Patent Publication Number: US-2018035765-A1

Title: Zipper

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to zippers and more particularly to a zipper having improved characteristics including zipper pull. 
     2. Description of Related Art 
     A conventional zipper  101  is shown in  FIGS. 8 and 9  and comprises a slider head  110 , a coupling  120 , a zipper pull  130  and a torsion spring  133 . The slider head  110  includes a base  111 , two opposite walls  112  on two sides of the base  111  respectively, two roofs  113  each inwardly extending from a top of the wall  112 , a division wall  114  on a longitudinal central line of the base  111 , two grooves  115  each defined among and by the roof  113 , the wall  112  and the base  111  of the same side, a front mounting block  116  on a top of the division wall  114 , and a rear mounting member  118  having a through hole  1181  and a closed wall  1182  on an inner surface of the through hole  1181 . The coupling  120  is pivotably secured to the front mounting block  116  by means of a pivot  125  and includes a hook  121  at a rear end. The hook  121  passes through a front loop  131  of the zipper pull  130  into the through hole  1181  to attach the zipper pull  130  to the slider head  110 . The torsion spring  133  is anchored in a receptacle of the front mounting block  116  and has a top end urging against a front end of the coupling  120 . 
     However, the closed wall  1182  is thin and has a lower height. Further, only three edges of the hook  121  contact the closed wall  1182  for fastening the coupling  120 , the loop  131  and the rear mounting member  118  together. Furthermore, the hook  121  is subject to deformation and/or breakage because the cross-section of the three contact edges of the hook  121  is small. In addition, the zipper being pulled cannot be stopped by the deformed or broken hook  121 . Additionally, the triangular loop  131  attached to the coupling  120  does not effect a smooth pulling of the zipper pull  130 . 
     Thus, the need for improvement still exists. 
     SUMMARY OF THE INVENTION 
     It is a first object of the invention to provide a zipper comprises a coupling including a hook at a rear end, the hook being reliable in use. 
     It is a second object of the invention to provide a zipper comprises a coupling including a hook at a rear end, the hook being easy to install. 
     It is a third object of the invention to provide a zipper comprising a zipper pull which is easy to pull. 
     For achieving above and other objects, the invention provides a zipper comprising a slider head including a base; two opposite side walls on two sides of the base respectively; two roofs each inwardly extending from a top of the side wall; a division wall on a longitudinal central line of the base; two grooves each defined among and by the roof, the side wall, and the base at the same side; a front mounting block on a top of the division wall and having a longitudinal central trough and a receptacle on a front end of the longitudinal central trough; a rear mounting member having a through hole and two opposite side walls on two sides of the through hole respectively; and a well between the front mounting block and the rear mounting member; a biasing member anchored in the receptacle; a coupling partially disposed in the longitudinal central trough and including a hook at a rear end, and an intermediate recess wherein the coupling is pivotably secured to the front mounting block and has a front end urged against by the biasing member; and a zipper pull releasably secured to the hook; wherein the hook is disposed in the through hole to hold the zipper pull and the slide head in position. 
     The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a zipper according to the invention; 
         FIG. 2  is an exploded view of the zipper; 
         FIG. 3  is a side elevation in part section of the zipper of  FIG. 1 ; 
         FIG. 4  is a view similar to  FIG. 3  showing the coupling being unfastened and a rearward pulling of the zipper pull for separating two series of the locking teeth; 
         FIG. 5  is a perspective view of  FIG. 4  showing the zipper being pulled along a fabric strip; 
         FIG. 6  is a view similar to  FIG. 3  showing the coupling being unfastened and a forward pulling of the zipper pull for engaging two series of the locking teeth; 
         FIG. 7  is a perspective view of  FIG. 6  showing the zipper being pulled along a fabric strip; 
         FIG. 8  is an exploded view of a conventional zipper; and 
         FIG. 9  is a side elevation in part section of the assembled zipper of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 to 7 , a zipper  1  in accordance with the invention comprises a slider head  10 , a coupling  20 , and a zipper pull  30  as discussed in detail below. 
     The slider head  10 , the coupling  20 , and the zipper pull  30  are formed of thermoplastics, zinc alloy, aluminum alloy or the like and can be made by injection molding, squeeze molding, casting or the like. 
