Abstract:
A floating fastener includes a mounting base member affixed to a first panel member and including an upper locating flange and a lower locating flange disposed at different elevations around the periphery, 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 between the upper and lower locating flanges of the mounting base member and elastically deformably movable over the lower locating flange and stoppable at a bottom side of the lower locating flange when fastening the rotary fastening member to the second panel member to lock the first and second panel member together.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to fastener means for detachably securing two panel members together, and more particularly to a floating fastener consisting of a mounting base member, a rotary fastening member, an elastic member and a cap member, which facilitates mounting and dismounting between two panel members with less effort. 
         [0003]    2. Description of the Related Art 
         [0004]    When joining panel members, a fastening device 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. 
         [0005]    Further, a floating fastener, formed of a cap member, a rotary fastening member, a spring member and a socket member, has also been created for detachably fastening two panel members together by: affixing the socket member of the floating fastener to a mounting through hole of one panel member and then threading the spring-loaded screw member into a mounting screw hole of the other panel member. After separation between the two panel members, the floating fastener is kept secured to the respective panel member.  FIG. 12  illustrates a floating fastener of this design. As illustrated, this design of floating fastener comprises a socket member A, which comprises a bottom mounting flange A 4  extended from the bottom side thereof and affixed to a panel member D by welding and an outside stop flange A 2  extending around the periphery thereof and stopped at the top wall of the panel member D, a rotary fastening member B, which comprises a head B 1  suspending above the socket member A and screw rod B 2  perpendicularly downwardly extended from the center of the bottom wall of the head B 1  and inserted through the socket member A, a spring member A 1  mounted around the socket member A and stopped between the head B 1  of the rotary fastening member B and the outside stop flange A 2  of the socket member A, a stop member A 3  mounted in the inside space A 0  in the socket member A around a plain segment of the rotary fastening member B between the head B 1  and the screw rod B 2  to keep the rotary fastening member B in the socket member A, and a nut C threaded onto the screw rod B 2  of the rotary fastening member B and stopped at the bottom side of the panel member D. 
         [0006]    The floating fastener shown in  FIG. 12  enables the socket member A to be positively and accurately bonded to the panel member D without causing damage to the threads of the screw rod B 2  or the structure of the panel member D. However, when welding the socket member A to the panel member D, the applied solder paste can flow into tiny gaps in between the screw rod B 2  and the nut C, and the nut C can get stuck. A thread damage may occur when using a tool to remove the nut C from the screw rod B 2 . Thus, mounting and dismounting of this design of floating fastener will take much time and labor. 
         [0007]      FIG. 13  illustrates another prior art fastener design for detachably fastening two panel member together. This design of fastener comprises a socket member E fixedly fastened to a first panel member G, and a rotary fastening member F mounted in the socket member E and fastenable to a second panel member H to lock the second panel member H to the first panel member E. The rotary fastening member F comprises a head F 1  suspending above the socket member E, a shoulder F 2  stoppable below an annular top wall E 1  of the socket member E, a neck F 21  connected between the head F 1  and the shoulder F 2  and inserted through the annular top wall E 1  of the socket member E, and a screw rod F 3  axially forwardly extended from the shoulder F 2  in a concentric manner for threading into a mounting screw hole in the second panel member H. Rotating the rotary fastening member F in the reversed direction to disengage the screw rod F 3  from the second panel member H allows separation between the first panel member G and the second panel member H. 
         [0008]    According to the design of the fastener shown in  FIG. 13 , the screw rod F 3  is constantly kept outside the socket member E. When attaching the first panel member G to the second panel member H, it is difficult to keep the screw rod F 3  in accurate alignment with the mounting screw hole in the second panel member H. Thus, an impact between the screw rod F 3  and the second panel member H may occur accidentally, causing damage to the threads of the screw rod F 3  or the structure of the second panel member H. An improvement in this regard is necessary. 
       SUMMARY OF THE INVENTION 
       [0009]    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 detachably fastening two panel members together, which has the advantages of ease of use, high installation reliability and high positioning accuracy. 
