Patent Publication Number: US-2003226282-A1

Title: Footwear having a preformed closed-loop welt structure

Description:
[0001] This application claims priority to Taiwan Patent Application No. 091,208,706, filed on Jun. 11, 2002, entitled, “Reinforced Welt”, which is incorporated by reference in its entirety.  
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] This invention relates to footwear construction, particularly to durable and rugged footwear construction.  
       [0004] 2. Description of Related Art  
       [0005] Footwear worn for outdoor hiking or on rugged surfaces often feature better durability than other types of footwear thanks to their comparatively higher structural and manufacturing standards. The Goodyear Welt Construction is a well-known standard in rugged footwear construction. The Goodyear Welt Construction involves using a welt strip as an intermediary structure for joining an outsole to a shoe upper. FIG. 1 is a side view of portions of a footwear  1  employing the conventional Goodyear Welt Construction, in which the toe section of the footwear  1  is shown in cross-sectional view. The footwear  1  includes a conventional welt strip  2 , an upper  5  (having a vamp  7  and a quarter  9 ), an outsole  12 , and a midsole  13 . The welt strip  2  provides an intermediary structure for joining the outsole  12  to the upper  5 .  
       [0006]FIG. 2 is a perspective view of the conventional welt  2 . The welt  2  is an open-loop strip-like structure made of plastic or leather having two ends  14  and  15 . The welt  2  has a substantially L-shaped cross section having a sidewall  16  and a rib  17  extending from the sidewall  16 . The sidewall  16  has an upper portion  18  above the topside of the rib  17  and a lower portion  19  below the bottom side of the rib  17 . The height “h” of the upper portion  18  is substantially uniform along the length of the welt strip  2 . As shown in FIG. 1, the height of the upper portion  18  is short as compared to the height of the vamp  7  or the quarter  9 . Furthermore, in this particular welt configuration, the height “h” of the upper portion  18  is shorter than the width “w” of the rib  17 . In other words, the surface area of the sidewall  16  is substantially negligible as compared to the surface area of the upper  5 . The welt  2  can also include a groove  21  located on the bottom side of the rib  17  at the junction of the lower portion  19  and the rib  17 .  
       [0007] Referring to FIGS. 1 and 2, the welt  2  facilitates the joining of the outsole  12  to the upper  5 . In accordance with Goodyear Welt Construction, the welt strip  2  is placed along the junction of the outsole  12  and the upper  5 . The welt strip  2  is then coupled to the upper  5  by horizontally machine stitching (i.e., in a direction along the periphery of the upper  5 ) or stapling the lower portion  19  of the sidewall  16  to the upper  5  and/or the insole  13  along the groove  21 . The upper portion  18  is not coupled to the upper  5 . The welt strip  2  is also coupled to the outsole  12  by horizontally machine stitching or stapling the rib  17  of the welt strip  2  to the outsole  12 . The horizontally machine stitching commences from the end  14  of the welt strip  2  and continues around the periphery of the upper-outsole junction until the end  15  is almost joined with the end  14 . FIG. 3 is a bottom perspective view of the footwear  1  showing the ends  14  and  15  of the welt strip  2  almost joined together.  
       [0008] Because the welt  2  has an open-loop strip shape, the two ends  14  and  15  of the strip must inevitably be joined together, resulting in seam  22 . Current Goodyear inseam trimming machines do not allow the welt  2  to be cut and the two ends  14  and  15  to be stitched together smoothly. Consequently, manual operation is required to precut the welt strip  2  to a length slightly longer than the periphery of the upper-outsole junction. FIG. 3 shows the extra length of welt strip  23 . The extra length of welt strip  23  is shown by the dotted line. The welt strip  2  is stitched from the end  14  to almost the other end  15 . Before the ends  14  and  15  are joined, the extra length  23  of welt strip  2  is manually cut and the remaining unstitched welt strip  2  is stitched. It is critical that the ends  14  and  15  be cut so that the ends  14  and  15  match with each other. FIG. 3 shows the break  22  where the ends  14  and  15  meet. This manual operation has caused some obstacles in the streamline automation of the footwear-making process. Thus, it is desirable to have a footwear construction that lends itself to minimal manual operation in the construction process to allow for a more streamlined automation in the footwear-making process.  
