Patent Publication Number: US-6669509-B2

Title: Watertight connector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a watertight connector. 
     2. Description of the Related Art 
     A known watertight connector has a ring-shaped seal mounted on the outer peripheral surface of a female housing. The female housing can be fit into a receptacle of a male connector so that a clearance between the inner peripheral surface of the receptacle and the outer peripheral surface of the female housing is held watertight by the seal. 
     A good watertight performance in a connector of this type requires the sealing surfaces of both housings to be smooth and a degree of resilient deformation of the sealing member needs to be uniform over the entire circumference. However, the sealing surface on the outer peripheral surface of the female housing may not necessarily be smooth depending on the inner construction of the female housing. For example, resiliently deflectable locks may be formed along the inner wall surfaces of the cavities in the female housing for locking the female terminal fittings in the cavities. The sealing surface may be defined in an area having a back-to-back relationship with the locks and may be located behind the locks. The thickness between the inner surface of the cavity and the corresponding outer peripheral surface of the housing is the sum of the thickness of the lock, the thickness of the deformation permitting space for the lock and the thickness of the wall on the side of the deformation permitting space opposite the lock. Thus, portions of the wall of the housing near the deformation permitting space and the lock are likely to be very thick, and these thick portions of the walls are likely to include the sealing surface on the outer periphery of the female housing. 
     A deformation called a “sink mark” often occurs during the resin molding of a thick part. Thus, a “sink mark” is likely to be formed at part of the sealing surface along the thick area of the wall, and that part of the sealing surface may not be smooth., 
     The present invention was developed in view of the above problem and an object thereof is to prevent a deformation of a sealing surface resulting from formation of a “sink mark” during resin molding. 
     SUMMARY OF THE INVENTION 
     The invention is directed to a watertight connector constructed such that a clearance between a sealing surface on the outer peripheral surface of a housing made of a synthetic resin and the inner peripheral surface of a mating connector can be sealed by a sealing member. The connector has at least one cavity formed in the housing for receiving at least one terminal fitting. At least one lock is arranged along an inner wall surface of the cavity for preventing the corresponding terminal fitting from coming out. The lock is arranged along an inner wall surface of the cavity that has a back-to-back relationship with the sealing surface and preferably is spaced from or before the sealing surface along the longitudinal direction of the watertight connector. At least one cut-away portion or channel is formed in a wall portion between the sealing surface and the inner wall surfaces of the cavity that has a back-to-back relationship with the sealing surface by cutting the inner wall surface of the cavity. Thus, even if the wall is thick, a “sink mark” is not likely to be formed when the connector housing is molded by the mold and a deformation of the sealing surface resulting from the “sink mark” can be prevented. 
     Preferably, the channels are formed along the widthwise left and right edges of the inner wall surfaces of the cavities having a back-to-back relationship with the sealing surface. 
     Mold-removal slits preferably are formed at the opposite sides of the locks by removing a mold when the connector housing is molded. The channels and the mold-removal slits preferably communicate with each other. The channels are wider than the mold-removal slits. Thus, the mold for forming the channels can be wider and stronger. 
     A mating connector preferably can be pulled into the connector housing and connected therewith by a cam action of a cam mechanism when a lever on the watertight connector is rotated. 
     These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view partly in section showing a state of an initial stage of connection with a mating connector in accordance with the invention. 
     FIG. 2 is a plan view partly in section showing a connected state with the mating connector. 
     FIG. 3 is a section along  3 — 3  of FIG.  2 . 
     FIG. 4 is a partial enlarged view of FIG.  3 . 
     FIG. 5 is a section along  5 — 5  of FIG.  3 . 
     FIG. 6 is a section along  6 — 6  of FIG.  3 . 
     FIG. 7 is a section along  7 — 7  of FIG.  4 . 
     FIG. 8 is a section along  8 — 8  of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The letter F in FIGS. 1 to  8  identifies a watertight lever-type connector according to the invention. The connector F has a synthetic resin housing  10  into which female terminal fittings  23  are insertable. The illustrated connector F also has a lever  24  made e.g. of a synthetic resin. A mating connector M to be connected with the watertight connector F accommodates male terminal fittings (not shown) inside and includes a substantially rectangular forwardly projecting receptacle Mf. Cam pins Mp project from the left and right side surfaces of the receptacle Mf. The lever  24  can be rotated with the cam pins Mp engaged in cam grooves  25  formed in the lever  24 . Thus, the two connectors F, M are connected with each other. 
     In the following description, a mating side of the watertight connector F (left side in FIGS. 1 to  6 ) is referred to as the front side and reference is made to FIGS. 3 and 4 concerning the vertical direction. 
     The housing  10  has a substantially block-shaped main body  11  formed with cavities  12   a ,  12   b ,  12   c  into which the female terminal fittings  23  are insertable from behind, and a substantially rectangular tubular fitting  13  substantially surrounds the main body  11 . The rectangular receptacle Mf of the mating connector M is fittable into a space defined between the tubular fitting  13  and the main body  11 . An area of the outer peripheral surface of the connector housing  10  near the rear end of the tubular fitting  13  is a sealing surface  14 . A ring-shaped seal  15  is mounted beforehand on the sealing surface  14 . The seal  15  seals a space between the inner peripheral surface of the receptacle Mf and the sealing surface  14  watertight when the receptacle Mf of the mating connector M is fitted in the tubular fitting  13 . 
