Patent Publication Number: US-2005117998-A1

Title: Fastener assembly with locking washer

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority from U.S. Provisional Application No. 60/526,040, filed Dec. 1, 2003. 
    
    
     TECHNICAL FIELD  
      The present invention relates to a fastener assembly. More specifically, the present invention provides a fastener assembly with a locking washer to secure a first structure to a second structure.  
     BACKGROUND OF THE INVENTION  
      There are numerous fastener assemblies currently available for both commercial applications and residential use. Conventional fastener assemblies generally include a bolt, a washer, and a nut to fasten a first object to a second object. Typically, the first object is positioned adjacent to the second object such that the first object is in direct contact with the second object. The washer and nut receive an extent of the bolt to secure the first and second objects. In use, the washer is positioned between the nut and one of the objects. Conventional washers are usually fabricated from metal or plastics and have ring-shaped configuration with a central opening to receive a portion of the bolt. Conventional nuts are also formed from metal or plastics and have a hexagonal configuration with a central opening to receive the bolt.  
      Generally, the first object has a portion that passes through a slot in the second object. The fastener assembly extends through an opening in the second object. A clearance or gap is defined by the distance between a surface of the second object and the fastener assembly. Conventional fastener assemblies have no structures that reduce or eliminate the clearance. Specifically, neither the washer nor the nut can reduce or eliminate the clearance. Thus, conventional fastener assemblies cannot properly secure the first object and the second object.  
      Therefore, there is a need for a fastener assembly with at least one structure that eliminates the clearance to secure the first object to the second object.  
      The present invention is provided to solve these and other deficiencies.  
     SUMMARY OF THE INVENTION  
      The present invention relates to a fastener assembly that includes a nut, a locking washer, and a bolt. The fastener assembly is configured to rigidly secure a first structure to a second or support structure. A tab extends from the first structure through a slot in the support structure. The tab has an opening that receives the bolt and to which the locking washer and the nut are attached. The locking washer is adapted to engage an inner surface of the second structure to secure the first structure thereto. The locking washer has a plurality of side walls and a plurality of rounded corners. Preferably, each side wall has numerous teeth, which can be linear or angled. The locking washer has an internal aperture; however, the aperture is not aligned with the center of the locking washer. Thus, the aperture is positioned off-center within the locking washer. Because the aperture is positioned off-center, the distance from the edge or periphery of the aperture to each of the side walls and corners is distinct. Similarly, the distance from the center of the aperture to each of the side walls and corners is distinct.  
      The first structure is positioned adjacent to the second structure whereby the tab is inserted through the slot. Once the first structure is properly positioned with respect to the second structure, the bolt is inserted through the opening in the tab. The locking washer is then placed in a first position wherein the bolt is received by the locking washer. In the first position, a first clearance exists and is defined by the distance between the first side wall of the locking washer and the inner surface of the second structure. Due to the clearance, there is no engagement between the locking washer and the second structure. Because the locking washer has an eccentric aperture and the lengths to the side walls are distinct, the locking washer can be selectively rotated to eliminate the clearance and bring a side wall into engagement with the inner surface. Depending upon the amount of rotation necessary, a corner region of the locking washer may engage the inner surface of the support structure. The corner region is deformable such that the locking washer can be further rotated to bring a side wall into engagement with the inner surface. When the side wall engages the inner surface of the support structure, the locking washer and the fastener assembly are in a locking position. In the locking position, the locking washer exerts a clamping force and a gripping force on the inner surface.  
      Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:  
       FIG. 1  is a perspective view of a fastener assembly of the invention, showing a first structure secured by the fastener assembly to a second structure;  
       FIG. 2  is a perspective view of a locking washer of the fastener assembly of  FIG. 1 ;  
       FIG. 3  is a top plan view of the locking washer of the fastener assembly of  FIG. 1 ;  
       FIG. 4  is a cross-section of the locking washer taken along line  4 - 4  of  FIG. 3 ;  
       FIG. 5  is a cross-section of the locking washer taken along line  5 - 5  of  FIG. 3 ;  
       FIG. 6  is a cross-section of the locking washer taken along line  6 - 6  of  FIG. 3 ;  
       FIG. 7  is an exploded view of the fastener assembly, the first structure and the second structure of  FIG. 1 ;  
       FIG. 8  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing the locking washer in a first position;  
       FIG. 9  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing the locking washer in a second position;  
       FIG. 10  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing the locking washer in a third position;  
       FIG. 11  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing the locking washer in a fourth position;  
       FIG. 12  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing the locking washer in a fifth position; and,  
       FIG. 13  is a partial cross-section view of the fastener assembly of  FIG. 1 , showing an alternate embodiment of the locking washer in the fifth position. 
