PATENT DOCUMENT

Publication Number: US-10024352-B2
Application Number: US-201615268233-A
Country: US
Kind Code: B2

Title: Low profile fastening method with torque-limiting disengaging head

Abstract:
A fastener is disclosed. The fastener can be used to couple together two or more parts in an electronic device. The fastener may include a head coupled with a platform having a shaft extending from the platform. The head is coupled with the platform in a manner that allows the head to decouple from the platform. For example, the head is secured with the platform by an adhesive that provides an adhesive bonding force. In this regard, a rotational force applied to the head that is greater than the adhesive bonding force causes the head to decouple from the platform. The shaft may include several blades and several protrusions. The blades may be used to engage one of the parts. The protrusions may also engage the same part as the blades, and interlock with the part to provide a retaining force that prevents the fastener from decoupling from the parts.

Claims:
What is claimed is: 
     
       1. A fastener comprising:
 a platform having a shaft extending from the platform, the shaft capable of securing to at least one of a first part and a second part; and 
 a head bonded with the platform by a material that includes a bonding force, wherein a rotational force to the head greater than the bonding force causes the head to decouple from the platform. 
 
     
     
       2. The fastener of  claim 1 , wherein the material comprises an adhesive having an adhesive bonding force. 
     
     
       3. The fastener of  claim 2 , wherein the shaft comprises a threaded region configured for threaded engagement with at least one of the first part and the second part. 
     
     
       4. The fastener of  claim 1 , wherein the head comprises a recess capable of receiving a tool, wherein the rotational force to the head comprises a rotational force by the tool. 
     
     
       5. The fastener of  claim 1 , wherein:
 a first surface defined by the head, the first surface engaged with the material and comprising a first surface roughness, 
 a second surface defined by the platform, the second surface engaged with the material and comprising a second surface roughness different from the first surface roughness, and 
 the rotational force causes the material to decouple from the second surface such that the material remains engaged with the first surface. 
 
     
     
       6. The fastener of  claim 1 , wherein:
 the head includes a first dimension along an axis defined by the shaft, 
 the platform includes a second dimension along the axis defined by the shaft, and 
 the second dimension different from the first dimension. 
 
     
     
       7. The fastener of  claim 6 , the second dimension is less than the first dimension. 
     
     
       8. A method for forming a fastener the method comprising:
 forming a platform having a shaft extending from the platform, the shaft capable of securing to at least one of a first part and a second part; and 
 securing the platform with a head by a material that includes a bonding force, wherein a rotational force to the head greater than the bonding force causes the head to decouple from the platform. 
 
     
     
       9. The method of  claim 8 , wherein securing the platform with the head by the material comprises providing an adhesive, the adhesive defining the bonding force. 
     
     
       10. The method of  claim 8 , wherein the shaft comprises a threaded region configured for threaded engagement with at least one of the first part and the second part. 
     
     
       11. The method of  claim 8 , further comprising:
 forming a first surface defined by the head, the first surface engaged with the material and comprising a first surface roughness, 
 forming a second surface defined by the platform, the second surface engaged with the material and comprising a second surface roughness different from the first surface roughness, wherein the rotational force causes the material to decouple from the second surface such that the material remains engaged with the first surface. 
 
     
     
       12. The method of  claim 8 , wherein the shaft comprises a threaded region configured for threaded engagement with at least one of the first part and the second part. 
     
     
       13. The method of  claim 12 , further comprising a non-threaded portion, wherein the non-threaded portion is positioned between the platform and the threaded region. 
     
     
       14. A fastener, comprising:
 a head comprising a first portion and a second portion; 
 a bonding material that couples the first portion with the second portion; and 
 a shaft extending from the second portion, wherein a rotational force to the head that causes the shaft to couple a first part with a second part further causes the first portion to break away from the second portion such that the second portion is engaged with the first part. 
 
     
     
       15. The fastener of  claim 14 , wherein the shaft comprises:
 a threaded portion; and 
 a non-threaded portion, wherein the non-threaded portion is positioned between the second portion and the threaded portion. 
 
     
     
       16. The fastener of  claim 14 , wherein the bonding material comprises an adhesive, and wherein the rotational force causes the adhesive to break away from the second portion such that the adhesive remains on the first portion. 
     
     
       17. The fastener of  claim 14 , wherein:
 the first portion includes a first dimension along an axis defined by the shaft, 
 the second portion includes a second dimension along the axis defined by the shaft, and 
 the second dimension is less than the first dimension. 
 
     
     
       18. The fastener of  claim 14 , wherein the head comprises a recess capable of receiving a tool that provides the rotational force. 
     
     
       19. The fastener of  claim 14 , further comprising:
 a platform extending from the shaft; 
 a first surface defined by the head, the first surface engaged with the bonding material and comprising a first surface roughness, 
 a second surface defined by the platform, the second surface engaged with the bonding material and comprising a second surface roughness different from the first surface roughness, and 
 the rotational force causes the bonding material to decouple from the second surface such that the material remains engaged with the first surface. 
 
