Patent Publication Number: US-10330139-B2

Title: Tools and ratchet locking mechanisms for threaded fasteners

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 14/460,037 filed Aug. 14, 2014, which claims priority to and the benefits of U.S. Provisional Patent Application Ser. No. 61/891,002 filed Oct. 15, 2013, and U.S. Provisional Patent Application Ser. No. 61/866,332 filed Aug. 15, 2013, and is a continuation-in-part of U.S. patent application Ser. No. 14/319,453 filed Jun. 30, 2014, which is a divisional application of U.S. patent application Ser. No. 13/068,171 filed May 4, 2011, (now U.S. Pat. No. 8,784,027), which claims priority to and the benefits of U.S. Provisional Patent Application Ser. No. 61/403,332 filed Sep. 14, 2010, each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The field of the disclosure relates generally to fasteners, and more particularly, to a ratcheting locking mechanism for threaded fasteners. 
     Threaded fasteners designed to lock male and female threaded components together are well known in the art and include, for example, lock washers, blind thread bores filled with resilient inserts, and screw thread profiles that deform when tightened. Fasteners with self-locking accessories such as cotter pins and lock wires are also known. Other examples of self-locking threaded fasteners are disclosed in U.S. Pat. No. 5,460,468 to DiStacio on Oct. 24, 1995; U.S. Pat. No. 5,538,378 to Van der Drift on Jul. 23, 1996; and U.S. Pat. No. 5,713,708 to Van der Drift et al. on Feb. 3, 1998, each of which is incorporated herein by reference. 
     In addition, it is known in the art to apply temporary adhesives to screw threads. Once cured, the adhesive helps prevent loosening. However, normal removal torque can break the bond for removal. Such adhesives tend to perform poorly in high temperature applications. 
     BRIEF DESCRIPTION 
     In one embodiment, the subject technology is directed to a fastening device having a fastener with a head portion and an elongated threaded body portion extending axially from the head portion. The fastening device also includes a lock washer and a threaded lock nut for rotatably mating with the fastener. The lock washer has a lower surface with a plurality of ratchet teeth extending therefrom. The lock washer is configured to couple to the fastener for axial movement but is fixed rotationally. The threaded lock nut has an upper surface defining at least one pawl arm. The pawl arm includes at least one pawl tooth for engagement with at least one of the plurality of ratchet teeth, and a flange extending radially outward from the pawl arm. 
     The threaded lock nut may include an axially extending recessed portion between a lower surface of the threaded lock nut and the pawl arm. The lock washer can have an axial aperture having at least one flat inner surface corresponding to at least one longitudinally extending flat section of the threaded body portion. The longitudinally extending flat section is configured to mate with the flat inner surface of the lock washer to rotationally fix the lock washer when the elongated threaded body portion is inserted in the axial aperture. The head portion of the fastener can be a tulip head defining a transverse channel and opposing prongs. The axial aperture of the lock washer can also include a bar, wherein the bar extends between opposing sides of the axial aperture to define two discrete axial apertures. Each axial aperture can correspond to one of the respective prongs of the tulip head. The axial aperture of the lock washer can be radially inward of the ratchet teeth. The ratchet teeth can entirely cover the lower surface of the lock washer or the lower surface of the lock washer can include a surface portion without ratchet teeth defined radially between the ratchet teeth and the axial aperture. 
     It is contemplated that the fastening device can also include a tool. The tool can include a distal working portion forming a tapered surface to apply a removal force to temporarily lift the pawl arm away from the ratchet teeth and unthread the threaded lock nut, and a proximal end adapted to mount to a ratchet. The tool can include an inner diameter tier and an outer diameter tier on a distal working portion. The inner diameter tier of the tool can correspond to the axially extending recessed portion for tightening the threaded lock nut during clock-wise rotation of the tool. The outer diameter tier can include a tapered ramp for applying a removal force to a surface of the flange of the pawl arm to bend the pawl arm and the at least one pawl tooth away from the ratchet teeth for disengagement during counter-clockwise rotation of the tool. The tapered ramp may be defined in a slot defined in the outer diameter tier, and/or on a circumferentially extending flange of the outer diameter tier. 
