Abstract:
A double open end zipper for both end positioning-based luggage includes first and second housing members respectively equipped with an N-shaped plastic strip at the rim thereof, and a double open end zipper including first and second zipper tapes respectively stitched to the N-shaped plastic strips at the first and second housing members in reversed directions with the box and pin of the first zipper tape respectively disposed adjacent to the pin and box of the second zipper tape subject to the guidance of a mark line at each N-shaped plastic strip, a seam allowance constraint block located at an outer rear side of the box of each of the first and second zipper tapes, two zipper sliders respectively coupled to first and second zipper tapes, allowing adjustment of the combined storage capacity defined in between the first and second housing members.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to luggage technology and more particularly, to the fabrication of a double open end zipper for both end positioning-based luggage, which has a seam allowance constraint block provided at an outer rear side of the box of each of the first and second zipper tapes for abutting against or attaching onto the associating N-shaped plastic strip at the first or second housing member before stitching, ensuring accurate control of stitching alignment and stacked stitching quality, preventing friction between the zipper sliders and the respective N-shaped plastic strips, facilitating sliding of the zipper sliders and avoiding stretching of the fabric tape bodies of the first and second zipper tapes. 
         [0003]    2. Description of the Related Art 
         [0004]    In the fabrication of a conventional hard shell luggage, the left and right zipper tapes  71 , 72  of a double open end zipper  7  are respectively stitched to the rims of the first housing member  81  and the second housing member  82  in an asymmetric manner (see reference  7 ′ in  FIG. 1 ). When the two zipper sliders  9  to force the longitudinal series of interlocking teeth of the left zipper tape  71  into engagement with the longitudinal series of interlocking teeth of the right zipper tape  72 , the two longitudinal series of interlocking teeth may not be accurately meshed, causing one of the left and right zipper tapes  71 , 72  to protrude outwardly as the two zipper sliders  9  met up, at this time, the four wheels  83  at the bottom side of the first and second housing members  81 , 82  are not maintained in balance, affecting moving smoothness. At this time, a correction work is necessary. However, if a correction work cannot be performed at this time, the product becomes defective. 
         [0005]    Further, when stitching the left and right zipper tapes  71 , 72  of the double open end zipper  7  to the rims of the first and second housing members  81 ,  82 , a proper seam allowance must be well controlled. Improper control of the seam allowance will affect the sliding smoothness of the zipper sliders  9 . 
         [0006]    Further, according to the aforesaid conventional design, the first housing member  81  and the second housing member  82  are fixedly connected together by a flexible plastic sheet member that is directly stitched to the first housing member  81  and the second housing member  82 . Thus, the first housing member  81  and the second housing member  82  are neither detachable, nor adjustable to expand the total storage capacity. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a double open end zipper for both end positioning-based luggage and its method of fabrication, which achieves accurate stitching of the first and second zipper tapes of the double open end zipper by marking a mark line as a stitching start point for stitching alignment, ensuring accurate engagement between the longitudinal series of teeth at the first zipper tape and the longitudinal series of teeth at the second zipper tape. 
         [0008]    It is another object of the present invention to provide a double open end zipper for both end positioning-based luggage and its method of fabrication, which has a seam allowance constraint block provided at an outer rear side of the box of each of the first and second zipper tapes for abutting against or attaching onto the associating N-shaped plastic strip at the first housing member (lower housing member) or second housing member (upper housing member) before stitching, ensuring accurate control of stitching alignment and stacked stitching quality, preventing friction between the zipper sliders and the respective N-shaped plastic strips, facilitating sliding of the zipper sliders and avoiding stretching of the fabric tape bodies of the first and second zipper tapes. 
         [0009]    It is still another object of the present invention to provide a double open end zipper for both end positioning-based luggage and its method of fabrication, which provides a T-shaped protector detachably mountable in between the first and second housing members to shield the boxes of the first and second zipper tapes, allowing expansion of the combined storage capacity of the first and second housing members and maintaining thee first and second housing members in a balanced manner. 
         [0010]    To achieve these and other objects of the present invention, a double open end zipper for both end positioning-based luggage fabrication method comprises a step of fastening a first zipper tape and a second zipper tape to a first housing member (lower housing member) and a second housing member (upper housing member). This step is achieved by: attaching an N-shaped plastic strip to the rim of the first housing member (lower housing member), and then using a L-type gauge or like length measurement tool means to mark a mark line on the N-shaped plastic strip at the first housing member (lower housing member) as a stitching start point corresponding to the box of the first zipper tape, and then stitching the first zipper tape to the rim of the first housing member (lower housing member) in direction from the box toward the pin to the extent about 1-2 centimeters from the pin, and then coupling one zipper slider to the pin of the first zipper tape and moving the zipper slider to the box of the first zipper tape, and then attaching another N-shaped plastic strip to the rim of the second housing member (upper housing member), and then using the same L-type gauge or like length measurement tool means to mark a mark line on the N-shaped plastic strip at the second housing member upper housing member) as a stitching start point corresponding to the box of the second zipper tape, and then stitching the second zipper tape to the rim of the second housing member (upper housing member) in direction from the box toward the pin to the extent about 1-2 centimeters from the pin, and then coupling the other zipper slider to the pin of the second zipper tape and moving the zipper slider along to the box, and then coupling the zipper slider at the first zipper tape onto the pin of the second zipper tape and the zipper slider at the second zipper tape onto the pin of the first zipper tape. The double open end zipper for both end positioning-based luggage thus made further comprises a T-shaped protector detachably mountable in between the first housing member (lower housing member) and the second housing member (upper housing member) to shield the boxes of the first and second zipper tapes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]      FIG. 1  is a schematic drawing illustrating an opened status of a double open end zipper for both end positioning-based luggage according to the prior art. 
           [0012]      FIG. 2  is a schematic drawing illustrating an opened status of a double open end zipper for both end positioning-based luggage in accordance with a first embodiment of the present invention. 
           [0013]      FIG. 3  corresponds to  FIG. 2 , illustrating the first housing member (lower housing member) and the attached first zipper tape separated from the second housing member (upper housing member) and the attached second zipper tape. 
           [0014]      FIG. 4  is a schematic plain view of a part of the double open end zipper for both end positioning-based luggage in accordance with the first embodiment of the present invention. 
           [0015]      FIG. 5  is an exploded view of a double open end zipper for both end positioning-based luggage in accordance with a second embodiment of the present invention. 
           [0016]      FIG. 6  is a schematic plain view of a part of the double open end zipper for both end positioning-based luggage in accordance with the second embodiment of the present invention. 
           [0017]      FIG. 7  is a schematic enlarged top plain view of a part of the double open end zipper for both end positioning-based luggage in accordance with the second embodiment of the present invention. 
           [0018]      FIG. 8  is a schematic enlarged side view of a part of the double open end zipper for both end positioning-based luggage in accordance with the second embodiment of the present invention. 
           [0019]      FIG. 9  is an elevational exploded view of the T-shaped protector of the double open end zipper for both end positioning-based luggage in accordance with the second embodiment of the present invention. 
           [0020]      FIG. 10  corresponds to  FIG. 7 , illustrating male retaining member and a female retaining member used the T-shaped protector instead of a spring clip. 
           [0021]      FIG. 11  is a schematic drawing of the present invention, illustrating two stopper members respectively detachably fastened to the semi-flexible plastic reinforcing bars of the aforesaid two reinforcing structures. 
           [0022]      FIG. 12  is an exploded view of one reinforcing structure of the double open end zipper for both end positioning-based luggage in accordance with the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The invention provides a double open end zipper for both end positioning-based luggage and a method for the fabrication of the double open end zipper for both end positioning-based luggage. The method for the fabrication of the double open end zipper for both end positioning-based luggage is characterized as follows: 
         [0024]    I: Zipper preparation: As illustrated in  FIG. 3 , prepare a double open end zipper  1  that comprises a first zipper tape  11  having a box  111  located at its one end and a pin  112  located at its opposite end, a second zipper tape  12  having a pin  121  located at its one end corresponding to the box  111  of the first zipper tape  11  and a box  122  at its opposite end corresponding to the pin  112  of the first zipper tape  11 , and two zipper sliders  2 , and then sleeve one zipper slider  2  onto the pin  112  of the first zipper tape  11  and then move the zipper slider  2  along the length of the first zipper tape  11  to the box  11  of the first zipper tape  11 , and then sleeve the other zipper slider  2  onto the pin  121  of the second zipper tape  12  and then move the zipper slider  2  along the length of the second zipper tape  12  to the box  122  of the second zipper tape  12 . 
         [0025]    II: Zipper stitching: Attach an N-shaped plastic strip  13  to the rim of a first housing member (lower housing member)  10  that is selectively made from PC (polycarbonate) or ABS (acrylonitrile-butadiene-styrene) (see  FIG. 4 ), and then use a L-type gauge, L-type carpenter ruler or other length measurement tool  5  to mark a mark line on the N-shaped plastic strip  13  at the first housing member (lower housing member)  10  as a stitching start point corresponding to the box  111  of the first zipper tape  11 , and then stitch the first zipper tape  11  to the rim of the first housing member (lower housing member)  10  in direction from the box  111  of the first zipper tape  11  toward the pin  112  of the first zipper tape  11  to the extent about  1 - 2  centimeters from the pin  112  of the first zipper tape  11  (see  FIG. 3 ), and then couple the zipper slider  2  to the pin  112  of the first zipper tape  11  and move the zipper slider  2  along the length of the first zipper tape  11  to the box  11  of the first zipper tape  11 , and then attach another N-shaped plastic strip  13  to the rim of a second housing member (upper housing member)  20  (see  FIG. 4 ), and then use the same L-type gauge, L-type carpenter ruler or other length measurement tool  5  to mark a mark line on the N-shaped plastic strip  13  at the second housing member (upper housing member)  20  as a stitching start point corresponding to the box  122  of the second zipper tape  12 , and then stitch the second zipper tape  12  to the rim of the first housing member (lower housing member)  10  in direction from the box  122  of the second zipper tape  12  toward the pin  121  of the second zipper tape  12  to the extent about 1-2 centimeters from the pin  121  of the second zipper tape  11  (see  FIG. 3 ), and then couple the zipper slider  2  at the first zipper tape  11  onto the pin  121  of the second zipper tape  12  and the zipper slider  2  at the second zipper tape  12  onto the pin  112  of the first zipper tape  11 , and then move the two zipper sliders  2  in direction toward each other to force the longitudinal series of teeth at the first zipper tape  11  into engagement with the longitudinal series of teeth at the second zipper tape  12  (see  FIG. 2 ) (As an alternate form of the present invention, the first zipper tape  11  can be stitched to the rim of the first housing member (lower housing member)  10  from the pin  112  to the box  111 ; the second zipper tape  12  can be stitched to the rim of the second housing member (upper housing member)  20  from the box  122  to the extent about  1 - 2  centimeters from the pin  121 ). 
         [0026]    III: The invention adopts the technical measures: Draw a mark line as a stitching start point for enabling the first and second zipper tapes  11 , 12  to be respectively and accurately stitched to the first and second housing members  10 , 20  so that the zipper sliders  2  can be moved to force the longitudinal series of teeth at the first zipper tape  11  into engagement with the longitudinal series of teeth at the second zipper tape  12  accurately, preventing misengagement and enhancing the quality and fabrication efficiency. This is a luggage fabrication operation of two-way corresponding positioning configuration arrangement. 
         [0027]    Referring to  FIGS. 5-8 , in a second embodiment of the present invention, spacer blocks seam (allowance constraint blocks)  1111 , 1221  are respectively stitched to the boxes  111 , 122  of the first and second zipper tapes  11 , 12  of the double open end zipper  1  (see  FIG. 5  and  FIG. 6 ), and a T-shaped protector  3  is mountable in between the first and second housing members  10 , 20  to shield the spacer blocks (allowance constraint blocks)  1111 , 1221 . 
         [0028]    If the stitching line on each zipper tape is not well controlled, it will affect the smoothness of the sliding of the zipper slider  2 . The transverse distance of the stitching line from the outer edge of each zipper tape  11  or  12  of the double open end zipper  1  is determined subject to: ½ of the difference between the largest width at one end of the zipper slider  2  and the smallest width at an opposite end of the zipper slider  2 . The difference between the largest width of the zipper slider  2  (at one end of the zipper slider  2 ) and the smallest width of the zipper slider  2  (at the other end of the zipper slider  2 ) is approximately equal to the difference between the width of the box  111 , 122  and the largest width of the zipper slider  2  just because the width of the box  111 , 122  is approximately equal to the smallest width of the zipper slider  2 . The difference between the largest width and the smallest width is divided by 2, and the quotient thus obtained is the minimum value required for single side stitching, and a tolerance about 1-2 mm can be added thereto for allowing free twisting of the zipper slider  2 , i.e., in actual practice, a width allowance corresponding to a protruding part (seam allowance constraint block  1111 , 1221 ) at the end of the box  111 , 112  must be provided for the seam allowance in correcting stitching. This innovative measure prevents friction between the zipper sliders  2  and the N-shaped plastic strips  13 , facilitating sliding of the zipper sliders  2  and avoiding stretching of the fabric tape bodies  110 , 120  of the first and second zipper tapes  11 , 12  (see  FIG. 6 ). Some workers may often neglect to control or could not really understand how to control the seam allowance at the stitching start point, and therefore, it is necessary to attach a seam allowance constraint block  1111 , 1221  at an outer side of the distal end of the box  111 , 122  (see  FIG. 5  and  FIG. 6 ). As illustrated in  FIG. 6 , the seam allowance constraint block  1111 , 1221  is adapted for abutting against or attaching onto the associating N-shaped plastic strip  13  before stitching, ensuring accurate control of stitching alignment and stacked stitching quality. This design of seam allowance constraint block  1111 , 1221  for abutting against or attaching onto the associating N-shaped plastic strip  13  for the control of the seam allowance is a small improvement but it achieves large effects. 
         [0029]    A double open end zipper for both end positioning-based luggage comprises a first housing member (lower housing member)  10  and a second housing member (upper housing member)  20  respectively and selectively made from PC (polycarbonate) or ABS (acrylonitrile-butadiene-styrene), an N-shaped plastic strip  13  attached to a rim of each of the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20 , a double open end zipper  1  that comprises a first zipper tape  11  stitched to and extended around the N-shaped plastic strip  13  at the rim of the first housing member (lower housing member)  10 , the first zipper tape  11  having a box  111  located at one end thereof and a pin  112  located at an opposite end thereof, a second zipper tape  12  stitched to and extended around the N-shaped plastic strip  13  at the rim of the second housing member (upper housing member)  20 , the second zipper tape  12  having a pin  121  located at one end thereof corresponding to the box  111  of the first zipper tape  11  and a box  122  at an opposite end thereof corresponding to the pin  112  of the first zipper tape  11 , two zipper sliders  2  respectively coupled to the first zipper tape  11  and the second zipper tape  12  and movable to open and close the first zipper tape  11  and the second zipper tape  12 , the first zipper tape  11  being stitched to the N-shaped plastic strip  13  at the rim of the first housing member (lower housing member)  10  from the box  111  toward the pin  112  with an area about  1 - 2  cm from the pin  112  remained unstitched, the second zipper tape  12  being stitched to the N-shaped plastic strip  13  at the rim of the second housing member (upper housing member)  20  from the box  122  toward the pin  121  with an area about 1-2 cm from the pin  121  remained unstitched, a first seam allowance constraint block  1111  of a predetermined shape protruded from an outer rear side of the box  111  of the first zipper tape  11 , and a second seam allowance constraint block  1221  of a predetermined shape protruded from an outer rear side of the box  122  of the second zipper tape  12 . 