     
     
       20. The fastener of  claim 14 , wherein the bonding material is positioned between the first portion and the second portion, and bonding material extends to an outer edge of the first portion and the second portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/232,958, filed on Sep. 25, 2015, and titled “LOW PROFILE FASTENING METHOD WITH TORQUE-LIMITING DISENGAGING HEAD,” the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate to fasteners. In particular, the described embodiments relate to fasteners having a shaft and a fastener head, with the fastener head designed to break away from the shaft in response to torque, or twisting force. In addition, some fasteners include several blades designed to engage and interlock with a part. 
     BACKGROUND 
     Fasteners are commonly known in the art for securing parts together. A fastener may include a head and a shank. The head may be designed to receive a tool that provides a rotational force to drive the head and the shank into the parts. The shank may be threaded, or partially threaded. The head may be driven until the fastener extends through the parts. 
     However, some fasteners may not be well-equipped for small spaces. For example, in order to fasten together two or more parts in a desired manner, the shank may require a number of threads, which adds to the overall length of the shank, and in turn, the fastener. Also, the head may be unnecessarily large, due in part to a clearance required between 1) a recess in the head that receives a tool and 2) the shank. Both the head and the shank may cause the fastener to include a length too large for certain applications. For example, when the fastener is used in an electronic device, other components in an electronic device proximate to the fastener must be moved to another location causing a redesign of the electronic device. Alternatively, the component may include a reduced size or may be removed altogether, which may limit the capability of the electronic device. 
     SUMMARY 
     In one aspect, a fastener suitable for securing a first part with a second part is described. The fastener may include a platform having a shaft extending from the platform. The fastener may further include a head bonded with the platform by a material that includes a bonding force. In some embodiments, in response to a rotational force to the head greater than the bonding force, the head decouples from the platform. 
     In another aspect, a fastener used to secure together a first part with a second part is described. The second part may include an extension. The fastener may include a shaft configured to extend through the first part and the second part. The fastener may further include a blade extending radially from the shaft and configured to secure around the extension. The fastener may further include a protrusion extending radially from the shaft and configured to engage the extension to interlock the shaft with the extension. 
     In another aspect, a method for making a fastener suitable for securing a first part with a second part is described. The method may include forming a platform having a shaft extending from the platform. The method may further include securing the platform with a head by a material that includes a bonding force. In some embodiments, in response to a rotational force to the head greater than the bonding force, the head decouples from the platform. 
     Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims. 
    
    
     
       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, and in which: 
         FIG. 1  illustrates an isometric view of an embodiment of a fastener, in accordance with the described embodiments; 
         FIG. 2  illustrates a cross sectional view of the fastener shown in  FIG. 1 , taken along the A-A line in  FIG. 1 ; 
         FIG. 3  illustrates an isometric view of the fastener driven into a first part and a second part; 
         FIG. 4  illustrates an isometric view of the fastener shown in  FIG. 3 , showing the fastener substantially driven into the first part and the second part; 
         FIG. 5  illustrates an isometric view of the fastener shown in  FIG. 4 , showing the head decoupling from the platform in response to a force greater than the adhesive bonding force of the material; 
         FIG. 6  illustrates an isometric view of the fastener shown in  FIG. 5 , with the platform remaining subsequent to removal the head and the material (shown in  FIG. 5 ); 
         FIG. 7  illustrates a cross sectional view of an alternate embodiment of a fastener that include multiple material layers, in accordance with the described embodiments; 
         FIG. 8  illustrates an isometric view of an alternate embodiment of a fastener, showing the fastener having a head secured with the platform by several posts, in accordance with the described embodiments; 
         FIG. 9  illustrates an isometric view of an alternate embodiment of a fastener, with a platform of the fastener having ridges that may be used in conjunction with a tool, in accordance with the described embodiments; 
         FIG. 10  illustrates an embodiment of a tool used to engage the ridges of the platform in  FIG. 9 ; 
         FIG. 11  illustrates an isometric view of an alternative embodiment of a fastener having a shaft that includes several blades extending radially outward from the shaft; 
         FIG. 12  illustrates an isometric bottom view of the fastener shown in  FIG. 11 , showing the blades as well as several protrusions; 
         FIG. 13  illustrates an exploded view of the fastener shown in  FIGS. 11 and 12 , further illustrating the fastener used to secure together two parts; 
         FIG. 14  illustrates an isometric view of the fastener shown in  FIG. 13 , further showing the fastener being rotationally driven to fasten the first part with the second part; 
         FIG. 15  illustrates a bottom view of the fastener shown in  FIGS. 13 and 14 , with the blades extending at least partially through the opening of the second part; 
         FIG. 16  illustrates a bottom view of the fastener shown in  FIG. 15 , with the fastener rotated with respect to the second part, causing the fastener to engage the second part; 
         FIG. 17  illustrates an isometric view of the first part and the second part secured together by way of the fastener, with the head removed subsequent to a rotation of the fastener; 
         FIG. 18  illustrates a cross sectional view of the fastener, the first part, and the second part, shown in  FIG. 17 , taken along line B-B in  FIG. 17 ; 
         FIG. 19  illustrates an isometric view of an embodiment of an electronic device; 
         FIG. 20  illustrates a cross sectional view of the electronic device shown in  FIG. 19 , taken along line C-C in  FIG. 19 , showing the fastener used to secure a first part with a second part, in accordance with the described embodiments; and 
         FIG. 21  illustrates a flowchart showing a method for making a fastener suitable for securing a first part with a second part, in accordance with the described embodiments. 
     
