Abstract:
A floating fastener includes a mounting base member affixed to a first panel member, a rotary fastening member supported on an elastic member in the mounting base member for locking a second panel member to the first panel member through a rotary motion, and a cap member affixed to the head of the rotary fastening member and axially slidably coupled to the mounting base member and rotatable to shift inside longitudinal ribs relative to vertical guide grooves at a locating flange around the periphery of the mounting base member and to move the rotary fastening member between a locking position and an unlocking position.

Description:
This application claims the priority benefit of Taiwan patent application number 101219654, filed on Oct. 11, 2012. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to fastener means for detachably securing two panel members together and more particularly, to a floating fastener, which comprises a mounting base member affixed to a first panel member, a rotary fastening member supported on an elastic member in the mounting base member for locking a second panel member to the first panel member through a rotary motion, and a cap member affixed to the head of the rotary fastening member and axially slidably coupled to the mounting base member and rotatable to shift inside longitudinal ribs thereof relative to vertical guide grooves at a locating flange around the periphery of the mounting base member and to move the rotary fastening member between a locking position and an unlocking position. 
     2. Description of the Related Art 
     When joining panel members, fastening devices respectively formed of a lock screw, a rotary knob and a washer may be used. During application, the lock screw, rotary knob and washer of each fastening device are assembled and then mounted at a first panel member. When fastening the first panel member to a second panel member, rotate the rotary knob of each fastening device to drive the respective lock screw into a respective mounting screw hole at the second panel member, and then use a hand tool to fasten tight the lock screw. These fastening devices are widely used in server racks for telecommunication, industrial computers, machine tools, and other situations where multiple panel members are to be fastened in a stack. 
     Further,  FIG. 11  illustrates a floating fastener D for use to lock panel members together. As illustrated, this design of floating fastener D comprises a socket member C, which comprises a bottom mounting flange C 2  extended from the bottom side thereof and affixed to a first panel member E and a top stop flange C 1  around the periphery of the top side thereof, a lock screw A 1  inserted through the socket member C and fastenable to a second panel member E 1  that is attached to the bottom side of the first panel member E, a spring member B mounted in the socket member C around the lock screw A 1  and stopped between an inside part of the socket member C and the flat bottom wall of the head A 11  of the lock screw A 1 , and a cap member A affixed to the head A 11  of the lock screw A 1  with an inside bottom flange A 2  thereof axially slidably coupled to the periphery of the socket member C and stoppable at the bottom side of the top stop flange C 1  of the socket member C. 
     When using the aforesaid floating fastener D in a server rack for telecommunication, industrial computer or machine tool to lock panel members, the application of the floating fastener D may be restricted due to space limitation. Further, it needs a proper hand tool to fasten the lock screw A 1  of the floating fastener D to a panel member E 1 . If a proper hand tool is not available, the mounting or dismounting work will be interrupted, resulting in increased cost of work. An improvement in this regard is required. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a floating fastener for locking two panel members together, which has the advantages of ease of use, high installation reliability and high positioning accuracy. 
     To achieve this and other objects of the present invention, a floating fastener comprises a mounting base member affixed to a first panel member, a rotary fastening member including a head suspending outside the mounting base member and a shank extended from the head and inserted through the mounting base member and terminating in a locking tip for locking a second panel member to the first panel member through a rotary motion, a compression spring mounted around the shank of the rotary fastening member and stopped between the head of the rotary fastening member and an inside part of the mounting base member, and a cap member affixed to the head of the rotary fastening member and axially slidably coupled to the mounting base member and rotatable to move the rotary fastening member between a locking position and an unlocking position. The mounting base member comprises a locating flange extending around the periphery thereof, and a plurality of vertical sliding grooves located in the locating flange and equiangularly spaced from one another. The cap member comprises a plurality of longitudinal ribs equiangularly spaced around the inside wall thereof and respectively slidably coupled to the vertical sliding grooves. When rotating the cap member to move the rotary fastening member between the locking position and the unlocking position, the longitudinal ribs are shifted relative to the vertical sliding grooves. 
     Further, the cap member comprises an inside bottom stop flange curved from the bottom edge thereof and slidably coupled to the periphery of the mounting base member and stoppable at the bottom side of the locating flange of the mounting base member, and a raised portion protruded from the inside wall thereof above the inside bottom stop flange. When lowering the cap member to force the locking tip of the rotary fastening member through an elongated locking hole of the second panel member during a locking operation, the raised portion will be moved over the locating flange of the mounting base member, and the user&#39;s hand can sense the elevational change of the cap member relative to the mounting base member where the locking tip of the rotary fastening member has reached the elevation below the bottom edge of the elongated locking hole of the second panel member, and thus the user can rotate the cap member and the rotary fastening member to lock the second panel member to the first panel member. 
     Further, when rotating the cap member in the reversed direction through a 90° angle to shift the longitudinal ribs from one respective vertical sliding groove of the mounting base member to another respective vertical sliding groove, the rotary fastening member will be pushed upwardly in direction away from the second panel member by the elastic potential energy of the elastic member to the extent where the raised portion of the cap member is stopped at the bottom edge of the locating flange of the mounting base member. At this time, impart an upward pulling force to the cap member to move the raised portion of the cap member over the locating flange of the mounting base member, and thus, the rotary fastening member is disengaged from the second panel member, allowing removal of the first panel member from the second panel member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique top elevational view of a floating fastener in accordance with the present invention. 
         FIG. 2  is an exploded view of the floating fastener in accordance with the present invention. 
         FIG. 3  is another exploded view of the floating fastener in accordance with the present invention when viewed from another angle. 
         FIG. 4  is a sectional side view of the floating fastener in accordance with the present invention. 
         FIG. 5  is a sectional top view of the floating fastener in accordance with the present invention. 
         FIG. 6  is a schematic applied view of the present invention, illustrating the floating fastener installed in a first panel member before attachment of the first panel member to a second panel member. 
         FIG. 7  is a schematic sectional applied view of the present invention, illustrating the cap member of the floating fastener lowered relative to the attached first panel member and second panel member and the locking tip inserted through the elongated locking hole of the second panel member. 
         FIG. 8  corresponds to  FIG. 7 , illustrating the cap member and rotary fastening member of the floating fastener rotated from an unlocking position to a locking position. 
         FIG. 9  is a sectional top view of the present invention, illustrating the rotary fastening member of the floating fastener rotated with the cap member to the locking position. 
         FIG. 10  is an oblique top elevational view of an alternate form of the floating fastener in accordance with the present invention. 
         FIG. 11  is a sectional applied view of a floating fastener according to the prior art. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 ,  2  and  3 , a floating fastener in accordance with the present invention is shown. The floating fastener comprises a mounting base member  1 , a rotary fastening member  2 , an elastic member, for example, compression spring  24 , and a cap member  3 . 
     The mounting base member  1  is an open-ended cylindrical member comprising a recessed accommodation chamber  111  defined in a top side thereof, a through hole  11  vertically extending through opposing top and bottom sides thereof across the recessed accommodation chamber  111 , a bottom mounting neck  12  downwardly extended from the bottom side around the through hole  11 , a mounting groove  121  extending around the periphery of the bottom mounting neck  12 , and a locating flange  13  extending around the periphery thereof. The locating flange  13  defines a plurality of alternatingly arranged guide block portions  131  and stop block portions  132 , a vertical sliding groove  133  disposed between each guide block portion  131  and each adjacent stop block portion  132 , and a bevel guide face  134  upwardly inwardly extended from the guide block portions  131 , the stop block portions  132  and the vertical sliding grooves  133  and merged into the periphery of the mounting base member  1 . Preferably, the vertical sliding grooves  133  are respectively spaced from one another at a 90° angle. 
     The rotary fastening member  2  comprises a head  21  suspending above the mounting base member  1 , an engagement portion  211  extending around the periphery of the head  21 , a shank  22  perpendicularly downwardly extended from the flat bottom wall of the head  21  and inserted into the through hole  11  of the mounting base member  1  and terminating in a locking tip  23  that suspends outside the cap member  21 . The locking tip  23  defines an arrowhead-shaped locking portion  233 , a neck portion  232  connected between the bottom edge of the shank  22  and the top edge of the arrowhead-shaped locking portion  233 , and at least one, for example, two longitudinal cut planes  231  located at the neck portion  232  and the arrowhead-shaped locking portion  233  at two opposite lateral sides. 
     The compression spring  24  is mounted in the recessed accommodation chamber  111  of the mounting base member  1  around the shank  22  of the rotary fastening member  2 , and stopped between the bottom wall of the accommodation chamber  111  and the flat bottom wall of the head  21  of the rotary fastening member  2 . 
     The cap member  3  comprises an accommodation open space  30  surrounded by an inside wall thereof and extending through opposing top and bottom sides thereof, an inside locating groove  301  extending around the accommodation open chamber  30  and disposed near the top side for engagement with the engagement portion  211  of the rotary fastening member  2 , a plurality of longitudinal ribs  31  spaced around the inside wall corresponding to the vertical sliding grooves  133  of the locating flange  13  of the mounting base member  1 , an inside bottom stop flange  32  curved from the bottom edge of the bottom wall and suspending below the longitudinal ribs  31 , at least one raised portion  33  protruded from the inside wall above the inside bottom stop flange  32 , and a grip  34  located at the top side around the accommodation open space  30 . Further, each longitudinal rib  31  defines a smoothly arched outer surface  311 . 
     Further, the aforesaid rotary fastening member  2  can be a one-piece metal member made by forging, extrusion or machining technology. The cap member  3  can be a plastic member directly molded on the head  21  of the rotary fastening member  2  by insert molding. Alternatively, the engagement portion  211  of the rotary fastening member  2  can be forced into engagement with the inside locating groove  301  of the cap member  3  using a mounting technique. Further, the engagement portion  211  of the rotary fastening member  2  can be formed on the periphery of the head  21  of the rotary fastening member  2  using extrusion, embossing or grinding. All modifications and equivalent structural changes made from the specification and drawings of the present invention shall be included in the appended claims of the present invention. 
     When assembling the floating fastener, sleeve the compression spring  24  onto the shank  22  of the locking device  2  after the cap member  3  is molded on or fastened to the head  21  of the locking device  2 , and then insert the shank  22  of the locking device  2  into the through hole  11  of the mounting base member  1  to have the compression spring  24  be stopped between the bottom wall of the recessed accommodation chamber  111  and the flat bottom wall of the head  21  of the rotary fastening member  2 , and then lower the cap member  3  to move the smoothly arched outer surfaces  311  of the longitudinal ribs  31  over the vertical sliding grooves  133  of the locating flange  13  of the mounting base member  1  respectively. After the raised portion  33  passed over the bevel guide face  134  of the locating flange  13  of the mounting base member  1 , the mounting base member  1  is accommodated in the accommodation open space  30  of the cap member  3 . At this time, the inside bottom stop flange  32  of the cap member  3  is stopped at the bottom side of the locating flange  13  of the mounting base member  1  to prevent the cap member  3  from falling out of the mounting base member  1 , and thus, the floating fastener is well assembled. 
     Referring to  FIGS. 6-9 , during application of the floating fastener, the mounting base member  1  of the floating fastener is installed in a mounting through hole  41  of a first panel member  4  and then detachably fastened to an elongated locking hole  51  of a second panel member  5  to lock the first panel member  4  and the second panel member  5  in a stacked condition. When installing the floating fastener in the first panel member  4 , insert the bottom mounting neck  12  of the mounting base member  1  into the mounting through hole  41  of the first panel member  4 , and then use a punching tool to punch the head  21  of the rotary fastening member  2  against the first panel member  4 , forcing the mounting groove  121  of the bottom mounting neck  12  into tightly engagement with the deformed periphery of the mounting through hole  41  of the first panel member  4 . 