       [0009] Wearers of rugged footwear also require a certain amount of water proofing in their footwear. Under current Goodyear Welt Construction, the upper portion  18  of the sidewall  16  and the upper  5  are not coupled together. The lower portion  19  of the sidewall  16  is stitched to the upper  5  along groove  21 . As the conventional welt strip  2  is sewn along the upper  5 , chinks can form between the welt  2  and the upper  5 . Any chinks can render the footwear I pervious to water, especially in light of the fact that the chinks can occur near the bottom of the footwear  1  where there is more chance of water contact. The chinks can reduce the footwear&#39;s durability and life span. As such, it is desirable to have a footwear construction that minimizes chinks in the footwear.  
       [0010] Use of the conventional welt strip in footwear construction is disclosed in U.S. Pat. No. 6,226,895, to McClelland, issued on May 8, 2001, entitled Footwear Construction. McClelland describes the welt strip as being conventional (col.  3 , lines  38 - 54 ) and being manufactured by conventional techniques and apparatus such as extruding the welt from a hard durable rubber material (col.  4 , lines  64 - 66 ), suggesting a welt having a strip shape. The reference discloses stitching the welt by conventional apparatus and techniques, which suggests use of the conventional process of manually precutting an additional length of welt and then manually sizing the ends of the welt just prior to completion. Use of the conventional welt is also disclosed in co-pending U.S. patent application Ser. No. 09/777,130, by Ho, filed Feb. 5, 2001, entitled Footwear with Fixedly Secured Insole for Structural Support.  
       SUMMARY OF THE INVENTION  
       [0011] The present invention is directed to a footwear having a preformed closed-loop welt that lends itself to a footwear-making process that is more streamlined and automated than footwear employing conventional welts. The preformed closed-loop welt of the present invention allows the footwear to be manufactured more durable and water-resistant.  
       [0012] In one aspect of the present invention, the welt is preformed to a closed-loop structure. Unlike conventional welts that are open loop strip-shaped having ends, the welt of the present invention is a formed welt that has no ends. The welt is formed to a continuous closed-loop shaped structure prior to coupling with the footwear upper and outsole. In some aspects of the present invention, the welt is preformed to the closed-loop shape by coupling the ends of the welt prior to coupling the welt to the footwear upper and outsole. In some aspects of the present invention, the welt is preformed to the closed-loop shape having no seams. In some aspects of the present invention, the welt can be specifically sized and shaped to receive a particular footwear or be universally sized and shaped for any particular footwear.  
       [0013] In another aspect of the present invention, the closed-loop welt has a tall sidewall and a rib extending from the tall sidewall, such that the height of the sidewall is longer than the width of the rib. The tall sidewall defines a sufficiently large surface area that provides the welt with a larger contact surface for coupling the sidewall to an upper of the footwear. Additionally, the larger surface area allows aesthetic and functional elements to be defined on the welt. In some aspects of the present invention, the sidewall has a variable height that is taller near the toe and heel sections of the welt. In another aspect of the present invention, the closed-loop welt includes an adhesion layer for facilitating coupling the welt to the footwear.  
       [0014] The present invention is also directed to a method of manufacturing a footwear that is more durable and water-resistant, in which the method lends itself to a more fully automated process. The method includes providing a preformed closed-loop welt, coupling the welt to the upper, and coupling the welt to the outsole. Providing the preformed closed-loop welt permits coupling the welt to the upper and the outsole with conventional stitching means from beginning to end, thus allowing for a continuous automated process. In some aspects of the present invention, coupling the welt to the upper includes bonding the welt to the upper with an adhesive material. The larger surface area of the sidewall provides a larger contact surface for applying the adhesive material between the sidewall and the upper. The bonding step allows the footwear to be manufactured more durable and water-resistant.  
     
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS  
     [0015] The present invention will be more clearly understood when considered in conjunction with the accompanying drawings. In the following drawings, like reference numerals designate like or similar parts throughout the drawings.  
