PATENT DOCUMENT

Publication Number: US-10149518-B1
Application Number: US-201615382585-A
Country: US
Kind Code: B1

Title: Clasp assembly for a wearable device

Abstract:
An attachment strap for a wearable electronic device is disclosed. The attachment strap attaches the wearable electronic device to a wearer, and may attach to a wrist of a wearer. The attachment strap includes two bands which attach to a clasp. The clasp operates in an open and closed configuration. When in the closed configuration, the clasp may not present a visible indication of its mechanism.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising: a housing; a first band configured to attach to a first side of the housing; a second band configured to attach to a second side of the housing; and a clasp configured to attach the first band to the second band, the clasp comprising: a flexible linking portion having a first latching feature extending along a majority of a length of the flexible linking portion; a rigid linking portion having a second latching feature extending along a majority of a length of the rigid linking portion; and a hinge operably connecting the flexible linking portion and the rigid linking portion, wherein: the hinge is configured to provide rotation of the flexible linking portion with respect to the rigid linking portion until the length of the flexible linking portion is aligned with the length of the rigid linking portion, wherein the length of the flexible linking portion and the length of the rigid linking portion extend away from the hinge; and the first latching feature is configured to engage the second latching feature; and the flexible linking portion comprises a pair of arms configured to be positioned within the rigid linking portion when the first latching feature engages the second latching feature. 
     
     
       2. The electronic device of  claim 1 , wherein:
 the second latching feature comprises a recess; and 
 the first latching feature comprises a beveled edge. 
 
     
     
       3. The electronic device of  claim 1 , wherein the first band is further configured to attach to the clasp with a spring pin. 
     
     
       4. The electronic device of  claim 3 , wherein an end portion of the spring pin has an elliptical cross-section. 
     
     
       5. The electronic device of  claim 3 , wherein:
 the spring pin partially protrudes from a periphery of the first band; and 
 the spring pin is operably coupled to a spring positioned within the first band. 
 
     
     
       6. The electronic device of  claim 5 , wherein the spring is serpentine. 
     
     
       7. The electronic device of  claim 1 , wherein the first band comprises:
 a first outer layer; 
 a second outer layer; 
 a rigid insert positioned between the first outer layer and the second outer layer; and 
 a spring pin at least partially positioned within the rigid insert and configured to attach to the clasp. 
 
     
     
       8. An attachment strap for securing an electronic device to a user, the attachment strap comprising: a first band configured to attach to a first side of the electronic device; a second band configured to attach to a second side of the electronic device; a flexible linking portion comprising: a flexible linking portion first end attached to the first band; a flexible linking portion second end opposite the flexible linking portion first end; and a first latching feature between the flexible linking portion first end and the flexible linking portion second end; a rigid linking portion comprising: a rigid linking portion first end attachable to the second band; a rigid linking portion second end opposite the rigid linking portion first end; and a second latching feature between the rigid linking portion first end and the rigid linking portion second end; and a hinge rotatably connecting the flexible linking portion second end and the rigid linking portion second end, such that the flexible linking portion rotates relative to the rigid linking portion until the first latching feature engages the second latching feature; the flexible linking portion comprises a pair of arms configured to be positioned within the rigid linking portion when the first latching feature engages the second latching feature. 
     
     
       9. The attachment strap of  claim 8 , wherein:
 the first latching feature extends along a majority of a length of the flexible linking portion; 
 the second latching feature extends along a majority of a length of the rigid linking portion; and 
 the length of the flexible linking portion and the length of the rigid linking portion extend away from the hinge. 
 
     
     
       10. An attachment strap for securing an electronic device to a user, the attachment strap comprising: a first band; a second band; a flexible linking portion attached to the first band at one of opposing ends of the flexible linking portion, the flexible linking portion having a first latching feature between the opposing ends of the flexible linking portion; a rigid linking portion attached to the second band at one of opposing ends of the rigid linking portion, the rigid linking portion having a second latching feature between the opposing ends of the rigid linking portion; and a hinge rotatably connecting the other of the opposing ends of the flexible linking portion and the other of the opposing ends of the rigid linking portion, such that the flexible linking portion rotates relative to the rigid linking portion until the first latching feature engages the second latching feature; the flexible linking portion comprises a pair of arms configured to be positioned within the rigid linking portion when the first latching feature engages the second latching feature. 
     
