Sandal construction
12611001 ยท 2026-04-28
Assignee
Inventors
Cpc classification
A43B3/126
HUMAN NECESSITIES
International classification
Abstract
A sandal construction providing lightweight, highly adjustable sandals. The sandal includes an EVA midsole configured to receive the wearers footwear and an outsole configured to engage the ground. The sandal includes an upper having a heel assembly that seats the heel of the wearer's foot and a strap that retains the forward portion of the wearer's foot. The forefoot strap is a single, adjustable length strap that passes over the wearer's foot and is slidably threaded through passages in the sole. The midsole includes embedded strap inserts that define portions of the passages to receive and facilitate lengthwise movement of the strap. The strap inserts are substantially more rigid than the EVA. Each strap insert may include a web shepherding the strap across the bottom of the midsole and a pair of upright sleeves that shepherd the strap through at least a portion of the thickness of the midsole.
Claims
1. A sandal comprising: a sole having a heel region, a midfoot region and a forefoot region, the sole including a midsole and an outsole, the midsole having an upper surface, a lower surface and a thickness; a first strap insert disposed along the bottom surface of the midsole, the first strap insert being of a rigid one-piece construction and having a rigid web and a pair of rigid upright sleeves, the web defining a downwardly-opening channel extending across at least a portion of the midsole, the upright sleeves being integral with and extending upwardly from opposite ends of the web through at least a portion of the thickness of the midsole, each upright sleeve defining an internal through-passage opening into the channel; a heel assembly attached to the sole in the heel region, the heel assembly having a lateral post, a medial post and a heel strap extending between the lateral post and the medial post; and an adjustable-length strap affixed to the sole and the heel assembly, the strap having a first end affixed to the heel assembly on a lateral side and a second end affixed to the heel assembly on the medial side, the strap movably threaded through a first passage in the sole, the first passage being at least partially defined by the first strap insert, the strap extending through the channel in the web and through each of the upright sleeves.
2. The sandal of claim 1 wherein the upright sleeves extend vertically through only a portion of the thickness of the midsole.
3. The sandal of claim 2 wherein the web defines a plurality of perforations, the midsole extending into at least some of the perforations.
4. The sandal of claim 3 wherein the outsole is affixed to the midsole covering the strap insert, the outsole closing the channel in the web.
5. The sandal of claim 2 wherein the perforations are arranged in a regular repeating pattern over a majority of the web.
6. The sandal of claim 1 wherein the midsole and the strap insert are joined to one another through compression molding.
7. The sandal of claim 1 further including a second strap insert, the second strap insert being of a rigid one-piece construction and having a rigid web and a pair of rigid upright sleeves extending from opposed ends of the web, the web of the second strap insert defining a downwardly-opening channel, each upright sleeve of the second strap insert defining an internal through-passage opening into the channel of the second strap insert; and wherein the first strap insert is disposed in one of the forefoot region and the midfoot region and the second strap insert is disposed in the other of the forefoot region and the midfoot region.
8. The sandal of claim 7 wherein the sole defines a second passage through the midsole, the second passage being at least partially defined by the second strap insert.
9. The sandal of claim 8 wherein the strap extends through the channel in the web of the second strap insert and through each of the upright sleeves of the second strap insert.
10. The sandal of claim 9 wherein the outsole closes the channel in the web of the first strap insert and the channel in the web of the second strap insert.
11. The sandal of claim 10 wherein the midsole has a hardness in the range of about 40 Shore C to about 56 Shore C and the first strap insert has a hardness in the range of about 80 Shore A to about 100 Shore A.
12. The sandal of claim 11 wherein the strap overlaps itself in an X-configuration over the midsole in at least one of the midfoot region and the forefoot region.
13. The sandal of claim 12 wherein the first strap insert and the second strap insert are fully embedded with the sole.
14. The sandal of claim 13 wherein the first strap insert extends across the midsole forwardly from a lateral side to a medial side at an angle of about 20 degrees and the second strap insert extends across the midsole across forwardly from a medial side to a lateral side at an angle of about 25 degrees.
15. The sandal of claim 14 wherein the uprights are recessed at least about 3 millimeters below an upper surface of the midsole.