     The cavities  12   a ,  12   b ,  12   c  are arrayed transversely at specified intervals in each of three stages, and are substantially rectangular when viewed from front. Locks  17  are cantilevered forward at substantially front halves of ceiling surfaces  16   a ,  16   b ,  16   c  of the respective cavities  12   a ,  12   b ,  12   c . The locks  17  are configured to prevent the female terminal fittings  23  inserted into the cavities  12   a ,  12   b ,  12   c  from coming out backwardly. A projection  17   a  at the front end of each lock  17  interferes with the upper surface of the corresponding female terminal fitting  23  during the insertion of the female terminal fitting  23  into the cavity  12   a ,  12   b ,  12   c . Thus, the lock  17  is deformed resiliently into a deformation permitting space  18  and is retracted from an insertion path for the female terminal fitting  23 . When the female terminal fitting  23  reaches a proper insertion position, the lock  17  returns resiliently to engage the projection  17   a  with a locking hole (not shown) of the female terminal fitting  23 . As a result, the female terminal fitting  23  is locked and will not come out. 
     The ceiling surfaces  16   a  of the cavities  12   a  at the uppermost stage have a back-to-back relationship with the sealing surface  14 , and a partition wall  19  is provided therebetween. The locks  17  that extend along the ceiling surfaces  16   a  of the cavities  12   a  have a back-to-back relationship with the sealing surface  14 . The rear ends of the locks  17  are more forward than or more towards a mating side than the front end of the sealing surface  14 . Accordingly, the rear ends of the locks  17  also are before the front end of the seal  15  mounted on the sealing surface  14 . In other words, the points of support of the locks  17  are spaced from the closest end of the sealing surface  14  along the longitudinal direction of the watertight connector F toward its mating side with the mating connector M. 
     The partition wall  19  between the ceiling surfaces  16   a  of the cavities  12   a  at the uppermost stage and the sealing surface  14  is considerably thick in view of the required thickness of the locks  17  and the thickness of the deformation permitting spaces  18  for the locks  17 . Thus, a “sink mark” may be formed in the partition wall  19  when the housing is molded and, as a result, the sealing surface  14  may not be smooth. 
     As a countermeasure, grooves in the ceiling wall  16   a  of each cavity  12   a  form left and right cut-away channels  20  in the partition wall  19 . The channels  20  extend in forward and backward directions along the widthwise left and right edges of the ceiling walls  16   a  (see FIG.  5 ). Each channel  20  has a depth from the ceiling surfaces  16   a  that exceeds its width (see FIG.  7 ). The outer side surfaces of the channel  20  are substantially flush with the side surfaces of the cavities  12   a . Left and right mold-removal slits  21  are formed at the left and right sides of each lock  17  by removing the mold when the connector housing  10  is molded. The front ends of the channels  20  communicate with the rear ends of the mold-removal slits  21 , and the channels  20  are wider than the mold-removal slits  21 . Communication grooves  22  provide communication between the channels  20  and the mold-removal slits  21 , and have a depth from the ceiling surfaces  16   a  that is less than the channels  20 . The outer side surfaces of the communication grooves  22  are substantially flush with both the outer side surfaces of the mold-removal slits  21  and those of the channels  20 . The inner side surfaces of the communication grooves  22  are slanted surfaces  22   s  oblique to both the inner side surfaces of the mold-removal slits  21  and those of the channels  20 . 
     As described above, the channels  20  are formed in the partition wall  19  between the sealing surface  14  and the ceiling surfaces  16   a  of the cavities  12   a  at the uppermost stage having a back-to-back relationship with the sealing surface  14  by cutting the ceiling surfaces  16   a . Thus, even if the partition wall  19  is thick, the “sink mark” is not likely to be formed when the housing  10  is molded. Therefore, deformation of the sealing surface  14  resulting from the “sink mark” can be prevented, thereby allowing the sealing surface  14  to be smooth. As a result, a high sealing function can be displayed. 
     The mold for forming the channels  20  and the mold-removal slits  21  has a mold section (not shown) that is narrow and long in forward and backward directions. This mold section is removed backward after molding. The channels  20  are wider than the mold-removal slits  21 . Therefore, the mold portion for forming the channels  20  is wider than a mold section for forming the side surfaces of the locks, thereby being strengthened. 
     The invention is not limited to the above described and illustrated embodiment. For example, the following embodiments are also embraced by the technical scope of the present invention as defined by the claims. Beside the following embodiments, various changes can be made without departing from the scope and spirit of the present invention as defined by the claims. 
     Although the channels are formed along the opposite side edges of the inner wall surfaces of the cavities in the foregoing embodiment, they may be formed at the widthwise center positions of the inner wall surfaces of the cavities according to the present invention. 
     Although the channels are wider than the mold-removal slits at the opposite sides of the locks in the foregoing embodiment, they may have the same width as the mold-removal slits at the opposite sides of the locks according to the present invention. 
     Although the channels and the mold-removal slits communicate with each other in the foregoing embodiment, they may not communicate according to the present invention. 
     Although the invention is applied to the female connector housing with female terminal fittings in the foregoing embodiment, it may be applied to a male connector housing with male terminal fittings. 
     Although the invention is applied to a lever-type connector in the foregoing embodiment, it may be applied to connectors other than lever-type connectors.