PATENT DOCUMENT

Publication Number: US-10385904-B2
Application Number: US-201615246476-A
Country: US
Kind Code: B2

Title: Press nut designs to minimize stack thickness

Abstract:
The described embodiments relate to embedding a threaded insert into a thin-walled housing. A recess can be formed with a machining tool that forms a recess in a thickened portion of the thin-walled housing. In some embodiments, the recess can be formed along one of the walls of the thin-walled housing in a location having highly a constrained amount of space available. Once the recess is formed a threaded insert can be pressed into the recess. An interference fit can be utilized to lodge the press-nut securely within the recess. Alternatively, a retaining member can be positioned across a front portion of the recess to trap the threaded insert between the retaining member and a rear surface of the recess.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing comprising:
 a wall that includes a first groove and a second groove, the first groove intersecting with the second groove to form an X-shaped recess, the first groove and the second groove each comprising a concave surface that defines the X-shaped recess; 
 
 a threaded insert positioned within the X-shaped recess and having a surface that is flush with the wall; and 
 a threaded fastener in threaded engagement with the threaded insert and securing an internal component against the wall. 
 
     
     
       2. The electronic device as recited in  claim 1 , wherein the first groove is arranged approximately perpendicular to the second groove. 
     
     
       3. The electronic device as recited in  claim 1 , wherein the threaded insert has a size and shape such that the threaded insert is retained in the X-shaped recess with an interference fit. 
     
     
       4. The electronic device as recited in  claim 1 , wherein the wall comprises a protrusion, the protrusion comprising the first groove and the second groove. 
     
     
       5. The electronic device as recited in  claim 4 , wherein the threaded insert is formed from a material that is substantially harder than a material of the protrusion. 
     
     
       6. The electronic device as recited in  claim 1 , wherein the threaded insert comprises engaging features that deform portion of a surface defining the first groove and the second groove so that the threaded insert is secured within the first groove and the second groove. 
     
     
       7. The electronic device as recited in  claim 1 , wherein the threaded insert comprises stainless steel, and wherein the wall comprises aluminum. 
     
     
       8. An attachment feature for an electronic device, the attachment feature comprising:
 a sidewall comprising a protrusion that includes an X-shaped recess; and 
 a threaded insert having a size and shape in accordance with the X-shaped recess, the threaded insert comprising a front face, wherein the threaded inserts fills the X-shaped recess such that the front face is flush with respect to a surface of the sidewall, and wherein threading of the threaded insert is oriented along an axis that is substantially normal to a front surface of the protrusion. 
 
     
     
       9. The attachment feature of  claim 8 , wherein a wall is disposed proximate the sidewall and wherein the sidewall cooperates with the wall to define a channel that the protrusion extends into. 
     
     
       10. The attachment feature of  claim 8 , wherein a material forming the protrusion is softer than a material that forms the threaded insert.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/288,215 filed May 27, 2014, of the same title, the content of which is incorporated herein by reference in its entirety for all purposes. 
    
