Patent Publication Number: US-2009232618-A1

Title: Fastener assembly

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 61/036,309 filed on Mar. 13, 2008, the entire content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to fasteners. 
     BACKGROUND OF THE INVENTION 
     When securing components with fasteners, the fasteners are typically provided separately from the components themselves and must be brought to the components using either an automated or manual process during assembly of the components. For example, when securing two components by a bolt, the two components are often first brought together in their final assembled positions, the bolt is then brought to the pre-assembled components, and lastly the bolt is inserted through respective apertures in the components and tightened to secure the components together. 
     SUMMARY OF THE INVENTION 
     Unitizing fasteners with one or more of the components which the fasteners will secure can reduce the number of steps required to assemble the components and subsequently decrease the amount of time spent on the component assembly. 
     The present invention provides, in one aspect, a fastener assembly including a fastener having a head and a shank extending from the head. The shank has a necked portion. The fastener assembly also includes a retainer having an aperture through which the shank is inserted and at least one radially inwardly-projecting tang engaged with the necked portion of the shank to limit movement of the retainer along the shank to within the necked portion. 
     The present invention provides, in another aspect, a unitized engine component assembly including an engine component having an aperture and a lip projecting into the aperture, and a fastener including a head and a shank extending from the head. The shank has a necked portion. The unitized engine component assembly also includes a retainer positioned in the aperture of the engine component. The retainer includes an aperture through which the shank is inserted and at least one radially inwardly-projecting tang engaged with the necked portion of the shank to limit movement of the retainer along the shank to within the necked portion. Engagement of the retainer and the lip substantially prevents removal of the shank from the engine component aperture. 
     The present invention provides, in yet another aspect, a method of unitizing a fastener and a component. The method includes providing the component with an aperture and a lip projecting into the aperture, providing the fastener with a shank and a necked portion on the shank, inserting the shank through an aperture in a retainer, deflecting a radially inwardly-projecting tang of the retainer upon inserting the shank through the retainer aperture, engaging the necked portion of the shank with the radially inwardly-projecting tang, inserting the retainer into the component aperture, and resiliently deforming the retainer upon moving the retainer past the lip. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a fastener assembly of the present invention, including a fastener and a retainer. 
         FIG. 2  is a bottom perspective view of the fastener assembly of  FIG. 1 . 
         FIG. 3  is an exploded, perspective view of the fastener and retainer of  FIG. 1 , before the retainer is positioned on the fastener. 
         FIG. 4  is a top view of the retainer shown in  FIG. 3 . 
         FIG. 5  is a partial cross-sectional view of the fastener assembly of  FIG. 1 , illustrating the retainer being positioned on the fastener. 
         FIG. 6  is a partial cross-sectional view of the fastener assembly of  FIG. 1 , illustrating the retainer engaging a necked portion of the retainer. 
         FIG. 7  is a partial cutaway view of an engine component configured to receive the fastener assembly of  FIG. 1 . 
         FIG. 8  is a partial cross-sectional view of the fastener assembly of  FIG. 1  being coupled to the engine component. 
         FIG. 9  is a partial cross-sectional view of the fastener assembly of  FIG. 1  unitized to the engine component, the fastener assembly being shown in a first position relative to the engine component. 
         FIG. 10  is a partial cross-sectional view of the fastener assembly of  FIG. 1  unitized to the engine component, the fastener assembly being shown in a second position relative to the engine component. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  illustrate a fastener assembly  10  including a fastener  14  and a retainer  18  coupled to the fastener  14 . The fastener  14  includes a head  22  and a shank  26  extending from the head  22 . Although the illustrated fastener  14  is in the form of a bolt, the fastener  14  may be configured in any of a number of different ways. The shank  26  includes a non-threaded necked portion  30 , having a reduced diameter relative to the portions of the shank  26  adjacent the necked portion  30 , spaced from the head  22 , and a threaded portion  34  adjacent the necked portion  30 . Alternatively, the necked portion  30  of the shank  26  may be spaced from the threaded portion  34  of the shank  26 . Further, the necked portion  30  of the shank  26  may be adjacent the head  22 . As shown in  FIG. 5 , the necked portion  30  of the shank  26  is defined between an upper shoulder  38  on the shank  26  and a lower shoulder  42  on the shank  26 , which substantially coincides with the upper extent of the threaded portion  34 . Alternatively, the lower shoulder  42  may be spaced from the threaded portion  34  as previously mentioned. 
