Bonding of an upper and a shell in a shoe
A shoe upper and a shoe shell are attached to one another by molding. The upper is placed on a mold core, which includes a portion resembling a foot and a portion on which the upper fits. A flap provided on the upper extends along at least a portion of a bottom rim of the upper and has opposing interior and exterior sides. A mold is provided around the mold core and the flap so as to define a cavity between the mold and the mold core. The flap extends into the cavity so that both the interior and exterior sides of the flap are exposed within the cavity. A shell material is introduced into the cavity so as to mold the shell material directly around the mold core portion resembling a foot and to cohere the shell material to both the interior and exterior sides of the flap.
This disclosure relates generally to shoes and more particularly to bonding of an upper and a shell in a shoe.
BACKGROUNDShoes provide an important barrier between our feet and the physical world. In many circumstances, such as cold-weather environments, a waterproof shoe is desirable. However, the consumer market for shoes is a highly competitive market, in which buyers demand low prices. Thus, additional shoe features, such as waterproofing, will not lead to commercial success, unless those features can be provided affordably. Because making shoes is a labor-intensive activity, costs are most effectively contained by minimizing the amount of labor needed to add new features to shoes.
SUMMARYAccording to one method, a shoe shell is attached to a shoe upper by molding. The upper is placed on a mold core, which includes a portion resembling a foot and a portion on which the upper fits. A flap provided on the upper extends along at least a portion of a bottom rim of the upper and has opposing interior and exterior sides. A mold is provided around the mold core and the flap so as to define a cavity between the mold and the mold core. The flap extends into the cavity so that both the interior and exterior sides of the flap are exposed within the cavity. A shell material is introduced into the cavity so as to mold the shell material directly around the mold core portion resembling a foot and to cohere the shell material to both the interior and exterior sides of the flap.
According to another method, a shoe shell is attached to a shoe upper without stitching. The upper has opposing interior and exterior sides and a bottom periphery rim for attachment to the shell. The shell has a top periphery rim, which coheres to portions of both the interior and exterior sides of the upper in proximity to the bottom periphery rim of the upper.
A shoe may be made in accordance with either method described in the preceding paragraphs. Regardless of its method of manufacture, a shoe comprises an upper and a shell. The upper has opposing interior and exterior sides and a bottom rim. The shell has an upper rim, which coheres to at least portions of both the interior and exterior sides of the upper in proximity to the bottom rim of the upper, without stitching of the upper to the shell. As used herein, the term “shoe” encompasses all types of footwear, including, for example, boots.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the above-listed drawings, this section describes particular embodiments and their detailed construction and operation. As one skilled in the art will appreciate, certain embodiments may be capable of achieving certain advantages over the known prior art, including some or all of the following: (1) attachment of a shoe shell to an upper without stitching; (2) a waterproof interface between a shoe shell and an upper; (3) simpler and less expensive construction; and (4) greater design freedom by relaxing restrictions on permissible curves and angles imposed by a stitching allowance. These and other advantages of various embodiments will be apparent upon reading the following.
As shown in
The upper 100 may be any material suitable for a shoe upper, such as natural leather, synthetic leather, a textile, or the like. The upper 100 is preferably waterproof, as the interface between it and a shell (not shown in
The upper 100 has two opposing sides: an interior side 140 and an exterior side 150. Along the bottom of the upper 100 is a bottom periphery rim 160. The interior side 140 generally fits snugly against the mold core 110, except along the bottom periphery rim 160, which may be more loosely disposed on the mold core 110. Optionally, jigs, pins, pegs, pinchers and wipers, or the like (not shown) can be fitted between the mold core 110 and the interior side 140 of the upper 100 in the vicinity of the bottom periphery rim 160 to separate the upper 100 from the mold core 110 along the bottom periphery rim 160 or portions thereof. Alternatively or additionally, the bottom periphery rim 160 is or comprises a flap of the upper 100. As will be described in greater detail below, that flap is an area of attachment of the upper to a shell (not shown in
A next step is shown in
When the front mold piece 210 and the rear mold piece 220 contact, they define an interior chamber, in which is typically disposed the mold core 110, or a portion thereof, clad with the upper 100. The interior cavity is defined by an interior wall 240 of the mold 200. A bottom portion of the interior chamber is slightly larger than the foot-like bottom portion 130 of the mold core 110. Thus, when the mold 200 is fully engaged around the mold core 110, there is a cavity or space between the interior wall 240 of the mold 200 and the mold core 110. It is in that cavity where the shell will be formed, as described in further detail below.
Along the interior wall 240 is a ridge 250 positioned to contact and press against the upper 100 somewhat above the flap or bottom periphery rim 160 of the upper 100 when the mold 200 is fully engaged around the mold core 110 clad with the upper 100. The ridge 250 functions to dam the flow of the shell material and retain the shell material in place when it is injection molded, as explained in more detail below. In some cases, it may be helpful to apply an upward force to the mold core 110 and a downward force to the mold 200 to aid in pinching the upper 100 between the mold 200 and the mold core 110 above the flap. (Directional terms, such as “upward” and “downward” are used herein consistently with the orientation of the drawings, to facilitate ready understanding; however, the use of directional terms should not be construed to imply that any particular directional orientation is required; the mold core 110, the upper 100, and the mold 200, for example, may be oriented upside down, sideways, or in any other spatial direction during the manufacturing method; moreover, the directional orientation may change from stage to stage of manufacture.) Alternatively, a gasket or dam may be useful at the external interface between the upper 100 and the mold 200. The mold 200 also preferably has one or more sprues, runners, or flow ports 260 through which shell material can be inserted to form the shell. The number and placement of the flow ports 260 are not critical. The mold 200 is typically made of a metal, such as steel, capable of withstanding the heat associated with an injection molding process.
Other types of flowable or deformable material may not require heating to flow. For example, some materials cure or harden upon mixing (e.g., two-part foams, resins, or epoxies), heating, exposure to ultraviolet light, or other environmental conditions. Such materials may be used as the shell material 300.
Although
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The bulge in the upper 100 shown in
Note that although
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The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations can be made to the details of the above-described embodiments without departing from the underlying principles of the invention. For example, just a portion of the shell may be formed and attached to the upper in the manner described above, so as to permit modular shoe designs and constructions. The scope of the invention should therefore be determined only by the following claims, and their equivalents, in which all terms are to be understood in their broadest reasonable sense unless otherwise indicated.
Claims
1. A method for attaching a shoe upper to a shoe shell material by molding, the method comprising:
- placing the upper on a mold core, which includes a portion resembling a foot and a portion on which the upper fits;
- providing a flap on the upper, the flap extending along at least a portion of a bottom rim of the upper, the flap having opposing interior and exterior sides;
- providing a mold around the mold core and the flap so as to define a cavity between the mold and the mold core, the flap extending into the cavity so that both the interior and exterior sides of the flap are exposed within the cavity; and
- introducing the shell material into the cavity so as to mold the shell material directly around the mold core portion resembling a foot and to cohere the shell material to both the interior and exterior sides of the flap.
2. The method of claim 1, wherein the step of introducing the shell material into the cavity attaches the shell material to the upper in the absence of stitching between the shell material and the upper.
3. The method of claim 1, wherein the step of introducing the shell material into the cavity effectuates a substantially waterproof seal between the upper and the shell material.
4. The method of claim 1, further comprising:
- folding a portion of the flap upon itself to create a bulge on a side of the flap, thereby resulting in a bulged side of the upper.
5. The method of claim 4, wherein the step of introducing the shell material into the cavity comprises:
- cohering the shell material to the bulged side of the upper at a portion of the upper above the bulge.
6. The method of claim 1, wherein the step of introducing the shell material into the cavity comprises:
- injecting the shell material into the cavity.
7. The method of claim 1, wherein the shell material is a thermoplastic material.
8. The method of claim 1, wherein the step of introducing the shell material into the cavity is performed after the step of providing a mold around the mold core and the flap.
9. The method of claim 1, further comprising:
- pressing the mold and the mold core together so as to pinch the upper between the mold and the mold core above the flap.
10. The method of claim 1, further comprising:
- attaching an outsole to the shell material.
11. The method of claim 1, wherein the flap is an integral part of the upper.
12. A shoe made in accordance with the method of claim 1.
13. A method for attaching a shoe shell to a shoe upper without stitching the shell to the upper, the upper having opposing interior and exterior sides and a bottom periphery rim for attachment to the shell, the shell having a top periphery rim, the method comprising:
- cohering the top periphery rim of the shell to portions of both the interior and exterior sides of the upper in proximity to the bottom periphery rim of the upper.
14. The method of claim 13, further comprising:
- providing a bulge on one or more sides of the upper along the bottom periphery rim, thereby resulting in one or more bulged sides of the upper, wherein the cohering step comprises cohering the upper rim of the shell to at least one of the bulged sides of the upper at a portion of the upper above the bulge.
15. The method of claim 14, wherein the providing step comprises:
- folding a portion of the upper upon itself along at least a portion of the bottom periphery rim, whereby the folded portion creates the bulge.
16. The method of claim 13, wherein the cohering step comprises:
- welding the shell to the upper.
17. The method of claim 16, wherein the welding step comprises:
- melting the upper;
- partially mixing the melted upper and the shell together; and
- solidifying the mixed melted upper and the shell.
18. The method of claim 13, further comprising:
- molding the shell.
19. The method of claim 18, wherein the molding step comprises:
- providing a mold core including a portion resembling an ankle and a portion resembling a foot;
- placing the upper on the mold core;
- providing a mold that defines an interior chamber sized to fit at least a bottom portion of the mold core;
- placing the mold generally around at least a bottom portion of the mold core, thereby defining a space between the mold core and the mold, such that a portion of the upper proximate to the bottom periphery rim of the upper extends into the space; and
- introducing into the space a deformable material, whereby the deformable material solidifies, coheres to the portion of the upper extending into the space, and thereby forms the shell.
20. The method of claim 19, wherein the deformable material is a flowable material.
21. The method of claim 20, wherein the deformable material comprises a liquid, and the step of providing the deformable material comprises:
- injecting the liquid into the space.
22. The method of claim 21, wherein the liquid is a thermoplastic material.
23. The method of claim 18, wherein the step of introducing the deformable material is performed after the step of placing the mold generally around the mold core.
24. The method of claim 13 wherein the shell has an interior side facing the mold core and an opposing exterior side, the method further comprising:
- attaching an outsole to the exterior side of the shell.
25. A shoe made in accordance with the method of claim 13.
26. A shoe comprising:
- an upper having opposing interior and exterior sides and a bottom rim;
- a shell having an upper rim, the upper rim being cohered to at least portions of both the interior and exterior sides of the upper in proximity to the bottom rim of the upper without stitching of the upper to the shell.
27. The shoe of claim 26, wherein the upper comprises leather.
28. The shoe of claim 26, wherein the upper comprises a waterproof layer on the interior side and a textile disposed on the exterior side.
29. The shoe of claim 26, wherein the waterproof layer is a waterproof coating.
30. The shoe of claim 26, wherein the waterproof layer is a waterproof membrane.
31. The shoe of claim 30, wherein the waterproof membrane includes a polytetraflouroethylene layer.
32. The shoe of claim 26, wherein the upper rim of the shell comprises a channel along the length of the upper rim, and the portions of the upper are disposed at least partially within the channel.
33. The shoe of claim 26, wherein the shell is formed of a substance, the upper is a fibrous material having fibers, and the substance extends at least partially about at least some of the fibers.
34. The shoe of claim 26, wherein the shell is formed of a substance, the upper is a woven material having woven strands, and the substance extends at least partially about at least some of the strands.
35. The shoe of claim 26, wherein the shell is formed of a substance, the upper is a porous material having pores, and the substance extends at least partially into at least some of the pores.
36. The shoe of claim 26, wherein the shell is formed of a substance, the upper comprises one or more perforations between the exterior and interior sides of the upper in proximity to the bottom rim of the upper, and the substance extends through at least some of the perforations.
37. The shoe of claim 26, wherein the shell is made of a thermoplastic material.
38. The shoe of claim 26, wherein the upper comprises:
- a bulge on one or more sides of the upper along at least a portion of the bottom rim, thereby resulting in at least one bulged side of the upper, wherein the shell extends around the bulge and coheres to a bulged side of the upper on a portion of the upper above the bulge.
39. The shoe of claim 36, wherein the bulge is formed by a fold of a portion of the upper onto itself along at least a portion of the bottom rim of the upper.
40. The shoe of claim 26, wherein the shoe is substantially waterproof along the interface of the upper and the shell.
Type: Application
Filed: Jul 12, 2004
Publication Date: Jan 12, 2006
Inventors: Daniel Laska (Portland, OR), Daniel Bennette (Portland, OR)
Application Number: 10/889,586
International Classification: A43B 1/10 (20060101);