     In another embodiment, a fixation system for coupling a rod to bone includes an elongated bone screw fastener having, a lock washer and a threaded lock nut. The elongated hone screw fastener includes a threaded tulip head portion defining a transverse channel and opposing prongs, and an elongated threaded body portion depending from the tulip head portion. The lock washer includes opposed upper and lower surfaces with a pair of discrete axial apertures extending therebetween, and ratchet teeth. The lock washer includes a bar extending between the pair of discrete axial apertures. Each discrete axial aperture is configured to receive one of the respective prongs of the tulip head portion of the elongated bone screw fastener for axial movement of the lock washer along the prongs of the tulip head portion to secure the rod between the lock washer and the tulip head portion. The threaded lock nut is configured to rotatably mate with the threaded tulip head portion. The lock nut has opposed upper and lower surfaces. The upper surface defines at least one pawl arm. The pawl arm includes at least one pawl tooth for engagement with at least one of the ratchet teeth. 
     In another embodiment, a fastening device includes a lock washer with opposed upper and lower surfaces and a circumferential surface therebetween. The circumferential surface has an array of ratchet teeth extending radially outward of the circumferential surface. A tapered slot is defined between the pawl arm and the threaded lock nut. The pawl arm includes a tapered inner surface such that the tapered slot is smaller proximate the at least one pawl tooth. 
     The fastening device can also include a tool for tightening and removing the fastener. The tool may include at least one projection on a distal working portion. The projection can include a recessed extension configured to engage the tapered slot defined between the pawl arm and the threaded lock nut. The projection can correspond to an axially extending recessed portion defined in the threaded lock nut between the lower surface of the threaded lock nut and the pawl arm. The recessed extension can correspond to the tapered slot so that during tightening the recessed extension is in the larger portion of the tapered slot and during removal the recessed extension rotates counter-clockwise into the smaller portion of the tapered slot proximate the pawl tooth to splay the pawl arm radially outward. 
     In one aspect, a fastening device is provided. The fastening device includes a fastener including a head portion. An elongated threaded body portion extends axially from the head portion, and at least one longitudinally-extending flat section is formed in the elongated threaded body portion. The fastening device also includes a lock washer including opposed upper and lower surfaces and a circumferential surface therebetween. The circumferential surface includes an array of radially-extending ratchet teeth. The lock washer further includes an aperture having at least one flat inner surface configured to engage the at least one longitudinally-extending flat section of the elongated threaded body portion and rotationally fix the lock washer with respect to the fastener. In addition, the fastener device includes a threaded lock nut for rotatably mating with the threaded body portion. The threaded lock nut has opposed upper and lower surfaces and a peripheral outer surface defining an axially-extending recessed portion. The upper surface includes an integrally-formed pawl arm comprising a tapered inner surface that defines a tapered slot between the pawl arm and the threaded lock nut in axial alignment with the axially-extending recessed portion. The pawl arm includes a pawl tooth for engagement with at least one ratchet tooth of the array of ratchet teeth. 
     In another aspect, another fastening device is provided. The fastening device includes a fastener having an axially-extending elongated threaded body portion. The fastening device also includes a lock washer having an upper surface, an opposite lower surface, and a circumferential surface therebetween. The circumferential surface includes an array of ratchet teeth extending radially therefrom. The lock washer is configured to couple to the threaded body portion for axial movement but is fixed rotationally by the fastener. The fastening device also includes a threaded lock nut for rotatably mating with the threaded body portion. The threaded lock nut includes an upper surface and an opposite lower surface. The upper surface defines a pair of integrally-formed opposing pawl arms. Each pawl arm of the pair of integrally-formed opposing pawl arms includes a proximal end coupled to the threaded lock nut, a flexible arm portion extending from the proximal end, a distal end extending from the flexible arm portion, and a pawl tooth disposed on the distal end for engagement with at least one tooth of the array of ratchet teeth as said flexible arm portion flexes relative thereto. Each flexible arm portion defines a tapered slot between the threaded lock nut and each flexible arm portion for receiving a portion of a tool for flexing the flexible arm portion. 