    
    
     Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings may be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     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, it is 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. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     The described embodiments relate to a fastener designed to reduce its overall footprint. For example, a portion of the fastener can be designed to break off, or decouple, from a remaining portion of the fastener after the fastener is positioned to secure together two or more parts. As a result of the decoupled portion, the fastener includes a reduced size and accordingly, occupies less space. In some instances described herein, the fastener is used to secure together parts in an electronic device. Further, the fastener can be used to secure together two or more parts in a relatively small space of the electronic device based upon a removal of the decoupled portion. 
     In an example embodiment, a fastener may include a platform and a shaft, or shank, extending from the platform. In some cases, the shank is integrally formed with the platform. The phrase “integrally formed” refers to a single, continuous material that may include two or more features. As non-limiting examples, the features may be formed by extruding or machining a single piece of material. The fastener may also include a head secured with the platform and designed to receive a tool to rotationally drive or actuate the fastener through the parts to be fastened together. 
     The head may be secured with the platform by a material such as an adhesive, an epoxy, or a resin. The material may be selected based upon its known bonding forces or bonding properties in order to create a bond with a predetermined (or known) bonding force between the head and the platform. Using an initial rotational force, or initial torque, the tool may engage the head to rotationally drive the head, which in turn, rotational drives shaft between two or more parts. The initial rotational force may also drive the platform to engage the first part (closest to the platform). At this point, the initial rotational force may no longer drive the fastener, as the platform prevents further movement of the shaft into the parts. However, by providing an additional rotational force, or additional torque, greater than the initial rotational force, the tool causes shear stress to the material used to bond the head with the platform. The additional rotational force is associated with a greater amount of force than that of the initial rotational force. The additional rotational force may overcome the predetermined bonding force (between the head and the platform), causing a breakdown in the material such that the head breaks away, or decouples, from the platform. As a result, the size of the fastener based on the head being removed from the fastener. However, the platform and the shaft remain, and combine to retain and secure the parts together without the head. 
     In another example embodiment, the threads of the shaft may be replaced by one or more blades, or lobes, which extend radially outward from the shaft. The blades are designed to engage at least one of two or more parts to be secured together. The head may be driven in a rotational manner causing the blades to rotate and engage one of the parts. The shaft may also include several protrusions that also extend radially outward from the shaft. In some cases, one of the parts may include an opening that includes several extensions, or ramps, extending inward in a direction toward the shaft. The number of extensions may correspond to the number of protrusions. In this manner, when the shaft and the blades are rotationally driven into an opening of the part, each blade of (of the shaft) is secured around an extension. Further, each protrusion (of the shaft) engages a protrusion (of the part) to form an interlock between the shaft and the part. The interlock may create frictional forces between the fastener and the part, thereby preventing the fastener from decoupling from, or falling out of, the part. 
     These and other embodiments are discussed below with reference to  FIGS. 1-21 . 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  illustrates an isometric view of an embodiment of a fastener  100  designed to secure together two or more parts, in accordance with the described embodiments. As shown, the fastener  100  may include a head  102 , or head portion, that includes a recess  104  designed to receive a tool (not shown). While the recess  104  is shown having a particular size and shape, the size and shape of the recess  104  may vary in other embodiments, according to the desired tool to be used. Also, although not shown, the recess  104  may be removed and the head  102  may include a polygonal shape that may be received by a tool, such as a ratchet, having a size and shape corresponding to that of the head  102 . The fastener  100  may further include a platform  106  and a shaft  108  extending from the platform  106 . In some embodiments, the shaft  108  is generally smooth and free of threads or other features. In the embodiment shown in  FIG. 1 , the shaft  108  includes a threaded region  110 . Although the threaded region  110  includes a particular number of threads, the threaded region  110  may include fewer or more threads based in part on the size of the shaft  108 . The head  102 , the platform  106 , and the shaft  108  may be formed from a metal, such as steel, aluminum, nickel, or an alloy that combines several metals. Alternatively, the head  102 , the platform  106 , and the shaft  108  may be formed from a polymeric material, such as plastic. Also, in some embodiments, the shaft  108  is integrally formed with the platform  106 . 
     The head  102  may be secured with the platform  106  by a material  112 . In some embodiments, the material  112  is an adhesive material with known adhesive properties. For example, a known adhesive property of the material  112  may include a predetermined adhesive bond strength. In this manner, a predetermined bonding force between the material  112  and the head  102  (at an interface between the material  112  and the head  102 ) as well as a predetermined bonding force between the material  112  and the platform  106  (at an interface between the material  112  and the platform  106 ) may be known, or at least approximately known. The predetermined bonding forces may determine a bonding force between the head  102  and the platform  106  by way of the material  112 . In this manner, a rotational force provided to the head  102  to overcome the aforementioned bonding forces can be determined. Further, the rotational force may cause the material  112  to break down and release the head  102  from the platform  106 . In some instances, the rotational force is applied subsequent to the fastener  100  securing together two (or more) parts. Further, the removal of the head  102  causes a reduction in the size of the fastener  100 . This will be shown and described below. Also, when the material  112  is removed along with the head  102 , the fastener  100  is further reduced in size. 
       FIG. 2  illustrates a cross sectional view of the fastener  100  shown in  FIG. 1 , taken along the A-A line in  FIG. 1 . As shown, the material  112  separates the head  102  from the platform  106 . Also, the head  102 , the platform  106 , and the material  112  may combine to define a first dimension  114  of the fastener  100 . Further, when the head  102  decouples from the platform  106 , and when the material  112  remains on the head  102  (or is otherwise removed from the platform  106 ), the fastener  100  reduces to a second dimension  116  less than the first dimension  114 . The second dimension  116  may define a low-profile fastener having a reduced size without the head  102 . As a result of the reduced dimensional profile, or reduced footprint, the fastener  100  may occupy less volume, which may be useful when the fastener  100  is located in a relatively small space. 
       FIGS. 3-6  show a fastening operation using the fastener  100  shown and described in  FIGS. 1-2 . The fastening operation may include using the fastener  100  to secure together multiple parts.  FIG. 3  illustrates an isometric view of the fastener  100  driven into a first part  130  and a second part  132 . For purposes of simplicity, only a portion of the first part  130  and the second part  132  are shown. However, in some embodiments, the first part  130  and the second part  132  are structural components in an electronic device (not shown). For example, the first part  130  may include a support feature or frame that carries a protective layer, such as a cover glass. Further, the second part  132  may include a support feature for an operational component used by the electronic device, such as a circuit board. Also, while only the first part  130  and the second part  132  are shown, the fastener  100  may be designed to engage and secure together three or more parts. 
     As shown in  FIG. 3 , the fastener  100 , by way of the recess  104  in the head  102 , receives a tool  140  that rotationally drives the fastener  100 , causing a threaded engagement between the threaded region  110  of the fastener  100  and a threaded region (not shown) of the first part  130  and/or the second part  132 . In other embodiments in which the fastener  100  does not include the threaded region  110 , the fastener  100  may be disposed in the first part  130  and the second part  132  without a driving force. Also, it will be appreciated that the first part  130  and the second part  132  may be stationary with respect to the fastener  100  while a rotational force is applied to the fastener  100 . 
       FIG. 4  illustrates an isometric view of the fastener  100  shown in  FIG. 3 , showing the fastener  100  substantially driven into the first part  130  and the second part  132 . The fastener  100  may be “substantially driven” when, for example, the platform  106  engages the first part  130 , and/or when the shaft (not shown) “bottoms out,” or engages a bottom wall (not shown) of the second part  132 . In either event, the fastener  100  may be require additional rotational force by the tool  140  to further rotationally drive the fastener  100 . 
     However, an additional rotational force, or additional torque, exerted on the fastener  100  may cause an additional force, including shear stress, on the material  112  used to secure the head  102  with the platform  106 . Further, when the force is greater than the adhesive bonding force of the material  112 , the material  112  may no longer be able to secure together the head  102  with the platform  106 . For example,  FIG. 5  illustrates an isometric view of the fastener  100  shown in  FIG. 4 , showing the head  102  decoupling from the platform  106  in response to a force greater than the adhesive bonding force of the material  112 . As shown, the head  102 , along with the material  112 , is removed in response to the rotational force. The adhesive bonding force of the material  112  may be based in part on the chemical makeup of the material  112 . In this regard, when the adhesive bonding force of the material  112  is known, the rotational force required to overcome the adhesive bonding force of the material  112  to remove the head  102  can be determined (for example, prior to providing the rotational force). Also, the material and/or roughness of the head  102  and the platform  106  may account for the bond strength between the material  112  and the head  102 , and also for the bond strength between the platform  106  and the material  112 . For example, when the platform  106  includes a textured, non-planar surface, the adhesive bond between the material  112  and the platform  106  may be enhanced, thereby requiring additional rotational force to overcome the bond between the platform  106  and the material  112 . 
       FIG. 6  illustrates an isometric view of the fastener  100  shown in  FIG. 5 , with the platform  106  remaining subsequent to the removal the head  102  and the material  112  (shown in  FIG. 5 ). As shown, the platform  106  along with the shaft  108  may be used to secure the first part  130  together with the second part  132 . Also, the platform  106  may include a smooth or flat surface to enhance an overall appearance of the fastener  100 , and in turn, an electronic device (not shown) that includes the fastener  100 , first part  130  and the second part  132 . However, in some instances, the adhesive bond between the platform  106  and the material  112  is different from the adhesive bond between the head  102  and the material  112 . For example, the platform  106  may include a surface roughness less than that of the head  102  (shown in  FIG. 4 ) in locations in which the head  102  and the platform  106  are bonded with the material  112 . This may cause a stronger bond between the material  112  and the head  102 , as compared to that between the platform  106  and the material  112 . As a result, the bond between the material  112  and the platform  106  may break down before the bond between the material  112  and the head  102 , causing the material  112  to decouple from the platform  106 , as shown in  FIG. 6 . Accordingly, the fastener  100  may include a design detail to control the removal of the material  112  from the platform  106 . 
     In other embodiments, the relative surface roughness of the head  102  and the platform  106  are switched, causing the bond between the head  102  and the material  112  to break down first, such that the material  112  remains on the platform  106 . The material  112  may then be used provide a protective coating to the platform  106  against other operations used to form an electronic device (not shown), such as an anodization process in which an electronic device is exposed to an anodic bath with one or more acids designed to form an oxidation layer over a metal (such as an enclosure or housing of the electronic device). In this manner, the material  112  may shield the platform  106  from acidic compounds from the anodic bath. The material  112  may then be removed subsequent to the anodization process. Also, although not shown, the platform  106  may include a rounded or dome-like surface resembling, generally, a semi sphere. This may prevent or limit the ability to remove the fastener  100  from the first part  130  and the second part  132 . For example, once the fastener  100  secures the first part  130  with the second part  132 , a user may be prevented from sufficiently gripping the fastener  100  and applying a rotational force to the fastener  100  to remove the fastener  100 . This may prevent or limit tampering of the electronic device. 
     The fastener  100  shown and described in  FIGS. 3-6  may offer additional advantages. For example, the head  102  may decouple from the platform  106  only in response to a sufficient rotational force. Accordingly, the removal of the head  102  may confirm a sufficient amount of rotational force, or torque, is applied to the fastener  100  such that the fastener  100  is secured with the first part  130  and the second part  132  in a desired manner. In other words, an “under torque” of the fastener  100  may be avoided as the head  102  decoupling from the platform  106  provides an indication of sufficient applied torque. Further, the fastener  100  may be prevented from an “over torque” event due in part to the decoupling between the head  102  and the platform  106 , as the decoupling causes a rotational force of the fastener  100  to cease. Accordingly, the fastener  100  is designed to limit the overall torque applied to the fastener  100  by allowing the head  102  to decouple from the platform  106  in response to sufficient rotational force applied to the fastener  100 , and in particular, to the material  112 . This may prevent damage to the fastener  100  as well as the first part  130  and the second part  132 . 
       FIGS. 7-9  illustrate alternate embodiments of a fastener. However, the fasteners shown and described in  FIGS. 7-9  may include several feature or features previously described for a fastener, such as a head, a platform, and a material that secures the head with the platform.  FIG. 7  illustrates a cross sectional view of an alternate embodiment of a fastener  200  that include multiple material layers, in accordance with the described embodiments. For example, the fastener  200  may include a head  202  secured with a platform  206  by a material assembly that includes a first type material surrounding a second type material. For example, the first type material may include a first adhesive layer  212  and a second adhesive layer  214 . The first adhesive layer  212  and the second adhesive layer  214  may include a first (predetermined) bonding force or first bonding strength. The second type material may include a third adhesive layer  216  sandwiched between the first adhesive layer  212  and the second adhesive layer  214 . In some embodiments, the third adhesive layer  216  includes a polyamide material. The third adhesive layer  216  may include a second (predetermined) bonding force or bonding strength different from that of the first adhesive layer  212  and the second adhesive layer  214 . 
     In some embodiments, the third adhesive layer  216  provides a bonding force or bonding strength that is less than that of the first adhesive layer  212  and the second adhesive layer  214 . In this manner, a rotational force applied to the fastener  200  may cause the third adhesive layer  216  to fail or break down at an interface between the first adhesive layer  212  and the third adhesive layer  216 , and/or at an interface between the second adhesive layer  214  and the third adhesive layer  216 . In this manner, the platform  206  may not be affected by shear stresses from the rotational force as the adhesive breakdown occurs only at an interface (and/or interfaces) between adhesives and not at the platform  206 . Accordingly, the fastener  200  may undergo less stress, thereby reducing the likelihood of breaking. 