         [0010]    To achieve this and other objects of the present invention, a floating fastener of the present invention comprises a mounting base member, a rotary fastening member, an elastic member, and a cap member. The mounting base member comprises a through hole vertically extending through opposing top and bottom sides thereof, a bottom mounting neck downwardly extended from the bottom side and affixed to a first panel member, and a lower locating flange extending around the periphery thereof adjacent to the bottom mounting neck. The rotary fastening member comprises a head suspending above the mounting base member, a shoulder perpendicularly downwardly extended from a flat bottom wall of the head and a screw rod axially forwardly extended from the shoulder in a concentric manner and adapted for threading into a mounting screw hole of a second panel member to detachably fasten the first panel member to the second panel member. The elastic member is mounted around the shoulder of the rotary fastening member and stopped between the flat bottom wall of the head of the rotary fastening member and a part inside the mounting base member. The cap member is affixed to the head of the rotary fastening member, comprising an accommodation open space surrounded by an inside wall thereof and extending through opposing top and bottom sides thereof for accommodating the mounting base member and the rotary fastening member, and an inside bottom stop flange extended around the inside wall of the cap member at a bottom side of the accommodation open space and axially slidably coupled to the periphery of the mounting base member and elastically deformably movable in direction from the top side of the mounting base member toward the bottom side of the mounting base member over the lower locating flange and then stoppable at a bottom side of the lower locating flange. By means of rotating the rotary fastening member in the reversed direction to disengage the screw rod from the mounting screw hole of the second panel member, the first panel member can then be directly separated from the second panel member. 
         [0011]    Preferably, the mounting base member further comprises an upper locating flange extending around the periphery near the top side thereof. The upper locating flange defines a sloping thrust surface at a top side thereof, and a bottom abutment surface at a bottom side thereof. Further, the upper locating flange is relatively larger in diameter than the lower locating flange. Normally, the inside bottom stop flange of the cap member is axially slidably coupled to the periphery of the mounting base member between the upper locating flange and the lower locating flange, prohibiting the rotary fastening member from falling out of the mounting base member. 
         [0012]    Further, when mounting the mounting base member of the floating fastener in the first panel member, the cap member is lowered to move the inside bottom stop flange of the cap member over the sloping guide surface of the lower locating flange of the mounting base member by force. Subject to the elastic material property of the cap member, the inside bottom stop flange of the cap member can easily downwardly be moved over the sloping guide surface of the lower locating flange and then stopped at the bottom stop surface of the lower locating flange. Thus, the mounting base member can be riveted or welded to the first panel member positively and accurately, achieving a high quality and cost-effective installation. 
         [0013]    Further, when attaching the first panel member (for example, a face panel) to the second panel member (for example, a rack), the inside bottom stop flange of the cap member is kept axially slidably coupled to the periphery of the mounting base member between the upper locating flange and the lower locating flange. At this time, the screw rod of the rotary fastening member can be moved back to the inside of the mounting base member to prevent impact between the screw rod and the first panel member and any thread damage. 
         [0014]    After the screw rod of the rotary fastening member is fastened to the mounting screw hole of the second panel member, the inside bottom stop flange of the cap member is moved over the sloping guide surface of the lower locating flange of the mounting base member and stopped at the bottom stop surface of the lower locating flange. Thus, the lower locating flange of the mounting base member can stop the inside bottom stop flange of the cap member to prevent backward rotation of the screw rod relative to the mounting screw hole of the second panel member, enhancing installation stability. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is an oblique top elevational view of a floating fastener in accordance with the present invention. 
           [0016]      FIG. 2  is an exploded view of the floating fastener in accordance with the present invention. 
           [0017]      FIG. 3  corresponds to  FIG. 2  when viewed from another angle. 
           [0018]      FIG. 4  is a sectional side view of the floating fastener in accordance with the present invention. 
           [0019]      FIG. 5  is a schematic installed view of the present invention, illustrating the installation of the floating fastener in a mounting through hole of a first panel member (I). 
           [0020]      FIG. 6  is a schematic installed view of the present invention, illustrating the installation of the floating fastener in a mounting through hole of a first panel member (II). 
           [0021]      FIG. 7  corresponds to  FIG. 6 , illustrating the inside bottom stop flange of the cap member coupled to the periphery of the mounting base member between the upper locating flange and lower locating flange after the mounting base member riveted to the first panel member. 