     With reference to  FIGS. 1-3 , the retainer  18  is configured as a thin washer having substantially planar upper and lower surfaces  46 ,  50 . The retainer  18  is made from a thin, resilient material capable of supporting the weight of the fastener  14  (see  FIG. 9  and the accompanying discussion below). Any of a number of different plastic or metallic materials may be employed to function in this manner. As shown in  FIG. 4 , the retainer  18  includes a circular outer periphery  52  and a substantially circular inner periphery  53  defining an aperture  54 . The retainer  18  also includes one or more radially inwardly-projecting tangs  58 . Although the illustrated retainer  18  includes two opposed tangs  58 , the retainer  18  may alternatively be configured with one or more than two tangs  58 . For example, the retainer  18  may be configured with three tangs  58  spaced equally from each along the inner periphery  53 . Likewise, four, five, six, etc. tangs  58  could be employed on the retainer  18  in a similar manner. 
     With reference to  FIGS. 3 and 4 , each of the tangs  58  includes an arcuate edge  62  configured to engage the shank  26 . The ratio of the radius (R 1 ) defining the arcuate edge  62  of each of the tangs  58  to the radius (R 2 ) defining the inner periphery  53  of the retainer  18  is about 0.75:1. Alternatively, this ratio (i.e., R 1 /R 2 ) may be customized to the particular fastener to which the retainer  18  will be coupled or to suit the material used for the retainer  18 . As a further alternative, each of the tangs  58  may include a “V”-shaped edge, a substantially flat edge, or any of a number of differently-configured edges or surfaces, configured to engage the necked portion  30  of the shank  26 . 
     With reference to  FIGS. 5 and 6 , the steps employed to couple the retainer  18  to the fastener  14  are shown. As shown in  FIG. 5 , the retainer  18  is aligned with the shank  26  and the bottom of the shank  26  is initially inserted through the aperture  54 . Upon contact between the tangs  58  and the threaded portion  34  of the shank  26 , continued displacement of the shank  26  causes the retainer  18 , particularly the tangs  58 , to resiliently deform to allow the retainer  18  to slide relative to the threaded portion  34  toward the head  22 . 
     Upon reaching the lower shoulder  42  of the necked portion  30 , the retainer  18  at least partially rebounds towards its undeflected shape, however, the tangs  58  may remain at least partially deflected from their co-planar orientation shown in  FIGS. 3 and 4  to engage the necked portion  30  of the shank  26 . In the illustrated construction of the retainer  18  in  FIG. 6 , each of the tangs  58  is substantially perpendicular to the upper and lower surfaces  46 ,  50  of the retainer  18 . Specifically, each of the tangs  58  forms an included angle A with the lower surface  50  of about 90 degrees. Depending upon the particular configurations of the fastener  14  and the retainer  18 , each of the tangs  58  may form an included angle A with the lower surface  50  greater than about 90 degrees (e.g., the tangs  58  may be allowed to substantially resume their undeflected shape to yield an included angle A of about 180 degrees). The fastener  14  and the retainer  18  may have any of a number of different configurations provided that the outer diameter of the necked portion  30  is greater than or equal to twice the radius R 1  of the arcuate edges  62 , and equal to or less than twice the radius R 2  of the aperture  54  (see  FIG. 4 ). 
     As shown in  FIG. 6 , the retainer  18  is movable along the necked portion  30  between extreme positions, with the engagement of the tangs  58  and the lower shoulder  42  providing the lower-most limit to the movement of the retainer  18  relative to the shank  26 , and the engagement of the tangs  58  or the upper surface  46  of the retainer  18  and the upper shoulder  38  providing the upper-most limit to the movement of the retainer  18  relative to the shank  26  (shown in phantom). 