     
       11. The attachment strap of  claim 10 , wherein:
 the first latching feature extends along a majority of a length of the flexible linking portion; 
 the second latching feature extends along a majority of a length of the rigid linking portion; and 
 the length of the flexible linking portion and the length of the rigid linking portion extend away from the hinge.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 62/371,857, filed Aug. 8, 2016 and titled “Clasp Assembly for a Wearable Device,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to wearable devices. More particularly, the present embodiments relate to attachment straps for wearable devices. 
     BACKGROUND 
     Conventional wearable devices, such as wristwatches, include straps that couple the device to a user. For example, a conventional wristwatch typically includes a strap that attaches the watch to a user&#39;s wrist. Straps may be formed from various materials, such as fabric, leather, links, and the like. In order for straps to be applied to and removed from a user, straps may use clasps, buckles, or other closure mechanisms that allow the strap to expand or open so that a user can apply the device to a desired body part or object, and also secure the strap together (at a smaller size) to retain the device to the wearer. 
     SUMMARY 
     Embodiments of the present disclosure relate to attachment straps for a wearable device. A pair of bands are coupled together by a clasp to form an attachment strap. The clasp may have a minimal appearance when closed, such that the pair of bands may appear as a nearly continuous band. In addition, the closing mechanism of the clasp may be hidden from view while the clasp is closed, as well as while the clasp is open. 
     In a first embodiment, an attachment strap for a wearable device includes a first band which attaches to a first portion of the wearable device. A second band attaches to a second portion of the wearable device, and a clasp attaches the first band to the second band. The first band includes a rigid insert positioned between two outer layers of the band. The clasp has a receiving portion which couples to the rigid insert of the first band, and the clasp also has a receiving portion for the second band. 
     In another embodiment, an electronic device includes a housing, and a first and second band which attach to sides of the housing A clasp attaches the first band to the second band. The clasp includes a flexible linking portion having a first attachment feature along a majority of a length of the flexible linking portion and a rigid linking portion having a second attachment feature along a majority of a length of the rigid linking portion. The first attachment feature couples to the second attachment feature. A hinge operably connects the flexible linking portion and the rigid linking portion and moves the flexible linking portion toward and through the rigid linking portion. 
     In still another embodiment, a method for assembling a band for a wearable device includes the steps of bonding a rigid insert to a first end of a molded component and placing the molded component adjacent a core layer. A first outer layer is bonded to the rigid insert, the molded component, and the core layer. A second outer layer is bonded to the rigid insert, the molded component, and the core layer. The first outer layer is bonded to the second outer layer. An attachment pin is placed through the rigid insert and the attachment pin is attached to a clasp which attaches to the band. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements. 
         FIG. 1  depicts a wearable electronic device having a strap incorporating features of the present disclosure. 
         FIG. 2  depicts a rotated view of the wearable electronic device depicted in  FIG. 1 . 
         FIG. 3A  depicts an exploded view of an attachment strap for the wearable electronic device. 
         FIG. 3B  depicts another exploded view of the attachment strap for a wearable device. 
         FIG. 4A  depicts a clasp of the attachment strap, illustrating the clasp in an open configuration. 
         FIG. 4B  depicts an enlarged view of a detail of the clasp. 
         FIG. 5A  depicts the clasp in a closed configuration. 
         FIG. 5B  depicts the clasp in a closed configuration, illustrating a force applied to a flexible linking portion of the clasp to open the clasp. 
         FIG. 6A  depicts a cross-section of the clasp, illustrating attachment features of the clasp. 
         FIG. 6B  depicts another cross-section of the clasp, illustrating attachment features of the clasp. 
         FIG. 7  depicts a transparent view of the attachment strap. 
         FIG. 8  depicts a cross-sectional view of a head band shown in  FIG. 7 . 
         FIG. 9A  depicts a first example rigid insert. 
         FIG. 9B  depicts attachment of the first example rigid insert to the head band. 
         FIG. 9C  depicts a second example rigid insert. 
         FIG. 9D  depicts attachment of the second example rigid insert to the head band. 
         FIG. 9E  depicts a third example rigid insert. 
         FIG. 9F  depicts attachment of the third example rigid insert to the head band. 
         FIG. 10A  depicts the clasp, illustrating features for attaching to the head band. 
         FIG. 10B  depicts a partial top view of the clasp depicted in  FIG. 10A . 
         FIG. 10C  depicts another partial top view of the clasp depicted in  FIG. 10B . 
         FIG. 11A  depicts an example spring pin having a round cross-section. 
         FIG. 11B  depicts an example spring pin having an elliptical cross-section. 
         FIG. 11C  depicts an example spring pin having a complex cross-section. 
         FIG. 11D  depicts an alternative spring pin having a serpentine spring. 
         FIG. 11E  depicts another alternative spring pin having a serpentine spring. 
         FIG. 12  depicts an exploded view of an example head band, illustrating various layers within the head band. 
         FIG. 13  depicts a flow diagram illustrating a method for assembling a band for a wearable device. 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, they are intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     Wearable devices, such as watches, are typically secured to a wearer or to an object with a strap. Some straps are composed of flexible materials, such as fabrics, leather, polymers, or the like. Other straps have multiple rigid links that can articulate with respect to one another to allow the strap to flex to conform to a wearer&#39;s wrist. Discussed herein are straps that use a hinged clasp to facilitate coupling a wearable device to a wearer. 
     For example, the clasp may be designed such that when the clasp is closed (e.g., around a wearer&#39;s wrist) the closing mechanism of the clasp may be hidden from view. While the clasp is open, at least a portion of its closing mechanism may not be apparent. The clasp itself may be minimally visible as well, giving the visual appearance of a near-continuous strap. The clasp may also be designed such that the strap will have few protrusions, reducing the likelihood that the clasp or one of the bands that attach to it will snag on objects when worn. 
     The strap may include two bands attached together by the clasp. The bands may be termed a “head band” and a “tail band.” The head band may typically be fixed to the clasp, while the tail band may be removable from the clasp. The tail band may also provide adjustability for the size of the strap. For example, the tail band may have a series of holes along its length such that a post may be placed through one of the holes to attach the clasp at a desirable point on the tail band. In some embodiments, both the head band and the tail band may be removable from the clasp (e.g., to allow for repair, maintenance, or replacement of the bands or clasp). 
     The bands may attach to separate receiving portions of the clasp. The receiving portions of the clasp may be adjoined by a hinge. The hinge may allow the portions of the clasp to fold from an open to a closed position. When closed, the hinge may place one of the bands, such as the head band, in a position overlaying the other band. The head band may overlay the hinge and the majority of the clasp, hiding the clasp mechanism from view. 
     The head band may have and/or maintain a relatively thin cross-section, and may additionally visually conceal its point of attachment to the clasp. To achieve these ends, the head band in this disclosure may directly attach to the clasp by means of a spring pin placed through the band, rather than being looped around an attachment feature. The head band may include internal features that add rigidity and/or provide a location through which the spring pin may pass, particularly in embodiments where the head band is made from a flexible material. The spring pin may also be designed to have a low profile while maintaining or increasing its strength. 
     Even while the clasp is open, its latching mechanism may not be readily apparent to a wearer. The clasp may include a flexible linking portion and a rigid linking portion that are attached to one another by a hinge. When the clasp is closed, the flexible linking portion may pass inside the rigid linking portion. Both the flexible linking portion and the rigid linking portion may have a latching feature along a portion of their lengths which abut one another when the clasp is closed. The latching features facilitate a secure latch when the clasp is closed, but may be less discernible when the clasp is open. The clasp may also include buttons (or other release structures) connected to the flexible linking portion which, when pressed, cause the flexible linking portion to flex away from the rigid linking portion, thereby releasing the latching features and opening the clasp. 
