Abstract:
A waterproof zipper consisting of a first zipper tape, a second zipper tape, and a zipper slider consisting of slide, a pressure plate and a pull tab is disclosed. The first zipper tape and the second zipper tape are specially configured to enhance the tensile strength and waterproof characteristics of the zipper. The pressure plate defines with the topmost edges of the two second stop walls of the slider a constraint space for holding down the first zipper tape and the second zipper tape to prevent accidental displacement of the zipper slider relative to the first and second zipper tapes.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to zip fasteners and more particularly, to a waterproof zipper, which has good tensile strength and waterproof characteristics. Embodiments provide a constraint space between a bottom edge of a pressure plate and the topmost edges of two second stop walls of a slider of a zipper slider thereof for enabling the zipper slider to be positively locked to the zipper tapes. 
     2. Description of the Related Art 
     A conventional zipper generally comprises two zipper tapes, each having an interlocking series of teeth, and a zipper slider slidable to force the two series of teeth into engagement with each other or to cause separation of the two series of teeth. However, if the zipper is accidentally vibrated, the zipper slider can be forced to displace, causing separation of the two series of teeth. Therefore, when a zipper is used in an article that needs to protect against wind and water (such as a raincoat), a shielding strip and a fastener must be provided at an outer side of the zipper so that the shielding strip can be locked to shield the zipper. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. An object of embodiments of the present invention is to provide a waterproof zipper, which has good tensile strength and waterproof characteristics, and which provides a constraint space between a bottom edge of a pressure plate and the topmost edges of two second stop walls of a slider of a zipper slider thereof for enabling the zipper slider to be positively locked to the zipper tapes. 
     To achieve this and other objectives of the invention, an embodiment waterproof zipper comprises a first zipper tape, a second zipper tape, and a zipper slider including a slider, a pressure plate and a pull tab. The first zipper tape provides a first rim strip portion, a second rim strip portion suspended above the first rim strip portion, a first series of teeth located at the first rim strip portion, and a lateral coupling strip portion located at the second rim strip portion. The second zipper tape provides a third rim strip portion, a fourth rim strip portion suspended above the third rim strip portion, a second series of teeth located at the third rim strip portion, and a lateral retaining strip portion located at the fourth rim strip portion. The slider is coupled to the first zipper tape and the second zipper tape. When moving the slider, the first series of teeth and the second series of teeth are forced into engagement with each other or separated from each other, and at the same time, the lateral coupling strip portion and the lateral retaining strip portion are abuted against each other or moved apart. The pull tab is operable to control the pressure plate toward or away from the two second stop walls of the slider, enabling the slider to be locked to or unlocked from the first and second zipper tapes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a waterproof zipper in accordance with an embodiment of the present invention. 
         FIG. 2  is top a perspective view of the zipper slider of the waterproof zipper in accordance with an embodiment of the present invention. 
         FIG. 3  is a bottom perspective view of the zipper slider of the waterproof zipper in accordance with an embodiment of the present invention. 
         FIG. 4  is an exploded view of the zipper slider of the waterproof zipper in accordance with an embodiment of the present invention. 
         FIG. 5  is a side view of the zipper slider of the waterproof zipper in accordance with an embodiment of the present invention, illustrating an arc convex portion of each coupling block engaged in a respective concave surface portion. 
         FIG. 6  is a schematic sectional applied view of an embodiment of the present invention. 
         FIG. 7  is a side view of the zipper slider of the waterproof zipper in accordance with an embodiment of the present invention, illustrating one protruding rib of each coupling block engaged in a respective concave surface portion. 
         FIG. 8  is another schematic sectional applied view of an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-8 , a waterproof zipper in accordance with an embodiment of the present invention is shown. The waterproof zipper comprises a first zipper tape  1 , a second zipper tape  2 , and a zipper slider formed of a slider  3 , a pressure plate  4  and a pull tab  5 . 
     The first zipper tape  1  comprises a first base portion  11 , a first rim strip portion  12  extended from one lateral side of the first base portion  11 , a second rim strip portion  13  extended from the same lateral side of the first base portion  11  and suspending above the first rim strip portion  12 , a first series of teeth  14  arranged along one lateral side of the first rim strip portion  12  remote from the first base portion  11 , a lateral coupling strip portion  15  extended along one lateral side of the second rim strip portion  13  remote from the first base portion  11 , a coupling flange  151  located at a bottom side of the lateral coupling strip portion  15  remote from the second rim strip portion  13  and extended along the length of the lateral coupling strip portion  15 , and a first bearing edge  152  located at the bottom side of the lateral coupling strip portion  15  and abutted against the second rim strip portion  13 . 
     The second zipper tape  2  comprises a second base portion  21 , a third rim strip portion  22  extended from one lateral side of the second base portion  21 , a fourth rim strip portion  23  extended from the same lateral side of the second base portion  21  and suspending above the third rim strip portion  22 , a second series of teeth  24  arranged along one lateral side of the third rim strip portion  22  remote from the second base portion  21 , a lateral retaining strip portion  25  extended along one lateral side of the fourth rim strip portion  23  remote from the second base portion  21 , a retaining groove  251  located at a bottom side of the lateral retaining strip portion  25  remote from the fourth rim strip portion  23  and extended along the length of the lateral retaining strip portion  25 , and a second bearing edge  252  located at the bottom side of the lateral retaining strip portion  25  and abutted against the fourth rim strip portion  23 . 
     The slider  3  comprises a first slider frame  31  and a second slider frame  32 . The first slider frame  31  comprises a first base wall  311 , two first stop walls  312  respectively upwardly extended from two opposite lateral sides of the first base wall  311 , a first spacer wall  313  upwardly extended from the first base wall  311  and equally spaced between the two first stop walls  312 , two first diverging guide channels  314  defined between the first stop walls  312  and separated by the first spacer wall  313 , and a first converging open chamber  315  defined between the first stop walls  312  at a rear side of the first spacer wall  313  and disposed in communication with the first diverging guide channels  314 . The second slider frame  32  comprises a second base wall  321  integrally connected with the first spacer wall  313  and spaced above the first base wall  311 , two second stop walls  322  respectively upwardly extended from two opposite lateral sides of the second base wall  321 , a second spacer wall  323  upwardly extended from the second base wall  321  and equally spaced between the two second stop walls  322 , two second diverging guide channels  326  defined between the second stop walls  322  and separated by the second spacer wall  323 , a second converging open chamber  327  defined between the second stop walls  322  at a rear side of the second spacer wall  323  and disposed in communication with the second diverging guide channels  326 , a pivot hole  324  transversely cu through the second spacer wall  323  near a top end thereof, and a bearing step  325  located on a middle part of the second spacer wall  323 . When the waterproof zipper is assembled, the first series of teeth  14  and the first series of teeth  24  are respectively received in the two first diverging guide channels  314  and the first converging open chamber  315 ; the lateral coupling strip portion  15  and the lateral retaining strip portion  25  are respectively received in the two second diverging guide channels  326  and the second converging open chamber  327 . 
     The pressure plate  4  is supported on the bearing step  325  of the second spacer wall  323 , comprising a center slot  41  coupled to the second spacer wall  323 , two locating blocks  42  raised from a top wall thereof and disposed at two opposite lateral sides relative to the center slot  41 , and a concave surface portion  421  located on each locating block  42 . Further, the pressure plate  4  has a bottom surface thereof inwardly curved, defining with the topmost edges of the two second stop walls  322  of the slider  3  a constraint space  6 . 
     The pull tab  5  comprises a finger plate  52 , two coupling blocks  51  extended from one end of the finger plate  52  in a parallel manner and pivoally coupled to the pivot hole  324  at the second spacer wall  323  of the slider  3  by a pivot pin  513 . Each coupling block  51  comprises a pivot hole  512  coupled to the pivot pin  513 , two protruding ribs  511  symmetrically located at two opposite lateral sides thereof, and an arc convex portion  514  located at a bottom side thereof and equally spaced from the two protruding ribs  511 . The distance between the outer peripheral edge of each protruding rib  511  and the center of the pivot hole  512  is larger than the distance between the outer peripheral edge of the arc convex portion  514  and the center of the pivot hole  512 . 
     Referring to  FIGS. 1-3  again, in application, the first zipper tape  1  and the second zipper tape  2  are bonded or stitched to a hand bag, bag, raincoat, travel bag, etc., keeping the first series of teeth  14  and the second series of teeth  24  as well as the lateral coupling strip portion  15  and the lateral retaining strip portion  25  at two opposite lateral sides relative to the first spacer wall  313  and the second spacer wall  323 . At this time, the user can pull the pull tab  5  to move the slider  3  between the first rim strip portion  12  and the third rim strip portion  22  and also between the second rim strip portion  13  and the fourth rim strip portion  23  from one end toward the other end, forcing the first series of teeth  14  and the first series of teeth  24  toward each other. By means of the guiding of the first stop walls  312 , the first series of teeth  14  and the first series of teeth  24  are forced into engagement with each other in the first converging open chamber  315 , and therefore, the first series of teeth  14  and the first series of teeth  24  are interlocked and will not be disengaged from each other even if the first zipper tape  1  and the second zipper tape  2  are stretched by an external force, providing enhanced tensile strength. During sliding movement of the zipper slider, the lateral coupling strip portion  15  and the lateral retaining strip portion  25  are moved toward each other. At this time, the first bearing edge  152  of the lateral coupling strip portion  15  and the second bearing edge  252  of the lateral retaining strip portion  25  are guided by the second stop walls  322 , causing the lateral coupling strip portion  15  and the lateral retaining strip portion  25  to abut against each other in the second converging open chamber  327  and forcing the coupling flange  151  into engagement with the retaining groove  251  to prohibit passing of any external wind or fluid from one side of the waterproof zipper to the other side of the waterproof zipper. Thus, the invention achieves excellent windproof and waterproof effects, i.e., the waterproof zipper of the invention is practical for use in any article that needs to protect against wind and water (such as: raincoat). When wishing to separate the first zipper tape  1  and the second zipper tape  2 , pull the pull tab  5  in the reversed directions to move the first spacer wall  313  between the first series of teeth  14  and the first series of teeth  24 . Subject to the guiding of the first stop walls  312 , the first series of teeth  14  and the first series of teeth  24  are respectively abutted against the two opposite lateral sides of the first spacer wall  313  and the second spacer wall  323  is put in between the lateral coupling strip portion  15  and the lateral retaining strip portion  25 . Further, subject to the guiding of the second stop walls  322 , the lateral coupling strip portion  15  and the lateral retaining strip portion  25  are respectively abutted against the two opposite lateral sides of the second spacer wall  323 , causing disengagement of the coupling flange  151  from the retaining groove  251 , and thus, the slider  3  is returned to its former position. 
     Referring to  FIGS. 1 and 5-8  again, as illustrated, when positioning the slider  3 , operate the finger plate  52  of the pull tab  5  to force one protruding rib  511  of each coupling block  51  into engagement with one respective concave surface portion  421  of the pressure plate  4  to further move the pressure plate  4  toward the second slider frame  32 , enabling the second rim strip portion  13  of the first zipper tape  1  and the fourth rim strip portion  23  of the second zipper tape  2  to be squeezed by the bottom edge of the pressure plate  4  and the topmost edges of the second stop walls  322  and firmly secured in the constraint space  6 , and thus, the slider  3  is locked to the first zipper tape  1  and the second zipper tape  2 . When wishing to unlock the slide  3  from the first zipper tape  1  and the second zipper tape  2 , operate the finger plate  52  of the pull tab  5  to shift the arc convex portion  514  of each coupling block  51  into the respective concave surface portion  421  of the pressure plate  4 , at this time, the pressure plate  4  is released from the pressure of the coupling blocks  51 , allowing the second rim strip portion  13  of the first zipper tape  1  and the fourth rim strip portion  23  of the second zipper tape  2  to be moved in the constraint space  6 , and thus, the slider  3  is unlocked from the first zipper tape  1  and the second zipper tape  2  for free movement. 
     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.