16. A sandal comprising: a sole including: an outsole having an upper surface and a ground engaging lower surface; a midsole affixed to the upper surface of the outsole, the midsole having an upper surface, a lower surface and a thickness; a first strap insert embedded within the midsole, the first strap insert being of a rigid one-piece construction and having a rigid web extending across at least a portion of the midsole in the midfoot region and a pair of rigid upright sleeves extending from opposite ends of the web through at least a portion of the thickness, the web of the first strap insert defining a downwardly opening channel and each of the upright sleeves of the first strap insert defining an internal through-passage opening into the channel of the first strap insert; and a second strap insert embedded within the midsole, the second strap insert being of a rigid one-piece construction and having a rigid web extending across at least a portion of the midsole in the forefoot region and a pair of rigid upright sleeves extending from opposite ends of the web through at least a portion of the thickness, the web of the second strap insert defining a downwardly opening channel and each of the upright sleeves of the second strap insert defining an internal through-passage opening into the channel of the second strap insert; and an upper including: a heel assembly with a lateral post affixed to the sole, a medial sole affixed to the sole and a heel strap extend between the lateral post and the medial post; and an adjustable-length strap having a first end affixed to the lateral post of the heel assembly and a second end affixed to the medial post of the heel assembly, a first portion of the strap movably threaded through the first strap insert and a second portion of the strap movably threaded through the second strap insert.
17. The sandal of claim 16 wherein the upright sleeves extend vertically through only a portion of the thickness of the midsole.
18. The sandal of claim 17 wherein the web of the first strap insert and the web of the second strap insert are perforated, the midsole extending into the perforations in the first strap insert and the second strap insert.
19. The sandal of claim 18 wherein the downwardly opening channels are closed by the outsole.
20. The sandal of claim 19 wherein the web and the uprights of the first strap insert are joined at corners, the corners being rounded to provide a smooth corner facilitating movement of the strap about the corners.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE CURRENT EMBODIMENT
(9) Overview.
(10) A sandal constructed in accordance with a preferred embodiment of the present invention is shown in
(11) The sandal 10 of
Construction of Illustrated Embodiment
(12) As noted above, the sandal 10 of
(13) In this embodiment, the outsole 16 forms the ground-engaging layer of the sandal 10. The outsole 16 of
(14) The midsole 18 of the illustrated embodiment is affixed to the top surface of the outsole 16 and is of a one-piece construction. In the embodiment of
(15) The midsole 18 is configured to receive the upper 14 in an arrangement that allows the upper 14 to secure the wearer's foot to the sole 12. More specifically, the midsole 18 is configured so that the heel assembly 32 can be attached in the heel region 34 of the midsole 18 and the strap 30 can be attached in the midfoot region 36 and the forefoot region 38 of the midsole 18. In the illustrated embodiment, the strap 30 and heel assembly 32 are attached to midsole 18 in part through various passages that extend through the thickness of the midsole. The midsole 18 of the illustrated embodiment defines a pair of through-slots 40a-b that facilitate attachment of the heel assembly 32. The heel assembly through-slots 40a-b are disposed in the heel region 36 on opposite sides (i.e. lateral and medial sides) of the midsole 18. In this embodiment, a shallow recess 41 is defined along the bottom of the midsole 18 joining the heel assembly through-slots 40a-b. In this embodiment, the heel assembly through-slots 40a-b and the heel assembly recess 41 are defined to closely receive the attachment ends 33 of the heel assembly 32 as described in more detail below. The midsole 18 also defines a pair of midfoot through-slots 40c-d and a pair of forefoot through-slots 40e-f that are configured to receive the strap 30 (discussed in more detail below). Each of the through-slots 40c-f are shaped to allow a portion of the strap 30 to pass through the thickness of the midsole 18. As can be seen, the midfoot and forefoot through-slots 40c-f closely correspond in size and shape with the cross-sectional size and shape of the material used to form the strap 30.