           [0022]      FIG. 8  is a sectional side view of an alternate form of the floating fastener in accordance with the present invention. 
           [0023]      FIG. 9  is a schematic applied view of the present invention, illustrating connection between the first panel member and the second panel member after installation of the floating fastener in the first panel member. 
           [0024]      FIG. 10  corresponds to  FIG. 9 , illustrating the screw rod of the rotary fastening member of the floating fastener threaded into the mounting screw hole of the second panel member. 
           [0025]      FIG. 11  corresponds to  FIG. 10 , illustrating the screw rod of the rotary fastening member of the floating fastener disengaged from the mounting screw hole of the second panel member for allowing removal of the first panel member from the second panel member. 
           [0026]      FIG. 12  is a sectional side of a floating fastener according to the prior art. 
           [0027]      FIG. 13  illustrates another design of panel member fastener according to the prior art. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]    Referring to  FIGS. 1-4 , 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 . 
         [0029]    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 thereof around the through hole  11 , a mounting groove  121  extending around the periphery of the bottom mounting neck  12 , and a lower locating flange  13  and an upper locating flange  14  extending around the periphery thereof at different elevations. The lower locating flange  13  defines a sloping guide surface  131  at a top side thereof, and a bottom stop surface  132  at a bottom side thereof. The upper locating flange  14  is relatively larger in diameter than the lower locating flange  131 . Further, the upper locating flange  14  defines a sloping thrust surface  141  at a top side thereof, and a bottom abutment surface  142  at a bottom side thereof. 
         [0030]    The rotary fastening member  2  comprises a head  21  suspending above the mounting base member  1 , an engagement portion  213  made in the form of an array of teeth, an embossed pattern, an array of tiny protrusions or any of a variety of other positioning designs and disposed around the periphery of the head  21 , a shoulder  22  perpendicularly downwardly extended from a center area of a flat bottom wall  211  of the head  21  and inserted into the through hole  11  of the mounting base member  1 , a screw rod  23  axially extended from a bottom end of the shoulder  22  opposite to the head  21  in a concentric manner and defining a spiral outer thread  231  around the periphery thereof, and a tool-positioning means  212  formed in an opposing top wall of the head  21  for the positioning of a hand tool for rotating the rotary fastening member  2 . The tool-positioning means  212  can be made in the form of a straight slot, crossed slot, star shaped slot or hexagonal slot, or in the form of a straight block, crossed block, star shaped block or hexagonal block. 
         [0031]    The compression spring  24  is mounted around the shoulder  22  and screw rod  23  of the rotary fastening member  2 , and stopped between the bottom wall  211  of the head  21  of the rotary fastening member  2  and the recessed accommodation chamber  111  of the mounting base member  1 . 
         [0032]    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 inside wall near the top side for engagement with the engagement portion  213  of the rotary fastening member  2 , an inside bottom stop flange  31  extended around the inside wall at a bottom side of the accommodation open space  30 , and a grip  32  extending around the periphery thereof and made in the form of a series of longitudinal teeth, an embossed pattern, an array of raised portions, or any anti-slip design. Preferably, the cap member  3  is directly molded on the head  21  of the rotary fastening member  2  by insert molding. 
         [0033]    When assembling the floating fastener, sleeve the compression spring  24  onto the shoulder  22  of the rotary fastening member  2  after the cap member  3  is molded on or fastened to the head  21  of the rotary fastening member  2 , and then insert the screw rod  23  and shoulder  22  of the rotary fastening member  2  into the through hole  11  of the mounting base member  1  to let the compression spring  24  be stopped between the bottom wall of the recessed accommodation chamber  111  and the flat bottom wall  211  of the head  21  of the rotary fastening member  2 , and then lower the cap member  3  to move the inside bottom stop flange  31  of the cap member  3  over the sloping thrust surface  141  of the upper locating flange  14  of the mounting base member  1  by force. Subject to the elastic material property of the cap member  3 , the inside bottom stop flange  31  of the cap member  3  can easily downwardly be moved over the sloping thrust surface  141  of the upper locating flange  14  of the mounting base member  1 . After the inside bottom stop flange  31  is moved over the sloping thrust surface  141  of the upper locating flange  14  and the applied downward pressure is disappeared, the elastic potential energy of the compression spring  24  immediately pushes the rotary fastening member  2  and the cap member  3  upwards, causing the inside bottom stop flange  31  of the cap member  3  to be stopped against the bottom abutment surface  142  of the upper locating flange  14  of the mounting base member  1 , and thus, the rotary fastening member  2  is prohibited from escaping out of the mounting base member  1 . Thus, the mounting base member  1 , the rotary fastening member  2  and the cap member  3  are assembled, forming the desired floating fastener. 