     These and other embodiments are discussed below with reference to  FIGS. 1-13 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these Figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  depicts a wearable electronic device  100  having a strap incorporating features disclosed herein with respect to various embodiments. The wearable electronic device  100  includes a two-band attachment system (together forming an attachment strap  102 ) for securing to a wrist of a wearer or any other body part or suitable structure. An attachment strap  102  includes a head band (e.g., a first band)  104  and a tail band  106  (e.g., a second band) coupled to a clasp  108 . In many examples, the wearable electronic device may be or include a multifunction device  101 , as described in more detail at the end of this specification. 
     As noted above, the wearable electronic device  100  can be removably connected to a wearer (or removably or permanently attached to another object) via an attachment strap  102 . The attachment strap  102  may be configured to attach to the housing  110  and provide a loop for securing the wearable electronic device  100  to the wrist of a wearer or to any other suitable object. The attachment strap  102  can be integral with the housing  110  or it can be a separate part. If integral to the housing  110 , the attachment strap  102  is a continuation of the housing  110 . In some cases, the attachment strap  102  is partially formed from the same material as the housing  110 . If the attachment strap  102  is separate from the housing  110 , it may be fixed or releasably coupled to the housing  110 . The attachment strap  102  may be formed from similar or different materials as the housing  110 . 
     In some embodiments, the attachment strap  102  may include a head band  104  and a tail band  106  attached to opposite sidewalls of the housing  110 . The head band  104  and the tail band  106  operate in an open and closed configuration for the attachment strap  102 . For example, each of the head band  104  and the tail band  106  may attach to a clasp  108 . The clasp  108  allows a wearer to open the strap  102  for placement on a wrist and, thereafter, close the strap  102  in order to secure the wearable electronic device  100  and the strap  102  to the wrist. In other embodiments the attachment strap  102  may be formed as a single band with a middle portion coupled to the housing  110  and ends which attach to the clasp  108 . 
     The head band  104  and tail band  106  may be flexible to facilitate attachment of the wearable electronic device  100 , and to provide a comfortable and secure fit to a wearer. The head band  104  and tail band  106  may be flexible along substantially their whole lengths, or only along certain portions. 
     The head band  104  and tail band  106  may be formed from or include any appropriate materials. For example, each of the head band  104  and the tail band  106  may include one or more layers of flexible material, such as fabrics (e.g., natural or synthetic fabrics), polymers (e.g., silicone, thermoplastic polyurethane (TPU), polyvinylchloride, rubber, or fluoroelastomer), leather, metal, mesh, links and/or the like. Example layers forming the head band  104  (and/or the tail band  106 ) are further illustrated below with respect to  FIG. 12 . 
     The clasp  108  may removably attach the head band  104  to the tail band  106 . The head band  104  may be fixed to the clasp  108 , while the tail band  106  may be removable from the clasp  108 . In some embodiments, both the head band  104  and the tail band  106  may be removable from the clasp  108  (e.g., for maintenance and/or replacement). The tail band  106  may include multiple attachment points or an attachment area, allowing for the attachment strap  102  to be adjusted in size. The clasp  108  may further provide for a portion of the tail band  106 , such as excess length, to pass underneath the head band  104 . Features of the clasp are further illustrated below with respect to  FIGS. 3A-6B . 
     As shown in  FIG. 2 , the clasp  108  may be formed such that the function of its closing mechanism is not visible when it is closed, since the head band  104  may obscure much of the clasp  108 . This may present an aesthetically pleasing view to a wearer, and may result in the attachment strap  102  having the appearance of a near-continuous band. Further, the design of the clasp  108  may present fewer protrusions than traditional attachment straps, decreasing the risk of the wearable electronic device  100  being caught on objects. 
       FIG. 2  depicts another view of the wearable electronic device  100  depicted in  FIG. 1 . The wearable electronic device  100  is depicted with a multifunction device  101  attached to a head band (e.g., a first band)  104  and a tail band (e.g., a second band)  106  of an attachment strap  102 . The head band  104  is coupled to the tail band  106  via a clasp  108 , depicted here in a closed configuration. The clasp  108  includes a release button  214 , which operates to release the clasp  108  from its closed configuration. In the closed configuration, the clasp  108  operates to place a portion of the head band  104  over the tail band  106 . 
       FIGS. 3A and 3B  depict exploded views of a sample attachment strap  102  for a wearable electronic device. These views illustrate the attachment of the clasp  108  to the head band  104  and the tail band  106 .  FIGS. 3A and 3B  also illustrate the clasp  108  in greater detail. 
     As shown in  FIGS. 3A and 3B , the clasp  108  includes a head band receiving portion (e.g., a first band receiving portion)  316  coupled to a tail band receiving portion (e.g., a second band receiving portion)  318  by a hinge  320 . The hinge  320  provides for the head band receiving portion  316  and the tail band receiving portion  318  to move or pivot between an open configuration and a closed configuration (shown in  FIGS. 3A and 3B  in an open configuration). The clasp  108  may include latching features to hold the head band portion  316  and the tail band portion  318  in a closed configuration. Example latching features are illustrated below with respect to  FIGS. 4A-6B . A release button  214  may facilitate releasing the latching features such that the head band portion  316  and the tail band portion  318  may move or swivel at the hinge, changing from the closed configuration to the open configuration. 
     The head band receiving portion  316  attaches to an end of the head band  104 . The head band  104  may include one or more attachment features, such as a spring pin  321 . The spring pin  321  may include a pair of retention pins  322  coupled to a spring  324 . An opening may be provided through the head band  104  and the spring pin  321  may be positioned within the opening. The spring pin  321  may attach the head band  104  to the head band receiving portion  316 . 
     The tail band receiving portion  318  adjustably attaches to the tail band  106 . The tail band receiving portion  318  may contain one or more attachment features which allow for a wearer to adjust the size of the attachment strap  102 . In the example shown, the tail band receiving portion  318  includes a stud (e.g., post)  354  which may penetrate one or a series of holes  307  in the tail band  106 . The series of holes  307  may allow a wearer to tighten the attachment strap by placing the stud  354  through a hole  307  which is closer to the multifunction device. 
     The stud  354  and holes  307  are illustrated in a round shape. In some embodiments, the stud  354  and/or holes  307  may be formed in a variety of shapes, including square, rectangular, triangular, and other shapes, including non-regular geometric shapes. In addition, the stud  354  is illustrated having a flared head, but in other embodiments this may be omitted or replaced with another retention feature for retaining the tail band  106 . 
     The clasp  108  and its function are further detailed below with respect to  FIGS. 4A-6B . Configuration of the head band is further detailed below with respect to  FIGS. 7-9F . Attachment of the spring pin  321  to the head band receiving portion  316  of the clasp  108  is further illustrated below with respect to  FIGS. 10A-10C . Embodiments of the spring pin  321  are further illustrated below with respect to  FIGS. 11A-1E . Example layers and a method of assembly of the head band are detailed below with respect to  FIGS. 12-13 . 
     Design of the Clasp 
       FIGS. 4A-6B  depict the clasp  108  and its function. The clasp  108  includes two main components, a flexible linking portion  450  attached to a head band receiving portion  316 , and a rigid linking portion  452  attached to a tail band receiving portion  318 . The components are coupled together by a hinge, the hinge allowing the clasp to open (as illustrated in  FIG. 4A ) and close (as shown in  FIG. 5A ). The clasp  108  components have latching features  451 ,  453  (as further illustrated in  FIGS. 6A and 6B ) to retain the clasp  108  closed. 
     The clasp  108  is designed to close and open for attachment to and removal from an object, such as a wearer&#39;s wrist. While open, the wearable electronic device may be placed on a wearer&#39;s wrist. The head band may be fixed to the clasp  108  at the head band receiving portion  316 , while the tail band is initially separated. A wearer may place the wearable electronic device on a wrist and thread the tail band into an opening  455  in the clasp  108 . The wearer may adjust the length of the tail band for fit and comfort and secure the tail band to the clasp  108  at the tail band receiving portion  318 . Once the tail band is secured, a wearer may close the clasp  108 , securing the wearable electronic device to the wearer&#39;s wrist. 
     To remove the wearable electronic device, the wearer may press release buttons  214  in the clasp  108 , which allow the clasp  108  to open by releasing the latching features  451 ,  453  of the clasp  108  components. Once the clasp  108  is open, the wearable electronic device may be removed from the wearer&#39;s wrist or adjusted. While open, the tail band may be removed from the clasp  108 , while the head band may remain fixed to the clasp  108 . In some embodiments, the head band may also be removed from the clasp  108  in the open configuration, e.g., for maintenance and/or replacement. 