       FIG. 8  illustrates an isometric view of an alternate embodiment of a fastener  300 , showing the fastener  300  having a head  302  secured with the platform  306  by several posts, in accordance with the described embodiments. Rather than using adhesives, the head  302  may be secured with the platform by, for example, a first post  312  and a second post  314 . A partial cross sectional view of the head  302  is shown to reveal the first post  312 . While only two posts are shown in  FIG. 8 , the fastener  300  may include additional posts. In some embodiments, the first post  312  and the second post  314  are secured with the head  302  and the platform  306  by an adhesive (not shown) having a known bonding force or bonding strength. Alternatively, the fastener  300  may undergo a machining operation to remove material and define the first post  312  and the second post  314  (and any additional posts). In this regard, the fastener  300  includes a single body of a known material (or materials) that define the fastener  300 . In either event, the properties (including bonding forces or material properties) used to secure the head  302  with the platform  306  are known. Accordingly, a rotational force may be applied to the head  302  sufficient to overcome and break down the adhesive bonds, in the first example, or break the first post  312  and the second post  314  (and any additional posts), in the second example, causing the head  302  to decouple from the platform  306  in a manner previously described. Regarding the latter, any remains of the posts may be removed from the platform  306  by a subsequent machining operation. 
       FIG. 9  illustrates an isometric view of an alternate embodiment of a fastener  400 , with a platform  406  of the fastener  400  having ridges  408  that may be used in conjunction with a tool (not shown), in accordance with the described embodiments. A head used to facilitate a rotational force is removed for purposes of illustration. However, the fastener  400  may include a head used in any manner previously described for a head of a fastener. As shown in the enlarged view, the ridges  408  of the platform  406  are disposed across the platform  406 . The ridges  408  may be referred to as micro-ridges as the ridges may be relatively small, with the pitch between adjacent rides having being less than 1 millimeter. 
       FIG. 10  illustrates an embodiment of a tool  410  used to engage the ridges  408  of the platform  406  shown in  FIG. 9 . As shown, the tool  410  may include ridges  418  designed to mate with the ridges  408  shown in  FIG. 9 . Accordingly, the ridges  418  may be disposed across a platform  416  of the tool in locations corresponding to the ridges  408  of the platform  406  in  FIG. 9 , and may also include a similar pitch between adjacent ridges. In this manner, the tool  410  provides a “key” in the form of the ridges  418  designed to pair with a “keyhole” in the form of the ridges  408  of the platform  406 , allowing the tool  410  to engage the platform  406  and provide a rotational force to rotationally drive the fastener  400 . This may allow the fastener  400  to be removed from the parts after the fastener  400  has previously secured together the parts and a head (not shown) is removed from the fastener  400 . In this manner, the fastener  400  may allow for a rework operation of an electronic device (not shown). Also, the tool  410  may include a proprietary tool distributed only by the manufacturer of the fastener  400 . 
       FIG. 11  illustrates an isometric view of an alternative embodiment of a fastener  500  having a shaft  508  that includes several blades extending radially outward from the shaft  508 . As shown, the fastener  500  may include a head  502  having a recess  504  designed to receive a tool (not shown). Also, the head  502  may be secured with a platform  506  by a material  512  that may include any material or materials previously described for a material that secures a head with a platform. This may allow the head  502  to decouple in response a shear stress exerted on the material  512  by providing a rotational force to the head  502  in a manner previously described. 
     As shown, the shaft  508  includes a first blade  514  and a second blade  516 . The shaft  508  may also include a third blade (shown below). The number of blades may vary in other embodiments. Also, the blades may replace a threaded region show in previous embodiments of a fastener, and the fastener  500  may use the blades to secure together two or more parts. The blades are designed to frictionally couple with one or more features of at least one of the parts. This will be shown below. Further, the shaft  508  carrying the blades may be adjusted in length based upon the size and the number of parts secured together by the fastener  500 . 
       FIG. 12  illustrates an isometric bottom view of the fastener  500  shown in  FIG. 11 , showing the blades as well as several protrusions. As shown, the first blade  514 , the second blade  516 , and a third blade  518  may extend radially outward from the shaft  508 . Also, each blade may generally include an L-shape configuration. For example, the first blade  514 , representative of the remaining blades, may include a first portion  522  designed to slide and engage at least one of the parts. The first blade  514  may further include a second portion  524  coupled with, and perpendicular with respect to, the first portion  522 . The second portion  524  may be used as a stop that abuts the same part (and/or an additional part) engaged with the first portion  522 . Also, the second portion  524  may extend to a rear portion of the platform  506  as shown in  FIG. 12 . However, in other embodiments, the second portion  524  does not extend to the rear portion of the platform  506 . 
     Also, the fastener  500  may include several protrusions extending from the shaft  508 . As shown, the fastener  500  includes a first protrusion  534  and a second protrusion  536 . The fastener  500  may further and a third protrusion (shown below). In some embodiments, the number of protrusions is equal to the number of blades. As shown, the first protrusion  534  is positioned between the first blade  514  and the second blade  516 , and the second protrusion  536  is positioned between the first blade  514  and the third blade  518 . Although not shown, the third protrusion may be positioned between the second blade  516  and the third blade  518 . The protrusions may combine to provide an interlock with at least one of the parts fastened by the fastener  500 . Further, the interlock may provide by a frictional force between the protrusions and the part, which may resist or prevent the fastener  500  from loosening and/or decoupling from the parts. This will be shown below. 