         [0034]    Further, in this preferred embodiment, the mounting base member  1  and the rotary fastening member  2  are metal members of one-piece design. Further, the cap member  3  can be directly molded on the head  21  of the rotary fastening member  2  by insert molding. Alternatively, the rotary fastening member  2  and the cap member  3  can be separately made and then fastened together by forcing the engagement portion  213  of the rotary fastening member  2  into friction engagement with the inside locating groove  301  of the cap member  3 . Further, in this preferred embodiment, the inside bottom stop flange  31  of the cap member  3  is stopped against the bottom abutment surface  142  of the upper locating flange  14  of the mounting base member  1  to prohibit the rotary fastening member  2  from escaping out of the mounting base member  1 . However, this design of preventing the rotary fastening member  2  from escaping out of the mounting base member  1  is not a limitation. C-shaped retainer, ring cushion or any other stoppage device can be used and mounted between the mounting base member  1  and the rotary fastening member  2 , allowing the rotary fastening member  2  to move axially relative to the mounting base member  1  and prohibiting the rotary fastening member  2  from falling out of the mounting base member  1 . 
         [0035]    Referring to  FIGS. 5-7 , the floating fastener can be used in a telecommunication server rack, computer server, machine tool, board set structure, cabinet or keyboard rack, or other situations where multiple panel members are to be fastened in a stack. For example, the floating fastener can be installed in a first panel member  4  in a server case to detachably fasten a second panel member  5  to the first panel member  4 , wherein the server case houses a motherboard, power supply device, data access equipment (hard disk drive, CD-ROM player, etc.), interface cards and/or other electronic devices. 
         [0036]    When installing the floating fastener in the first panel member  4 , lower the cap member  3  to move the inside bottom stop flange  31  of the cap member  3  over the sloping guide surface  131  of the lower locating flange  13  of the mounting base member  1  by force. Subject to the elastic material property of the cap member  3 , the inside bottom stop flange  31  of the cap member  3  can easily downwardly be moved over the sloping guide surface  131  of the lower locating flange  13 . After the inside bottom stop flange  31  is moved over the sloping guide surface  131  of the lower locating flange  13  and the applied downward pressure is disappeared, the elastic potential energy of the compression spring  24  immediately pushes the rotary fastening member  2  and the cap member  3  upwards relative to the mounting base member  1 , causing the inside bottom stop flange  31  of the cap member  3  to be stopped against the bottom stop surface  132  of the lower locating flange  13 . At this time, the cap member  3  is axially slidably secured to the mounting base member  1 . Thereafter, a vacuum suction type pickup device (not shown) can be operated to pick up the head  21  of the rotary fastening member  2  of the floating fastener and then to position the mounting base member  1  in the mounting through hole  41  of the first panel member  4 , enabling the mounting base member  1  to be riveted or welded to the first panel member  4  positively and accurately. Thus, a high quality and cost-effective installation can be achieved. 
         [0037]    During operation of the vacuum suction type pickup device to pick up the floating fastener, the pickup head of the vacuum suction type pickup device is attached to the head  21  of the rotary fastening member  2  that is exposed to the outside of the cap member  3 , and then the vacuum suction type pickup device is controlled to position the mounting base member  1  of the floating fastener in the mounting through hole  41  of the first panel member  4 , thereafter, a stamping tool (not shown) is operated to stamp on the head  21  of the rotary fastening member  2  against the mounting base member  1 , forcing the mounting groove  121  of the bottom mounting neck  12  into engagement with the peripheral edge of the mounting through hole  41  of the first panel member  4  tightly. Thus, the mounting base member  1  is affixed to the mounting through hole  41  of the first panel member  4 . Further, a reflow soldering can be employed with the use of a solder paste to bond the mounting base member  1  to the first panel member  4 . 