    
    
     DETAILED DESCRIPTION  
      While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.  
      A fastener assembly  10  is shown in  FIGS. 1 and 7 . The fastener assembly  10  includes a nut  20 , a locking washer  30 , and a bolt  50 . In general terms, the fastener assembly  10  is configured to rigidly secure a first or display structure  12  to a second or support structure  14 . As shown in  FIG. 1 , the first structure  12  and the second structure  14  are generally vertical structures and the fastener assembly  10  secures the first structure  12  to the second structure  14 . A tab  16  extends from the first structure  12  through a slot  18  in the support structure  14 . Once the tab  16  is inserted thorough the slot  18 , the bolt  50  is inserted through an opening  17  of the tab  16 . Although the tab  16  is shown with a lower lobe  16   a  that interacts with the second structure  14 , the lobe  16   a  can be omitted from the tab  16 . As explained in greater detail below, the nut  20  and the locking washer  30  are brought into engagement with the portion of the bolt  50  that extends beyond the tab  16 . Although only a single fastener assembly  10  is shown, it is understood that multiple assemblies  10  could be used to secure the first and second structures  12 ,  14 . The nut  20  can be a lock nut.  
      The locking washer  30  is adapted to engage an inner surface  14   a  of the second structure  14  to secure the first structure  12  thereto. Referring to  FIGS. 2 and 3 , the locking washer  30  has a plurality of side walls  32  and a plurality of corners  34 . Preferably, the corners  34  have a rounded configuration. The locking washer  30  has a first end wall  31  and a second end wall  33  wherein the end walls  31 ,  33  are substantially parallel. Alternatively, at least one of the end walls  31 ,  33  is angled or sloped. The locking washer  30  has a center or centrum  35 . Preferably, each side wall  32  has numerous teeth  36 . Although shown as being curvilinear, the teeth  36  can be linear or angled. Also, the teeth  36  can span the entire length of the side wall  32 , or be intermittently spaced along the side wall  32 . The locking washer  30  has a thickness T that varies with the design parameters of the washer  30 . The locking washer  30  has a perimeter P, which is defined by the side walls  32 .  
      The locking washer  30  has an internal aperture  38 ; however, the aperture  38  is not aligned with the center  35  of the locking washer  30 . In other words, the aperture  38  is positioned off-center within the locking washer  30 . Described in a different manner, a center  40  of the aperture  38  is eccentric with the center  35  of the locking washer  30 . Although not shown, the aperture  38  can be threaded. Because the aperture  38  is positioned off-center, the distance from the edge or periphery  42  of the aperture  38  to each of the side walls  32  and corners  34  is distinct. Similarly, the distance from the center  40  of the aperture  38  to each of the side walls  32  and corners  34  is distinct. Referring to  FIGS. 3-6 , the distance from the aperture center  40  to the first side wall  32   a  is L 1 ; the distance from the aperture center  40  to the second side wall  32   b  is L 2 ; the distance from aperture center  40  to the third side wall  32   c  is L 3 ; the distance from aperture center  40  to the fourth side wall  32   d  is L 4 ; the distance from aperture center  40  to the fifth side wall  32   e  is L 5 ; and, the distance from aperture center  40  to the sixth side wall  32   f  is L 6 . Due to the fact that the aperture  38  is off-center, these distances (L 1 -L 6 ) are dissimilar. As shown in  FIGS. 4-6 , there is an unequal amount of material in the regions about the aperture  38 .  
      Referring to  FIG. 3 , the distance from the aperture center  40  to the first corner  34   a  is L 7 ; the distance from the aperture center  40  to the second corner  34   b  is L 8 ; the distance from the aperture center  40  to the third corner  34   c  is L 9 ; the distance from the aperture center  40  to the fourth corner  34   d  is L 10 ; the distance from the aperture center  40  to the fifth corner  34   e  is L 11 ; and, the distance from the aperture center  40  to the sixth corner  34   f  is L 12 . Since the aperture  38  is off-center, these distances (L 7 -L 12 ) are dissimilar.  
