridges. This encourages a person to hold the shell with his thumb against the ridges, and avoids slippage especially when the shell is pulled rearwardly to unmate the connector from another mating connector. 
     The front body has a pair latch arms with projections that snap into openings in the shell to latch the body assembly to the shell. The latch arms are made more robust by forming each of the slots that forms one latch arm, with opposite ends that are enlarged, and preferably with the enlargements at opposite sides of each latch arm projecting towards each other beyond the rest of the slot. 
     The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front isometric upside-down view of a connector of the present invention. 
     FIG. 2 is a top view of the connector of FIG.  1 . 
     FIG. 3 is a side view of the connector of FIG.  1 . 
     FIG. 4 is a bottom view of the connector of FIG.  1 . 
     FIG. 5 is an exploded isometric view of the upside-down connector of FIG.  1 . 
     FIG. 6 is a sectional view of the connector of FIG. 1, with all parts assembled and the connector oriented right-side-up. 
     FIG. 7 is a front isometric view of the snap lock sleeve of the connector of FIG.  5 . 
     FIG. 8 is a sectional view of the sleeve of FIG.  7 . 
     FIG. 9 is a side elevation view of the sleeve of FIG.  7 . 
     FIG. 10 is a plan view of the sleeve of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a connector  10  of the invention with a shell  12  having front and rear shell portions  14 ,  16 . A cable  20  extending from the rear of the connector has wires that connect to contacts  22 , and the connector is mated to another connector by moving the connector  10  forwardly F. FIG. 5 shows that the connector includes a front body  50  that includes a snap lock sleeve  30  and a contact holder  32  with passages  34  that hold the contacts  22 . A rear body  40  lies rearward of the front body, and a wire-surrounding sleeve  42  lies largely within the rear body  40 . 
     FIG. 6 shows the parts assembled. The contacts  22  have been fixed in the passages  34  of the contact holder  32  and the contact holder lies within the snap lock sleeve  30 . The holder  32  and sleeve  30  are part of a front body  50  that is attached to the rear body  40  by external threads  52  at the rear portion of the front body that are threadably engaged with internal threads  54  at the front portion of the rear body. Prior to such threadable attachment, wires  60  of the cable  20  have their conductors  64  bared, inserted into bores at the rear end portions of the contacts, and held in place as by crimping or soldering. The cable also includes a jacket  68  that lies around the wires. 
     After the cable wires have been terminated to the rear portions of the contacts, and the rear body  40  is threadably attached to the front body, the passageway  70  of the rear body is filled with a potting material  72 . Although rigid potting materials such as epoxy could be used, applicant usually prefers to provides an elastomeric potting material such as silicone, to provide stress relief for the cable  20 . That is, the elastomeric material deflects sidewardly when the cable  20  is pulled perpendicular to the forward F and rearward R directions. In most cases, the potting material is injected into the passageway under a pressure of at least 1 psi, and preferably about 9 psi. This assures that the potting material will reliably seal the areas around the rear contacts portions  66 . Some of the potting material may leak around the rear portion  45  of the contact holder  32  and through the gaps between threads  52 ,  54 . If a potting material such as epoxy is used, it can be applied without pressure. 
     Applicant provides an O-ring seal  80  between outer and inner cylindrical surfaces  82 ,  84  of the rear portion of the snap lock sleeve  30  and of the front portion of the rear body  40 . The O-ring lies in a groove  86  formed in one of the cylindrical surfaces such as the inner surface. As a result, as the flowable potting material is injected under pressure into the passageway and leaks between the threads, the O-ring  80  prevents further leakage of the potting material. Leakage of the potting material could hinder or prevent motion between the shell  12  and the snap lock sleeve  30 , resulting in the latching mechanism not functioning properly. After the potting material has solidified, a boot  90  may be applied between the rear of the rear body and the cable  20 , especially if the potting material is rigid. In many cases, a flexible potting material forms a flexible boot, and a separate boot is not required. 
     Applicant provides the wire surrounding sleeve  42  with a front end  44  that lies closely between the outside of a rear portion  45  of the contact holder and the inside of the rear portion  46  of the snap lock sleeve (“close” means a clearance of no more then 0.02 inch between them). Any leaked potting material passes forward inside the wire surrounding sleeve front end and then rearward along the outside before reaching the threads  52 ,  54  and the O-ring  80 . 
     Prior to insertion of the contacts and molding of potting material, the snap lock sleeve  30  will have been inserted forwardly F into the shell. Such insertion proceeds until two latches  100 ,  102  (FIG. 5) formed on the snap lock sleeve  30  of the front body, snap into latch-receiving openings  104  of the front portion  110  of the shell, which is of a smaller diameter than the rear portion  112  of the shell. The contacts and other parts are assembled and potting material is molded and allowed to solidify. The shell  12  with the cable trailing behind it, then can be mated to another connector indicated at  114  in FIG. 6, by grasping the shell and pushing it forwardly. Unmating of the connectors is accomplished by a person firmly grasping the shell rear portion  112  and pulling the shell rearwardly R. It is noted that for some purchasers of the connectors, the latch shoulders  80  are angled for easy unlatching, as by a rearward force of under five pounds. For other customers, a large rearward force is required for unlatching. In many cases, it is more difficult to achieve unmating than mating. 