         [0038]    Further, a screw joint can be used to fasten the mounting base member  1  of the floating fastener to the mounting through hole  41  of the first panel member  4  instead of the technique of riveting or soldering. In an alternate form of the present invention, as shown in  FIG. 8 , the mounting base member  1  eliminates the aforesaid bottom mounting neck  12  and comprises an inner thread  122  in the bottom side thereof for threading onto an outer thread  411  at the top side of the first panel member  4  around the mounting through hole  41 . 
         [0039]    Referring to  FIGS. 9-11 , the aforesaid first panel member  4  is an angled panel having a horizontal panel portion  42  and a vertical panel portion  43 , wherein the mounting through hole  41  is located at the vertical panel portion  43 . When fastening the first panel member  4  to the second panel member  5 , cover the horizontal portion  43  of the first panel member  4  on the second panel member  5  to keep the mounting through hole  41  in axial alignment with a mounting screw hole  51  in the second panel member  5 . At this time, the inside bottom stop flange  31  of the cap member  3  is coupled to the periphery of the mounting base member  1  and axially slidable relative to the mounting base member  1  between the lower locating flange  13  and upper locating flange  14 . Subject to the elastic potential energy of the compression spring  24 , the rotary fastening member  2  is supported in such a position where the screw rod  23  is received inside the through hole  11  of the mounting base member  1 . This, when covering the first panel member  4  on the second panel member  5 , the rotary fastening member  2  is prohibited from touching the second panel member  5 , avoiding damage. 
         [0040]    After the vertical panel portion  43  of the first panel member  4  is closely attached to the surface of the second panel member  5  to keep the mounting through hole  41  in accurate alignment with the mounting screw hole  51 , force the head  21  of the rotary fastening member  2  and the cap member  3  in direction toward the second panel member  5  to insert the tip of the screw rod  23  of the rotary fastening member  2  into the mounting screw hole  51 , and then rotate the cap member  3  and the rotary fastening member  2  to thread the spiral outer thread  231  of the screw rod  23  into the mounting screw hole  51 , and then use a power hand tool, or a hand tool (screwdriver or wrench) to fasten tight the rotary fastening member  2 . Because the mounting base member  1  is fixedly fastened to the first panel member  4  and the rotary fastening member  2  is supported on the compression spring  24  in the mounting base member  1 , the screw rod  23  of the rotary fastening member  2  can accurately fastened to the mounting screw hole  51  of the second panel member  5 , avoiding thread damage. 
         [0041]    When fastening the spiral outer thread  231  of the screw rod  23  of the rotary fastening member  2  into the mounting screw hole  51  of the second panel member  5 , the inside bottom stop flange  31  of the cap member  3  can be moved over the sloping guide surface  131  of the lower locating flange  13  to the space around the periphery of the mounting base member  1  between the bottom stop surface  132  of the lower locating flange  13  and the vertical panel portion  43  of the first panel member  4 . Thus, the lower locating flange  13  of the mounting base member  1  can stop the inside bottom stop flange  31  of the cap member  3  to prevent backward rotation of the screw rod  23  relative to the mounting screw hole  51  of the second panel member  5 . 
         [0042]    When going to remove the first panel member  4  from the second panel member  5 , operate the grip  32  of the cap member  3  to rotate the cap member  3  and the rotary fastening member  2  in the reversed direction, thereby disengaging the screw rod  23  of the rotary fastening member  2  from the mounting screw hole  51  of the second panel member  5 . During rotation of the rotary fastening member  2  in direction away from the mounting screw hole  51  of the second panel member  5 , the inside bottom stop flange  31  of the cap member  3  is kept stopped at the bottom stop surface  132  of the lower locating flange  13  of the mounting base member  1  to prohibit the screw rod  23  from moving back to the inside of the through hole  11  of the mounting base member  1 . Thus, after disengagement between the screw rod  23  of the rotary fastening member  2  and the mounting screw hole  51  of the second panel member  5 , the floating fastener and the first panel member  4  can be directly separated from the second panel member  5 . Thus, using the floating fastener enables the first panel member  4  to be fastened to or separated from the second panel member  5  conveniently with less effort. 
         [0043]    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.