    
     FIELD 
     The described embodiments relate generally to means for securing components to a thin walled housing. More particularly, the present embodiments relate to methods and apparatus for forming a recess suitable for receiving a press nut that includes a threaded opening in a small form factor electronic device. 
     BACKGROUND 
     As electronic devices grow increasingly smaller, space available within a device housing that has a desirable external size and shape can be insufficient to accommodate requisite internal operational components. One way to increase available volume within the device without making the housing any bigger is to reduce a thickness of interior and/or exterior walls of the device housing. Unfortunately, when the walls of the device housing are reduced below a minimum threshold, forming attachment points for internal operational components can become problematic. For example, when the walls become too thin to define a threaded opening having a sufficient depth to retain a fastener this can leave only adhesive couplings, which may be insufficient to properly secure components within the housing. Furthermore, in some embodiments, small form factor device housings can have internal geometries such as closely spaced walls that prevent line of sight to enable formation of a standard screw point normal to an interior surface of the small form factor housing. 
     SUMMARY 
     This paper describes various embodiments that relate to forming an attachment point within a device housing. 
     An electronic device is disclosed. The electronic device includes at least the following: a housing, including a first wall and a second wall, the first wall adjacent to the second wall; a protrusion extending from the first wall and towards the second wall, the protrusion including a concave surface defining a recess; and a threaded insert trapped within the recess by a number of retaining members extending across the recess and in front of at least a portion of the threaded insert, wherein the threaded insert is configured to receive a threaded fastener for securing an internal component against the first wall. 
     A method for forming an attachment point in a thin-walled housing is disclosed. The method includes at least the following steps: positioning a machining tool between two adjacent walls of the thin-walled housing; forming a channel with the machining tool in a protrusion extending from an interior surface of one of the walls; forming a number of holes that extend through both a top portion and a bottom portion of the protrusion; inserting a threaded insert into the channel, the threaded insert including a plurality of flanges; and driving a shaft through each of the openings so that each of the flanges is trapped between one of the shafts and a back surface that defines the channel. 
     An attachment feature, including at least the following elements: a protrusion extending from an inside surface of a sidewall, the protrusion having an inward curving surface disposed along a front surface of the protrusion, the inward curving surface defining a recess; a threaded insert disposed within the recess; and a retaining feature that prevents removal of the threaded insert from the recess, the retaining feature disposed across a front opening leading into the recess. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       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. 1A  shows a perspective view of a housing suitable for use with the described embodiments; 
         FIGS. 1B-1C  show how a T-Cutter can be utilized to cut a substantially linear recesses into a protrusion of the housing depicted in  FIG. 1A ; 
         FIGS. 1D-1E  show how a T-Cutter can be utilized to cut a cross-shaped recess into a protrusion of the housing depicted in  FIG. 1A ; 
         FIGS. 2A-2E  show a recess that can be formed in accordance with the machining operations depicted in  FIGS. 1B-1C  and how a threaded insert can engage the formed recess; 
         FIGS. 3A-3F  show a specific configuration that can be created by utilizing a T-Cutter and a drill; 
         FIGS. 4A-4D  show a specific configurations that can be created by utilizing a T-Cutter in accordance with the discrete machining operations depicted in  FIGS. 1D-1E ; 
         FIGS. 5A-5D  show another specific configuration that can be created by utilizing a T-Cutter in accordance with the machining operations depicted in  FIGS. 1D-1E . 
         FIGS. 6A-6E  show another method for forming a recess in a wall of a housing with an end mill; 
         FIGS. 6F-6I  show how a threaded insert can be engaged within a recess formed in accordance with the machining operation depicted in  FIGS. 6A-6E ; 
         FIGS. 7A-7E  show yet another method for forming a recess in a wall of a housing with a ball cutter; 
         FIGS. 7F-7J  show how a threaded insert can be engaged within a recess formed in accordance with the machining operation depicted in  FIGS. 7A-7E ; and 
         FIG. 8  shows a flow chart representing a method for forming an attachment point by embedding a threaded insert in a recess of a thin-walled housing 
     
    
    
     DETAILED DESCRIPTION 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     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. 
     As smaller form factor devices become more common place, ways to fit numerous electrical components and/or sensors within the small form factor devices gets increasingly more challenging. One way to increase an amount of available room is to utilize a thin-walled device housing that provides the benefit of increased internal volume when compared with a device housing of similar size having thicker walls. Unfortunately, when particularly thin walls are used, formation of attachment or screw points in the thin walls can become challenging. For example, when engaging a threaded screw in a threaded opening, the threaded opening generally requires a minimum depth of threading that allows the threaded fastener to be securely engaged within the threaded opening. When the wall is not thick enough to support the minimum threading depth, coupling between the threaded screw and the threaded opening can be compromised. 
     One solution to this problem is to use a housing with walls that are selectively thickened in places where attachment points are desired. By forming attachment points only in the thickened portions of the walls of the housing, the wall thickness problems associated with attachment point formation can be overcome. In some embodiments, thickened portions of the walls can correspond to portions of the housing that would otherwise go unused or at least underutilized. In this way, the thickened walls can provide a material thickness suitable for supporting a threaded opening without adversely affecting space available within the housing. Another challenge of forming attachment points in small form factor housings is positioning a tool between adjacent walls to form the attachment points. The aforementioned targeted wall thickening can make positioning of the tool between adjacent walls even more difficult because the thickened walls can further reduce an amount of space between the walls. For example, when two walls are particularly close together forming an attachment point with conventional tooling can be problematic as the additional wall or any other internal blocking feature may not leave sufficient room to position the convention tool at an appropriate angle to form the attachment point. Conventional tooling often requires alignment of a shaft normal to an inside surface along which a threaded opening is desired to be formed. Some less conventional tools along the lines of T-cutters, and ball cutters can be used to form attachment points in minimal clearance areas because only the cutting portion of the blade needs to be oriented normal to a direction of the cut. 
     Unfortunately, the aforementioned tools are not well suited for forming a threaded aperture directly into a wall of the housing. Instead these tools can be utilized to form a recess in thickened portions of the housing. The recess can be shaped to receive a preformed press nut or threaded insert that can include threading to receive a threaded fastener. The threaded insert can be formed of a material that is harder than material used to form the wall of the housing. In this way, as the threaded insert is pressed into the housing the threaded insert deforms material of the housing so that the threaded insert becomes securely affixed within the recess. The recess can include geometry that discourages rotation of the threaded insert within the recess. In some embodiments, the threaded insert itself can include protruding features that dig into the material that defines the recess during an insertion operation. Once the threaded insert is inserted, the protruding features also act to discourage free rotation of the threaded insert within the recess. It should be noted that in some embodiments the threaded insert can be formed of a softer material than the housing and can be configured to deform around features defined by the housing. 
     These and other embodiments are discussed below with reference to  FIGS. 1A-8 ; 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. 1A  shows a perspective view of a portion of housing  100 . Housing  100  can include a number of protrusions  102 . Protrusions  102  are securely joined with interior sidewalls of housing  100 . In one embodiment, protrusions  102  can be formed during a subtractive machining operation. For example housing  100  can start as a single block of material from which material is machined away. By machining away a central portion of the block, a housing can be formed that defines a cavity within the single block of material. As the cavity is enlarged the walls of housing  100  become progressively thinner. Portions of the walls forming housing  100  can be purposefully left thicker where an attachment point is desired, thereby leaving protrusion  102 . In this way, protrusions  102  can be integrally formed with the walls. Furthermore, a geometry of the protrusions can be easily customized by changing the machining operation during which material is removed. Alternatively, the walls can be formed having a uniform thickness and then protrusions  102  can be coupled to interior surfaces of the walls of housing  100 . For example, protrusions  102  can be joined to housing  100  by a welding operation or by an adhesive coupling. Although only two protrusions  102  are depicted it should be understood that housing  100  can include any number of protrusions  102  having varying sizes and shapes. When a distance  104  between walls  106  and  108  is too small to position a machining tool, such as for example a drill, between walls  106  and  108  or drive the drill in a direction normal to an inside surface of protrusion  102 , alternative machining tools can be utilized. 
       FIGS. 1B-1C  show how a T-Cutter can be utilized to cut a substantially linear recesses into protrusion  102 .  FIG. 1B  shows T-Cutter  110  positioned between walls  106  and  108  to prepare to engage at least one of protrusions  102 . T-Cutter  110  can include a shaft rotatably coupled to a substantially circular cutting blade. It should be noted that in some alternative embodiments, a non-circular cutting blade having, for example an elliptical shape can be utilized. In some embodiments, the non-circular cutting blade can help to fit T-Cutter  110  between walls  106  and  108 . While T-Cutter  110  is shown taking up a majority of space between walls  106  and  108 , it should be understood that a cutting blade of T-Cutter  110  can have any diameter that is less than a distance  104  while maintaining a radius greater than a depth of a recess that is desired to be cut into protrusion  102 . A size of the cutting blade can be sized to correspond with a desired curvature of a cut formed by the cutting blade.  FIG. 1C  shows a portion of a notch that can be formed by T-Cutter  110  as it cuts through a portion of protrusion  102 . While a relatively narrow linear notch is depicted, it should be understood that a shape and width of the notch can be varied by maneuvering T-Cutter  110  in different directions during a cutting operation. In some embodiments, T-Cutter  110  can be translated back and forth at different elevations during a number of linear cutting operations to give the linear notch a desired geometry. 
       FIGS. 1D-1E  show how a cross-shaped recess can be created by orienting T-Cutter  110  at a 45 degree angle with respect to housing base  112  of the housing prior to initiating a first cutting operation. Subsequent to the first cutting operation, T-Cutter  110  can be rotated 90 degrees from the orientation utilized in the first cutting operation prior to initiating a second cutting operation (see  FIG. 1E ). In other embodiments, instead of utilizing two discrete cutting operations T-Cutter  110  can be rotated between the two orientations depicted in  FIGS. 1D and 1E  during a single cutting operation to form a butterfly shaped recess, subsequently depicted in  FIG. 5A . 
       FIGS. 2A-2E  show a recess that can be formed in accordance with the machining operations depicted in  FIGS. 1B-1C  and how a threaded insert can engage the formed recess.  FIG. 2A  depicts a perspective view of a housing having recess  202  machined into protrusion  102  in accordance with the discrete machining operation depicted in  FIGS. 1B-1C . Depending on a height of a channel formed by recess  202 , a number of machining operations can be utilized to create recess  202 .  FIG. 2B  shows threaded insert  204  engaged within recess  202 . Threaded insert  204  can be pressed directly into recess  202  until a front face of threaded insert  204  is substantially flush with a front face of protrusion  102 .  FIG. 2C  shows a top view of protrusion  102  and threaded insert  204  that illustrates how far threaded insert  204  extends into recess  202  and how close threaded insert  204  comes to a back wall  208  that defines. As depicted, threaded insert  204  extends almost all the way into the thickness provided by protrusion  102 .  FIG. 2D  shows a front view of threaded insert  204  and how threaded insert  204  can include a number of protruding features  210  that engage an interior surface defining recess  202 . These protruding features  210  create grooves in walls that define recess  202  and can prevent least lateral shift of threaded insert  204  within recess  202 .  FIG. 2E  shows a side cross-sectional view of threaded insert  204  in accordance with section line A-A of  FIG. 2B . This depiction shows how threaded insert  204  extends nearly to the back of recess  202 . In some embodiments, the gap between a rear surface of threaded insert  204  and back wall  208  can leave room for material deformed by threaded insert  204  during an insertion operation. In this way, threaded insert  204  can be fully inserted within recess  202 . It should also be noted that recess  202  has a depth that leaves a remaining amount of material to structurally stabilize wall  108 . In the depicted embodiment, wall  108  has a minimum thickness of about 0.55 mm. In some embodiments, this can be about the same as the rest of the wall, thereby preventing a weak structural area from coinciding with the attachment point. Depending upon design characteristics of the case the minimum thickness can be thicker or thinner. 