     In yet another aspect, another fastening device is provided. The fastening device includes a fastener having an axially-extending elongated threaded body. The fastening device also includes a lock washer including a circumferential surface having an array of radially-extending ratchet teeth. The lock washer is configured to move axially along the threaded body portion while being fixed rotationally by the threaded body portion. The fastening device also includes a threaded lock nut including a pair of integrally-formed opposing pawl arms. Each pawl arm of the opposing pawl arms includes a flexible arm portion having a proximal end coupled to the threaded lock nut and a distal end having a pawl tooth disposed thereon for engagement with at least one tooth of the array of ratchet teeth. Each flexible arm portion defines a tapered slot between the flexible arm portion and the threaded lock nut. 
     It should be appreciated that the present technology can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device, a method for applications now known and later developed. These and other unique features of the technology disclosed herein will become more readily apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those having ordinary skill in the art to which the disclosed technology appertains will more readily understand how to make and use the same, reference may be had to the following drawings. 
         FIG. 1  is an exploded perspective view of a fastening device constructed in accordance with the subject technology, showing a fastener, a lock washer, a threaded lock nut and a tool; 
         FIG. 2  is a perspective view of the threaded lock nut of  FIG. 1 , showing an upper surface of the threaded lock nut having opposing pawl arms; 
         FIG. 3A  is a side perspective view of the tool of  FIG. 1 , showing tapered ramps defined in outward extending flanges; 
         FIG. 3B  is a side cross-sectional view of the tool of  FIG. 1 , showing inner and outer diameter tiers; 
         FIG. 4  is a side perspective view of another embodiment of a threaded lock nut, showing the threaded lock nut having a pair of axially extending recessed portions defined between upper and lower surfaces of the threaded lock nut; 
         FIG. 5  is a perspective view of another embodiment of a tool constructed in accordance with the subject technology, showing tapered ramps defined in slots; 
         FIG. 6  is a side perspective view of another embodiment of a lock washer constructed in accordance with the subject technology, showing a portion of the lower surface of the lock washer without ratchet teeth; 
         FIG. 7  is an exploded perspective view of another embodiment of a fastening device constructed in accordance with the subject technology, showing a fastener, a lock washer, a threaded lock nut and a tool; 
         FIG. 8  is a top view of the threaded lock nut of  FIG. 6 , showing an upper surface of the threaded lock nut having opposing pawl arms and tapered slots; 
         FIG. 9  is a side perspective view of the tool of  FIG. 1 , showing a pair of projections and recessed extensions; 
         FIG. 10  is a partially exploded perspective view of a fixation system for coupling a rod to bone constructed in accordance with the subject technology, showing a fastener, a rod, a lock washer, and a threaded lock nut; 
         FIG. 11  is a perspective view of the lock washer of  FIG. 9 , showing an axial aperture with a bar defined therein, and a lower surface of the lock washer having ratchet teeth; 
         FIG. 12  is a partially exploded perspective view of another embodiment of a fixation system for coupling a rod to bone constructed in accordance with the subject technology, showing a fastener, a rod, a lock washer, and a threaded lock nut; and 
         FIG. 13  is a perspective view of the lock washer of  FIG. 11 , showing a pair of discrete apertures with a bar defined therebetween, and a circumferential surface of the lock washer having ratchet teeth. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure overcomes many of the prior art problems associated with threaded fasteners. In general, threaded fasteners are used to fixedly connect two or more pieces in a variety of applications such as, without limitation, with surgical implants, industrial applications, aerospace applications, and building applications. Among other features and benefits, the disclosed fastening devices and systems facilitate quick and easy installation and/or removal with low torque requirements while providing a reliably vibration resistant secured tightness. The advantages, and other features of the technology disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain embodiments taken in conjunction with the drawings which set forth representative embodiments of the present disclosure and wherein like reference numerals identify similar structural elements. 
     All relative descriptions herein such as upward, downward, left, right, up, down, length, height, width, thickness and the like are with reference to the Figures, and not meant in a limiting sense. Additionally, the illustrated embodiments can be understood as providing exemplary features of varying detail of certain embodiments, and therefore, features, components, modules, elements, and/or aspects of the illustrations can be otherwise combined, interconnected, sequenced, separated, interchanged, positioned, and/or rearranged without materially departing from the disclosed fastener assemblies. Additionally, the shapes and sizes of components are also exemplary and can be altered without materially affecting or limiting the disclosed technology. 