     With reference to  FIG. 7 , an engine component  66  including an aperture  70  and a lip  74  projecting into the aperture  70  is shown. The illustrated engine component  66  is configured as a rocker arm pivot  78  of an engine valve train. Alternatively, the engine component  66  may be configured as any other component to be secured to the engine utilizing the fastener assembly  10  of  FIGS. 1 and 2 . As shown in  FIG. 7 , the lip  74  is positioned toward the upper end of the aperture  70 . Alternatively, the lip  74  may be positioned toward the bottom end of the aperture  70 , the middle of the aperture  70 , or at any location along the depth of the aperture  70  or adjacent to the aperture  70 . The illustrated lip  74  includes a circular inner periphery  82  defined by an inner diameter d 1 , and an inner peripheral surface  86  of the rocker arm pivot  78  defining the aperture  70  is defined by an inner diameter D 2  (see  FIG. 8 ). A ratio of the diameters of the inner periphery  82  of the lip  74  and the inner peripheral surface  86  of the rocker arm pivot  78  is about 0.9:1. Depending upon the particular configurations of the fastener  14  and the retainer  18 , this ratio (i.e., D 1 /D 2 ) maybe greater or less than about 0.9:1. In other embodiments, the lip need not be annular, but may be a non-annular projection extending radially inwardly from the surface  86 . 
     To unitize the fastener  14  and the rocker arm pivot  78 , the shank  26  is initially aligned with the aperture  70  in the rocker arm pivot  78  and inserted into the aperture  70 . The retainer  18  is initially situated on the shank  26  such that the tangs  58  engage the lower shoulder  42  of the necked portion  70 . Upon contact between the lip  74  and the retainer  18 , continued insertion of the shank  26  into the aperture  70  in the rocker arm pivot  78  causes the retainer  18  to slide upwardly, relative to and within the necked portion  30  of the shank  26 , until the tangs  58  and/or the upper surface  46  engage the upper shoulder  38  of the necked portion  30 . From this point, continued insertion of the shank  26  into the rocker arm pivot  78  causes the retainer  18  to resiliently deflect or bow due to the obstruction caused by the lip (see  FIG. 8 ), until the deflection of the retainer is sufficient to allow the retainer to move past the lip  74 , at which time the retainer  18  (with the exception of the tangs  58 ) rebounds or substantially resumes its undeflected shape (see  FIGS. 9 and 10 ). Although  FIGS. 9 and 10  illustrate the fastener assembly  10  installed on the rocker arm pivot  78 , the rocker arm pivot  78  may alternatively first be pre-assembled with the rocker arm itself (not shown) before the fastener assembly is installed on the rocker arm pivot  78 . 
     The retainer  18  facilitates handling of the fastener  14  and the rocker arm pivot  78  as a unit, without substantial concern that the fastener  14  and the rocker arm pivot  78  may become unintentionally separated. For example,  FIGS. 9 and 10  illustrate the retention of the fastener  14  to the rocker arm pivot  78  while the rocker arm pivot  78  is situated in an inverted orientation and a non-inverted orientation, respectively. When the rocker arm pivot  78  is handled in an inverted orientation ( FIG. 9 ), the retainer  18  is abutted or engaged with the lip  74 , and the tangs  58  are engaged with the lower shoulder  42  of the necked portion  30 , such that the fastener  14  is supported by the rocker arm pivot  78  via the retainer  18 . When the rocker arm pivot  78  is handled in a non-inverted or upright orientation ( FIG. 10 ), the head  22  of the fastener  14  is directly supported on the rocker arm pivot  78 . As a result, the movement of the fastener  14  relative to the rocker arm pivot  78  is constrained between a first extreme position, in which the retainer  18  and the lip  74  are engaged ( FIG. 9 ), and a second extreme position, in which the head  22  of the fastener  14  is directly supported on or engaged with the rocker arm pivot  78  ( FIG. 10 ). 
     Various features of the invention are set forth in the following claims.