      As mentioned above, the fastener assembly  10  is configured to rigidly secure the first structure  12  to the second structure  14 . This is accomplished primarily by the locking washer  30  which engages the inner surface  14   a  of the second support  14 . Referring to  FIGS. 1 and 7 , the first structure  12  is positioned adjacent to the second structure  14  whereby the tab  16  is inserted through the slot  18 . Once the first structure  12  is properly positioned with respect to the second structure  14  and to begin the process of securing the structures  12 ,  14 , the bolt  50  is inserted through the opening  17  in the tab  16 . As shown in  FIG. 8 , the locking washer  30  is then placed in a first position P 1  wherein the bolt  50  is received by the locking washer  30 . Preferably, the locking washer  30  and the bolt  50  are cooperatively dimensioned, meaning the inner diameter of the aperture  38  of locking washer  30  corresponds to the threads on the bolt  50 , to prevent “slop” or unwanted movement transverse to the longitudinal axis of the bolt  50  during rotation of the locking washer  30 .  
      In the first position P 1 , a first clearance C 1  is defined as the distance between the first side wall  32   a  and the inner surface  14   a  of the second structure  14 . In the first position P 1 , there is no engagement between the locking washer  30  and the second structure  14 . Because the locking washer  30  has an eccentric aperture  38  and the lengths to the side walls  32  are distinct, the locking washer  30  can be selectively rotated to eliminate the clearance and bring a side wall  32  into engagement with the inner surface  14   a . As shown in  FIG. 9 , the locking washer  30  has been rotated in a counter-clockwise direction to a second position P 2 . To reach the second position, the locking washer  30  is rotated approximately 30 degrees; however, the precise amount of rotation varies with the design parameters of the locking washer  30 . Unlike conventional washers, the locking washer  30  is rotated by applying a rotational force to its periphery. Described in a different manner, a standard wrench is used to engage the side walls  32  and rotate the locking washer  30 . In the second position P 2 , a second clearance C 2  is defined as the distance between the first corner  34   a  and the inner surface  14   a . There, the first corner  34   a  is positioned closest to the inner surface  14   a  and the first and second side walls  32   a,b  are angularly positioned with respect to the inner surface  14   a . As shown in  FIG. 10 , the locking washer  30  has been rotated in a counter-clockwise direction to a third position P 3 . In the third position P 3 , a third clearance C 3  is defined as the distance between the second side wall  32   b  and the inner surface  14   a . Due to the configuration of the locking washer  30 , the first clearance C 1  is greater than the second clearance C 2 , and the second clearance C 2  is greater than the third clearance C 3 . Since there is no engagement between the locking washer  30  and the inner surface  14   a , the locking washer  30  must be further rotated. As shown in  FIG. 11 , the locking washer  30  has been rotated in a counter-clockwise direction to a fourth position P 4 . In the fourth position P 4 , the second rounded corner  34   b  engages the inner surface  14   a  and precludes any clearance between the locking washer  30  and the inner surface  14   a . There, the second and third side walls  32   b,c  are angularly positioned with respect to the inner surface  14   a . At least the corners  34  of the locking washer  30  are deformable and as a result, the locking washer  30  can be rotated past the fourth position P 4 . Once the second corner  34   b  is brought into contact with the inner surface  14   a , additional rotational force is applied to the locking washer  30  thereby causing deformation of the second corner  34   b  and permitting the locking washer  30  to further rotate. As shown in  FIG. 12 , the locking washer  30  has been rotated in a counter-clockwise position to a fifth position P 5 . Because the corners  34  are rounded and deformable, the locking washer  30  can be rotated from the fourth position P 4  to the fifth position P 5 . In the fifth position P 5 , the third side wall  32   c  engages the inner surface  14  thereby precluding any clearance between the locking washer  30  and the inner surface  14   a . Specifically, the teeth  36  of the third side wall  32   c  fixedly grip the inner surface  14   a . Once the locking washer  30  is in the fifth position P 5 , the nut  20  can be applied to the bolt  50  and tightened against the locking washer  30 .  