     [0016]FIG. 1 is a side view of portions of a footwear employing the conventional Goodyear Welt Construction, wherein the toe section of the footwear is shown in cross-sectional view.  
     [0017]FIG. 2 is a perspective view of a conventional Goodyear welt. FIG. 3 is a bottom perspective view of the footwear of FIG. 1 showing the ends of the welt strip almost joined together.  
     [0018]FIG. 4 is a side view of a footwear having a preformed closed-loop welt in accordance with one embodiment of the present invention.  
     [0019]FIG. 5 is a perspective view of the preformed closed-loop welt in accordance with one embodiment of the present invention.  
     [0020]FIG. 6 is a side view of the preformed closed-loop welt shown in FIG. 5.  
     [0021]FIG. 7 is a bottom view of the preformed closed-loop welt shown in FIG. 5.  
     [0022]FIG. 8 is a side view of the footwear shown in FIG. 4, in which the welt is shown in cross-sectional view.  
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
     [0023] The present description is the best contemplated mode of carrying out the invention. This description is made for the purpose of illustrating general principles of the invention and should not be taken in a limiting sense.  
     [0024]FIG. 4 is a side view of a footwear  25  having a preformed closed-loop welt  30  in accordance with one embodiment of the present invention. The footwear  25  includes an upper  60 , an outsole  70 , and the preformed closed-loop welt  30 . The upper  60  includes a vamp  63  and a quarter  66 . The upper  60  is sized and shaped to receive a foot of a wearer and to secure the foot of the wearer within the upper  60 . The outsole  70  is coupled to the upper  60  at an upper-outsole junction  72 . The outsole  70  is adapted to support the weight of the wearer on top and is capable of traction against rough outside contact surfaces on bottom. The outsole  70  can be formed from a substantially wear resistant material, such as high-density carbon rubber.  
     [0025]FIG. 5 is a top perspective view of the preformed closed-loop welt  30  in accordance with one embodiment of the present invention. The preformed closed-loop welt  30  includes a tall sidewall  32  and a rib  34  extending from the sidewall  32 . FIG. 6 is a side view of the preformed closed-loop welt  30  shown in FIG. 5. The sidewall  32  has an upper portion  35  above the rib  34  and a lower portion  46  below the rib  34 . The sidewall  32  is tall in that the height “h” of the upper portion  35  is substantially greater than the width “w” of the rib  34  (shown in FIG. 5). Accordingly, the tall sidewall  32  defines a substantially large surface area, which enhances the contact surface the sidewall  32  has with the upper  60 .  
     [0026] Referring to FIG. &#39;s  5  and  6 , the height “h” of the upper portion  35  is variable along the periphery of the welt  30 . For example, the height of the upper portion  35  at a toe section  36  and a heel section  37  is taller than at a middle section  38 . As such, the surface area of the upper portion  35  at the toe and heel sections  36  and  37  are greater than at the middle section  38 . The upper portion  35  at the toe and heel section  36  and  37  is sized and shaped such that the welt  30  can include any number of aesthetic and/or functional elements. For example, at the toe section  36 , the upper portion  35  can include an anti-friction corrugated surface  39 . The added surface area also provides the welt  30  with a larger contact surface with the upper  60  to facilitate the upper portion  35  being coupled to the upper  60  during construction of the footwear  25 . In alternative embodiments of the present invention (not shown), the height of the upper portion can be substantially uniform along the periphery of the welt or can be taller at the middle section than at the other sections of the welt.  
     [0027] In certain embodiments of the present invention, the welt  30  is preformed to the relative shape of the upper  60 . For example, the vamp  63  and the quarter  66  portions of the upper  60  have a slight curved or arched profile. As shown in FIG. 6, the toe and heel sections of the welt  36  and  37  are preformed having substantially the same relative curved profile. The formed shape of the sidewall  32  facilitates securely coupling the welt  30  to the upper  60  and minimizes the formation of chinks between the upper  60  and the sidewall  32 .  