       FIG. 13  illustrates an exploded view of the fastener  500  shown in  FIGS. 11 and 12 , further illustrating the fastener  500  used to secure together two parts. The shaft  508 , along with the blades and the protrusions, may extend through an opening  542  of a first part  540 . As shown in  FIG. 13 , the first part  540  may include a washer used to facilitate a securing operation between the fastener  500  and a second part  550 . However, in other embodiments, the first part  540  is a structural component of an electronic device (not shown) used to support or carry another structural component of the electronic device. 
     The second part  550  may include a plate that secures with the fastener  500 . However, in other embodiments, the second part  550  includes an structural component of an electronic. As shown, the second part  550  includes an opening  552  through which the shaft  508 , along with the blades and the protrusions, may at least partially extend. The opening  552  of the second part  550  may include extensions, or ramps, or other inclined features designed to engage with the protrusions (shown in  FIG. 12 ) of the shaft  508  to define the interlock previously described. For example, the second part  550  may include a first extension  564  used to engage the first protrusion  534  (shown in  FIG. 12 ). 
       FIG. 14  illustrates an isometric view of the fastener  500  shown in  FIG. 13 , further showing the fastener  500  rotationally driven to fasten the first part  540  with the second part  550 . As shown, a tool  520  is used to rotationally drive the fastener  500 . When the shaft  508  (shown in  FIG. 13 ) is positioned in the first part  540  and the second part  550 , the fastener  500  may be rotationally driven such that the blades engage the second part  550 . This will be shown below. 
       FIG. 15  illustrates a bottom view of the fastener  500  shown in  FIGS. 13 and 14 , with the blades extending at least partially through the opening  552  of the second part  550 . As shown, the opening  552  of the second part  550  accommodate the first blade  514 , the second blade  516 , and the third blade  518 . The opening  552  may also accommodate the first protrusion  534 , the second protrusion  536 , and a third protrusion  538 . Also, as shown in  FIG. 15 , the second part  550  may include several extensions, such as a first extension  564 , a second extension  566 , and a third extension  568 . The number of extensions of the second part  550  may include the same number as that of the protrusions of the fastener  500 . Also, although not shown, the first part  540  may be positioned between the fastener  500  and the second part  550  in a manner similar to that shown in  FIG. 14 . 
       FIG. 16  illustrates a bottom view of the fastener  500  shown in  FIG. 15 , with the fastener  500  rotated with respect to the second part  550 , causing the fastener  500  to engage the second part  550 . As shown, the protrusions of the fastener  500  may engage the extensions of the second part  550 . For example, in the enlarged view, the fastener  500  is rotated such that the first protrusion  534  engages the first extension  564 . In this regard, the first extension  564 , as well as the remaining extensions, may include an asymmetric design that allows the first blade  514  to fit into the opening  552 , while also allowing the fastener  500  to rotate (in the opening  552 ) such that the first protrusion  534  engaged the first extension  564  to lock the fastener  500  with the second part  550 . The engagement between the first protrusion  534  and the first extension  564  may be a representative engagement between the remaining protrusions and extensions. This engagement provides a frictional force designed to limit or prevent the fastener  500  from loosening and/or decoupling from the second part  550 . 
       FIG. 17  illustrates an isometric view of the first part  540  and the second part  550  secured together by way of the fastener  500 , subsequent to a rotational operation to the fastener  500  that causes the head (not shown) to decouple from the fastener  500 , in accordance with the described embodiments. As shown, the platform  506  remains after the head is removed. Further, the platform  506  may combine with the blades (not shown) to provide a retaining force to maintain the first part  540  with the second part  550 , as the platform  506  engages the first part  540  and the blades engage the second part  550 . Also, as shown in  FIG. 17 , the second part  550  may be referred to as a furthermost part, relative to the first part  540 , to the platform  506 . Further, in other embodiments, with three or more parts, the furthermost part may be the part furthest from the platform  506 , relative to the remaining parts. Also, the furthermost part may include an opening having features (such as the extensions) that interlock with the fastener  500 . 
       FIG. 18  illustrates a cross sectional view of the fastener  500 , the first part  540 , and the second part  550 , shown in  FIG. 17 , taken along line B-B in  FIG. 17 . As shown, when the fastener  500  is rotated with respect to the second part  550 , the first blade  514  engages the first extension  564  by securing around the first extension  564 . Although not shown, the first extension  564  is engaged with the first protrusion  534  (shown in  FIG. 16 ). The remaining blades may engage the remaining extensions in a similar manner, and the fastener  500  interlocks with the second part  550 , and the first part  540  is secured together the second part  550 . 
       FIG. 19  illustrates an isometric view of an embodiment of an electronic device  600 . In some embodiments, the electronic device  600  is a tablet device. In the embodiment shown in  FIG. 19 , the electronic device  600  is a smartphone used as mobile telecommunication device. The electronic device  600  may include several components commonly used in an electronic device, such as an enclosure  602  that encloses several internal components (such as processor circuits, memory circuits, battery, etc.). The electronic device  600  may also include a display assembly  604  overlaid by a protective cover  606  formed from a transparent material, such as glass or sapphire. 
