Abstract:
Disclosed is a fastener assembly comprising a first wedge portion having an angled end, a second wedge portion having an angled end, and a fastener extending through the first wedge portion and the second wedge portion, wherein a portion of the fastener protrudes from one of the first and second wedge portions for interfacing with a component to be mounted, wherein the angled end of the first wedge portion and the angled end of the second wedge portion are interfaced when the fastener is extended through the first wedge portion and the second wedge portion.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates in general to mounting fasteners, and in particular to a wedge-lock fastener for variable mounting.  
         DESCRIPTION OF RELATED ART  
         [0002]    In the past, when a system component was to be mounted securely to another component, such as a host circuit board, a system housing, or device cage, with a variable mount, such as to allow adjustment along an axis before securing the device, a slotted fastener receiver, such as a slotted bracket, was used. This was done to allow the mounting fastener to slide in the slot as the position of the component was adjusted prior to locking the part in the desired position. Such a slot is elongated in the direction of the relative motion between the components (the adjustment axis), and the mounting fastener is tightened from a direction perpendicular to the axis of adjustment. Accordingly, this slotted bracket design requires access from a side of the component, perpendicular to the direction of adjustment in order to engage the mounting fastener. When such a side of the component cannot be accessed, such as due to the constraints of parts adjacent to the component being mounted, the component cannot be locked down in a variable location without great difficulty, such as disassembly of other system components. However, such adjustable mounts are often necessary to accommodate system component mechanical tolerances, such as tolerance stack-up in the assembly caused by the upper and lower limit parts coming together.  
           [0003]    As a specific example of implementation of the prior art design, a system processor, having a large heat sink thereon, may be provided which interfaces with a cell board via a connector assembly. The tolerances of the pieces of the connector assembly, the processor packaging, the heat sink, and/or supporting framework of the cell board or system housing may result in appreciable variation in the position of the heat sink relative to a mounting point, such as a mounting point on supporting framework of the cell board or system housing. The processor and heat sink assembly may be relatively heavy, and may be provided in a configuration in which the heat sink is cantilevered with respect to the connector assembly, thereby necessitating firmly attaching the heat sink to supporting framework to allow for the cell board shock loads without dislodging the connector assembly parts. Accordingly, a variable mount according to the prior art, wherein a slot is disposed at the mounting point parallel to the axis of adjustment (here parallel to the direction of insertion of the processor into the connector assembly), may be provided to accommodate the aforementioned tolerances. Access to a fastener to firmly hold the processor onto the cell board in this prior art design would be perpendicular to the adjustment axis (perpendicular to the slot) and on a side of the processor heat sink orthogonal to the direction of insertion of the processor in the connector assembly. However, it may not always be possible to access this side of the processor heat sink to tighten a fastener, such as a screw, extending through the slot into the processor heat sink for tightening.  
           [0004]    Another prior art solution is shown in U.S. Pat. No. 4,819,713 issued to Weisman, the disclosure of which is hereby incorporated herein by reference. The mounting system of Weisman provides a retainer for retaining an electronic circuit board in the slots of a cold plate, incorporating a square wedge-type design to press the circuit board between two edges of a slot. Accordingly, the retainer is limited to uses in which it is disposed parallel to a surface of the circuit board, which may be problematic, such as in situations where an adjustment axis is desired which is perpendicular to the circuit board surface. Furthermore, the mounting system would need a stationary opposable surface, such as a wall or “C” channel, to act against in the prior art. Moreover, access to the mounting components in at least two directions is utilized, one for inserting the circuit board and one for engagement of the mount, which may be problematic in particular situations where access is limited.  
           [0005]    In another prior art solution, a standoff may be used, such as protruding from the cell board where processor is placed. An end of the processor heat sink may be placed on the standoff and a fastener, such as a screw, passed through the heat sink into the standoff. Although this configuration provides for tightening the fastener from a same direction as the insertion of the processor in the connector assembly (a direction from which there will presumably be access to facilitate insertion of the processor in the connector assembly), the standoff does not allow for adjustment of the attachment point without removal and replacement of the standoff. Accordingly, the processor assembly may be not be held orthogonal with respect to the connector assembly, i.e., the processor assembly may be tilted applying bending forces upon the connector assembly and/or one edge of the connector assembly remaining only partially engaged, because of the inability to adjust the mount to accommodate variances due to tolerances etcetera.  
