Patent Publication Number: US-2011070051-A1

Title: Fastener

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a fastener, more particularly to a fastener adapted to be driven rotatably by a socket wrench. 
     2. Description of the Related Art 
     A fastener, such as a bolt or a nut, is generally used with a hexagonal wrench or a hexagonal socket wrench. Taiwanese Utility Model No. 0213143 discloses a nut that has an outer surrounding surface formed with engaging grooves, and a spline socket wrench that has an inner surface provided with engaging keys. When the socket wrench is sleeved on the nut, the engaging keys of the socket wrench engage respectively the engaging grooves of the nut, so that the nut can be driven rotatably by the socket wrench. However, such nut can only be used with the abovementioned spline socket wrench having engaging keys that correspond in number and in structure to the engaging grooves of the nut rather than an ordinary socket wrench. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of the present invention is to provide a fastener that can be driven rotatably by either a spline socket wrench or a normal hexagonal socket wrench. 
     Accordingly, a fastener of the present invention is adapted to be driven rotatably by any one of a spline socket wrench and a hexagonal socket wrench. The spline socket wrench has an annular inner surface that defines a receiving hole, and a plurality of angularly spaced-apart keys protruding in radial inward directions from the annular inner surface. The hexagonal socket wrench has six inner surface portions that cooperatively define a hexagonal receiving space. The fastener comprises a socket-engaging part having an external surrounding surface that surrounds an axis and that has at least one planar surface region, and a plurality of angularly spaced-apart grooves that are formed in the external surrounding surface and that extend parallel to the axis. One of the grooves is formed adjacent to the planar surface region. Each of the grooves has opposite edges parallel to the axis. The edges of the grooves and the planar surface region are disposed on an imaginary hexagonal prism slightly smaller than the receiving space of the hexagonal socket wrench, thereby permitting the socket-engaging part to be sleeved in the hexagonal socket wrench. One of the edges of each of the grooves is adapted to contact a respective one of the inner surface portions of the hexagonal socket wrench, and the planar surface region is adapted to contact one of the inner surface portions of the hexagonal socket wrench when the hexagonal socket wrench is sleeved on and rotated to drive rotation of the socket-engaging part. An imaginary circumscribed cylinder of the external surrounding surface has a diameter slightly shorter than that of the receiving hole of the spline socket wrench, thereby permitting the socket-engaging part to be sleeved in the spline socket wrench in a manner that each of the keys of the spline socket wrench is retained in a respective one of the grooves of the socket-engaging part. The fastener further comprises a securing part connected to the socket-engaging part and formed with a screw thread. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which: 
         FIG. 1  is a perspective view of a spline socket wrench, a hexagonal socket wrench and a first preferred embodiment of a fastener according to the invention; 
         FIG. 2  is a top view of the first preferred embodiment; 
         FIG. 3  is a side view of the first preferred embodiment; 
         FIG. 4  is a cross-sectional view of the first preferred embodiment sleeved in the spline socket wrench; 
         FIG. 5  is another cross-sectional view of the first preferred embodiment sleeved in the hexagonal socket wrench; and 
         FIG. 6  is a perspective view of a second preferred embodiment of the fastener according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIGS. 1 ,  4  and  5 , the fastener  1  according to the present invention is adapted to be driven rotatably by any one of a hexagonal socket wrench  2  and a spline socket wrench  3 , and is adapted to be used for securing a vehicle wheel to a wheel axle. The hexagonal socket wrench  2  has an inner surface  20  having six inner surface portions  21  that cooperatively define a hexagonal receiving space  23 . The spline socket wrench  3  has an annular inner surface  32  that defines a receiving hole  31 , and a plurality of angularly spaced-apart keys  33  that protrude in radial inward directions from the annular inner surface  32 . 
     The fastener  1  comprises a socket-engaging part, and a threaded securing part connected to the socket-engaging part. Referring to  FIGS. 1 to 3 , the first preferred embodiment of the fastener  1  is configured as a bolt having a bolt head  11  that serves as the socket-engaging part, and a shank segment  12  that serves as the securing part and that has an external screw thread  121  formed on an outer surface of the shank segment  12 . 
     In this embodiment, the socket-engaging part has an external surrounding surface  110  that surrounds an axis (L) and that has a plurality of main surface portions  113  and a plurality of bridging surface portions  115  that are alternatingly arranged (i.e., each of the bridging surface portions  115  interconnects an adjacent pair of the main surface portions  113 ). The socket-engaging part further has a plurality of angularly spaced-apart grooves  112  that are formed respectively in the main surface portions  113  and that extend parallel to the axis (L). Each of the grooves  112  has opposite edges parallel to the axis (L). In this embodiment, each of the main surface portions  113  has a pair of planar surface regions  114  formed circumferentially adjacent to and at opposite sides of a corresponding one of the grooves  112 . 
     In this embodiment, an imaginary circumscribed cylinder  100  (see  FIG. 2 ) of the external surrounding surface  110  of the socket-engaging part has a diameter slightly shorter than that of the receiving hole  31  (see  FIG. 1 ) of the spline socket wrench  3 . Each of the bridging surface portions  115  of the external surrounding surface  110  is a curved surface and overlaps the imaginary circumscribed cylinder  100  of the external surrounding surface  110 . Referring further to  FIG. 4 , the aforesaid configuration of the socket-engaging part permits the socket-engaging part to be sleeved in the spline socket  3  in a manner that each of the keys  33  of the spline socket  3  is retained in a respective one of the grooves  112  of the socket-engaging part. Therefore, the fastener  1  of the invention can be driven rotatably by the spline socket wrench  3  through the engagement between the socket-engaging part and the spline socket wrench  3 . 
     As shown in  FIG. 5 , the edges of the grooves  112  and the main surface portions  113  of the external surrounding surface  110  of the socket-engaging part are disposed on an imaginary hexagonal prism (H) that is slightly smaller than the receiving space  23  of the hexagonal socket wrench  2 . Such configuration of the socket-engaging part permits the socket-engaging part to be sleeved in the hexagonal socket wrench  2  with each of the bridging surface portions  115  of the external surrounding surface  110  being disposed to face a corner  22  defined by an adjacent pair of the inner surface portions  21  of the hexagonal socket wrench  2 . When the hexagonal socket wrench  2  is sleeved on and rotated to drive rotation of the socket-engaging part, one of the edges of each of the grooves  112  and an adjacent one of the planar surface regions  114  contact the respective one of the inner surface portions  21  of the hexagonal socket wrench  2 . Therefore, the fastener  1  of the invention can also be driven rotatably by the hexagonal socket wrench  2  through the abutment of the main surface portions  113  of the external surrounding surface  110  of the socket-engaging part against the inner surface portions  21  of the hexagonal socket wrench  2 . 
     As shown in  FIG. 6 , the second preferred embodiment of the fastener  1 ′ according to the present invention differs from the previous embodiment in that the fastener  1 ′ is configured as a nut having an internally threaded part  12 ′ that serves as the securing part, and an external part  11 ′ that serves as the socket-engaging part. An internal screw thread  121 ′ is formed on an inner surface of the internally threaded part  12 ′ radially opposite to the external part  11 ′. The second preferred embodiment has the same advantages as those of the first preferred embodiment. 
     While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.