     As shown in  FIG. 1 , a fastening device constructed in accordance with one embodiment is designated generally by reference numeral  100 . Fastening device  100  includes a fastener  102  with a head portion  104  and an elongated threaded body portion  106  extending axially from head portion  104 , a lock washer  108 , and a threaded lock nut  110  for rotatably mating with threaded body portion  106 . Lock washer  108  has a lower surface  112  with a plurality of ratchet teeth  114  that entirely cover lower surface  112  of lock washer  108 . Lock washer  108  is configured to couple to threaded body portion  106  for axial movement. Lock washer  108  has an axial aperture  116  with a pair of opposing flat inner surfaces  118  corresponding to the pair of opposing longitudinally extending flat sections  130  of threaded body portion  106 . Flat sections  130  mate with flat inner surfaces  118  of lock washer  108  to rotationally fix lock washer  108  when elongated threaded body portion  106  is inserted in axial aperture  116 . Lock washer  108  is permitted to move axially along threaded body portion  106 . Those skilled in the art will readily appreciate that the head portion  104  of fastener  102  can take any conventional form known in the art including, for example, a hexagonal head or a tulip head, as will be described below. 
     Now with reference to  FIG. 2 , threaded lock nut  110  has an upper surface  120  that defines a pair of opposing pawl arms  122 . Each pawl arm  122  includes a flange  126  extending radially outward from pawl arm  122  and respective pawl teeth  124  for engagement with at least one of ratchet teeth  114 . Those skilled in the art will readily appreciate that while each pawl arm  122  is described herein as having a pair of pawl teeth  124 , any suitable number of pawl teeth  124  can be used. Threaded lock nut  110  includes an axial aperture  123  with threads  125  defined in the circumference of aperture  123  for mating with the threads of threaded body portion  106  for axial movement along threaded body portion  106  by rotating about threaded body portion  106 . Threaded lock nut  110  includes a pair of axially extending recessed portions  128 . Each recessed portion  128  is defined between a lower surface  121  of threaded lock nut  110  and a respective pawl arm  122 . 
     As shown in  FIGS. 1, 3A, and 3B , fastening device  100  includes a tool  140  for tightening and removing fastener  102 . A distal working portion  142  of tool  140  includes opposing inner diameter tiers  146  and opposing outer diameter tiers  148 . A proximal end  161  includes a socket  163  adapted to mount to a ratchet. Inner diameter tiers  146  of tool  140  each correspond to respective axially extending recessed portions  128  of threaded lock nut  110  for tightening threaded lock nut  110  during clockwise rotation of tool  140 . During tightening, inner diameter tiers  146  of distal working portion  142  of tool  140  are positioned within their respective axially extending recessed portion  128  of lock nut  110  with outer diameter tiers  148  disposed radially outward of lock nut  110 , and tool  140  is rotated clockwise. During clockwise rotation, a respective neck surface  147  of each inner diameter tier  146  contacts a respective shoulder surface  149  of lock nut  110 , forcing clockwise rotation of lock nut  110  about threaded body portion  106  and axial movement toward head portion  104  to tighten fastener  102  in position. 
     With continued reference to  FIGS. 1, 3A, and 3B , outer diameter tiers  148  each include a circumferentially extending flange  145  with respective tapered ramps  144  for applying a removal force to respective upper surfaces  125  of radially outward extending flanges  126  of pawl arms  122 . During removal, inner diameter tiers  146  are again positioned within their respective axially extending recessed portions  128  with outer diameter tiers  148  disposed radially outward of lock nut  110 , and tool  140  is rotated counter-clockwise. During counter-clockwise rotation, each tapered ramp  144  contacts a respective upper surface  125  of each flange  126  lifting each pawl arm  122  away from ratchet teeth  114  of lock washer  108  and disengaging pawl teeth  124  from ratchet teeth  114 . Once pawl arms  122  are lifted and pawl teeth  124  are disengaged, the continued counter-clockwise rotation causes a respective second neck surface  151  of each inner diameter tier  146  to contact a respective second shoulder surface  153  of lock nut  110 , forcing counter-clockwise rotation of lock nut  110  about threaded body portion  106  and axial movement away from head portion  104  to remove lock nut  110 . 