     In many embodiments, the clasp  108  is curved. As the strap to which the clasp is attached may be worn on a curved surface (e.g., a wearer&#39;s wrist), the clasp  108  may be curved to better conform to the curved surface, which may further increase comfort and/or secure attachment of the strap and the wearable device. 
       FIG. 4A  depicts the clasp  108  in an open configuration, with some parts exploded for illustrative purposes. The clasp  108  includes a head band receiving portion (e.g., a first band receiving portion)  316  and a flexible linking portion  450  coupled to a tail band receiving portion (e.g., a second band receiving portion)  318  and a rigid linking portion  452  by a hinge  320 . The hinge  320  provides for the flexible linking portion  450  and the rigid linking portion  452  to pivot open and closed. 
     The clasp  108  can be formed from a variety of materials including metal or metal alloy (e.g., stainless steel, aluminum, and so on), precious metals (e.g., gold, silver, platinum, titanium, and so on), plastic, rubber, wood, silicone, glass, ceramic, fiber composite, or other suitable materials, or a combination of these materials. In some embodiments, the various parts of the clasp  108 , such as the head band receiving portion  316 , the flexible linking portion  450 , the tail band receiving portion  318 , and the rigid linking portion  452  may be formed from the same material. In other embodiments, some or all of the parts of the clasp  108  may be formed from different materials appropriate to the function of each part. 
     Turning in more detail to the flexible linking portion  450 , at an end of the flexible linking portion  450  is a hinge  320 , which couples to the rigid linking portion  452 . The hinge  320  may have an opening through which a hinge pin  458  passes. The hinge pin  458  may be retained within the hinge  320  through a groove, undercut, screw, or other retention feature appropriate to retain the hinge pin  458  while allowing for motion of the hinge  320 . The retention feature may be partially or entirely formed within the flexible linking portion  450 , or it may be partially or entirely formed within the rigid linking portion  452 . 
     The end of the flexible linking portion  450  forming a portion of the hinge  320  may be placed inside the rigid linking portion  452  such that the hinge pin  458  passes first through one arm of the rigid linking portion  452 , through the flexible linking portion  450 , then through a second arm of the rigid linking portion  452 . The end of the flexible linking portion  450  forming a portion of the hinge  320  may be substantially a single piece, which may then split into two arms moving away from the hinge  320 . 
     The flexible linking portion  450  may be shaped in a curve or arc along a portion of its length, or along its entire length. The curve or arc may have a radius which is suitable to assist the clasp  108  to conform to a wearer&#39;s wrist. In other embodiments, the flexible linking portion  450  may be formed in other shapes, such as flat, stepped, partially curved, bent, polygonal, or other geometric shapes (including non-regular shapes). 
     Along a portion of its length, the flexible linking portion  450  may be split into two parallel arms. Each arm may be formed with a latching feature  451  along at least a portion of its length. The latching feature  451  may facilitate a removable latch between the flexible linking portion  450  and the rigid linking portion  452  when the clasp  108  is closed. 
     The latching feature  451  may include one or more latching features suitable for forming a mechanical latch with the rigid linking portion  452 , such as a tongue, a groove, a beveled edge, a step, an undercut, etc., or a combination of such features. The latching feature  451  may match with a corresponding latching feature  453  on the rigid linking portion  452  as discussed further below. 
     The latching feature  451  may be tapered along each arm of the flexible linking portion  450 . For example, where the latching feature  451  is a tongue, it may begin at a portion of the arm near the hinge  320  as a flat, smooth side. The flat, smooth side may gradually form a slope and/or protrusion moving toward the opposite end of the arm near the head band receiving portion  316 . Thus portions of the latching feature  451  near the hinge  320  may barely be visually, tactilely, or otherwise perceptible as a latching feature, and only gradually may the latching feature  451  become more prominent while nearing the head band receiving portion  316 . This is further illustrated in  FIG. 4B , depicting an enlarged view of the latching feature  451 . 
     This tapered latching feature  451  may result in a mechanical latch that is achieved gradually as the clasp  108  is closed. This may, for example, provide a smoother closing transition and/or require less exertion of force to close than a uniform latching feature. At the same time, the latching feature  451  may provide a strong latch due to its prominence at the end opposite the hinge  320 . A cross-sectional view of the latching feature  451  is further illustrated below with respect to  FIGS. 6A and 6B . In other embodiments, the latching feature  451  may be uniform along its length, or it may cover a larger or smaller portion of the flexible linking portion  450  arms. 
     The arms of the flexible linking portion  450  may operate as springs, allowing for deflection when a sufficient force is applied and returning to an original position once that force is released or sufficiently dissipated. The arms of the flexible linking portion may further provide a pre-load force when the clasp  108  is closed to retain the latching features  451 ,  453  engaged with one another. To this end, the arms of the flexible linking portion  450  may be at least partially flexible. The arms may be formed from a material which allows for flexure, and the arms may additionally or alternatively have a length and cross-section designed to allow for some deflection. In some embodiments, the flexible linking portion may include an opening  459  near the hinge  458  and near where the arms adjoin, to further impart a spring-like flexibility to the arms of the flexible linking portion. The arms of the flexible linking portion  450  may further be spaced apart to allow for inward deflection. 
     The arms of the flexible linking portion  450  may further be bent near the head band receiving portion  316  in order to couple to and/or provide a leverage point for applying force to deflect the arms. The arms may further attach to release buttons  214  where a user may apply force to cause the flexible linking portion  450  to flex inward. When the arms of the flexible linking portion  450  are flexed or deflected inward, the latching feature  451  may decouple from the corresponding latching feature  453  on the rigid linking portion  452  to allow the latch to open. The response of the flexible linking portion  450  to a force applied to the release buttons  214  is further illustrated below with respect to  FIG. 5B . 
     The head band receiving portion  316  may be a rigid body to which the head band is coupled. The head band may be coupled by a spring pin, which may be retained within the head band receiving portion  316  by an attachment feature  448 . Where the head band receiving portion  316  of the clasp  108  is rigid, it may be movably coupled to the flexible linking portion  450  to allow the flexible linking portion  450  to deflect inward while the head band receiving portion  316  retains its shape. 
     For example, the end of the flexible linking portion  450  which attaches to the head band receiving portion  316  may protrude into or partially through an opening. A release button  214  may attach to each end of the flexible linking portion  450  (e.g., on opposite sides of the head band receiving portion  450 ), and may be affixed by a suitable technique, such as a button snap  456 , or other retention feature which will retain the release button  214  snugly against the end of the flexible linking portion  450  (e.g., an adhesive, screw, pin, etc.). In some embodiments, the button  214  and/or the end of the flexible linking portion  450  may include a retention feature to facilitate coupling to each other, and the button snap  456  may be fitted within the retention features to provide a one-way mechanical lock between the button  214  and the end of the flexible linking portion  450 . With the release button  214  attached, the flexible linking portion  450  may be flexed inward, but its motion may be limited, such as by a groove through which the release button  214  may not pass. 
     In other embodiments, the head band receiving portion  316  may be partially flexible, and force may be applied directly to the head band receiving portion  316  in order to cause the flexible linking portion  450  to deflect inward. In some of these cases, the head band receiving portion  316  and the flexible linking portion  450  may be fixedly attached together, or formed of a single piece. 
     Turning to the rigid linking portion  452 , an end of the rigid linking portion  452  couples to the flexible linking portion at the hinge  320 . The hinge  320  may have an opening through which a hinge pin  458  passes. The hinge pin  458  may be retained within the hinge  320  through a groove, undercut, screw, or other retention feature appropriate to retain the hinge pin  458  while allowing for motion of the hinge  320 . The retention feature may be partially or entirely formed within the flexible linking portion  450 , or it may be partially or entirely formed within the rigid linking portion  452 . 
     The end of the rigid linking portion  452  forming a portion of the hinge  320  may have two arms which surround the flexible linking portion  450  such that the hinge pin  458  passes first through one arm of the rigid linking portion  452 , through the flexible linking portion  450 , then through a second arm of the rigid linking portion  452 . 