         BRIEF SUMMARY OF THE INVENTION  
         [0006]    Embodiments of the present invention provide a fastener assembly comprising a first wedge portion having an angled end, a second wedge portion having an angled end, and a fastener extending through the first wedge portion and the second wedge portion, wherein a portion of the fastener protrudes from one of the first and second wedge portions for interfacing with a component to be mounted, wherein the angled end of the first wedge portion and the angled end of the second wedge portion are interfaced when the fastener is extended through the first wedge portion and the second wedge portion. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:  
         [0008]    [0008]FIGS. 1A and 1B depict a sectional view of a fastener assembly according to an embodiment of the present invention;  
         [0009]    [0009]FIG. 2 depicts an isometric view of the fastener assembly of FIGS. 1A and 1B;  
         [0010]    [0010]FIGS. 3A and 3B depict a prior art slotted bracket mounting device;  
         [0011]    [0011]FIG. 4 depicts a fastener assembly according to an alternative embodiment of the present invention;  
         [0012]    [0012]FIG. 5 depicts a fastener assembly according to an embodiment of the present invention providing a plurality of degrees of freedom with respect to adjustment of components;  
         [0013]    FIGS.  6 - 8  depict alternative embodiments of fastener assemblies of the present invention implementing various captivation techniques;  
         [0014]    [0014]FIG. 9 depicts a deployment of a fastener assembly according to an embodiment of the present invention; and  
         [0015]    [0015]FIG. 10 depicts a flow diagram according to an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0016]    The present invention is directed to systems and methods providing a fastener assembly for adjustably fastening components, wherein the fastener is engaged by access to the fastener from a direction parallel to an adjustment axis. For example, torque to engage a fastener assembly of an embodiment of the present invention, to lock down a system component in a variable location, may be provided when access to the fastener assembly is only available in the direction of adjustment or movement of the component.  
         [0017]    Embodiments of the present invention utilize wedge portions, as may be drawn together by an adjustment means such as a screw, bolt, rack, etcetera, to exert a retaining force orthogonal to an adjustment axis and the axis associated with fastener assembly engagement access. For example, embodiments of the invention may comprise two wedge portions, having ends cut at an angle, e.g., each at a 45° angle, thereby providing a wedge shaped profile, and a screw passed therethrough. Application of torque to the screw in such an embodiment may operate to draw the two wedge portions together, resulting in the wedge-shaped ends sliding against one another and, thus, causing sides of the two cylinders to move laterally in opposite directions. Accordingly, by inserting the fastener assembly into a receiver in a component to be fixedly mounted via a receiver at a mounting point of a supporting structure, wherein the receivers may comprise, for example, an opening of a size to accept at least a portion of the wedge portions therethrough, the component may be adjusted longitudinally along the wedge portions until a desired position relative to the supporting structure is achieved. Thereafter, the fastener wedge portions may be drawn together, causing sides of the wedge portions of the fastener assembly to move in opposite directions laterally, thereby providing binding forces against the aforementioned receivers.  
         [0018]    It should be appreciated that release of a fastener assembly of embodiments of the present invention may be achieved by removing the force drawing the aforementioned wedge portions together, such as by applying torque to a screw passed therethrough in a direction opposite that used to draw the wedge portions together. Embodiments of the invention may provide a bias force, such as using a spring disposed longitudinally within the wedge portions, to encourage the wedge portions to be repelled from one another and allowing sides thereof to retract from a binding position.  
         [0019]    Additionally, embodiments of the present invention allow for adjustment along at least 2 axes, thereby providing a plurality of degrees of freedom with respect to a mounting point. For example, the aforementioned receivers may comprise a slot elongated in the direction of a second adjustment axis to provide for additional freedom of movement with respect to the position of a component relative to a supporting structure.  
         [0020]    Embodiments of this invention may include captivating wedge portions of the fastener assembly to provide an assembly with no loose or free parts. For example, the wedge portions of the fastener assembly may be fitted on a threaded fastener, such as a screw, and captivation may be achieved through a threaded portion of the fastener passing through a threaded orifice in a lower wedge portion. Additionally or alternatively, captivation of pieces of a fastener assembly of embodiments of the present invention may utilize press-in pins on the sides of the fastener, a threaded collar on the fastener, a snap ring on the fastener, or the like.  
         [0021]    Directing attention to FIGS. 1A and 1B, an embodiment of fastener assembly  10  according to an embodiment of the present invention is shown in a sectional view. FIG. 2 provides a corresponding solid view of fastener assembly  10  of FIGS. 1A and 1B. In the embodiment of FIGS. 1A, 1B, and  2 , fastener assembly  10  serves to fixedly mount components  105  and  106  to one another. Components  105  and  106  may comprise any number of components to be affixed together. For example, according to one embodiment of the present invention, component  105  comprises a processor assembly and component  106  comprises a host cell board. Of course, other components may be fixedly mounted according to the concepts of the present invention.  
         [0022]    Fastener assembly  10  of the illustrated embodiment includes wedge portions  102  and  103 , here cylindrical bodies, having opposing ends  122  and  123  thereof cut at an angle, e.g., each at a 45° angle, thereby providing a wedge shaped profile. Fastener  100 , having head portion  101  and threaded portion  108 , is passed through a center shaft of wedge portions  102  and  103 . Fastener assembly  10  of the illustrated embodiment further includes threaded collar  109  disposed near an end of fastener  100  opposite head portion  101 , such that wedge portions  102  and  103  are disposed between head portion  101  and threaded collar  109 .  
         [0023]    Components  105  and  106  are preferably adapted to facilitate engagement of fastener assembly  10  of the illustrated embodiment and accommodate adjustment of the relative positions of components  105  and  106 . For example, component  105  of the illustrated embodiment includes receiver  104 , here a through hole, through which at least a portion of fastener assembly  10  extends and, when not engaged, is free to slide along adjustment axis A. Component  106  of the illustrated embodiment includes receiver  107 , here a threaded hole, into which at least a portion of fastener assembly  10  extends.  
         [0024]    The illustrated embodiment provides means for retaining fastener assembly  10  with component  105 , even prior to interfacing fastener assembly  10  with component  106  and prior to engaging fastener assembly  10 . Specifically, threaded collar  109  of fastener assembly  10  allows threaded portion  108  of fastener  100  to be threaded therethrough such that a non-threaded shaft portion of fastener  100  is disposed through threaded collar  109 . Thereafter, threaded portion  108  prevents fastener  100  from being extracted from threaded collar  109 . It should be appreciated that threaded collar  109  of the illustrated embodiment is sufficiently sized to prevent passage through the length of receiver  104 . Accordingly, when fastener assembly  10  of the illustrated embodiment is assembled after portions thereof are disposed in receiver  104 , fastener assembly  10  is retained with component  105  by head portion  101  and threaded collar  109  preventing extraction from receiver  104 .  
         [0025]    The embodiment illustrated in FIGS. 1A, 1B, and  2  includes a portion of receiver  104  having a somewhat wider cutout, e.g., counter bore, at a lower portion of component  105 , corresponding to threaded collar  109 . Such a counter bore facilitates the use of the aforementioned threaded collar while minimizing or eliminating the effect upon the size of gap W which may be achieved using fastener assembly  10 . Specifically, the counter bore of the illustrated embodiment allows component  105  to be adjusted to an extent that threaded collar  109  is recessed therein. Of course, gap W of the illustrated embodiment may be selected such that component  105  is disposed sufficiently off of component  106  that threaded collar  109  is not within the counter bore, if desired.  
         [0026]    It should be appreciated that fastener assembly  10  allows for adjustment of the relative position of component  105  with respect to component  106  along adjustment axis A. Accordingly, gap W may be adjusted as desired prior to engaging fastener assembly  10 , such as to allow component  105  to maintain a proper orientation and/or relative position with respect to other system aspects (not shown).  
         [0027]    According to the illustrated embodiment, threaded portion  108  of fastener  100  interfaces with receiver  107  to hold fastener assembly  10  thereto. Although component  105  is free to be adjusted along axis A, thereby adjusting gap W, prior to fastener assembly  10  being engaged, head portion  101  of fastener assembly  10  prevents component  105  from being removed from fastener assembly  10 .  
         [0028]    In operation according to the illustrated embodiment, torque (shown as T in FIG. 2) applied by access to fastener  100  along the direction of arrow  207 , corresponding to adjustment axis A, causes threaded portion  108  to interface further with receiver  107 . Threaded collar  109  abuts component  106 , thereby preventing all but fastener  100  of fastener assembly  10  from proceeding further in the direction of arrow  207 . As fastener  100  is drawn further in the direction of arrow  207 , head portion  101  is drawn toward threaded collar  109 , thereby drawing wedge portions  102  and  103  together. As the space between head portion  101  and threaded collar  109  becomes less than the combined lengths of wedge portions  102  and  103 , the angles of opposing ends  122  and  123  cause lateral movement of sides of wedge portions  102  and  103  in opposite directions as shown in FIG. 1B. Accordingly, as fastener  100  is tightened, upper and lower wedge portions  102  and  103  slip relative to one another along edges  122  and  123  and expand against the walls of receiver  104 , locking component  105  in place at a selected position along fastener assembly  10 .  
         [0029]    It should be appreciated that, according to the illustrated embodiment, receiver  104  is sized to both adjustably accept at least a portion of fastener assembly  10  and to fixedly engage fastener assembly  10 . Accordingly, a diameter of receiver  104  of embodiments of the present invention is selected to be slightly larger than a diameter of wedge portions  102  and  103  of fastener assembly  10 . Moreover, a depth (shown as D in FIGS. 1A and 1B) of receiver  104  of embodiments of the present invention is selected to be thick enough to accommodate a desired range of adjustment, wherein at any position throughout the adjustment range a side of both upper and lower wedge portions  102  and  103  is in contact with receiver  104  to thereby grip the inside of the receiver.  
         [0030]    In contrast to the operation of the embodiment of the present invention illustrated in FIGS. 1A, 1B, and  2 , FIGS. 3A and 3B show an example of adjustable mounting according to the prior art, wherein FIG. 3A shows an isometric view and FIG. 3B shows a sectional view thereof. In FIGS. 3A and 3B, fastener  300  serves to fixedly mount components  305  and  306  to one another. To provide for adjustment of the relative positions of components  305  and  306 , component  306  includes receiver  307  slotted in the direction of adjustment axis A. Receiver  304  of component  305  is threaded to interface with fastener  300 . When component  305  has been positioned as desired with respect to component  306 , torque is applied to fastener  300  from the direction of arrow  357  to thereby cause fastener  300  to further interface with receiver  304  and fixedly engage receiver  307 . It should be appreciated that, although providing adjustment along axis A, fastener  100  requires access along an axis orthogonal to axis A. In contrast, fastener assembly  10  of the embodiment described above provides adjustment along axis A using access along this same axis.  
         [0031]    Having described concepts of the present invention with reference to an embodiment as illustrated in FIGS. 1A, 1B, and  2 , various enhancements and/or alterations will be described. Directing attention to FIG. 4, an embodiment of fastener assemblies  40  of the present invention are shown adapted for use with frame  400 . In the embodiment of FIG. 4, fastener assemblies  40  are retained in corresponding ones of receivers  401  of frame  400 , to thereby provide a frame and fastener assembly for allowing adjustable fixed attachment of one or more system components, such as components  105  and  106  discussed above. However, fastener assemblies  40  of FIG. 4 provide flat surfaces  450  on upper wedge portions  402 . Preferably, flat surfaces  450  are provided upon opposing sides of wedge portions  402 . Flat surfaces  450  of the illustrated embodiment cooperate with corresponding flat surfaces of receiver  401  to control the orientation of the angles of opposing ends of wedge portions  402  and  103 , and thus the direction that these wedges apply pressure.  
         [0032]    [0032]FIG. 5 shows a further embodiment in which the aforementioned flat surfaces  450  are provided not only upon upper wedge portion  502 , but also upon lower wedge portion  503 . However, in the embodiment of FIG. 5, flat surfaces  450  are rotated 90° with respect to the angles of the opposing edges of wedge portions  502  and  503 , as compared to the embodiment of FIG. 4. Accordingly, binding forces resulting from operation of fastener assembly  50  of FIG. 5 will be provided in directions associated with a vector protruding orthogonally from the faces of flat surfaces  450 .  
         [0033]    Also in the embodiment of FIG. 5, receiver  504  of component  105  is slotted. Fastener assembly  50  is passed through slotted receiver  504  and into receiver  107  with flat surfaces  450  preferably corresponding to the long edges of slotted receiver  504 . In this embodiment, not only is adjustment provided along axis A, but a second degree of freedom is provided along axis A′ corresponding to the longitudinal direction of slotted receiver  504 . As torque is applied to fastener  100  of the illustrated embodiment, flat surfaces  450  of wedge portions  502  and  503  are encouraged to bind against the long edges of slotted receiver  504 , wherein the eccentric shape of the wedge portions prevents their rotating within slotted receiver  504 , to thereby provide fixed attachment as discussed above with respect to FIGS. 1A, 1B, and  2 .  
         [0034]    Spring  550 , such as may be disposed along the shaft of fastener  100  within wedge portions  502  and  503 , is shown in FIG. 5. This spring may provide a bias force, such as against a necked down portion at the distal ends of the through hole of wedge portions  502  and  503 , to encourage wedge portions to be repelled from one another and allowing sides thereof to retract from a binding position. Although shown only in the embodiment of FIG. 5, it should be appreciated that such a spring or other bias means may be utilized with respect to various embodiments of the present invention.  
         [0035]    The embodiments of FIGS.  6 - 9  illustrate various implementations of techniques for retaining the portions of fastener assemblies of the present invention as a single unit. For example, the embodiments of FIGS.  6 - 9  depict four potential embodiments for captivation of the fastener  100  prior to use.  
         [0036]    [0036]FIG. 6 depicts an embodiment for captivation of the assembly through use of press-in pins  605  and  606 . Captivation in this embodiment is achieved by having through holes  600  and  601  through the lower wedge portion  103  where pins  605  and  606  may be pressed in on each side of fastener  100  to prevent a larger portion thereof, here threaded portion  108 , from passing between pins  605  and  606 .  
         [0037]    [0037]FIG. 7 depicts an embodiment for captivation of the assembly through use of snap ring  700  on fastener  100 . Upper wedge portion  402 , lower wedge portion  103  and fastener  100  are preferably captivated by placement of snap ring  700  over a relieved section of fastener  100 .  
         [0038]    [0038]FIG. 8 depicts an embodiment for captivation of the assembly through use of press-in pins  805  and  806 . The embodiment of FIG. 8 is similar that of FIG. 6 in its use of press-in pins  805  and  806  in corresponding through holes (only through hole  800  is visible in the Figure) on either side of the fastener assembly  10 . However, in the embodiment of FIG. 8, pins  805  and  806  are pressed-in on opposing sides of fastener  100  such that a gap remains between opposing ends of pins  805  and  806  within wedge portion  103  which is sufficiently small to prevent threaded portion  108  from passing through.  
         [0039]    Having described various embodiments of fastener assemblies of the present invention, a specific example of a use thereof will be described with reference to FIG. 9. FIG. 9 shows components  905  and  906  of system  900 . For example, component  905  may comprise heat sink  951 , processor  952 , and connector  953  of a processor module. Component  906  may comprise electronic circuit board  961 , such as a cell board, having connector  963  to receive connector  953  and thus interface with the processor module. Heat sink  951  may be relatively large and/or heavy, thus suggesting it should be fixedly attached to circuit board  961  to accommodate expected shock forces. However, the position of heat sink  951  relative to circuit board  961  may not be exactly predictable due to tolerances associated with connector  963 , connector  953 , and processor  952 . Accordingly, a degree of adjustment with respect to fixedly attaching heat sink  951  to circuit board  961  along axis A may be desired to avoid a situation in which heat sink  951  is mounted in a tilted relationship to circuit board  961 , and thus connectors  953  and  963  are not squarely interfaced.  
         [0040]    By disposing fastener assembly  10  through a receiver of heat sink  951 , such as described above with respect to receiver  106  of component  105 , and into a receiver of circuit board  961 , such as described above with respect to receiver  107  of component  106 , connectors  953  and  963  may be fully and squarely engaged and heat sink  951  allowed to slide along axis A to any position of fastener assembly  10 . Thereafter, fastener assembly  10  may be engaged to cause wedge portions  102  and  103  to slip in relation to one another and overlap in heat sink  951 . Accordingly, wedge portions  102  and  103  bind against the receiver of heat sink  951  and hold the relative positions of components  905  and  906 . It should be appreciated that the interface between wedge portions  102  and  103  is shown in FIG. 9 disposed below heat sink  951 . However, prior to engaging heat sink  951  as described above, heat sink  951  will be moved relative to fastener assembly  10  such that at least a portion of the interface between wedge portions  102  and  103  will be disposed therein, thereby facilitating the aforementioned binding by wedge portions  102  and  103  against heat sink  951 .  
         [0041]    The flow diagram of FIG. 10 shows steps performed in implementing an adjustable mount as shown in FIG. 10. At step  1001 , a fastener (e.g., fastener  100 ) of a fastener assembly (e.g., fastener assembly  10 ) is inserted through first and second wedges of said fastener assembly (e.g., wedge portions  102  and  103 ). At step  1002  the first and second fastener assembly wedges are disposed in a receiver of a first component (e.g., component  905 ). At step  1003  a portion of the fastener is interfaced with a receiver of a second component (e.g., component  906 ). At step  1004  the fastener is adjusted such that the first and second wedges slip relative to one another and engage walls of the receiver of the first part, thereby locking the position of the first component relative to the second component.  
         [0042]    Although embodiments have been described herein with reference to wedge portions of a fastener assembly, it should be appreciated that the concepts of the present invention are not limited to use with cylindrical configurations. Accordingly, embodiments of the present invention may implement any number of geometries, provided such geometries are sized and/or shaped to provide binding forces to a corresponding receiver as described herein. For example, embodiments of the present invention may implement rectangular, ovular, and hexagonal portions for providing adjustable mounts as described herein.  
         [0043]    To aid the reader in understanding the concepts of the present invention various relative terms, such as upper and lower, top and bottom, etcetera, have been used. However, it should be appreciated that the concepts of the present invention are not limited to application in any particular orientation. Accordingly, such relative terms are not intended to limit the present invention to any particular orientation.