     As shown in  FIG. 4 , an alternative embodiment of a lock nut  210  is shown. Lock nut  210  is similar to lock nut  110 , except that axially extending recessed portions  228  are defined between upper and lower surfaces  220  and  221 , respectively, of threaded lock nut  210 , instead of between lower surface  221  and pawl arm  222 . It is contemplated that lock nut  210  can be used in conjunction with lock washer  108  and fastener  102 , similar to lock nut  110 , described above, but an alternative embodiment of a tool, e.g. tool  240 , described below, can be used for tightening and removal. 
     With reference now to  FIGS. 4 and 5 , tool  240  is shown. Tool  240  is similar to tool  140 , except that tapered ramps  244  are defined in slots  242  defined in outer diameter tiers  248 . While slots  242  are shown as being cut entirely through outer diameter tier  248 , it is contemplated that slots  242  could be partially cut through outer diameter tier  248 . For example, slots  242  could be partially cut through from the inner diameter surface side of outer diameter tier  248 . Each slot  242  includes a respective slot opening  243  that corresponds to a respective flange  226  of each pawl arm  222 . Tool  240  includes opposing inner diameter tiers  246  that correspond to respective axially extending recessed portions  228  of lock nut  210 . During tightening, inner diameter tiers  246  of tool  240  are each positioned within their respective axially extending recessed portion  228  of lock nut  210  with outer diameter tiers  248  disposed radially outward of lock nut  210  and with each flange  226  received in a respective slot opening  243 , and tool  240  is rotated clockwise. During clockwise rotation, a respective neck surface  247  of each inner diameter tier  246  contacts a respective shoulder surface  249  of lock nut  210 , forcing clockwise rotation of lock nut  210  about threaded body portion  106  and axial movement toward head portion  104  to tighten fastener  102  in position. 
     With continued reference to  FIGS. 4 and 5 , during removal, inner diameter tiers  246  are again positioned within their respective axially extending recessed portions  228  with outer diameter tiers  248  disposed radially outward of lock nut  210  and with flange  226  received in slot opening  243 , and tool  240  is rotated counter-clockwise. During counter-clockwise rotation, each flange  226  is free to rotate into its respective slot  242  and travel along tapered ramps  244 . Tapered ramps  244  contact respective upper surfaces  225  of flanges  226  lifting each pawl arm  222  away from ratchet teeth  114  of lock washer  108  and disengaging pawl teeth  224  from ratchet teeth  114 . Once pawl arms  222  are lifted and pawl teeth  224  are disengaged, the continued counter-clockwise rotation causes a respective second neck surface  251  of each inner diameter tier  246  to contact a respective second shoulder surface  253  of lock nut  210 , forcing counter-clockwise rotation of lock nut  210  about threaded body portion  106  and axial movement away from head portion  104  to remove lock nut  210 . 
     With reference now to  FIG. 6 , an alternative embodiment of lock washer  308  is shown. Lock washer  308  is similar to lock washer  108  except that a recessed portion  313  of lower surface  312  of lock washer  308  does not include ratchet teeth  314 . Lock washer  308  also includes a raised boss portion  315  defined radially between an aperture  316  and recessed portion  313  without ratchet teeth  314 . It is contemplated that raised boss portion  315  can extend radially outward to abut ratchet teeth  314 , or can be removed all together such that the surface is flush with recessed portion  313 . It is contemplated that by not having teeth  314  extend across the entire surface of the lock washer  308 , most of the damping force is applied on raised boss portion  315  as opposed to teeth  314 . This tends to allow for a greater clamping force to be applied to washer  308 , as the potential for the clamping force to deform teeth  314  is reduced. Those skilled in the art will readily appreciate that recessed portion  313  tends to ease manufacturing for certain tools, for example, a dovetail cutter. 
     As shown in  FIG. 7 , a fastening device  400  includes a fastener  402  with a head portion  404  and an elongated threaded body portion  406  extending axially from head portion  404 , a lock washer  408 , and a threaded lock nut  410  for rotatably mating with threaded body portion  406 . Lock washer  408  has opposed upper  413  and lower surfaces  412  and a circumferential surface  427  therebetween. Circumferential surface  427  has an array of ratchet teeth  414  extending radially outward of circumferential surface  427 . Lock washer  408  has an axial aperture  416  with a pair of opposing flat inner surfaces  418  corresponding to the pair of opposing longitudinally extending flat sections  430  of threaded body portion  430 , similar to flat inner surfaces  118  and corresponding flat sections  130 , as described above. 