     The rigid linking portion  452  may be shaped in a curve or arc along a portion of its length, or along its entire length. The curve or arc may have a radius which is substantially the same as the radius of the flexible linking portion  450  such that the two portions line up with each other when the clasp  108  is closed. In other embodiments, the flexible linking portion  450  may be formed in other shapes, such as flat, stepped, partially curved, bent, polygonal, or other geometric shapes (including non-regular shapes). In some embodiments the shape of the rigid linking portion  452  may not match the shape of the flexible linking portion  450 , and consequently they may latch together along a smaller portion of their lengths. 
     Along a portion of its length, the rigid linking portion  452  may be split into two parallel arms. Each arm may be formed with a latching feature  453  along at least a portion of its length. The latching feature  453  may be formed along a portion of the length of the rigid linking portion  452  which coincides with a latching feature  451  on the flexible linking portion  450 . The latching feature  453  may facilitate a removable latch between the flexible linking portion  450  and the rigid linking portion  452  when the clasp  108  is closed. 
     The latching feature  453  may include one or more latching features suitable for forming a mechanical latch with the flexible linking portion  450 , such as a tongue, a groove, a beveled edge, a step, an undercut, etc., or a combination of such features. The latching feature  453  may match with a corresponding latching feature  451  on the flexible linking portion  450 . For example, the rigid linking portion  452  may have a groove as its latching feature  453 , while the flexible linking portion  450  has a matching tongue for its latching feature  451 , or vice versa. In other embodiments only one of the latching features  451 ,  453  may be required, or other types of latching features  451 ,  453  may be used. 
     As with the flexible linking portion  450 , the latching feature  453  may be tapered along each arm of the rigid linking portion  452 . For example, where the latching feature  453  is a groove, it may begin at a portion of the arm near the hinge  320  as a flat, smooth side. The flat, smooth side may gradually form a shallow recess moving toward the opposite end of the arm, becoming a deeper groove near the tail band receiving portion  318 . Thus portions of the latching feature  453  near the hinge  320  may barely be visually, tactilely, or otherwise perceptible as a latching feature, and only gradually may the latching feature  453  become deeper while nearing the tail band receiving portion  318 . 
     As discussed above, this tapered latching feature  453  may result in a mechanical latch that is achieved gradually as the clasp  108  is closed. This may, for example, provide a smoother closing transition and/or require less exertion of force to close than a uniform latching feature  453 . At the same time, the latching feature  453  may provide a strong latch due to its depth at the end opposite the hinge  320 . A cross-sectional view of the latching feature  453  is further illustrated below with respect to  FIGS. 6A and 6B . In other embodiments, the latching feature  453  may be uniform along its length, or it may cover a larger or smaller portion of the rigid linking portion  452  arms. 
     The arms of the rigid linking portion  452  may be substantially rigid. The arms may be formed from the same material as the flexible linking portion  450  but with a more rigid cross-section and/or design, or the arms may be formed from a more rigid material. The spring-like flexible linking portion  450  may flex inward in order to move between the arms of the rigid linking portion  452  when closed. While closed, tension from the spring-like arms of the flexible linking portion  450  and/or the latching features  451 ,  453  may retain the flexible linking portion  450  between the arms of the rigid linking portion  452 . The flexible linking portion  450  may also flex inward in order to disengage the latching features  451 ,  453  and open the clasp  108 . 
     The rigid linking portion  452  may be attached to the tail band receiving portion  318 . The tail band receiving portion  318  and the rigid linking portion  452  may be formed as separate components coupled together or they may be formed as a single component. The tail band receiving portion  318  may include an attachment feature  354  and a slot or opening  455  to facilitate attachment of the tail band to the clasp  108 . 
     The attachment feature  354  of the tail band receiving portion  318  may be a post, as illustrated in  FIG. 4A . The post  354  may include a flared head or similar feature to attach the tail band to the clasp, e.g., by passing the post through an opening which may be somewhat smaller than the flared head of the post  354 . The post  354  may be internally threaded, and may be attached to a corresponding bolt, screw, or threaded post attached to or formed on the tail band receiving portion  318 . In other embodiments, the post  354  may be spot-welded, formed integral to, molded onto, adhered to, or otherwise attached to the tail band receiving portion  318 . 
     The tail band may have one or a series of openings through which the post  354  passes. When a wearer attaches a tail band to the clasp, an end of the tail band may pass through the slot, and the wearer may tighten the band a desirable amount, then place an opening in the band through the post  354 . In other embodiments, different attachment features may attach the tail band to the tail band receiving portion  318 , such as a magnet, buckle, loop, etc. 
       FIGS. 5A and 5B  illustrate the clasp  108  when closed.  FIG. 5A  shows the clasp with the rigid linking portion  450  and the flexible linking portion  452  latched together, while  FIG. 5B  illustrates the response of the flexible linking portion  450  to a force applied to the release buttons illustrated in  FIG. 4A . The force applied to the flexible linking portion  450  causes it to deflect inward and away from the rigid linking portion  452 , allowing the clasp  108  to unlatch and open. 
       FIG. 5A  depicts the clasp  108  in a closed configuration. The clasp  108  as depicted includes a tail band receiving portion  318  attached to a rigid linking portion  452 . The rigid linking portion  452  surrounds a flexible linking portion  450  while the latch  108  is closed. The flexible linking portion  450  and the rigid linking portion  452  may include latching features, as illustrated with respect to  FIGS. 6A and 6B . The latching features may operate to retain the clasp  108  closed. As shown, while the clasp  108  is closed the latching features may not be visible. 
     In order to open the clasp, force F may be applied to the flexible linking portion  450 , as depicted in  FIG. 5B . As depicted, force F is applied to ends of the flexible linking portion  450 , which may attach to buttons (such as release button  214  depicted above with respect to  FIG. 4A , omitted from  FIGS. 5A and 5B  for clarity). When force F is applied to the ends of the flexible linking portion  450 , the arms of the flexible linking portion  450  deflect or flex inwardly and away from the rigid linking portion  452 . This may cause the latching feature of the flexible linking portion  450  (illustrated below with respect to  FIGS. 6A and 6B ) to decouple from the latching feature of the rigid linking portion. With the latching features decoupled, the clasp  108  may be opened by rotating the flexible linking portion  450  and the rigid linking portion  452  apart at their respective ends opposite the hinge  320 . 
     In some embodiments the flexible linking portion  450  may instead surround the rigid linking portion  452 . In such an embodiment force may instead be applied to the flexible linking portion  450  to deflect it outward and away from the flexible linking portion  450 . In other embodiments, the rigid linking portion  452  may only partially surround the flexible linking portion  450 , and the clasp  452  may therefore latch along a smaller portion than shown in  FIGS. 5A and 5B . 
       FIGS. 6A and 6B  depict cross sections of the clasp illustrated in  FIG. 5A , taken along lines A-A and B-B respectively. The clasp includes a flexible linking portion  450  surrounded by a rigid linking portion  452 . The flexible linking portion  450  includes a latching portion  451 , here depicted as an angled tongue. The rigid linking portion  452  includes a corresponding latching feature  453 , here depicted as a groove. The tongue-and-groove of the latching features  451 ,  453  retains the clasp in a closed configuration until the flexible linking portion is deflected, allowing the latching features  451 ,  453  to separate. 
     As depicted in  FIGS. 6A and 6B , the latching feature  451  on the flexible linking portion  450  may be tapered along the length of the flexible linking portion  450 .  FIG. 6A  depicts a cross-section of the latch taken along line A-A, where the latching feature  451  on the flexible linking portion  450  is shallow. Moving toward line B-B, the latching feature  451  on the flexible linking portion  450  becomes deeper, resulting in a stronger latch at the critical load point opposite the hinge. The groove may be similarly tapered along the length of the rigid linking portion  452 . 
     Design and Components of the Head Band 
     Returning to  FIG. 3 , the clasp  108  attaches to a head band  104  at a head band receiving portion  316 . The head band  104  may be attached by a spring pin  321 . In order to achieve a thinner head band  104  and clasp  108 , the spring pin  321  may pass through an opening in the head band  104  while the head band  104  maintains a uniform thickness. 