         [0030]    Further, after installation of the double open end zipper  1  to join the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20 , the luggage thus made can be conveniently opened and closed, and can also be well enclosed after closed the double open end zipper  1 . After stitching of the double open end zipper  1  to the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20 , the area around the gap W is left between the two boxes  111 , 122  (see  FIGS. 7 and 8 ), the unstitched area of the first zipper tape  11  about 1-2 cm from the pin  112  and the unstitched area of the second zipper tape  12  about 1-2 cm from the pin  121  are less strong in structure and must be well protected. Therefore, the invention provides the aforesaid T-shaped protector  3  that is mountable in between the first and second housing members  10 , 20  to shield the boxes  111 , 122 . As illustrated in  FIGS. 7-9 , the T-shaped protector  3  is inserted in between the two boxes  111 , 122  from the outside of the luggage toward the inside thereof. The T-shaped protector  3  comprises a transversely extended and grooved shielding head  31  for shielding the boxes  111 , 122 , a flat shank  32  perpendicularly and downwardly extended from the midpoint of the bottom side of the transversely extended and grooved shielding head  31 , a transverse slot  321  located in the flat shank  32  near a distal end thereof remote from the transversely extended and grooved shielding head  31 , and a spring clip  6  (or any other equivalent retaining means) mounted in the transverse slot  321  for securing the T-shaped protector  3  to the first and second housing members  10 , 20  in a balanced and detachable manner, keeping the first and second housing members  10 , 20  well enclosed. Thus, the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20  are detachable and replaceable, and can be respectively marked with a different totem sign for a respective member in a family. 
         [0031]    Further, as stated above, the flat shank  32  of the T-shaped protector  3  is inserted in between the two boxes  111 , 122  from the outside of the luggage toward the inside thereof with the transversely extended and grooved shielding head  31  disposed outside the luggage to shield the boxes  111 , 122  of the first and second zipper tapes  11 ,  12 , and a the spring clip  6  is mounted in the transverse slot  321  to secure the T-shaped protector  3  to the first and second housing members  10 , 20  in a balanced and detachable manner, keeping the first and second housing members  10 , 20  well enclosed. This T-shaped protector  3  can be conveniently fastened to the luggage in a dismountable manner, enhancing connection stability between the first and second housing members  10 , 20  and holding the first and second housing members  10 , 20  in a well enclosed condition. Further, in the embodiment shown in  FIG. 10 , a male retaining member  6 ′ and a female retaining member  6 ′″ are used to replace the aforesaid spring clip  6  for securing the T-shaped protector  3  to the first and second housing members  10 , 20 . The male retaining member  6 ′ is inserted through the transverse slot  321  on the flat shank  32  of the T-shaped protector  3  and fastened up with the female retaining member  6 ′″ to secure the T-shaped protector  3  to the first and second housing members  10 , 20 . 
         [0032]    The double open end zipper for both end positioning-based luggage further comprises two reinforcing structures, as illustrated in  FIG. 11  and  FIG. 12 . Each reinforcing structure comprises a semi-flexible plastic reinforcing bar  42  that is transversely attached to the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20  on the inside and has two mounting through holes  421  respectively disposed near two distal ends thereof, a first plastic foot member  101  disposed outside the first housing member (lower housing member)  10  and having a threaded stem  102  inserted through the first housing member (lower housing member)  10  and one mounting through hole  421  of the semi-flexible plastic reinforcing bar  42 , a second plastic foot member  201  disposed outside the second housing member (upper housing member)  20  and having a threaded stem  202  inserted through the second housing member (upper housing member)  20  and the other mounting through hole  421  of the semi-flexible plastic reinforcing bar  42 , and two wing nuts  41  respectively attached to the semi-flexible plastic reinforcing bar  42  opposite to the first plastic foot member  101  and the second plastic foot member  201  and respectively threaded onto the threaded stems  102  of the first and second plastic foot members  101 , 201  to secure the semi-flexible plastic reinforcing bar  42 , the first and second plastic foot members  101 , 201  and the first housing member (lower housing member)  10  and the second housing member (upper housing member)  20  firmly together. Further, two stopper members  6 ″ are respectively detachably fastened to the semi-flexible plastic reinforcing bars  42  of the aforesaid two reinforcing structures, as illustrated in  FIG. 11 . Each stopper member  6 ″ has a mounting through hole  60 ″ for the passing of the semi-flexible plastic reinforcing bar  42  of the respective reinforcing structure.