Patent Publication Number: US-2012036685-A1

Title: Metal Tooth For Zipper

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an improved structure of metal zipper and more particularly, to a metal tooth for zipper, which enhances its engagement with the zipper tape, avoiding vibration relative to the zipper tape during operation of the metal zipper and prolonging the lifespan of the metal zipper. Further, the metal tooth has a concave surface portion formed in the protruding tooth head thereof so that less friction is produced when the metal zipper is closed or opened. 
     2. Description of the Related Art 
     In a regular metal zipper, as shown in  FIG. 1 , metal teeth  4  are respectively fastened to the longitudinal inner edges  31  of the respective zipper tapes  3  by a press or installation tool (not shown). According to this design, each metal tooth  4  comprises a base  40 , a mounting hole  41  transversely cut through two opposite lateral sides of the base  40  for mounting. The mounting hole  41  has an outer open end  411 , an inner close end  413  and a neck  412  spaced between the outer open end  411  and the inner close end  413 . The base  40  has two protruding engagement portions  414  disposed at two opposite sides of the neck  412  of the mounting hole  41  (see  FIG. 3 ) for engaging into the top and bottom sides of the longitudinal inner edges  31  of the respective zipper tape  3 . This design of metal tooth  4  has drawbacks as follows:
     1. The metal tooth  4  simply uses the two protruding engagement portions  414  of the base  40  to engage the top and bottom sides of the longitudinal inner edges  31  of the respective zipper tape  3 . When the user pulls the slide  5  to close or open the metal teeth  4 , the metal teeth  4  may be biased or forced out of place, causing a slide jam.   2. When sliding the slide  5  to close or open the metal zipper, the outer end edges  421  of the protruding tooth heads  42  of the metal teeth  4  at one zipper tape  3  may be forced to rub against the outer end edges  401 ′ of the bases  40 ′ of the metal teeth  4 ′ at the other zipper tape  3 , producing frictional resistance. Thus, closing or opening the metal zipper become unsmooth.   