     With reference now to  FIGS. 7 and 8 , threaded lock nut  410  has an upper surface  420  that defines a pair of opposing pawl arms  422 . Each pawl arm  422  includes a respective pair of pawl teeth  424  for engagement with at least one of ratchet teeth  414 . Each pair of pawl teeth  424  extends radially inward from its respective pawl arm  422 . Those skilled in the art will readily appreciate that while each pawl arm  422  is described herein as having a pair of pawl teeth  424 , any suitable number of pawl teeth  424  can be used. Threaded lock nut  410  includes an axial aperture  423  with threads  425  defined in the circumference of aperture  423  for mating with the threads of threaded body portion  406 , similar to aperture  123  and threads  125  described above. Threaded lock nut  410  includes axially extending recessed portions  428 . Each recessed portion  428  is defined between a lower surface  421  of threaded lock nut  410  and a pawl arm  422 . A tapered slot  411  is defined between each pawl arm  422  and threaded lock nut  410 . Each pawl arm  422  includes a tapered inner surface  426  effectively causing the taper of tapered slot  411 . The tapered slot  411  is smaller proximate pawl teeth  424 . 
     As shown in  FIGS. 7 and 9 , fastening device  400  includes a tool  440  for tightening and removing fastener  402 . Tool  440  includes a pair of projections  446  on a distal working portion  442 . Each projection  446  includes a recessed extension  448  configured to engage a respective tapered slot  411 . Each projection  446  corresponds to a respective axially extending recessed portion  428  of threaded lock nut. During tightening, projections  446  of tool are inserted into their respective axially extending recessed portions  428  and recessed extensions  448  extend into respective larger portions of each respective tapered slot  411 . Tool  440  is then rotated clockwise. During clockwise rotation of tool  440 , neck surfaces  447  of tool  440  each abut respective shoulder surfaces  449  of locking nut  410 , forcing clockwise rotation of lock nut  410  about threaded body portion  406  and axial movement toward head portion  404  to tighten fastener  402  in position. 
     With continued reference to  FIGS. 7 and 9 , during removal, projections  446  of tool  440  are again inserted into their respective axially extending recessed portions  428  and recessed extensions  448  extend into respective larger portions of each respective tapered slot  411 , and tool  440  is rotated counter-clockwise. During counter-clockwise rotation of tool  440 , each recessed extension  448  rotates into the smaller portion of its respective tapered slot  411  against tapered surface  426  proximate pawl teeth  424  splaying the pawl arms  422  radially outward away from ratchet teeth  414  disengaging pawl teeth  424  from ratchet teeth  414 . Once pawl teeth  424  are disengaged from ratchet teeth  414 , the continued counter-clockwise rotation causes respective a second neck surface  451  of each projection  446  to contact a respective second shoulder surface  453  of lock nut  410 , forcing counter-clockwise rotation of lock nut  410  about threaded body portion  406  and axial movement away from head portion  404  to remove lock nut  410 . It is contemplated that since lock washer  408  is recessed within lock nut  410 , a simple retaining clip may be used to retain lock washer  408  within lock nut  410  to make it one assembly. 
     As shown in  FIG. 10 , a fixation system  600  for coupling a rod  605  to bone, for example a spinal pedicle screw rod system, includes an elongated bone screw fastener  602  with a threaded tulip head portion  604  defining a transverse channel  607  and opposing prongs  603 , and an elongated threaded body portion  606  depending from tulip head portion  604 . Fixation system  600  also includes a lock washer  608  and a threaded lock nut  610 . Threaded lock nut  610  is substantially similar to lock nut  110  except that threaded lock nut  610  is configured to rotatably mate with tulip head portion  604 , instead of threaded body portion  606 . 
     With reference now to  FIGS. 10 and 11 , lock washer  608  is similar to lock washer  108  except that lock washer  608  includes a bar  611  defined within an axial aperture  616  and lock washer  608  is configured for axial movement along tulip head portion  604 , instead of a threaded body portion. Bar  611  extends between opposing sides of axial aperture  616  to create two discrete axial apertures  615 . Each discrete axial aperture  615  includes a pair of opposing flat inner surfaces  618  corresponding to a pair of opposing longitudinally extending flat sections  630  of each prong  603 . Flat sections  630  of each prong  603  are configured to mate with respective flat inner surfaces  618  of each discrete axial aperture  615  to rotationally fix lock washer  608  when prongs  603  of tulip head portion  604  are inserted in their respective discrete axial apertures  615 , while allowing axial movement of lock washer  608  along the prongs  603  of tulip head portion  604  to secure rod  605  within the transverse channel  607  between lock washer  608  and tulip head portion  604 . After rod  605  is placed within transverse channel  607 , lock washer  608  is inserted over prongs  603  of tulip head portion  604 . Bar  611  of lock washer  608  moves axially down transverse channel  607  and rests against rod  605 . 
     Those skilled in the art will readily appreciate that because lock nut  610  and lock washer  608  are substantially similar to lock nut  110  and lock washer  108 , a tool, e.g. tool  140  and/or tool  240 , can be used to tighten rod  605  to the fastener  602  or remove rod  605  from fastener by either rotating lock nut  610  clockwise or counterclockwise. Traditional spinal pedicle screw rod systems tend to require a significant amount of torque to be applied, in order to lock a rod to a fastener, e.g. a pedicle screw, or to remove the rod from the fastener. Those skilled in the art will readily appreciate, however, that embodiments of the present disclosure reduce the amount of torque required as compared with traditional spinal pedicle screw rod systems. 
     As shown in  FIG. 12 , a fixation system  700  for coupling a rod  705  to bone includes an elongated bone screw fastener  702  and rod  705 , similar to bone screw fastener  602  and rod  605 . Fixation system  700  also includes a lock washer  708  and a threaded lock nut  710 . Threaded lock nut  710  is substantially similar to lock nut  410  except that threaded lock nut  710  is configured to rotatably mate with tulip head portion  704 , instead of threaded body portion  706 . 
     With reference now to  FIGS. 12 and 13 , lock washer  708  is similar to lock washer  408  except that lock washer  708  includes a pair of discrete axial apertures  715  and includes a bar  711  defined therebetween, and is configured for axial movement along tulip head portion  704 , instead of a threaded body portion. Each discrete axial aperture  715  is configured to receive a respective prong  703  of tulip head portion  704  for axial movement of lock washer  708  along the prongs  703  to secure rod  705  between lock washer  708  and tulip head portion  704 . Similar to lock washer  408 , ratchet teeth  714  extend from a circumferential surface  723  radially outward of circumferential surface  723 . Those skilled in the art will readily appreciate that because lock nut  710  and lock washer  708  are substantially similar to lock nut  410  and lock washer  408 , a tool, e.g. tool  440 , can be used to tighten rod  705  to the fastener  702  or remove rod  705  from fastener by either rotating lock nut  710  clockwise or counter-clockwise. 
     Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only exemplary embodiments of the present disclosure are shown and described, simply by way of illustration of the best mode contemplated for carrying out the present disclosure. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. 
     The fastening device technology described herein has unlimited application in industry and other uses. Particularly advantageous applications will involve use near motors or moving equipment in which vibration may cause loosening of traditional fasteners such as in automotive applications, aerospace applications, oil and gas, and manufacturing machinery. The present fastening device technology is also well suited for medical applications such as attaching pedicle screws to spinal rods, attaching spinal plates and fracture plates, fixing artificial joints, like hips and knees, orthopedic and maxillofacial external fixator systems, and the like. In particular, those skilled in the art will readily appreciate that embodiments of the fastening device technology described herein can withstand high temperature applications, for example, they can withstand temperatures as high as the material they are fabricated from can tolerate, and are easily applied, removed and reused. In addition, it is contemplated that the tightening of a nut, e.g. locking nut  110 ,  210 ,  410 ,  610 , or  710 , on a fastener, e.g. fastener  102 ,  402 ,  602 , or  702 , can be blind. For example, instead of the head portions, e.g. head portions  104 ,  404 ,  604  and  704 , flats, e.g. flats  130 ,  430 ,  630 , or  730  on body  106  can be held or otherwise fixed during tightening. 
     While the subject invention has been described with respect to preferred and exemplary embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention as described herein and as defined by the appended claims.