     In order to prevent a person&#39;s fingers from slipping on the shell  12 , especially during unmating, applicant forms a gripping surface portion shown at  120  in FIGS. 1-3. The gripping surface portion is formed on a largely cylindrical surface  122  at the shell rear portion, and includes a main rib or ridge  124  that projects radially outward (with respect to the shell axis  126 ) of the largely cylindrical surface  122 . The ridge  124  (FIG. 2) extends in a loop, with ridge side portions  130 ,  132  extending primarily in front F and rear R longitudinal M directions, or parallel to the axis  126 . The ridge also includes a largely circumferentially extending end ridge portion  132  that extends primarily circumferential to the axis  126 . A line  134  that is 45° to the axis  126  is tangent to a point  136  between the side and end ridge portions  130 ,  132 . Applicant provides additional ridges  141 - 144  that each extends in a loop parallel to the loop of the outermost or main ridge  124 . 
     The main ridge sides are circumferentially spaced by an angle of about 120° about the axis  126 . As shown in FIG. 3, an opposite side  150  of the shell rear portion which lies opposite the ridge  124 , is devoid of ridges. The side  152  that contains the ridges, also contains front and rear directing arrows  154 ,  156  that indicate the direction and rotational position around the axis (e.g. the connector is pushed rather than rotated to mate). The mating connector can have a corresponding arrow, to indicate to the person that the connectors are to be mated with their arrows aligned. 
     As shown in FIG. 3, the rear end circumferentially-extending ridge portion  132  projects further from the axis  126  than other portions of the ridges. This provides support for the thumb T of a person who is grasping the connector. As indicated in FIG. 2, the ridge has a width W of about 2 centimeters so much of the thumb T can fit against the ridges. 
     As shown in FIG.  5  and as described earlier, the front and rear bodies are held together by engagement of the threads  52 ,  54 , and the body assembly  158  (FIG. 6) is held in the shell by the latches  100 ,  102  (FIG. 5) of the snap lock sleeve that snap into the latch-receiving openings  104  in the front portion of the shell. FIGS. 7-10 illustrate details of the snap lock sleeve and of the latches  100 ,  102 . The latches  100 ,  102  are identical, and lie on diametrically opposite sides of the axis  126 , although three or even more latches could be provided in a larger connector. The latch  100  is formed by a pair of slots  170 ,  172  that extend parallel to the axis  126  and that form a latch arm  174  between them. The latch arm also carries a projection  176  that projects radially outward with respect to the axis  126  and that forms a rearwardly-facing shoulder  180 . In FIG. 5, the rearwardly-facing shoulder  170  snaps into the shell opening  104  and lies forward of a forwardly-facing shell shoulder  182 . 
     The slots such as  170  (FIG. 7) have front and rear ends  190 ,  192  that are closed ends resulting in a latch arm such as  174  which is not cantilevered but which has opposite ends merging with the rest  176  of the snap lock sleeve  30 . This results in a stronger latch arm. However, the reduced flexibility can result in cracks developing in the sleeve, particularly at the opposite ends of the slots  170 ,  172 . Applicant avoids concentrated stresses at the slot ends by forming enlarged slot ends  190 ,  192 . That is, each slot end such as  192  has a width B (FIG. 8) in a circumferential direction, which is greater than the width C of the rest of the slot and of the average width of the slot. The width B is preferably more than twice as great as the width C. This results in stresses at the opposite ends of the slot being better distributed, and resulting in more robust latch arms. The enlargements in the slot ends such as  192  and  193  (FIG. 8) of the two slots that form one latch arm  174  between them, project toward one another. This reduces the width of the latch arm end, where much of the bending occurs, for greater flexibility. 
     The projection  176 , shown in FIG. 10, has opposite side walls  200 ,  202  and a rear wall  204 , with a gap  206  formed between the side ridges and rear wall  204 . This construction reduces the amount of material and enables more even cooling of the injection molded snap lock sleeve. Previously, shrinkage occurred when the plastic molded material lay in the gap  206 . The strength of the rear wall  204  against rearward movement, is adequate because the side walls  200 ,  202  adequately support the rear wall  204 . The side walls  200 ,  202  extend at a radially outward and rearward incline. 
     Thus, the invention provides a connector assembly which includes front and rear bodies that are joined together, with contacts lying in passages of a contact holder, of the front body and with a cable extending through a passageway in the rear body, and with the assembly of front and rear bodies being latched in place in a surrounding shell. A potting material that is preferably elastomeric, is injected under pressure in a passageway of the rear body. Leakage is reduced by a wire-surrounding sleeve and by an O-ring that lies axially beyond threadably engaged ends of the bodies. The outside of the shell is molded with ridges at one side. A main ridge extends in a loop, and additional ridges that are smaller than the main ridge lie within the main ridge loop. The rear of the main ridge extends circumferentially and projects radially further than the rest of the ridges. The snap lock sleeve, which has latches to latch into openings in a front portion of the sleeve, has latch arms formed by slots with enlarged front and rear ends, and with a projection on each latch arm having a gap. 
     Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents.