Footwear closure system with integrally molded hooks

Abstract

A footwear article with a hook and loop fastening system, wherein the hooks are a field of injection molded hooks. The injection molded hooks can be integral with a wall of the footwear article, such as the shell of a skate or ski boot, or the hooks can be formed on an injection molded subassembly that is assembled into the footwear article.

Description

[0001] This application claims the benefit of provisional patent application Serial No. 60/436,069, filed Dec. 23, 2002, under 35 U.S.C. .sctn. 119.

FIELD OF THE INVENTION

[0002] This invention relates to a novel footwear closure system that uses hook and loop fasteners to secure different kinds of footwear. In particular, the hook portion is integrally molded into a plastic portion of the footwear assembly, thereby eliminating the need for a separate and distinct hook portion that would otherwise have to be attached to the footwear in a separate manufacturing step.

BACKGROUND OF THE INVENTION

[0003] Hook and loop fasteners, such as those sold under the trademark VELCRO, have been used for many years in different products. Such hook and loop fasteners generally comprise two components. Each component has a flexible backing material having a surface thereon. One surface comprises a field of resilient hooks, while the other comprises a short-pile, looped fabric. As the two fastening surfaces are pressed together, the hooks releasably engage the loops, thus releasably holding the fastening materials together. The fastening surfaces are separated by pulling the fastening materials apart with sufficient force to cause the resilient hooks to straighten sufficiently to come out of engagement with the loops.

[0004] There is commercially available footwear that uses hook and loop fasteners in lieu of laces or other means for securing the footwear. The typical application has one or more straps containing both hook and loop sections that pass through a D-ring and back on to itself to secure the footwear. One example of footwear using hook and loop fasteners is described in U.S. Pat. No. 4,282,657, where the hook and loop fasteners were used as a heel restraint in a shoe, making it easy to adjust for and maintain the precise tension desired at the wearer's heel by providing a sturdy, adjustable heel restraint and stabilizer to independently control the tension on the heel section of the shoe. U.S. Pat. No. 4,486,965 describes a closure system comprising overlapping straps using hook and loop fasteners with strap receiving openings to permit the overlapping, thereby eliminating the need for laces on the shoe. U.S. Pat. No. 4,270,285 describes a shoe having an adjustable and flexible closure assembly utilizing hook and loop-type fastening means in combination with an elastic instep-gore or elastic side-gores. This permits the wearer to easily pull the uppers of the shoe inwardly and simultaneously to the precise desired tautness and fasten the shoe, using only one hand. U.S. Pat. No. 3,327,410 describes a flexible ankle brace for a shoe, said brace being attached to the shoe sole beneath the arch of the foot and including extensions on opposite sides of the sole of sufficient length to encircle the ankle and that portion of the leg immediately below the ankle, the extensions having terminal end fastener means.

[0005] All of the prior methods of using hook and loop fasteners to fasten footwear require the use of a separate hook section that has to be glued, stitched or fastened in some way to the main body of the footwear or its parts. The need for a separate hook section adds to the total number of parts needed and increases the complexity of the prior art. Also, there are additional labor costs involved in attaching the hook section to the footwear.

[0006] It is thus one object of the invention to provide a hook and loop footwear fastening system that is simpler in construction than prior art systems.

[0007] It is another object of the invention to provide a hook and loop footwear fastening system that requires less time and labor to manufacture than prior art systems.

[0008] It is still another object of the invention to provide a hook and loop footwear fastening system that can reduce or eliminate adhesives or stitching of the fastening system components.

[0009] It is yet another object of the invention to provide a hook and loop fastening system that is easier for the wearer to operate than prior art systems.

[0010] Other objects of and advantages of the invention will become apparent during the course of the detailed description that is part of this application.

SUMMARY OF THE INVENTION

[0011] The present invention relates to a novel footwear closure system comprising a hook bearing member and a loop bearing member to secure the footwear. In a preferred embodiment of the invention, the hook bearing member comprises a field of spaced rows of hooks, preferably along the length of the hook bearing member. However, unlike prior art in the field, the hook bearing member in the present invention is integrally injection-molded into a plastic portion of the footwear assembly. The footwear closure system also may feature an integral (as opposed to a separate) D-ring or formed slot used for looping the loop-bearing closure strap. The closure system may comprise one or more separate parts that are attached to the footwear during the assembly process, or in some cases, may be integrated into the design of the footwear itself, eliminating the need for additional subassembly parts.

[0012] A cooperative loop bearing member or strap engages the integrally molded hooks, thereby securing the footwear to the user. The loop bearing member or strap may include a retaining tab designed to prevent it from pulling back through the D-ring or slot when the closure system is released. This keeps the loop bearing member in a ready position, eliminating the need to guide it through the D-ring or slot each time. The retaining tab may be formed either integrally with the loop bearing member, or separately as an additional structure. The loop bearing member may be attached to the footwear or subassembly by conventional means which include sewing, welding, laminating or adhesives. It may also be attached to the subassembly or footwear by engagement to another field of integrally molded hooks.

[0013] The thermoplastic material, preferably polypropylene, used for injection-molding the integrally-formed hooks has a memory sufficient to cause the hooks to return substantially to their original position after being removed from the mold, and yet has sufficient flexibility to allow the hooks to bend during removal from the mold and during engagement and release with the attached strap loops. The hooks can be molded by the method described in U.S. Pat. No. 5,656,226, which is incorporated here by reference.

[0014] In the present invention, by virtue of the hooks being integrally molded into the closure system by injection molding, the part can have a variable thickness to meet specific design criteria. For example, the D-rings could have a thicker section to provide strength, whereas other areas might be very thin to allow flexibility and conformability to ergonomic design.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] These and other objects of the present invention will be more fully understood in conjunction with the detailed description and the accompanying drawings in which like numerals represent like elements and in which:

[0016] FIG. 1 is a view of a unitary embodiment of the closure system of the invention laid out flat along its longitudinal axis, with the bottom side facing up.

[0017] FIG. 2 is a top perspective view of a shoe with a footwear closure system of the present invention in the open position;

[0018] FIG. 3 is a top perspective view of a shoe with the footwear closure system of FIG. 1 in the closed position;

[0019] FIG. 4 is a cross-sectional view taken through line 4-4 of FIG. 1.

[0020] FIG. 5 is a perspective view of an alternative embodiment of the invention wherein the field of injection molded hooks is integral with a wall of the shoe.

[0021] FIG. 6 is a perspective view of the medial side of an in-line skate incorporating the closure system of the instant invention.

[0022] FIG. 7 is a perspective view of the lateral side of an in-skate incorporating the closure system of the instant invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0023] The novel closure system is described herein as used with many kinds of footwear including shoes, athletic shoes, skates, ski boots, and any other footwear that may employ the use of plastics or hook and loop fasteners.

[0024] FIG. 1 is a view of the bottom side of an injection molded subassembly 10 suitable for use in a footwear closure system of the instant invention. Subassembly 10 comprises a substantially flat body member 13 having a medial side 15 and a lateral side 17. Substantially flat body member 13 has a bottom or outwardly facing surface 11 and a top or inwardly facing surface 16. Extending from medial side 15 are two medial flaps 31, each medial flap 31 having at its distal end a slot 12. Each slot 12 is sized and dimensioned to receive a cooperative loop bearing member, as described more fully below.

[0025] Extending from lateral side 17 are two lateral flaps 19. Each lateral flap 19 has on the outwardly facing surface 11 thereof a field of integrally molded hooks 18. The hooks can be single tipped hooks or double tipped hooks. The hooks can all face in the same direction, or in alternating directions, or in any pattern that is desirable for a particular end use. Each lateral flap 19 also supports a cooperative loop bearing member 20. As best seen in FIG. 4, each cooperative loop bearing member 20 is advantageously configured as a flexible strap having a smooth side 21 and an opposed loop bearing side 22. Each loop bearing member 20 has a first end 23 for fixed operative attachment to inner surface 16 of lateral flap 19, and a second end 24 for releasable engagement with field of hooks 18, as described more fully below. Each lateral flap 19 is provided at its distal end with a slit 25 of sufficient length to accommodate the width of first end 23 of loop bearing member 20.

[0026] As illustrated in FIG. 4, first end 23 of loop bearing member 20 passes through slit 25 in the distal end of lateral flap 19, and the loop bearing side 22 of first end 23 is fixedly attached to the inner surface 16 of lateral flap 19. In one embodiment of the invention, if loop bearing member 20 has loops over the entire area of loop bearing side 22, then inner surface 16 of lateral flap 19 can be provided with its own field of integrally molded hooks 28 for operative fixed engagement with the loops on loop bearing side 22 of first end 23. This embodiment is illustrated in cross section in FIG. 4. Alternatively, side 22 of first end 23 can be bonded to surface 16 of lateral flap 19 by adhesives, laminating, welding, mechanical means such as rivets or stitching, or other equivalent means.

[0027] Second end 24 of loop bearing member 20 is provided with a field of loops over at least an area 29 of loop bearing side 22. In a preferred embodiment, second end 24 is wider than first end 23, and is provided with detents 26, for reasons explained below

[0028] FIG. 2 is a top perspective view of a shoe provided with subassembly 10 of FIG. 1 shown in the unsecured position. It may be seen that subassembly 10 advantageously provides a single, continuous structure that passes through the body of the shoe along the shoe's transverse axis, preferably passing between the outer sole and in-sole, and preferably without penetrating the sole. This feature of a preferred embodiment is not necessary for all embodiments. Loop bearing member 20 remains attached at its first end 23 to the inner surface 16 of lateral flap 19, and passes through slot 12 of medial flap 31. Second end 24 is prevented from slipping back through slot 31 by detents 26 when the user is either putting the shoe on or is taking it off. This enables the user to secure or remove the shoe with one hand rather than having to use both. In the absence of the detents 26, the end 24 would slip out through the slot 12 and a user would have to slide it back through the slot 12 every time he wanted to use the shoe.

[0029] FIG. 3 illustrates the embodiment of FIG. 1 but with the footwear closure system in the closed position. To secure the shoe, the second end 24 of the loop bearing member 20 is pulled toward the lateral direction until the user feels that the fit is sufficiently tight. When the desired fit is achieved, the second end 24 is then pulled downward towards the field of injection-molded hooks 18. Slot 12, therefore, essentially functions as the point at which the loop bearing member 20 changes direction, and folds over back onto itself. The area of loops 29 is then placed over the field of injection-molded hooks 18 to engage the hooks, thereby securing the shoe.

[0030] The preferred design contemplates that distal ends of medial flaps 31 having slots 12 therein can be molded thicker for added strength, while the remaining portions of body member 13, optionally including the proximal ends of flaps 31 and lateral flaps 19 can be molded thinner for added flexibility.

[0031] While subassembly 10 has been described as a unitary device, the present invention is not so limited. For example, an injection molded part with a field of hooks thereon and corresponding only to the structure of lateral flaps 19 can be assembled onto the external lateral side of a shoe by other means, without passing completely between the outer sole and in-sole of the shoe. Alternatively, if the footwear upper comprises an injection molded component, or a component formed by other molding means capable of integrally forming a field of hooks, the field of hooks can be integrally formed during the molding of that component, which is then assembled into footwear. In such embodiments, the cooperative loop bearing member can be assembled into the footwear by conventional means. Such an embodiment is illustrated in FIG. 5. The shoe upper is made of a moldable plastic material. D-rings 131 each having a slot 112 are integrally molded into the shoe upper. Fields of hooks 118 are integrally formed into the shoe upper. Cooperative loop bearing member 114 having loop bearing surface 122 is fixedly secured at one end to the upper by means such as stitching, adhesives, welding, or engagement with a second field of hooks [not shown] formed on the shoe upper. The loop bearing member 114 has a second end 124 with a field of loops 129 that can engage field of hooks 118 to secure the shoe on the wearer.

[0032] The footwear fastening system of the instant invention is also not limited to "gym shoe" type footwear as illustrate in FIGS. 2, 3 and 5, but is especially suitable for other types of footwear that can incorporate injection molded components, or molded by other methods that allow the integral molding of a field of hooks. Such footwear can include, for example, in-line roller skates, ice skates, ski boots, and snowboarding boots. FIGS. 6-7 illustrate medial and lateral views, respectively, of an in-line roller skate having a fastening system of the instant invention using a field of injection molded hooks as a component thereof. As illustrated, in-line skate 50 includes an injection-molded boot portion 51, having disposed on its lateral side integrally molded fields of hooks 53a, 53b. Each field of hooks 53a, 53b has associated therewith a cooperative loop bearing strap 55a, 55b, one end of which is fixedly secured adjacent the field of hooks such as by rivet 56 or other suitable mechanical means. Each cooperative loop bearing strap 55a, 55b has associated therewith a cooperative D-ring or slot 57a, 57b, which can be mounted to boot 51 by a mechanical rivet, or which can be integrally molded into boot 51. Optionally, the free end of each strap 55a, 55b can be provided with detents 59 to prevent the end of the strap from slipping back through D-ring or slot 57a, 57b. To use the illustrated in-line skate, the user can simply position a foot inside the skate boot, pull the straps through the D-rings in the medial direction, pull the straps back in the lateral direction until the desired tightness of fit is obtained, and press the loop-bearing free ends of the straps against the integral field of hooks to secure the straps. To release the straps, the sued simply pulls up on the ends of the straps. In the illustrated embodiment, strap 55a is shown in the unsecured position and strap 55b is shown in the secured position. These embodiments are illustrated by way of example and not by way of limitation.

[0033] Thus, there has been described a novel closure system for footwear wherein the system has a field of injection-molded hooks integrally formed in any predetermined area on the device to receive loops on a strap and retention tab, for releasably engaging the straps. The thermoplastic material used for injection-molding the integrally-formed hooks, preferably polypropylene, has a memory sufficient to cause the hooks to return substantially to their original positions after being removed from the mold and sufficient flexibility to allow the hooks to bend during removal from the mold and during release of the attached strap loops.

[0034] The hook bearing component of the fastening system of the instant invention with a field of hooks integrally formed on a portion thereof can be made by injection molding in accordance with the methods disclosed in the aforementioned patents U.S. Pat. No. 5,368,549, U.S. Pat. No. 5,656,226, and U.S. Re. 37,338. As disclosed therein, the injection molded hooks will have a radius and geometry that will promote the ejection of the hooks from the injection mold, while still maintaining the desired fastening function. The hooks will straighten momentarily as they are removed from the injection mold. The injection molded component is made of a thermoplastic material that has sufficient flexibility to allow the hooks to straighten during removal from the mold and during subsequent release from a field of loops, yet has a memory sufficient to return to substantially the original hook shape and geometry. A material that is too rigid or brittle would snap off during such flexing. On the other hand, a material that is too soft would lack the structural rigidity required for the hooks to function as a fastener. Suitable thermoplastic materials include but are not limited to polypropylene and polyurethane materials having the desired balance of flexibility and shape memory. The polypropylene can be, for example, an unfilled polyester blend of 50% homopolymer and 50% copolymer having melt flow index of 22 g/10 min and a flex modulus from 130,000 to 150,000 psi. Another suitable polypropylene material is sold by Washington Penn Plastic Company of Washington, Pa. as product PPC3CF1, having a melt flow index of 11.6 g/10 min.; a notched Izod impact strength of 3.1 ft-lbs./in., a tensile strength of 3000 psi, and a flex modulus of 163,300 psi.

[0035] Other propylene based resins that have been found suitable for use in forming molded hooks include Atofina polypropylene PPC 5660, having a melt flow index of 7, and a flex modulus of about 175,000 psi; various resins sold under the name "Pro-fax" by Basell, and having melt flow index values ranging from 18 to 35 and flex modulus values ranging from 150,000 to 200,000 psi; propylene copolymers sold by BP Amoco under the names Acclear.RTM. 8949 and Acctuf.RTM..RTM. impact copolymer 3934.times., having melt flow index values of 35 and 100, and flex modulus values of 190,000 psi and 250,000 psi, respectively; resins sold by Dow Plastics under the names Inspire C703-35U and Inspire C719-35RN HP, both having a melt flow index of 35, and flex modulus values of 180,000 psi and 160,000 psi, respectively; Exxtral.RTM. BMT 106 polypropylene impact copolymer, sold by ExxonMobil Chemical, having a melt index of 8 and flex modulus of about 218,000 psi; and, long glass fiber reinforced polypropylenes sold by StaMax, resin 30YM240/10010 having a flex modulus of about 856,000 psi, and resin 40YM240/10010 having a flex modulus of about 1,140,000 psi. With long glass fiber reinforced polypropylenes having very high flex modulus values, it is believed that the glass fibers do not migrate into the hook cavities of the mold, so that the integrally molded hooks are made up of only the polypropylene component of the resin. This gives the unexpected result of a field of flexible hooks integrally molded on a surface of a very strong, rigid molded object.

[0036] Resins other than propylene based resins also can be suitable for use in the manufacture of the molded integral hooks of the present invention. Such resins can include high impact polystyrene, acrylonitrile-butadiene-styrene, nylon, high density polyethylene, linear low density polyethylene, polycarbonate, and thermoplastic olefin resins. Melt index has been found to range from 1 to 100, and flex modulus values values have been found to range from under 30,000 to over 1,138,000. The melt index values and flex modulus values that will work depend on the particular resin chosen. Specific resins include high impact polystyrene API 550 from American Polymers, having a melt flow index of 8 and a flex modulus of 280,000 psi; acrylonitrile-butadiene-styrene, including ABS 9501 UHI from Diamond Polymers, having a melt flow index of 1 and a flex modulus of about 295,000 psi, and Starex ABS SD-0150, sold by Samsung, and having a flex modulus of 420,000 psi; nylon, including Akulon.RTM. K224-PG2U Nylon 6, sold by DSM Engineering and having a flex modulus of about 580,000 psi, and Celanese nylon 6/6 1000 sold by Ticona, and having a flex modulus of about 420,000; high density polyethylene Alathong H 5618, sold by Equistar Chemicals having a melt flow index of 18; linear low density polyethylene Petrothene.RTM. GA 564-000 sold by Equistar Chemicals and having a melt flow index of 21; polycarbonate Lexan ML499 1 R sold by General Electric, having a melt flow index of about 300,000; and thermoplastic olefin polymer Ecobarrier 1B00-2614 TP, having a melt index of 4 and a flex modulus of about 26,000. For polymers having such low flex modulus values, it may be necessary or desirable to use a thicker hook shape to provide a hook that is stiff enough and strong enough to provide the desired closure properties.

[0037] As further disclosed in the aforementioned patents, an apparatus for making the injection molded hook bearing component comprises a mold for forming the component, the mold having a recess in at least one predetermined area thereof, and means in the recess for simultaneously and integrally forming a field of injection molded hooks during the injection molding process. The field of hooks has a length and a width, the hooks being interspersed in both the length and width of the field. The means in the recess for forming the hooks has a plurality of hook shaped cavities. The means is in unitary assembly during the injection molding of the insert, and is maintained in unitary assembly during the removal of the injection molded insert therefrom. In a preferred embodiment, the means in the recess for forming the hooks during the injection molding process is an assembly of stacked plates, each plate having a plurality of hook shaped cavities formed in one edge thereof. In a most preferred embodiment, the plates having the hook shaped cavities alternate in the stack with plates called spacers, which have no hook shaped cavities. The spacer plates can have width less than, equal to, or greater than the plates with the hook shaped cavities.

[0038] In still another embodiment, the molded hooks can be included in the plastic molded parts of the footwear as pre-made mold inserts, as described in co-pending patent application "Injection Molded Fastening Article for Use as a Mold Insert" filed on even date herewith by the same inventor and assigned to the same assignee. As described therein, a mold insert is first provided, the mold insert being an article having a field of integrally formed hooks on at least a first surface thereof, and having a second surface opposite the first surface. The insert is then fitted into a recess in a mold of the desired final article, with the first surface having the field of hooks thereon facing the mold exterior and the second surface of the mold insert facing the interior of the mold. The molding process is then carried out. The plastic of the resulting molded article surrounds the second surface of the mold insert, such that the mold insert becomes integral with the resultant molded article. The hooks of the injection molded article are protected from the heat and pressure of the mold. The molding process by which the resultant molded article is made can be injection molding, compression molding, rotational molding, blow molding, foam molding and other known molding techniques. The instant invention is also applicable to molding processes in which a material is dispersed inside a mold be means such as a spray gun or a trowel, as in the manufacture of fiberglass articles.

[0039] The foregoing specification describes only the embodiment of the invention shown and/or described. Other embodiments may be articulated as well. The terms and expressions used, therefore, serve only to describe the invention by example and not to limit the invention. It is expected that others will perceive differences which, while different from the foregoing, do not depart from the scope of the invention herein described and claimed. In particular, any of the specific constructional elements described may be replaced by any other known element having equivalent function.

Claims

What is claimed is:

1. An article of footwear having a closure system, the closure system comprising a plastic portion, the plastic portion having a first field of hooks injection molded therein, said closure system further including a cooperative loop-bearing member for releasable engagement with said field of injection molded hooks.

2. The footwear article of claim 1 wherein said article is selected from the group consisting of a shoe, an athletic shoe, a boot, a ski boot, and a skate.

3. The footwear article of claim 1 wherein said plastic portion having said first field of injection molded hooks is integral with a wall of said footwear article.

4. The footwear article of claim 1 comprising an injection molded subassembly assembled into said footwear article, and wherein said first field of injection molded hooks is formed on a portion of said subassembly.

5. The footwear article of claim 4 wherein said subassembly has a first end and a second end and first and second opposing surfaces, such that when assembled into said footwear article said first end is on a first lateral side of the footwear and said second end is on the other lateral side of said footwear, said first field of hooks being injection molded near one end of said subassembly on a first surface thereof.

6. The footwear article of claim 5 wherein said other end of said subassembly comprises means for receiving said cooperative loop-bearing member.

7. The footwear article of claim 6 wherein said receiving means comprises a slot formed in said other end of said subassembly, said slot being of sufficient width to accommodate an end of said cooperative loop-bearing member.

8. The footwear article of claim 6 wherein said receiving means comprises a D-ring at said other end of said subassembly, said D-ring being of sufficient width to accommodate said cooperative loop-bearing member.

9. The footwear article of claim 4 wherein said subassembly has a central portion, said subassembly being assembled into said footwear article such that central portion is disposed between an inner sole and an outer sole of said footwear article.

10. The footwear article of claim 4 wherein said subassembly further comprises means for attaching said cooperative loop-bearing member to said footwear article.

11. The footwear article of claim 10 wherein said attachment means comprises a second field of hooks formed on the end of said subassembly having said first field of hooks, said second field of hooks being formed on the second surface of said subassembly opposite said first field of hooks.

12. The footwear article of claim 6 wherein said end of said subassembly having said receiving means is thicker than said end near said first field of injection molded hooks.

13. The footwear article of claim 1 further comprising a means for receiving said cooperative loop-bearing member, said receiving means having an opening therein, said cooperative loop-bearing member including a detent near one end thereof, said detent being wider than said opening so as to releasably retain said member within said receiving means.

14. The footwear article of claim 1 wherein said plastic portion having a field of hooks injection molded therein is made from a polymer selected from the group consisting of polypropylene, glass fiber reinforced polypropylene, polypropylene copolymers, high density polyethylene, linear low density polyethylene, polycarbonate, thermoplastic olefin polymer, nylon, high impact polystyrene and acrylonitrite-butadiene-styre- ne.