     To maintain a low profile, the head band  104  may contain an insert  726  as depicted in  FIGS. 7-9F . The insert  726  may be rigid, and may serve as a structure through which the spring pin  321  attaching the head band  104  to the clasp  108  passes. The rigid insert  726  may also add structural rigidity to the head band  104  to improve its function and/or durability. 
       FIG. 7  depicts a transparent view of the attachment strap  102 . The head band  108  attaches to a clasp  108  by a spring pin. The end of the head band  108  attaching to the clasp  108  may be reinforced with a rigid insert  726  within the band, and the spring pin may pass through the rigid insert  726  (the opening for the spring pin is further illustrated below with respect to  FIG. 8 ). 
     The rigid insert  726  may be formed from a variety of suitable substantially rigid materials. Example materials include metal or metal alloy (e.g., stainless steel, aluminum, and so on), plastic, silicone, glass, ceramic, fiber composite, or other suitable materials, or a combination of these materials. The rigid insert  726  may include a thick base  743  adjoined by thin flanges  741 . The rigid insert  726  may be formed as a single piece, or it may be formed from multiple pieces bonded together (e.g., through welding, an adhesive, mechanical attachment, etc.). 
     A spring pin may pass through the base  743 , and the base  743  may be thicker than the flanges  741  to facilitate retaining and/or supporting the spring pin. The flanges  741  may be thin in order to facilitate attachment to other components of the head band  104 . For example, one or more fillers may be bonded to one or both flanges  741  (as illustrated further below with respect to  FIG. 8 ), and the thin profile of the flanges  741  may act as a shelf for bonding. Once bonded, there may be a substantially uniform surface across the filler and the base  743 . 
     The flanges  741  may further include attachment features  740 , which may be any attachment feature suitable for promoting bonding between the rigid insert  726  and other components of the head band  104 . For illustrative purposes the attachment features  740  are here depicted as holes through the flanges  741 , which may be filled, e.g., with a portion of a molded filler to strengthen the bond between the filler and the rigid insert  726 . In other embodiments, the attachment features  740  may be beveled edges, undercuts, a roughened surface, divots, etc., or a combination of such features used to promote bonding between the rigid insert  726  and surrounding components of the head band  104 . 
     The rigid insert  726  may similarly include dual purpose holes  742  and/or stitching holes  744 , which may also promote bonding between the rigid insert  726  and other components of the head band  104 . The attachment features  740 , dual purpose holes  742 , and stitching holes  744  may be formed during formation of the rigid insert  726 , or they may be formed in a separate process. The attachment features  740 , dual purpose holes  742 , and stitching holes  744  are further discussed below with respect to  FIGS. 9A-9F . 
     In some embodiments, the rigid insert  726  may be a uniform size in the place of the thick base  743  and thin flanges  741 , or it may only include one flange  741 . Additionally or alternatively, the attachment features  740 , dual purpose holes  742 , and/or stitching holes  744 , or a portion thereof, may be omitted. 
       FIG. 8  depicts a cross-sectional view of the head band  104  shown in  FIG. 7 , taken along line C-C, showing the rigid insert  726  within the band. As depicted in  FIG. 7 , the rigid insert  726  may be placed at an end of the head band  104  which attaches to the clasp. The rigid insert  726  may include an opening  827  within the base  743  to house a spring pin (not shown) which attaches to the clasp. 
     A filler, such as a polymer filler  828  may be bonded to the rigid insert  726  on a flange  741  of the rigid insert  726  opposite the end of the head band  104 . The filler  828  may be made from a polymer to facilitate bonding between the filler  828  and the rigid insert  726 . For example, a polymer filler  828  may be readily and cost-effectively injection molded to the rigid insert  726 , where other filler materials may be more expensive or difficult to mold. The polymer filler  828  may also be more flexible than the rigid insert  726  while maintaining a strong bond to it. The polymer filler  828  may be formed from a suitable material, such as polyurethane, polyvinylchloride, rubber, or fluoroelastomer. 
     The polymer filler  828  may be bonded to the rigid insert  726  by a suitable method, such as injection molding. The flange  741  of the rigid insert  726  may act as a shelf which increases the surface area of the bond between the polymer filler  828  and the rigid insert  726 , as well as strengthening the mechanical bond between the two as the polymer filler  828  partially surrounds the rigid insert  726 . Referring to  FIG. 7 , when the polymer filler  828  is injection molded to the rigid insert  726 , it may fill the attachment features  742  in order to further enhance the bond between the polymer filler  828  and the rigid insert  726 . 
     Another filler material  830 , which may be a similar material to the polymer filler  828 , may be bonded to an end of the rigid insert  726  adjacent the end of the head band  104 . The end of the head band  104  may be covered with a paint  833 , or similar cover layer, which may block the filler material  830  from view and/or seal the layers of the head band  104 . Other embodiments may omit the filler material  830  and/or paint  833  from the end of the head band  104 . 
     As depicted, the polymer filler  828  may be formed in a curved shape which may match a curved shape of the clasp. This may give the head band  104  a pre-curved end that substantially conforms to the clasp when the clasp is closed. The polymer filler  828  may also have a cross section which may taper from the end of the polymer filler  828  bonded to the rigid insert  726 . 
     The tapered end of the polymer filler  828  may be placed adjacent to a core layer  832 . The core layer  832  may be a filler layer of the head band  104 . The tapered shape of the polymer filler  828 , along with the core layer  832 , may facilitate a uniform thickness to the head band  104  without noticeable bumps, depressions, or changes in the pliability of the head band  104 . The core layer  832  may further strengthen the head band. The core layer  832  may be formed from woven fabric (e.g., natural or synthetic fabric), polymer (e.g., silicone, thermoplastic polyurethane (TPU), polyvinylchloride, rubber, or fluoroelastomer), leather, metal, mesh, links and/or the like. The core layer  832  may be bonded to the polymer filler  828 , using an adhesive or other bonding agent, or the core layer  832  may not be bonded to the polymer filler  828 . 
     A first outer layer  834  and a second outer layer  836  may enclose the filler material  830 , the rigid insert  726 , the polymer filler  828 , and the core layer  832 . The outer layers  834 ,  836  may be formed from woven fabric (e.g., natural or synthetic fabric), polymer (e.g., silicone, thermoplastic polyurethane (TPU), polyvinylchloride, rubber, or fluoroelastomer), leather, metal, mesh, links and/or the like. The first outer layer  834  and the second outer layer  836  may be formed from the same material as the core layer  832  or from different materials. The outer layers  834 ,  836  may generally be formed from the same material, but in some embodiments the first outer layer  834  may be formed from a different material than the second outer layer  836 . 
     The first outer layer  834  may be formed, cut, or otherwise shaped with a tapered cross-section to match the tapered cross-section of the polymer filler  828 , resulting in the head band  104  having a substantially uniform thickness. The second outer layer  836  may have a uniform thickness, or it may also be tapered in a similar fashion to the first outer layer  834 . Tapering the first outer layer  834  and the polymer filler  828  may reduce the size of the core layer  832  and/or facilitate manufacturing of the head band  104  (e.g., by eliminating the need for the polymer filler to extend the length of the head band  104 ). The head band  104  may contain further layers, such as adhesive layers, as further illustrated in  FIG. 12 . 
     In some embodiments, the first outer layer  834  and/or second outer layer  836  may further be formed in a curved shape to match the curved shape of the polymer filler. The outer layers  834 ,  836  may be formed in a curved shape by cutting, treating, mechanically pre-curving, or similar appropriate methods. 
     In some embodiments, the core layer  832  and/or polymer filler  828  may be omitted from the head band  104 . For example, the polymer filler  828  may be tapered such that the first outer layer  834  and the second outer layer  836  may be bonded directly together without a core layer  832  past the polymer filler  828 . Alternatively, the polymer filler  828  may extend the length of the head band  104 . In other examples, both may be omitted, e.g., where the first outer layer  534  and or second outer layer  836  is a moldable material (e.g., fluoroelastomer) which may be directly bonded to the rigid insert  726 . 
       FIGS. 9A-9F  depict example rigid inserts  926   a ,  926   b ,  926   c  and attachment of the same to the head band  904   a ,  904   b ,  904   c .  FIGS. 9A, 9C, and 9E  depict example embodiments of the rigid insert  926   a ,  926   b ,  926   c , while  FIGS. 9B, 9D, and 9F  depict transparent views of head bands  904   a ,  904   b ,  904   c  to illustrate placement of the rigid inserts  926   a ,  926   b ,  926   c  within the head bands  904   a ,  904   b ,  904   c  respectively. 