     The slider head  10  includes a base  11 ; two opposite side walls  12  on two sides of the base  11  respectively; two roofs  13  each inwardly extending from a top of the wall  12 ; a division wall  14  on a longitudinal central line of the base  11 ; two grooves  15  each defined among and by the roof  13 , the side wall  12  and the base  11  of the same side; a front mounting block  16  on a top of the division wall  14  and having a longitudinal central trough  161 , a receptacle  164  on a front end of the trough  161 , two rear cavities  162  spaced apart by the trough  161 , and a hole  163  through the rear cavities  162 ; a rear mounting member  18  having a through hole  181 , two opposite side walls  182  on two sides of the through hole  181  respectively, and a cut  183  and a front wall  184  on a front end of the through hole  181 ; and a well  17  between the front mounting block  16  and the rear mounting member  18 , the well  17  communicating with both the cut  183  and the trough  161 . 
     The coupling  20  includes a hook  21  at a rear end, a contact portion  23  at a bottom of a front end, a through hole  24  adjacent to the contact portion  23 , and a recess  22  between the hook  21  and the through hole  24 . The coupling  20  is pivotably secured to the front mounting block  16  by means of a pivot  25  passing through the hole  163  and the through hole  24 . A torsion spring  33  is anchored in the receptacle  164  and has a top end urging against the contact portion  23 . The zipper pull  30  includes a rectangular loop  31  loosely attached thereto, the loop  31  having a front fixing edge  32  disposed in the well  17 . The loop  31  is placed on an outer surface of the rear mounting member  18 . The hook  21  inserts through the through hole  181  and the fixing edge  32  urges against the recess  22 . As a result, the zipper pull  30 , the coupling  20  and the slider head  10  are assembled. 
     As shown in  FIGS. 4 and 5 , a user may press the rear end of the coupling  20  to compress the torsion spring  33 . And in turn, the coupling  20  pivots clockwise to dispose the hook  21  completely in the through hole  181 . Also, the loop  31  is loosened. Thus, the user may grasp the zipper pull  30  and pull the zipper pull  30  rearward to separate two series of locking teeth  40  along a fabric strip. 
     As shown in  FIGS. 6 and 7 , in a reverse operation, the user may grasp the zipper pull  30  and pull the zipper pull  30  forward. And in turn, the fixing edge  32  moves upward along the hook  21 . Further, the hook  21  moves upward toward an unfastening state. Furthermore, the torsion spring  33  is compressed to store elastic force. In addition, the hook  21  is disengaged from the locking teeth  40  to allow the zipper pull  30  to pull. Thereafter, a pulling of the zipper pull  30  along the direction indicated by arrow can engage two series of the locking teeth  40  long a fabric strip. 
     It is understood that a release of the zipper pull  30  can return the expanding torsion spring  33  to its original shape. And in turn, the hook  21  moves downward and the fixing edge  32  also moves downward. Further, the hook  21  is pushed into the through hole  181  again to dispose (i.e., lock) between the two series of the locking teeth  40  due to the expansion of the torsion spring  33 . In the locked state, the zipper  1  is prevented from being pulled as shown in  FIG. 3 . 
     The invention has the following characteristics and advantages: Height of the side wall  182 , which is approximately equal to the height of the hook  21 , is labeled by X (see  FIG. 3 ), which is about 2.5 times greater than height of the closed wall  1182  of the conventional art which is labeled by Y (see  FIG. 9 ). This means a torsion force exerted by pulling the zipper pull  30  is about 2.5 times greater than a torsion force exerted by pulling zipper pull  130  of the conventional art. In one exemplary example, height of the side wall  182  is at least 60% of height of the hook  21 , and the hook  21  can withstand a torsion force about 1.5 times of that of the conventional hook, i.e., withstanding more torsion force. Further, the height increased side walls  182  facilitate pulling of the zipper pull  30 . Furthermore, the hook  21  is more durable. In addition, the assembly of the zipper  1  is made easy. 
     It is appreciated that the through hole  181  is configured of a substantially tapered and longitudinally deep shape, so as to have the hook  21  disposed in the through hole  181  to positively hold the zipper pull  30  and the slide head  10  in position, as viewed from the drawing of  FIGS. 3-6 . 
     Furthermore, the front wall  184  of the through hole  181  is further provided to protect the hook  21  in position, when a greater external torsion force is applied thereto. 
     While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.