     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a metal tooth for metal zipper, which enhances its engagement with the zipper tape, avoiding vibration relative to the zipper tape during operation of the metal zipper and prolonging the lifespan of the metal zipper. 
     It is another object of the present invention to provide a metal tooth for metal zipper, which reduces friction when the metal zipper is opened or closed, facilitating smooth operation of the metal zipper. 
     To achieve these and other objects of the present invention, a metal tooth for metal zipper has a mounting hole located on one end of the base thereof, two first engagement portions and two second engagement portions formed integral with the base at two opposite sides of the mounting hole for engaging into the top and bottom sides of the inner edge of the respective zipper tape to deform the respective inner edge during installation so that engagement between the zipper tape and the metal tooth is enhanced, avoiding vibration of the metal tooth relative to the zipper tape during operation of the metal zipper and prolonging the lifespan of the metal zipper. 
     Further, metal tooth has a concave surface portion formed in the protruding tooth head thereof so that less friction is produced when the metal zipper is closed or opened. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a schematic sectional view of a part of a metal zipper according to the prior art. 
         FIG. 2  is an enlarged view of a part of  FIG. 1 , illustrating the positioning of one metal tooth on the respective zipper tape. 
         FIG. 3  is a plain view of one metal tooth of the metal zipper according to the prior art. 
         FIG. 4  is a schematic sectional view illustrating a metal tooth fastened to one zipper tape according to the present invention. 
         FIG. 5  is a sectional view of one metal tooth for zipper according to the present invention. 
         FIG. 6  is an elevational view of the metal tooth shown in  FIG. 5 . 
         FIG. 7  is a schematic sectional view of a part of a metal zipper according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 4˜7 , a metal zipper  2  (see  FIG. 7 ) is shown, comprising two zipper tapes  21  each having a longitudinal inner edge  211 , two series of metal teeth  1  respectively and transversely affixed to the zipper tapes  21  and spaced along the respective longitudinal inner edges  211  in a staggered manner. By means of pulling a slide (not shown) in one direction, the two series of metal teeth  1  can be interlocked, forming a chain. Each metal tooth  1  comprises a base  10 , a mounting hole  11  transversely cut through one end, namely, the inner end of the base  10  on the middle (see  FIG. 6 ), and a protruding tooth head  12  protruded from one lateral side of an opposite end, namely, the outer end of the base  10 . The mounting hole  11  has an outer open end  111 , an inner close end  115 , a first neck  112  spaced between the outer open end  111  and the inner close end  115 , a second neck  114  spaced between the first neck  112  and the inner close end  115 , and a flank portion  113  defined between the first neck  112  and the second neck  114 . The base  10  has two opposing first engagement portions  116  respectively disposed at two opposite sides of the first neck  112 , and two opposing second engagement portions  117  respectively disposed at two opposite sides of the second neck  114 . By means of the first engagement portions  116  and second engagement portions  117 , the base  10  of each metal tooth  1  is affixed to the longitudinal inner edge  211  of one respective zipper tape  21 . During installation, the first engagement portions  116  and second engagement portions  117  of the base  10  of each metal tooth  1  are respectively engaged into the top and bottom sides of the inner edge  211  of the respective zipper tape  21  to deform the respective inner edge  211 , enhancing engagement between the zipper tape  21  and the metal tooth  1 , avoiding vibration of the metal tooth  1  relative to the zipper tape  21  and prolonging the lifespan of the metal zipper. 
     Each metal tooth  1  further comprises a notch  13  located on the other lateral side of the outer end of the base  10  opposite to the protruding tooth head  12 . Further, the protruding tooth head  12  has a bevel face  121  located on one side thereof adjacent to the mounting hole  11 , a slope face  122  located on an opposite side thereof remote from the mounting hole  11  and a concave surface portion  1221  formed in the slope face  122 . Further, the slope face  122  may be smoothly arched. Subject to the effect of the concave surface portion  1221 , less friction or resistance is produced when closing or opening the two series of metal teeth  1 , i.e., when closing or opening the metal zipper  2 , the concave surface portions  1221  of the metal teeth  1  at one zipper tape  21  provide a respective space for receiving the outer end edges  131  of the metal teeth  1  at the other zipper tape  21  (see  FIG. 7 ), avoiding friction between the two series of metal teeth  1  and facilitating metal zipper closing or opening operation. 
     When compared to the prior art design, the mounting hole  11  of the base  10  of each metal tooth  1  of the present invention has an outer open end  111 , an inner close end  115 , a first neck  112  spaced between the outer open end  111  and the inner close end  115 , a second neck  114  spaced between the first neck  112  and the inner close end  115  and a flank portion  113  defined between the first neck  112  and the second neck  114 , and the base  10  of each metal tooth  1  of the present invention has two opposing first engagement portions  116  respectively disposed at two opposite sides of the first neck  112 , and two opposing second engagement portions  117  respectively disposed at two opposite sides of the second neck  114 . During installation, the first engagement portions  116  and second engagement portions  117  of the base  10  of each metal tooth  1  are respectively engaged into the top and bottom sides of the inner edge  211  of the respective zipper tape  21  to deform the respective inner edge  211 , enhancing engagement between the zipper tape  21  and the metal tooth  1 , avoiding vibration of the metal tooth  1  relative to the zipper tape  21  and prolonging the lifespan of the metal zipper. Further, the protruding tooth head  12  has a bevel face  121  located on one side thereof adjacent to the mounting hole  11 , a slope face  122  located on an opposite side thereof remote from the mounting hole  11  and a concave surface portion  1221  formed in the slope face  122 . Subject to the effect of the concave surface portion  1221 , less friction or resistance is produced when closing or opening the two series of metal teeth  1 , 
     In general, the invention has the following benefits:
     1. By means of the first engagement portions  116  and second engagement portions  117 , the base  10  of each metal tooth  1  is affixed to the longitudinal inner edge  211  of one respective zipper tape  21 . During installation, the first engagement portions  116  and second engagement portions  117  of the base  10  of each metal tooth  1  are respectively engaged into the top and bottom sides of the inner edge  211  of the respective zipper tape  21  to deform the respective inner edge  211 , enhancing engagement between the zipper tape  21  and the metal tooth  1 , avoiding vibration of the metal tooth  1  relative to the zipper tape  21  and prolonging the lifespan of the metal zipper.   2. When closing or opening the metal zipper  2 , the concave surface portions  1221  of the metal teeth  1  at one zipper tape  21  provide a respective space for receiving the outer end edges  131  of the metal teeth  1  at the other zipper tape  21  (see  FIG. 7 ), avoiding friction between the two series of metal teeth  1  and facilitating metal zipper closing or opening operation.   

     While only one embodiment of the present invention has been shown and described, it will be understood that various modifications and changes could be made thereunto without departing from the spirit and scope of the invention disclosed.