     After installation of the floating fastener in the first panel member  4 , attach the first panel member  4  to the second panel member  5  to keep the mounting through hole  41  and the elongated locking hole  51  in alignment, and then apply a pressure to the cap member  3  to move the longitudinal ribs  31  along the vertical sliding grooves  133  of the locating flange  13  of the mounting base member  1  and to force the locking tip  23  into the elongated locking hole  51  of the second panel member  5  and to compress the compression spring  24 . When the raised portion  33  of the cap member  3  touches the bevel guide face  134  of the locating flange  13  of the mounting base member  1 , enhance the applied force to force the raised portion  33  over the bevel guide face  134  to the bottom side of the locating flange  13 . After the raised portion  33  has been moved over the bevel guide face  134  to the bottom side of the locating flange  13 , the user&#39;s hand can sense this elevational change. At this time, the locking tip  23  of the rotary fastening member  2  has reached the elevation below the bottom edge of the elongated locking hole  51  of the second panel member  5 . 
     After the locking tip  23  of the rotary fastening member  2  is lowered to the elevation below the bottom edge of the elongated locking hole  51  of the second panel member  5 , the two longitudinal cut planes  231  of the locking tip  23  respectively face toward two opposite long sides of the elongated locking hole  51  of the second panel member  5 . At this time, rotate the cap member  3  through a predetermined angle, for example, a 90° angle relative to the attached first panel member  4  and second panel member  5  either clockwise or counter-clockwise to move the longitudinal ribs  31  from one respective vertical sliding groove  133  over one respective adjacent guide block portion  131  to another respective vertical sliding groove  133  and stopped against one respective stop block portion  132 , at this time, the neck portion  232  of the locking tip  23  is suspended in a notched portion  511  in the elongated locking hole  51  of the second panel member  5 , and the arrowhead-shaped locking portion  233  of the locking tip  23  is stopped against the bottom wall of the second panel member  5 , avoiding escape of the locking tip  23  out of the elongated locking hole  51  of the second panel member  5  due to an accidental shearing force, and thus, the first panel member  4  and the second panel member  5  are locked together. 
     When going to remove the first panel member  4  from the second panel member  5 , rotate the cap member  3  in the reversed direction through a 90° angle to shift the longitudinal ribs  31  from one respective vertical sliding groove  133  to another respective vertical sliding groove  133  again. At this time, the two longitudinal cut planes  231  of the locking tip  23  are returned to face toward the two opposite long sides of the elongated locking hole  51  of the second panel member  5 , enabling the rotary fastening member  2  to be pushed upwardly in direction away from the elongated locking hole  51  of the second panel member  5  by the elastic potential energy of the compression spring  24  to the extent where the raised portion  33  of the cap member  3  is stopped at the bottom edge of the locating flange  13  of the mounting base member  1 . Thereafter, impart an upward pulling force to the cap member  3  to move the raised portion  33  over the locating flange  13  of the mounting base member  1 , and then remove the first panel member  4  from the second panel member  5 . Through a rotary motion to rotate the cap member  3  and the rotary fastening member  2  relative to the mounting base member  1 , the floating fastener can lock the first panel member  4  to the second panel member  5  or unlock the first panel member  4  from the second panel member  5 . Thus, the floating fastener has the advantages of ease of use, high installation reliability and high positioning accuracy. 
     Referring to  FIG. 10  and  FIG. 2  again, the grip  34  of the cap member  3  can be variously embodied. In the embodiment shown in  FIG. 10 , the grip  34  extends over the top side of the accommodation open space  30  of the cap member  3 , allowing the user to rotate the cap member  3  and the rotary fastening member  2  with less effort. 
     Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.