       FIGS. 3A-3F  show a specific configuration that can be created by utilizing a T-Cutter and a drill. Channel  302  can be created in accordance with the machining operations depicted in  FIGS. 1B-1C . Subsequent to creating channel  302  a drill can be utilized to create openings  304  that extend through top and bottom portions of protrusion  102  to create the configuration depicted in  FIG. 3A . In  FIG. 3B  a threaded insert  306  is pressed into channel  302 . Threaded insert  306  includes threading  308  and flanges  310 . Threaded insert  306  gets pressed into channel  302  until flanges  310  are pushed behind drilled openings  304 . Flanges  310  can have a curvature shaped to interact with shafts  312  inserted through openings  304 .  FIG. 3C  shows how shafts  323  can pass through openings  304  to trap threaded insert  306  within channel  302 . Shafts  312  passing through openings  304  trap flanges  310  of threaded insert  306  between shafts  312  and a rear surface that defines channel  302 . In some alternative embodiments, threaded insert  306  can include openings through which the shafts pass in lieu of flanges  310 . In an embodiment, threaded insert can fill up substantially all of the volume of channel  302  made by the T-Cutter, and the shafts  312  can pass through the aforementioned openings in the threaded insert discussed above. By substantially filling channel  302  with threaded insert  306  a structural integrity of protrusion  102  can be about the same as it was before channel  302  was formed.  FIG. 3D  shows how flanges  310  can be trapped between a back wall of recess  302  and a portion of shafts  312 .  FIG. 3E  shows how opening  308  can be disposed between and not covered by shafts  312 . Finally,  FIG. 3F  shows how threaded insert  306  can be in direct contact with a back wall of recess  302 . In this embodiment a wall thickness of 0.55 mm can provide thickness sufficient to maintain structural integrity of wall  108 . 
       FIGS. 4A-4D  show a specific configurations that can be created by utilizing a T-Cutter in accordance with the discrete machining operations depicted in  FIGS. 1D-1E .  FIG. 4A  depicts a perspective view of an X-Insert configuration. Each leg of recess  202  has a variable depth with a curvature in accordance with a curvature of the blade of the T-Cutter used to form recess  402 . While an X-Insert configuration is depicted, a cross-configuration is also possible by changing an angle at which the cutting blade of the T-Cutter contacts protrusion  102 .  FIG. 4B  shows threaded insert  404  having a size and shape in accordance with recess  402 . Threaded insert  404  may be made from a material that is harder than the material that forms protrusion  102 . For example, threaded insert  404  can be formed from stainless steel when protrusion  102  is formed from aluminum or an aluminum alloy. Threaded insert  404  can be slightly larger in places than recess  402 . In this way insert  404  can cause surfaces defining portions of recess  402  to deform around and retain threaded insert  404  with an interference fit. Threaded insert  404  can include threading  406  disposed in a central opening of insert  404 . Threading  406  can have a pattern of threading that is complementary to a fastener it is configured to receive. In this way, the fastener and threading  406  can retain various components to which the fastener is mechanically coupled against wall  108  and/or protrusion  102 . 
       FIG. 4C  shows a top view of threaded insert  204 . The top view shows a position of threaded insert  404  with respect to protrusion  102 . Individual legs of threaded insert  404  are depicted extending evenly from a central portion of threaded insert  404 .  FIG. 4D  illustrates a front view of threaded insert  404 . In this view protruding features  408  are depicted extending outward and away from a central portion of threaded insert  404 . Protruding feature  408  can bite into surfaces that define recess  402  so that threaded insert  404  is secured within recess  402  at a periphery of threaded insert  404 . In some embodiments, tips of protruding features  408  can be sharpened to reduce an amount of insertion force required as the sharply pointed protruding features  408  facilitate a greater concentration of force during an insertion event. 
       FIGS. 5A-5D  show another specific configuration that can be created by utilizing a T-Cutter in accordance with the machining operations depicted in  FIGS. 1D-1E .  FIG. 5A  depicts a perspective view of a recess  502  having a butterfly configuration created in accordance with a continuous machining operation in which the T-Cutter rotates about 90 degrees during a machining operation. In some embodiments, a greater or smaller angle of rotation can be used varying the angle in accordance with a shape of a threaded insert. It should be noted that by rotating the T-Cutter less than 180 degrees during the rotation two alignment features  504  can be left to prevent rotation of a threaded insert disposed within recess  502 . It should be noted that recess  502  extends outside of protrusion  102 , leaving a  FIG. 5B  shows threaded insert  506  engaged within recess  502 . In some embodiments, threaded insert  506  can include engaging features configured to deform portions of a surface defining recess  502  so that threaded insert  506  can be securely disposed within recess  502 . 
       FIG. 5C  shows how far threaded insert  506  extends into protrusion  102 . The depth of threaded insert  506  generally depends on a depth of threading needed for threaded insert  506  to be securely coupled with a threaded fastener. An amount of threading required can depend upon a number of factors including a pitch of the threading, a diameter of the fastener and a material used to form threaded insert  506 . In some embodiments the threading can pass entirely through the threaded insert while in other embodiments, the threaded insert can include a back wall that prevents a fastener from passing through the threaded insert. In other embodiments, the fastener can be configured to engage a portion of the wall  108  after passing through the threading of threaded insert  506 .  FIG. 5D  illustrates how threaded insert  506  can include protruding features  508  that in cooperation with alignment features  504  inhibit free rotation of threaded insert  506  within recess  502 . It should also be noted that threaded insert  506  includes protruding features  508  in locations that extend outside of protrusion  102 . This can be useful when protrusion have varying widths. For example, when the butterfly configuration is disposed entirely within protrusion  102 , each of protruding features  508  can bite into surfaces defining recess  502 . 
       FIGS. 6A-6E  show another method for forming a recess in a wall of a housing.  FIG. 6A  depicts sidewall  602  with a flat interior surface. End mill  604  is depicted in  FIG. 6B  just prior to engaging the wall of the housing. End mill  604  rotates about an axis of rotation defined by axis  606 . In some embodiments, end mill  604  can be oriented at an angle of about 45 degrees with respect to the inside surface of the housing.  FIG. 6C  shows how end mill  604  is inserted a fixed distance into the surface of the housing. In  FIG. 6D  end mill  604  is translated straight down so that a rear surface having a substantial constant shape is created. This creates a consistent shape against which a threaded insert can be pressed. Finally, in  FIG. 6E  end mill  604  is depicted being extracted from formed recess  608 . As can be seen in the figures, a 45 degree insertion angle has a benefit of providing top and bottom edges having substantially the same angle. Alternatively, different insertion and extraction angles can be utilized to provide differing angles for top and bottom portions of recess  608 . 
       FIGS. 6F-6I  show how a threaded insert can be engaged within recess  608 .  FIG. 6F  shows a perspective view of recess  608  formed in accordance with the machining operation depicted in  FIGS. 6A-6E .  FIG. 6G  shows how threaded insert  610  can be inserted into recess  608 . Threaded insert  610  can have a geometry in accordance with a back surface of recess  608  as depicted or in other embodiments can have a shape and size in accordance with all of recess  608  so that threaded insert fills substantially fills recess  608 . Threaded insert  610  includes threading  612  for retaining a threaded fastener. In some embodiments, threaded insert  610  can have a height that leaves upper and lower portions of recess  608  open. When threaded insert  610  has a that allows it to avoid the sloped surfaces created by insertion and extraction of the end mill, machining tolerances can be reduced as an angle of the insertion and extraction of the end mill need not be exact to facilitate proper fit of threaded insert  610  within recess  608 . 
       FIGS. 7A-7E  show yet another method for forming a recess in a wall of a housing  700 .  FIG. 7A  shows a cross-sectional side view of housing  700 .  FIG. 7B  shows ball cutter  702  which includes a cutting portion  704   a  and a holding portion  704   b . Cutting portion  704   a  can be used to engage an inside surface of housing  700 .  FIGS. 7C-7D  show how cutting portion  704   a  of ball cutter  702  can gradually cut through the inside surface of housing  700 . It should be noted that, as depicted in  FIG. 7D , as ball cutter  702  cuts deeper into housing  700  holding portion  704   b  can be rotated down to avoid contact between holding portion  704   b  and housing  700 . In this way, the holding portion  704   b  can remain clear of any other obstructions, such as interior sidewalls at the beginning of a cutting operation and then be maneuvered during the cutting operation to stay clear of housing  700 .  FIG. 7E  shows a geometry of recess  706  after ball cutter  702  is removed subsequent to the cutting operation. It should also be noted that housing  700  is depicted having a curved exterior surface that increases a thickness of the sidewall in a position that helps thicken the sidewall where a greatest amount of material is removed for recess  706 . Similarly, it should be understood that while other housings have shown flat exterior surfaces an exterior curvature of the sidewalls can be shaped to accommodate other recess geometries. 
       FIGS. 7F-7J  show how a threaded insert can be engaged within recess  706 .  FIG. 7F  shows a perspective view of recess  706  formed in a wall  108  of a housing in accordance with the machining operation depicted in  FIGS. 7A-7E .  FIG. 7G  shows how threaded insert  708  can be positioned when inserted into recess  706 . Threaded insert  708  can have a geometry in accordance with a circular geometry of recess  706  so that it fills at least a front portion of recess  706 , as depicted in  FIG. 7H . Also as depicted, threaded insert  708  is pressed into recess  706  until a front surface of threaded insert  708  is substantially flush with a front surface of protrusion  102 . In some embodiments, threaded insert  708  can be designed to fill substantially all of recess  706 . Threaded insert  708  also includes a threaded opening  710 , as depicted in  FIG. 7I . Threaded opening  710  can be configured to receive a threaded fastener in a way that mechanically couples the threaded fastener to threaded insert  708 . 