       FIGS. 9A and 9B  depict an example rigid insert  926   a , which may be placed in a head band  904   a . As discussed above with respect to  FIG. 7 , the rigid insert  926   a  may have a thick base  943   a  which may include an opening  927   a  for a spring pin  921   a ,  924   a . The rigid insert  926   a  may further include thin flanges  941   a  to which a polymer filler is bonded, as illustrated with respect to  FIG. 8 . 
     In some examples, the rigid insert  926   a  may function as an outer casing for the spring pin, taking the place of a traditional outer casing to control the compression of the spring  924   a  and retain the spring  924   a  and pins  921   a . Accordingly, the spring pin may be formed by placing a spring  924   a  (e.g., a helical or other appropriate spring) within the opening  927   a  in the rigid insert  926   a , and pins  921   a  at ends of the opening  927   a  abutting the spring. The opening  927   a  may be formed in an appropriate shape, such as a cylinder, and may additionally have retention features to retain the spring  924   a  and/or pins  921   a.    
     One or both flanges  941   a  of the rigid insert  926   a  may include attachment features  940   a , which may be formed as holes through the flange  941   a . While  FIGS. 9A and 9B  depict the attachment features  940   a  as rounded holes, they may take other forms such as oval, square, rectangular, or other geometric shapes (including non-regular shapes). The attachment features  940   a  may further be filled with a polymer filler (e.g., the polymer filler  828  of  FIG. 8 ) to enhance the filler&#39;s bond with the rigid insert  926   a.    
     The base  943   a  may include stitching holes  944   a . The stitching holes  944   a  may be formed to pass through the base  943   a  around the spring pin  921   a  opening  927   a . Once the rigid insert  926   a  is placed within the head band  904   a , the outer layers of the head band  904   a  may be joined together with stitching  946   a  (here schematically represented). The stitching  946   a  may enhance bonding of the head band  904   a  components and/or layers, and may additionally or alternatively be aesthetically pleasing. The stitching  946   a  may be formed from any suitable material (e.g., thread, yarn, rivets, etc.), and may pass through the stitching holes  944   a  of the base  943   a , enhancing attachment of the rigid insert  926   a  to the outer layers of the head band  904   a  and/or fixing its location within the head band  904   a.    
     One or both flanges  941   a  may also include dual-purpose holes  942   a . Stitching  946   a  may pass through the dual purpose holes  942   a , and the dual purpose holes  942   a  may additionally or alternatively be filled with a polymer filler to enhance its bond with the rigid insert  926   a.    
       FIGS. 9C and 9D  depict another example rigid insert  926   c , which may omit stitching holes in the base  943   c . Without stitching holes in the base  943   c , the head band  904   c  may be bonded together without stitching between the outer layers. In other embodiments, the outer layers may be stitched together but omit the end of the band with the rigid insert  926   c.    
     The rigid insert  926   c  may also include flanges  941   c  with attachment features  940   c , similar to those described above with respect to  FIGS. 9A and 9B . An opening  927   c  for a spring pin  921   c ,  924   c  may be provided through the base  943   c  for attaching the head band  904   c  to a clasp. 
       FIGS. 9E and 9F  depict another example rigid insert  926   e . The rigid insert  926   e  may be smaller than the previous rigid inserts, and may be placed in a head band  904   e  that is bonded together with stitching  946   e  between the outer layers that passes around the rigid insert  926   e . Similar to the rigid insert depicted in  FIGS. 9A and 9B , the rigid insert  926   e  may include a base  943   e  with an opening  927   e  for a spring pin  921   e ,  924   e  for attaching the head band  904   e  to a clasp. The rigid insert  926   e  may also include flanges  941   e  adjoining the base  943   e  that include attachment features  940   e.    
     Attachment of the Head Band to the Clasp 
     The head band depicted above with respect to  FIGS. 7-9F  may be attached to the clasp  108  through use of a spring pin  321 . The spring pin  321  may pass through a rigid insert in the head band, such as the rigid inserts depicted in  FIGS. 9A-F . The clasp  108  may include a U-shaped head band receiving portion  316  to surround the head band. The head band receiving portion  316  may have an attachment feature  448  to retain the head band. In some embodiments, the attachment feature  448  may also facilitate removal of the head band, with or without special tools. In some embodiments, a tail band receiving portion may additionally or alternatively include these features. 
     As depicted in  FIGS. 10A-10C , the attachment feature  448  may include a stepped recess  1047  and a ramp  1049 . The stepped recess  1047  may have rounded walls, or it may have squared walls, or another suitable geometric shape. The stepped recess  1047  may be shaped to mate with the spring pin (e.g., rounded walls to mate with a rounded pin), or it may have an arbitrary shape. The stepped recess  1047  may be stepped on three sides, and may adjoin the ramp  1049  on a fourth side. The ramp  1049  may be placed on the side of the stepped recess  1047  nearest the bottom of the “U”  1017  of the head band receiving portion  316 . 
     The ramp  1049  may facilitate removal of the spring pin without special tools. The head band receiving portion  316  may include a pair of attachment features  448  on opposite sides of an interior surface. Each attachment feature  448  may have a stepped recess  1047  with a ramp  1049  on a side of the recess  1047  near the bottom of the “U”  1017  of the head band receiving portion  316 . The stepped sides of the recess  1047  may normally retain the spring pin  321  within the recess  1047  when the clasp  108  is closed, as the head band would not be able to move toward the bottom of the “U”  1017  of the head band receiving portion  316 . The stepped sides of the recess  1047  would prevent the spring pin  321  from being disengaged from the recess  1047  in any other direction. 
     However, with the clasp  108  open, the head band may be able to rotate such that the head band could be moved toward the bottom of the “U”  1017 . From this position, a wearer or servicer may apply a force to the head band and/or spring pin  321  (e.g., near an end of the spring pin  321 ) along a direction toward the bottom of the “U”  1017 . As illustrated in  FIG. 10C , the ramp  1049  would translate a portion of the moving force to compress the spring pin, allowing the spring pin to move out from the stepped recess  1047 . 
     In other embodiments, the head band receiving portion  316  may have different attachment features  448 . For example, the attachment feature  448  may contain only a stepped recess  448  and omit the ramp  1049 , which may require special tools for removal. Other attachment features  448  may be used which are suitable to retain a spring pin  321  within the head band receiving portion  316 . 
     Example Spring Pins 
     The head band includes a spring pin, which may attach the head band to a clasp as depicted in  FIGS. 10A-10C . The spring pin may pass through the rigid insert of the head band, such as the example rigid insert illustrated above with respect to  FIGS. 9A-9F . The rigid insert may provide an opening which retains the spring pin, and may additionally provide a rigid structure to prevent the spring pin from bending. The rigid insert may thus take the place of prior art casings around watch band spring pins. 
     In some embodiments, the spring pin may be designed with a low profile in order to provide the head band with a low profile (e.g., thinner cross-section) than prior art bands, particularly when coupled with the features illustrated above with respect to  FIGS. 7-9F . Examples of spring pins  1121   a ,  1121   b ,  1121   c  for use in a rigid insert are depicted in  FIGS. 11A-11C .  FIGS. 11D and 11E  depict alternative example spring pins  1121   d ,  1121   e  which may be implemented in the head band with or without a rigid insert. 
       FIG. 11A  depicts an example spring pin  1121   a  which may be inserted through a rigid insert in the head band. The spring pin  1121   a  includes a pin  1122   a  coupled to a helical spring  1124   a . The pin  1122   a  has a circular cross section, which mates with an attachment feature (such as a recess) in the clasp of the attachment strap. The helical spring  1124   a  operates to apply tension (e.g., a biasing force) to the pin  1122   a  to maintain attachment of the head band to the clasp. 
       FIG. 11B  depicts another example spring pin  1121   b  which may be inserted through a rigid insert in the head band. The spring pin  1121   b  also includes a pin  1122   b  coupled to a helical spring  1124   b  (which provides a biasing force as described with respect to  FIG. 11A ). The pin  1122   b  has an elliptical cross section, which may increase the strength of the pin along a critical load path when it is held within an attachment feature of the clasp. For example, the critical load path may be along the x-axis (e.g., the direction which would pull the watch band away from the clasp). In such a case, the moment of inertia about the y-axis may be given as: 
               I   y     =       π   4     ⁢     a   3     ⁢   b           
where a is equal to the radius of an ellipse along the x-axis and b is equal to the radius of the ellipse along the y-axis. Thus, if the pin  1122   b  has the same height as the pin  1122   a  in  FIG. 11A , it will be stronger along the critical load path along the x-axis (i.e., about the y-axis) corresponding to the long side of its elliptical cross-section. In some embodiments, the height of the pin  1122   b  may also be reduced, while the elliptical cross-section maintains equal strength to the embodiment of  FIG. 11A  along the critical load path.
 
       FIG. 11C  depicts another example spring pin  1121   c  which may be inserted through a rigid insert in the head band. The spring pin  1121   c  likewise includes a pin  1122   c  coupled to a helical spring  1124   c  (which provides a biasing force as described with respect to  FIG. 11A ). The pin  1122   c  has a complex cross section, with an inner elliptical portion  1123   c  and an outer circular portion  1129   c . The inner portion  1123   c  may pass through the head band, and its elliptical cross section may provide the pin  1121   c  with strength along the critical load path while allowing for a lower profile, thinner head band, as described above with respect to  FIG. 11B . The outer portion  1129   c  may remain outside the head band, and its circular cross section may better mate with an attachment feature of the clasp and/or may allow for easier servicing. 
       FIG. 11D  depicts an alternative spring pin  1121   d  which may be utilized with a head band  1104   d  either with or without a rigid insert. The spring pin  1121   d  includes a pair of pins  1122   d  coupled to a flat spring  1124   d  having a planar serpentine shape. The pins  1122   d  are also coupled to the head band  1104   d  by a suitable retaining technique, such as bushing inserts  1125   d . The flat spring  1124   d  is enclosed by the head band  1104   d  (or a rigid insert shaped to accommodate the flat spring  1124   d ) and applies tension to the pins  1122   d . When the pins  1122   d  are pressed inward (e.g., when mated to a recess in the clasp), the serpentine coils are compressed along the plane of the spring, resulting in an opposing tension force being applied to the pins  1122   d , which operates as a biasing force to maintain attachment of the head band to the clasp. 
     Due to the planar compression of the flat spring  1124   d , it may have a lower profile than the helical springs of  FIGS. 11A-11C , which may facilitate reduced thickness in the head band  1104   d . The head band  1104   d  may be further thinned by coupling the flat spring  1124   d  with pins  1122   d  having at least a partially elliptical cross section. The head band  1104   d  may also be more flexible than implementations with the rigid insert. 
       FIG. 11E  depicts another alternative spring pin  1121   e , which may have features similar to  FIG. 11D . The spring pin  1121   e  depicted includes a pair of pins  1122   e  coupled to a pair of flat springs  1124   e , each having a planar serpentine shape. The flat springs  1124   e  are enclosed by the head band  1104   e  and may rest in chambers separated by a wall  1131   e . In some embodiments, the flat springs  1124   e  are additionally or alternatively enclosed by a rigid insert shaped to accommodate the flat springs  1124   e . The wall  1131   e  is substantially rigid, such that when force is applied to a pin  1122   e , the wall  1131   e  may maintain its position and cause the applied force to compress the flat spring  1124   e  (to provide a biasing force similar to  FIG. 11D ). The wall  1141   e  may be formed from a material common to the head band. The wall  1141   e  material may be selected to provide sufficient rigidity, or the wall  1141   e  may be sufficiently thick to be rigid. 
     Example Band Assembly Layers and Method 
       FIG. 12  depicts an exploded view of an example head band  104 , illustrating various layers within the head band  104 . The exploded view of  FIG. 12  is a rotated view with respect to  FIGS. 3A, 7, and 8 ; it is oriented similar to  FIG. 3B . An insert layer  1268  may include a rigid insert  726  coupled to a polymer filler  828 . The polymer filler  828  may be placed adjacent to or coupled to a core layer  832 , as described above with respect to  FIG. 8 . 
     The insert layer  1268  may be coupled to a number of other layers of the head band  104  as depicted in  FIG. 12 , including an inner adhesive layer  1239 , a fiber layer  1238 , first and second outer adhesive layers  1235 ,  1237 , and first and second outer layers  834 ,  836 . The polymer filler  828  may be molded in a curved shape (as shown). The remaining layers, while shown flat, may not be flat when the head band  104  is assembled (e.g., where they interact with the polymer filler  828  other layers may also be curved). 
     The head band  104  may be reinforced by a fiber layer  1238 . In an exemplary embodiment, the fiber layer  1238  may be formed from Vectran®, which exhibits high strength and low elasticity. However, any suitable fiber may be used to reinforce the head band  104 , including Kevlar (or other aramid or para-aramid fibers), xylow, nitinol, steel, or other natural, synthetic, and/or metallic fibers, or combinations of the above fibers. 
     An inner adhesive layer  1239  may bond the fiber layer  1238  to the insert layer  1268 , including the rigid insert  726 , polymer filler  828 , and core layer  832 . The inner adhesive layer  1239  can be any suitable material that promotes adhesion between the fiber layer  1238  and the components of the insert layer  1268  of the head band  104 . According to some embodiments, the inner adhesive layer  1239  can include a thermoplastic adhesive. In other embodiments, however, any suitable adhesive, such as an epoxy or glue may be used. 
     The first outer layer  834  can form one of the outer surfaces of the head band  104 , and may form an inner surface of the head band  104  to be placed adjacent to a wearer&#39;s skin. The material of the first outer layer  834  may be aesthetically appealing and/or comfortable when worn adjacent to a wearer&#39;s skin. Additionally or alternatively, the material of the first outer layer  834  may be resistant to skin oils, fluids, and/or environmental conditions. In some embodiments, the material of the first outer layer  834  may be absorbent or provide wicking action for moisture. In still other embodiments, the first outer layer  834  may be easily washable. The material of the first outer layer  834  may additionally or alternatively be selected for a particular coefficient of friction when touching a wearer&#39;s skin (e.g., to stay in place). 
     The first outer layer  834  may be bonded to the insert layer  1268  by a first outer adhesive layer  1235 . The first outer adhesive layer  1235  can be any suitable material that promotes adhesion between the first outer layer  834  and the components of the insert layer  1268 , such as a thermoplastic adhesive (e.g., the same or a different thermoplastic adhesive as in the inner adhesive layer  1239 ). In other embodiments, however, any suitable adhesive, such as an epoxy or glue may be used. 
     The second outer layer  836  can form an outer surface of the head band  104  opposite the first outer layer  834 , and may be visible when worn. The second outer layer  836  may be formed from a suitable material (e.g., the same or a different material used in the first outer layer  834 ), as noted above with respect to  FIG. 8 . The material of the second outer layer  836  may be aesthetically appealing and/or durable. Additionally or alternatively, the material of the second outer layer  836  may be resistant to fluids and/or environmental conditions. In some embodiments, the second outer layer  836  may be easily washable. The material of the second outer layer may additionally or alternatively be selected for a particular coefficient of friction when touching a wearer&#39;s skin (e.g., to slide freely). 
     The second outer layer  836  may be bonded to the fiber layer  1238  by a second outer adhesive layer  1237 . The second outer adhesive layer  1237  can be any suitable material that promotes adhesion between the second outer layer  836  and the fiber layer  1238 , such as a thermoplastic adhesive (e.g., the same or a different thermoplastic adhesive as in the inner adhesive layer  1239  and/or the first outer adhesive layer  1235 ). In other embodiments, however, any suitable adhesive, such as an epoxy or glue may be used. 
     In some embodiments, the first and second outer layers  834 ,  836  may be bonded together and/or formed from the same material. The first and second outer layer  834 ,  836  may also be molded or bonded onto the remaining layers (e.g., along their edges) and form a single outer layer. 
     The layers, their arrangements, and the materials described in  FIG. 12  are exemplary. Additional or fewer layers may be implemented in other embodiments. The arrangement of the various layers and the materials used may also differ in other embodiments. 
       FIG. 13  depicts a flow diagram illustrating a method for assembling a band for a wearable device. The band may be the head band (e.g., the first band), discussed above. The method  1300  includes step  1356 , where a rigid insert is formed. The rigid insert may be formed from a variety of suitable rigid materials. Example materials include metal or metal alloy (e.g., stainless steel, aluminum, and so on), plastic, silicone, glass, ceramic, fiber composite, or other suitable materials, or a combination of these materials. The rigid insert may be formed using an appropriate method, such as casting, molding, machining, extruding, rolling, milling, turning, grinding, cutting, etc. The rigid insert may also be previously formed and included in the assembly of the band. 
     At step  1358  a polymer filler is bonded to the insert. The polymer filler may be formed through a variety of methods. For example, the rigid insert may be placed into a mold and the polymer may be injected into the mold to form the filler and bond it to the rigid insert. The polymer filler  828  may be formed from a suitable material, such as polyurethane, polyvinylchloride, rubber, or fluoroelastomer. 
     At step  1360  the polymer filler is placed adjacent to a core layer of the band. The core layer may be formed from woven fabric (e.g., natural or synthetic fabric), polymer (e.g., silicone, thermoplastic polyurethane (TPU), polyvinylchloride, rubber, or fluoroelastomer), leather, metal, mesh, links and/or the like. The core layer may be bonded to the polymer filler, using an adhesive or other bonding agent, or the core layer may not be bonded to the polymer filler. The core layer and polymer filler may be cut or otherwise shaped such that the adjacent edges of the core layer and polymer filler match at a uniform thickness. 
     At step  1362  outer layers of the band are bonded to the inner assembly of the rigid insert, the polymer filler, and the core layer. There may be a first and a second outer layer, which may be formed from woven fabric (e.g., natural or synthetic fabric), polymer (e.g., silicone, thermoplastic polyurethane (TPU), polyvinylchloride, rubber, or fluoroelastomer), leather, metal, mesh, links and/or the like. The first and second outer layers may be formed from the same material as the core layer or from different materials. The first and second outer layers may generally be formed from the same material, but in some embodiments the first outer layer may be formed from a different material than the second outer layer. The band may include additional layers, such as those depicted in  FIG. 12 . 
     At step  1364  the outer layers may be stitched together. The stitching may enhance the bonding of the band components, it may be aesthetically appealing, or both. The stitching may be performed by machine or by hand, and may include any appropriate type of stitching which promotes bonding of the band components or is otherwise desirable. In some embodiments, step  1364  may not be performed. 
     At step  1366  the assembled band is attached to a clasp. The band may attach to a receiving portion of a clasp, which may also be configured to attach to an additional band. While step  1366  is illustrated as part of method  1300 , it may be performed in a separate method. 
     Attached Multifunction Device 
     Returning to  FIG. 1 , the wearable electronic device may be or include a multifunction device  101 . The multifunction device  101  may include features such as time keeping, health monitoring, sports monitoring, medical monitoring, communications, navigation, computing, and/or the like. The multifunction device  101  may take the form of a smart phone, a gaming device, a digital music player, a sports accessory device, a medical device, a watch, and other types of electronic or computing device suitable for attaching, at least partially, to the wearer. 
     The multifunction device  101  includes a housing  110  that carries, encloses, and/or supports operational and/or functional components of the multifunction device  101 . Examples of other operational or functional components that are carried, enclosed, and/or supported by the housing  110  include processing units, memory modules, displays, sensors, biosensors, wireless communication modules, speakers, microphones, haptic actuators, rotational input devices, buttons, biometric authentication sensors and systems, batteries, and so on. 
     The housing  110  can form an outer surface or partial outer surface (such as a protective case) for the internal components of the multifunction device  101 . In the illustrated embodiment, the housing  110  is a substantially rectangular cuboid, although this configuration is not required. The housing may be cylindrical in certain embodiments, for example, or may have another geometric shape (including non-regular shapes). 
     The construction of the housing  110  may vary from embodiment to embodiment. For example, the housing  110  can be formed from a variety of materials including plastic, rubber, wood, silicone, glass, ceramic, fiber composite, metal or metal alloy (e.g., stainless steel, aluminum, and so on), precious metals (e.g., gold, silver, platinum, titanium, and so on), or other suitable materials, or a combination of these materials. The housing  110  can be formed of one or more components operably connected together, such as a front piece and a back piece, or a top and bottom clamshell. Alternatively, the housing  110  can be formed of a single piece (e.g., uniform body or unibody). 
     The multifunction device  101  typically, although not necessarily, includes a display  112 . In some embodiments, the display  112  may be an analog display, such as an analog watch face. The analog watch may additionally include digital display elements (e.g., a liquid crystal display or light emitting diode display) and/or backlighting which may allow for viewing in dim or no ambient light. 
     In other embodiments, the display  112  may be digital and may use liquid crystal display technology, light emitting diode technology, organic light-emitting display technology, organic electroluminescence technology, electrophoretic ink, flexible display technology, or another type of display technology or combination of display technology types. The display  112  may further include a multi-touch and/or multi-force sensing touchscreen. In many examples, the display  112  may also incorporate an input device configured to receive touch input, force input, rotation input, and the like from the wearer. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20161216
Publication Date: 20181211
Grant Date: 20181211
Priority Date: 20160808
Inventors: DE IULIIS, DANIELE
CHAMBERS, TREVOR S.
WAISANEN, THOMAS J.
Assignee: APPLE INC
CPC Classifications: [{"code": "A44C27/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0226", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/0053", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/246", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/185", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/0007", "inventive": true, "first": true, "tree": "[]"}, {"code": "A44C5/2071", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/185", "inventive": true, "first": true, "tree": "[]"}, {"code": "G04B37/1486", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04B37/1486", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/2071", "inventive": false, "first": false, "tree": "[]"}, {"code": "A44C5/2071", "inventive": false, "first": false, "tree": "[]"}, {"code": "A44C5/0053", "inventive": false, "first": false, "tree": "[]"}, {"code": "A44C5/246", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/246", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C27/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/0053", "inventive": false, "first": false, "tree": "[]"}, {"code": "A44C5/185", "inventive": true, "first": false, "tree": "[]"}, {"code": "A44C5/0007", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 64502762