      In the fifth position P 5  or locking position, the locking washer  30  exerts a force generally transverse to the inner surface  14   a  which can be characterized as a clamping force. In addition, the engagement of the teeth  36  with the inner surface  14   a  imparts a gripping force. Unlike conventional washers, the locking washer  30  exerts a locking force on the inner surface  14   a  in the fifth position P 5 . In the fifth position P 5 , the locking washer  30  provides locking support for the first and second structures  12 ,  14 . This means that the engagement between the locking washer  30  and the inner surface  14   a  secures the first structure  12  to the second structure  14  and prevents movement along both the X-axis and the Y-axis (see  FIG. 1 ). In this manner, the locking washer  30  prevents unwanted movement of the first structure  12  with respect to the second structure  14 . When the nut  20  is sufficiently tightened, the nut  20  prevents movement of the fastener assembly  10  along the Z-axis (see  FIG. 1 ). In the fifth position P 5 , no additional structure, such as bracing or reinforcing supports, is required to secure the first structure  12  to the second structure  14 . This means that no bracing structures for the tab  16  and/or the second support  14  are necessary. However, the tab  16  must be configured to extend a sufficient distance beyond the inner surface  14  such that an opening  17  can be formed in the tab  16 .  
      One of skill in the art recognizes that the locking engagement depicted in the fifth position P 5  depends in part on the design parameters of the first and second structures  12 , 14 . One of skill further recognizes that the design parameters of the first and second structures  12 ,  14  could be altered such that the locking engagement provided by the locking washer  30  occurs with either less or more rotations than that shown in  FIGS. 8-12 . For example, the position of the opening  17  in the tab  16  of the second structure  12  can be altered to require a single rotation of the corners  34  of the locking washer  30  (shown as  FIGS. 10-12 ) to result in the locking position P 5 .  
      As shown in  FIGS. 1 and 8 - 12 , the first structure  12  is a blade-like element that is supported generally perpendicular to an outer surface  14   b  of the support structure  14 , which is depicted as a generally panel-like structure. Alternatively, the first structure  12  can be configured as a panel with an inner surface that mates with the outer surface  14   b  when the fastening assembly  10  is in the locking position. For example, the first structure  12  can be an exterior stone panel that is fixedly secured to a vertical wall of a building.  
      The locking washer  30  can be configured for greater or lesser engaging force between the first and second structures  12 ,  14 . For example, the diameter of the aperture  38  can be enlarged or reduced relative to the side walls  32  of the locking washer  30 . Also, the exact location of the aperture  38  within the locking washer  30  can be altered thereby affecting the degree of asymmetry. In addition, the angle or orientation of the aperture  38  relative to a surface plane of the locking washer  30  plane can be revised. Angling of the aperture  38  will permit the locking washer  30  to move transverse to the axis of rotation. Furthermore, the dimensions, including the perimeter P and thickness T, of the locking washer  30  can be varied. Lastly, the characteristics, including the pitch, height, angle, and patterns, of the teeth  36  can be adjusted.  
      Although shown in  FIGS. 1-12  as a hexagon with six side walls  32 , the locking washer  30  can have a variety of configurations. For example and as shown in  FIG. 13 , the locking washer  130  is an octagon with eight side walls. There the third side wall  132   c  engages the inner surface  14   a  to support the first and second structures  12 ,  14 . As another example, the locking washer can have between three to ten side walls. As shown in the Figures and previously described, the side walls  32  are substantially perpendicular to the end walls  31 ,  33 ; however, the side walls  32  can be angled or sloped. In this configuration, the side wall  32  can be angled towards the first end wall  31  or away from the first end wall  31 . The precise configuration of the locking washer  30 , including the number of side walls, can be varied with the design parameters of the locking washer  30  and the engineering dynamics of the first and second structures  12 ,  14 .  
      The locking washer  30  can be formed from a variety of materials. For example, the locking washer  30  can be fabricated from plastic or metal, such as aluminum or steel. In addition, the locking washer  30  can be fabricated from a composite of metals, plastics or ceramics. Since the locking washer  30  has rounded corners  34  that are deformable, the locking washer  30  can be easily rotated to ensure engagement between the side wall  32  and the inner surface  14   a  of the support structure  14 . To increase its utility, a standard wrench can be used to rotate and tighten the locking washer  30  by engaging the side walls  32 .  
      As explained above, the locking washer  30  is utilized to secure structures wherein at least one structure is in tension. The locking washer  30  can be utilized in a variety of other applications. For example, the locking washer  30  can secure structures wherein at least one structure is in compression and where the structure may have an irregular configuration. Furthermore, the locking washer  30  can be utilized to secure structures wherein the structures are in tension, compression, and/or shear. Also, the locking washer  30  can be utilized to secure structures where at least one structure experiences a bending or twisting force.  
      While the specific embodiment has been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying claims.