       FIG. 7J  shows an amount of clearance between threaded insert  708  and a back end of recess  706 .  FIG. 7J  also depicts how an annular channel  712  in threaded insert  708  causes material  714  from the housing to be trapped within annular channel  712  as threaded insert  708  is pressed into recess  706 . In this way, the material  714  of the housing that deforms into annular channel  712  effectively prevents removal of threaded insert  708  from recess  706 . It should be noted that while  FIG. 7J  shows specific dimensions of wall  108  and recess  706 , the dimensions should not be construed as limiting. For example, the thickness of material between recess  706  and an outside surface of wall  108  is depicted as about 0.5 mm, but can be greater or smaller depending upon a material used to form wall  108 . For example, if 0.5 mm were appropriate for a wall formed from aluminum or aluminum alloy, 0.25 mm may be sufficient for a stainless steel housing. 
     It should be understood that while many threaded insert configurations have been described, many of the features described with regards to any one of the described threaded inserts can be equally well applied to other ones of the threaded inserts. Furthermore, in some embodiments, the threaded insert itself can be a composite insert formed from multiple materials. For example, a plastic core can support metal threading and a metal periphery so that the threaded insert can be lighter but still configured to deforms the recess and be securely coupled with a threaded fastener. 
       FIG. 8  shows a flow chart representing a method for forming an attachment point by embedding a threaded insert in a recess of a thin-walled housing. In a first step  802  a thin-walled housing that includes at least two adjacent walls is obtained. A thickness of the walls can be varied to provide increased wall thicknesses only at select locations that require additional thickness to allow for retaining a threaded insert. At step  804  at least a cutting portion of a machining tool is positioned between the adjacent walls and near a protrusion formed resulting from the varied wall thicknesses. At step  806  the cutting portion of the machining tool engages at least one protrusion resulting from the varied wall thicknesses. Engagement of the protrusion by the cutting portion during a cutting operation forms a recess having a size and shape in accordance with a threaded insert. The cutting operation can include a number of discrete cutting operations or can be formed during a single cutting operation in which the machining tool is maneuvered in three dimensional space. 
     At step  808 , subsequent to forming the recess, a threaded insert is pressed into the recess. The threaded insert can be formed of a material that is either harder of softer than the surfaces defining the recess so that one of the threaded insert of the surfaces defining the recess can deform during the insertion operation. Deformation can result in the threaded insert being embedded within the recess. For example, a series of protruding features arranged along a periphery of the threaded insert can dig into the surfaces defining the recess so that anti-rotational grooves are established that resist rotation of the threaded insert within the recess. In some cases, the protruding features can define an annular groove that allows material to collect between a leading and trailing portion of each of the protruding features. In this way, pull out of the recess is made even more unlikely. Alternatively, a number of openings can be machined into the protrusion in addition to the recess for accommodating shafts or retaining members that interact with a portion of the threaded insert to keep the threaded insert from becoming dislodged from the recess. In one particular embodiment, the shafts can extend across the recess and in front of a lateral portion of the inserted threaded insert. In this way, the threaded insert can be replaced by removing the shafts from the openings. In other embodiments, a combination of retaining features and protruding features can be utilized to secure the threaded insert within the recess. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     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 specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described 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: 20160824
Publication Date: 20190820
Grant Date: 20190820
Priority Date: 20140527
Inventors: MAG, STEFAN C.
CHRISTOPHY, MIGUEL C.
JARVIS, DANIEL W.
Assignee: APPLE INC
CPC Classifications: [{"code": "B23C2220/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23C3/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B37/122", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B37/048", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49883", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23C3/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49883", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B37/048", "inventive": true, "first": true, "tree": "[]"}, {"code": "B23C3/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "F16B37/048", "inventive": true, "first": true, "tree": "[]"}, {"code": "B23C3/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23C2220/04", "inventive": false, "first": false, "tree": "[]"}, {"code": "F16B37/122", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23C3/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49883", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 54701209