     [0028]FIG. 7 is a bottom view of the preformed closed-loop welt  30  shown in FIG. 5. FIGS. 5 and 6 show the rib  34  extending from the sidewall  32 . The width “w” of the rib  34  is substantially uniform along the periphery of the welt  30 . The rib  34  can be shaped and sized to coextend with the periphery of the outsole  70 . As will be discussed below, the rib  34  provides an intermediary structure for coupling the upper  60  to the outsole  70 .  
     [0029] Referring to FIG. &#39;s  5  through  7 , the seamless welt  30  can include grooves  40  and  42 . The groove  40  is defined in the upper portion  35  of the sidewall  32  and is provided substantially along the toe section  36 . Alternatively, this groove can be provided substantially along the whole periphery of the welt (not shown). The groove  40  is adapted to receive a stitching  44  (shown in FIG. 4) for coupling the welt  30 , and more specifically the upper portion  35  of the sidewall  32 , to the upper  60 . The groove  42  is defined at the junction of the lower portion  46  and the rib  34 . The groove  42  can be provided substantially along the toe section  36  (as shown in FIG. 7), substantially along the heel section  37 , or substantially along the whole periphery of the welt (not shown). The groove  42  is likewise adapted to receive a stitching for coupling the welt  30 , and more specifically the lower portion  46 , to the upper  60 .  
     [0030] Referring to FIG. 6, the rib  34  extends from the sidewall  32  such that the lower portion  46  of the sidewall  32  extends below the bottom side of the rib  34 . The lower portion  46  of the sidewall  32  provides a structure for coupling the welt  30  to the upper  60 . The lower portion  46  and the groove  42  (shown in FIG. 7) facilitate stitching the welt  30  to the upper  60 .  
     [0031] As mentioned herein, the conventional Goodyear welt  2  (shown in FIG. 2) is in an open-loop strip having the two ends  14  and  15 . In the conventional footwear-making process, the welt strip  2  is machined stitched around the periphery of the footwear  1  until the ends  14  and  15  almost meet. At this point in the process, one end  15  of the welt strip  2  is manually cut to match the other end  14  so that the ends  14  and  15  can be joined. Conventional Goodyear inseam trimming machines do not allow for a smooth cutting and joining of the welt strip ends  14  and  15 . The seam or break  22  is formed at the junction where the two ends  14  and  15  of the welt strip  2  meet.  
     [0032] In contradistinction, the welt  30  of the present invention is in a preformed closed-loop configuration. In other words, the welt  30  is preformed having no seams or breaks and the material of the welt  30  is not joined at a seam to form the ring-shaped structure. The welt  30  is preformed as a continuous loop-shaped structure. As will be described below, the welt  30  has no ends that would require joinder of the ends in the footwear construction process. In some embodiments of the present invention, the welt  30  is preformed by coupling ends of the welt material into the closed-loop shape. The ends of the welt material can be coupled by an adhesive material, a staple, a stitching, or other coupling means allowing for secured coupling of the ends. In some embodiments of the present invention, the welt  30  is preformed having no seams.  
     [0033] In some embodiments of the present invention, the welt  30  is sized and shaped to receive the periphery of the upper-outsole junction. For instance, the welt  30  can be sized for a specific footwear size. Also, the welt  30  can be universally shaped for either a left or right foot construction (e.g., in a flexible circular ring), or can be specifically shaped for either left or right foot construction. In some embodiments of the present invention, the welt  30  is sized and shaped to snugly fit about the periphery of the upper-outsole junction  72 . In other words, the welt  30  is slightly undersized but is capable of being stretched slightly when being stitched.  
     [0034] The preformed closed-loop welt  30  allows for a more streamlined footwear construction process. In one embodiment of the present invention, a method for constructing a footwear includes providing a preformed closed-loop welt  30 , coupling the welt  30  to the upper  60 , and coupling the welt  30  to the outsole  70 .  
     [0035] A preformed welt  30  is selected for the particular size and shape of the footwear under construction. The welt  30  can be selected so that the welt  30  snugly fits the periphery of the upper-outsole junction  72 . Because the welt material may stretch as the welt  30  is being stitched, selecting the welt  30  so that it is undersized or snugly fitting the upper-outsole junction  72  minimizes the formation of chinks during the stitching process.  
     [0036] The welt  30  provides an intermediary structure for coupling the upper  60  to the outsole  70 . FIG. 8 is a side view of the footwear  25  shown in FIG. 4, in which the welt  30  is shown in cross-sectional view. The welt  30  is coupled to the upper  60  by stitching the sidewall  32  to the upper  60  with treated cotton twine  48  and  50 . The sidewall  32  can be stitched along grooves  40  and  42 , which are adapted to receive the stitching  48  and  50 . The upper portion  35  is stitched to the upper  60  along groove  40 . The lower portion  46  is also stitched to the upper  60  along groove  42 . By stitching the sidewall  32  at both the upper portion  35  and the lower portion  46 , the welt  30  can be more securely coupled to the upper  60 , which can result in the footwear  25  being manufactured more durable and rugged. The sidewall  32  being tall facilitates coupling the sidewall  32  to the upper  60  at both the upper portion  35  and the lower portion  46 . The welt  30  can be stitched with stitching means well known in the art, such as a Jupiter brand welt-stitching machine. Alternatively, the sidewall  32  can be stapled or nailed to the upper  60 .  
     [0037] In certain embodiments of the method, coupling the welt  30  to the upper  60  can include bonding the welt  30  to the upper  60  with an adhesive material. The welt  30  can include an adhesive material layer  51  (shown in FIG. 5). The adhesive material layer  51  can be an adhesive material well known in the art that allows for sufficient adhesion between the materials of the upper  60  and the welt  30 . The adhesive material layer  51  can be preformed on the welt  30  or can be applied just prior to fitting the welt  30  to the upper-outsole junction  72 . The adhesive material layer can be provided on the inner side of the sidewall  32  as shown in FIG. 5. The tall sidewall  32  is sized and shaped to define a contact surface with the upper  60  that allows for effective adhesion with the upper  60 . The adhesive material can enhance the bond between the welt  30  and the upper  60  to more securely couple the welt  30  to the upper  60 , and can minimize the formation of chinks between the sidewall  32  and the upper  60 , which can render the footwear  25  less water-resistant.  
     [0038] The outsole  70  is also coupled to the welt  30 . The outsole  70  is coupled to the welt  30  by stitching the rib  34  to the outsole  70  with twine  49 . The welt  30  can be stitched substantially along the periphery of the rib  34  or along portions of the periphery of the rib  34 . The welt  30  can be stitched with stitching means well known in the art, such as a Jupiter brand welt-stitching machine. Alternatively, the rib  34  can be stapled or nailed to the outsole  70 .  
     [0039] The preformed closed-loop welt  30  of the present invention lends itself to a seemingly streamlined footwear construction process. Because the welt  30  is preformed to the size and shape of the particular footwear  25  under construction, there is no manual welt precutting and sizing steps needed in the footwear-making process. The welt  30  does not have ends that would require any additional manual cutting and sizing in the construction process. The welt  30  can be fitted over the upper-outsole junction  72  and stitched in place. The entire stitching process can be entirely completed by conventional inseam trimming machines. The process of stitching the welt  30  to the upper  60  and to the outsole  70  is substantially uninterrupted, which can result in a more streamlined and automated footwear-making process, which in turn results in reducing the manufacturing time.  
     [0040] The welt  30  also provides footwear manufacturers with greater latitude in designing the footwear  25  with aesthetic and functional elements on the welt  30 . The sidewall  32  of the welt  30  is sized and shaped such that the sidewall  32  allows for a wider range of aesthetic and functional elements to be defined on the welt  30 . FIG. 4 shows elements  36  and  37  defined on the sidewall  32 . Elements  36  and  37  can be an aesthetic and/or functional element such as an anti-friction corrugated surface.  
     [0041] While the invention has been described in detail with respect to the illustrated embodiments in accordance therewith, it will be apparent to those skilled in the art that various changes, modifications, substitutions, alterations and improvement may be made without departing from the scope and spirit of the invention as defined by the appended claims.