       FIG. 20  illustrates a cross sectional view of the electronic device  600  shown in  FIG. 19 , taken along line C-C in  FIG. 19 , showing the fastener  500  used to secure a first part  740  with a second part  750 , in accordance with the described embodiments. As shown in the enlarged view, the first part  740  is adhesively secured with the enclosure  602  by an adhesive  608 . Also, the first part  740  may include a support feature or frame that supports the display assembly  604  and the protective cover  606 . Also, the second part  750  may include a support feature that carries an operational component, such as an integrated circuit  752 . Also, as shown in the enlarged view, both the first part  740  and the second part  750  may include an opening (not labeled) to receive the fastener, with the second part  750  having an opening with features (such as the extensions) shown and described for an opening  552  shown in  FIGS. 15 and 16 . 
     Prior to assembling the first part  740  and the second part  750  in the electronic device  600 , the first part  740  and the second part  750  may be assembled together by the fastener  500  in a prior sub-assembly. This allows for the fastener  500  to secure together the two parts, and also to remove a head (not) of the fastener  500  by a rotational driving force in a manner previously described. The fastener  500  may offer several advantages. For example, after the first part  740  is secured with the second part  750  (by the fastener  500 ) and both are installed in the electronic device  600 , the first part  740  may move laterally (horizontally, as shown) with respect to the enclosure  602  in order to optimize an adhesive interface surface  610  of the enclosure  602 . In other words, an amount of the adhesive interface surface  610  available to adhesively bond the first part  740  with the enclosure  602  may be increased, due in part to the fastener  500  having only a platform, and not a head (previously coupled with the platform), that could otherwise engage the enclosure  602 . This may allow the first part  740  to be positioned closer to the enclosure  602 . 
     Also shown in enlarged view, the shaft of the fastener  500  may be sub-flush with respect to the second part  750  such that fastener  500  (including the blades) does not protrude outward with respect to the second part  750  in a direction toward a second operational component  754 . Traditional fasteners having a minimum number of threads in order to secure together the first part  740  with the second part  750  may require a fastener to protrude outward from the second part  750 , and the second operational component  754  is prone to damage from the fastener  500 . However, the fastener  500  having several blades, rather than a threaded configuration, allows for a low-profile fastener having a relatively small shaft such that the fastener  500  remains sub-flush with respect to the second part  750  (as shown in  FIG. 20 ), thereby reducing the likelihood of contacting the second operational component  754 . 
       FIG. 21  illustrates a flowchart  800  showing a method for making a fastener suitable for securing a first part with a second part, in accordance with the described embodiments. In step  802 , a platform is formed. The platform may include a shaft extending from the platform. In some embodiments, the platform is a flat or planar surface. In some embodiments, the platform includes a ridge (or ridges) that define a key such that a tool having a corresponding ridge (or ridges) may mate with the key to rotational drive the platform. In some embodiments, the aforementioned shaft includes threads. In other embodiments, the aforementioned shaft includes several blades. Regarding the latter, the shaft may further include protrusions designed to engage extensions of one of the second part, and interlock the shaft (and in turn, the fastener) with the second part. 
     In step  804 , the platform is secured with a head by a material that includes a bonding force. In some instances, in response to a rotational force to the head greater than the bonding force, the head decouples from the platform. In this regard, the material may include an adhesive that provides an adhesive bonding force. The adhesive bonding force may be predetermined or known, based upon the chemical makeup of the adhesive. In this regard, a predetermined rotational force provided by a tool, for example, to the fastener that is greater than the adhesive bonding force causes shear stress to the adhesive and breaks down the adhesive. When the adhesive breaks down, the head may decouple from the platform. 
     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 targeted 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: 20160916
Publication Date: 20180717
Grant Date: 20180717
Priority Date: 20150925
Inventors: HUO, EDWARD S.
AUCLAIR, MARTIN J.
MYERS, SCOTT A.
WITTENBERG, MICHAEL B.
SHUKLA, ASHUTOSH Y.
CATER, TYLER B.
Assignee: APPLE INC
CPC Classifications: [{"code": "B29K2077/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C65/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29L2031/3437", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B31/021", "inventive": true, "first": true, "tree": "[]"}, {"code": "B29C65/562", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B11/008", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B31/021", "inventive": true, "first": true, "tree": "[]"}, {"code": "B29L2031/727", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B33/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B31/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B31/021", "inventive": true, "first": true, "tree": "[]"}, {"code": "F16B33/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29L2031/727", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29K2077/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B31/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/562", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29L2031/3437", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B11/008", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 58406905