(16) In the illustrated embodiment, the upper 12 includes a strap 30 affixed at one end to the lateral side of the heel assembly 32 and at the opposite end to the medial side of the heel assembly 32. The length of the strap 30 is laced through the midsole 18, for example, once in the midfoot region 36 and once in the forefoot region 38. In the illustrated embodiment, the strap 30 is arranged in a configuration that forms strap loops that criss-cross once over the forefoot of the wearer's foot and criss-cross again over the midfoot region adjacent to the ankle. The configuration of the strap 30 may vary from application to application to, for example, change the size, shape, orientation and relative position of the strap loops. To permit adjustment of the strap 30 (for example, individual adjustment of the size of the loops) the strap 30 is threaded through the through-slots 40c-f and extends across the bottom of the midsole 18 in a manner that allows lengthwise movement of the strap 30. To facilitate this lengthwise adjustment, the sole 12 includes a number of strap inserts 20a-b that are embedded within the midsole 18 and define a majority of the strap pathways through the midsole 18. The strap inserts 20a-b are manufactured from a relatively rigid material that allows the strap 30 to move more easily within the strap pathwayseven when the midsole 18 is being compressed when worn. In the illustrated embodiment, the midsole 18 is fitted with two strap inserts 20a-b, including a midfoot strap insert 20a and a forefoot strap insert 20b. The strap inserts 20a-b are embedded into the midsole 18 from the bottom, with the bottom of the strap inserts 20a-b extending essentially flush with the bottom surface of the midsole 18. Each strap insert 20a-b generally includes a web 60a-b that terminates at each end in an upright sleeve 62a-d. The web 60a-b is configured to extend at the desired angle across a majority of the width of the bottom of the midsole 18. For example, in the illustrated embodiment, the web 60a of the midfoot strap insert 20a extends across the midsole 18 forwardly from the medial side to the lateral side at an angle of about 20 degrees, or in the range of about 0 degrees to about 40 degrees. Similarly, the web 60b of the forefoot strap insert 20b extends across the midsole 18 forwardly from the lateral side to the medial side at an angle of about 25 degrees, or in the range of about 0 degrees to about 45 degrees. As shown in
(17) In the illustrated embodiment, the web 60a-b of each strap insert 20a-b is perforated, and the midsole 18 and strap inserts 20a-b are intimately joined together as an integral part of a compression molding process. As perhaps best shown in
(18) The upright sleeves 62a-d each define a vertical (or somewhat vertical) passage through which the strap extends vertically (or somewhat vertically) through at least a portion of the vertical thickness of the midsole 18. The vertical passages through the upright sleeves 62a-d may have a generally rectangular cross-section that corresponds with or is slightly greater than the cross-sectional shape of the strap. In this embodiment, the narrow edges of the strap 30 and the short edges of the generally rectangular cross-section of the upright sleeves 62a-d are curved, for example, having a constant radius of curvature defined by the spacing between the longer edges of the cross-section. It should be understood that the cross-sections of the strap and the vertical passages need not be precisely matched, but may vary substantially in some alternative applications. In the illustrated embodiment, the upright sleeves 62a-d extend only partially through the thickness of the midsole 18. In such applications, the midsole 18 defines supplemental slots 98 that are aligned with and complete the passageway through the thickness of the midsole 18. As shown in
(19) In the illustrated embodiment, the corner 86 defined by the mating surfaces of each upright sleeve 62a-d and the adjacent connected web 60a-b is rounded. Rounding these corners 86 facilitates movements of the strap 30 about the corners 86 and reduces the potential for wear of the strap 30 at the corners. The radius of curvature of the corners 86 may vary from application to application.
(20) As noted above, the strap inserts 20a-b are manufactured from a relatively rigid polymeric material, such as TPU. For example, the strap inserts 20a-b may be injection molded from TPU having a hardness in the range of 90 Shore A or in the range of about 80 Shore A to about 100 Shore A. The noted characteristics of the strap inserts are merely exemplary and the precise characteristics may vary from application to application.
(21) In the illustrated embodiment, the sandal includes two strap inserts (i.e. strap inserts 20a and 20b)one extending across the midfoot region and the other extending across the forefoot region. In alternative applications, the number and location of the strap inserts may vary to allow the strap to be threaded through the midsole a different number of times and/or at different locations.
(22) As discussed above, the upper 14 is affixed to the sole 12 to provide a structure for securing the sole 12 to the wearer's foot. In the illustrated embodiment, the upper 14 generally includes a strap 30 and a heel assembly 32 that and a strap 30. As shown in
(23) The midsole 18 is configured to receive the heel assembly 32. As shown in
(24) In use, the heel assembly 32 is configured to receive the heel portion of the wearer's foot. The design and configuration of the heel assembly 32 may vary from application to application. However, in the illustrated embodiment, the heel assembly includes lateral and medial posts 50 that joined by a heel strap 52. The lateral and medial posts 50 each include an attachment end 33 that is secured to midsole 18. In this embodiment, each attachment end 33 extends through the through-slot 40a-b and is folded into a portion of the bottom recess 41. The attachment ends 33 are sandwiched between the midsole 18 and the outsole 16, for example, in adjacent portions of the bottom recess 41. The attachment ends 33 may be cemented to the midsole 18 along the entire length of bottom recess 41 and, if desired, the vertical channels 40a-b. Additionally, the attachment ends 33 may be cemented to the outsole 16.
(25) Exemplary Manufacturing Process
(26) A sandal in accordance with the present invention may be manufactured using a wide variety of manufacturing methods and equipment. For purposes of disclosure, one method for manufacturing the sandal 10 of
(27) In the illustrated embodiment, the outsole 16 is generally conventional and may be manufactured by using conventional outsole manufacturing techniques and apparatuses. The outsole 16 may be manufactured as a single unitary sole component, or it may include separate parts that cooperate to form the outsole 16. For example, the outsole 16 may include parts of different hardness, different color or other different characteristics. The outsole 16 of the illustrated embodiment is injection or pour molded from a hard durable rubber using conventional molding apparatuses. The outsole 16 can be manufactured from other durable outsole materials. The tread pattern is formed during the molding operation as an integral part of the outsole 16.
(28) The strap inserts 20a-b are injection molded from TPU or other similar materials. For example, each strap insert 20a-b may be molded with the web 60a-b and uprights sleeves 62a-d formed as a single unitary component. The perforations 96 may be formed during the injection molding process or they may be added to the web 60a-b after injection molding.
(29) In the illustrated embodiment, the midsole 18 is manufactured using a compression molding process that is designed to allow the midsole 18 to be compression molded in direct contact with the strap inserts 20a-b. In this implementation, the bottom mold part includes interior features designed to receive and hold the strap inserts 20a-b in the appropriate locations within the compression mold. For example, the bottom mold part may include for each strap insert 20a-b interior mating features configured to interfit with the recess in the web and the passages through the upright sleeves. The mold part features that extend through the upright sleeves may continue beyond the upper end of the upright sleeves to function as a core to define the remainder of the vertical passages through the midsole. In this embodiment, the bottom mold part also include interior features that define the heel assembly through-slots 40a-d and the bottom recess 41. To form the midsole 18, a midsole preform containing and appropriate volume of the desired midsole material (e.g. EVA in the illustrated embodiment) is placed in the interior of the compression mold. The compression mold is then operated applying pressure and heat to compress and reshape the preform into the desired midsole 18. During this operation, the preform is compressed into the strap inserts 20a-b with sufficient pressure and heat for the midsole 18 and the strap inserts 20a-b to become intimately joined. The bond between the two components is enhanced by the perforations 96 in the web 60a-b. For example, as shown in
(30) The heel assembly 32 may be manufactured using conventional techniques and apparatus. For example, the heel assembly 32 may be assembled from different layers of material that provide adequate structure and a comfortable interface with the wearer's foot. For example, the heel assembly 32 may include a structural layer, a cushioning layer and a soft, yet durable, lining material. If desired, the heel strap may include an extra layer of padding selected to provide additional comfort. In this embodiment, the lateral and medial posts include attachment ends 33 that are cemented in place within the through-slots 40a-b and bottom recess 41. A layer of cement may be applied between the outsole 16 and the attachment ends 33, if desired.
(31) The strap 30 of the illustrated embodiment, including the buckle and adjustment segment, is generally conventional and will not be described is extensive detail. Suffice it to say that the strap 30 is manufactured from a conventional nylon webbing or other similar materials. In this embodiment, the strap 30 is threaded through the midsole 18 (as discussed above) before the outsole 16 is attached to undersurface of the midsole 18.
(32) The outsole 16 is attached to the bottom of the midsole 18, for example, by cement or other adhesive. The cement or other adhesive may be applied over the entirety of the undersurface of the midsole 18 and the attachment ends 33 extending along the undersurface of the midsole 18.
(33) The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles a, an, the or said, is not to be construed as limiting the element to the singular.