Abstract:
A floating fastener mounting structure includes a mounting socket having a locating groove extending around the periphery and defined between a relatively smaller annular step and a relatively larger stop flange thereof, a metal panel member having a mounting through hole attached to the mounting socket and stopped above the stop flange and stamped by a stamping press to provide a riveting portion and to force the riveting portion to engage into the locating groove and to wrap about the stop flange of the mounting socket, a spring-loaded locking member axially slidably mounted in the mounting socket for detachably locking the metal panel member to an external metal panel member, and a cap member capped on a mounting head of the locking member and affixed to the mounting head during the operation of the stamping press to stamp the metal panel member. Affixing the mounting socket to the metal panel member by riveting greatly enhances the shearing strength of the floating fastener mounting structure.

Description:
This application is a Continuation-In-Part of co-pending application Ser. No. 14/614,983, filed on Feb. 5, 2015, which is a Continuation of application Ser. No. 13/607,759, filed on Sep. 9, 2012, now abandoned, for which priority is claimed under 35 U.S.C. §120, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to floating fastener mounting technology and more particularly, to a floating fastener mounting structure comprised of a mounting socket, a locking member, a spring member, a cap member and a metal panel member, which enhances the strength of the connected structure between the mounting socket and the metal panel member by means of inserting the mounting socket upwardly inserted with the cap member through a mounting through hole of the metal panel member to let a stop flange of the mounting socket be stopped at the bottom wall of the metal panel member, and using a stamping press to stamp the metal panel member, the mounting socket and the cap member, deforming the peripheral wall of the mounting through hole into a riveting portion and simultaneously forcing the riveting portion thus formed into engagement with an annular locating groove of the mounting socket, and thus, the metal panel member and the mounting socket are firmly secured together and prohibited from separation. 
     2. Description of the Related Art 
     When joining metal 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 metal panel member. When fastening the first metal panel member to a second metal 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 metal panel member, and then use a hand tool to fasten tight the lock screw. This multiple metal panel member fastening method can be used in a machine tool or other situations where multiple metal panel members are to be fastened in a stack. In a machine tool, the location where metal panel members are fastened together may be at the power drive or speed-adjustment unit inside the housing. The lock screws of the fastening devices may fall from the metal panel members and missed easily due to user&#39;s negligence during a metal panel member dismounting procedure for the performance of a repair or speed adjustment operation, affecting further re-installation operation. 
     In order to eliminate the aforesaid problem, floating fasteners formed of a cap member, a locking screw, a spring member and a mounting socket are created. In application, the mounting socket is affixed to a metal panel member; the locking screw is inserted through the mounting socket; the spring member is mounted around the locking screw and stopped between the head of the locking screw and an inside wall of the mounting socket; the cap member is affixed to the head of the locking member and axially slidably coupled to the mounting socket. For example,  FIG. 9  illustrates a floating fastener according to the prior art. According to this design, the floating fastener comprises a mounting socket A that comprises a bottom mounting portion A 1  inserted into a mounting through hole B 0  at a metal panel member B and welded thereto, a lock screw C 1  inserted through a center hole A 0  of the mounting socket A, a spring member C 11  mounted around the shank of the lock screw C 1  and stopped between an inside step A 3  in the center hole A 0  of the mounting socket A and the head of the lock screw C 1  to floatably support the lock screw C 1  in the mounting socket A, and a cap member C affixed to the head of the lock screw C 1  and having an inside coupling flange C 2  protruded from the inner perimeter thereof at a bottom side and slidably coupled to the outer perimeter of the mounting socket A between an external top annular flange A 2  and an stop flange A 11  of the mounting socket A. The bottom mounting portion A 1  of the mounting socket A is inserted into the mounting through hole B 0  of metal panel member B and attached to a solder paste B 1  at the top wall of the metal panel member B around the mounting through hole B 0  and then welded thereto through reflow soldering. Due to limited contact surface area between the mounting socket A and the metal panel member B, the structural strength between the mounting socket A and the metal panel member B is not strong enough, and the bottom mounting portion A 1  of the mounting socket A may break easily when the mounting socket A is stretched accidentally by an external force. Further, when coupling the inside coupling flange C 2  of the cap member C to the outer perimeter of the mounting socket A between an external top annular flange A 2  and an stop flange A 11  of the mounting socket A, the applied force may stretch the mounting socket A, loosening the mounting socket A or even forcing the mounting socket A out of place. 
     In order to eliminate the drawbacks of the prior art floating fastener shown in  FIG. 9 , an improved design is created, as shown in  FIG. 10 . According to this improved design, the mounting socket A is riveted to the metal panel member B. As illustrated, the bottom mounting portion A 1  of the mounting socket A is a stub tube A 12  downwardly inserted into the mounting through hole B 0  of the metal panel member B. After riveting, the peripheral wall of the mounting through hole B 0  of metal panel member B is deformed and engaged into an annular groove A 121  around the stub tube A 12  to fixedly secure the mounting socket A to the metal panel member B. According to this design, the outer diameter of the mounting socket A is larger than the outer diameter of the stub tube A 12  of the bottom mounting portion A 1 . When mounting the cap member C on the mounting socket A, the mounting socket A can easily be biased to force the bottom mounting portion A 1  out of the mounting through hole B 0  of the metal panel member B. 
     Therefore, there is a strong demand for a floating fastener mounting structure that eliminates the drawbacks of the aforesaid prior art designs. 
     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 mounting structure, which comprises a metal panel member, a mounting socket affixed to the metal panel member, a locking member mounted in the mounting socket and insertable into a locating hole in an external metal panel member to lock the metal panel member to the external metal panel member, and a spring member mounted in the mounting socket to floatably support the locking member in the mounting socket. The mounting socket comprises a center hole vertically extending through opposing top and bottom surfaces thereof, an annular step extended around the periphery thereof at a selected elevation, a stop flange extended around the periphery thereof in flush with the bottom surface of the mounting socket, and a locating groove extended around the periphery thereof between the annular step and said stop flange. Further, the outer diameter of the stop flange is larger than the outer diameter of the annular step. The locking member comprises a shank inserted through the center hole of the mounting socket, a mounting head located at a top end of the shank and extended out of the top surface of the mounting socket, and an expanded locking end tip located at an opposing bottom end of the shank. The spring member is mounted around the shank of the locking member and stopped between a part of the mounting socket and a part of the locking member. The cap member is affixed to said mounting head of the locking member, comprising an accommodation chamber that accommodates a part of the mounting socket and a part of the locking member. Further, the outer diameter of the cap member is equal to or smaller than the outer diameter of the annular step of the mounting socket. The metal panel member comprises a mounting through hole cut through opposing top and bottom surfaces thereof for the insertion of the mounting socket and the cap member therethrough, and a riveting portion formed of a part of the metal panel member around the mounting through hole by stamping and engaged into the annular locating groove of the locking member and wrapped about the stop flange of the mounting socket to affix the mounting socket to the metal panel member. By means of riveting the mounting socket to the metal panel member, the floating fastener mounting structure has high shearing strength. 
     Further, when fasten the mounting socket and the metal panel member together, attach a negative mold cavity of a stamping die to the annular step of the mounting socket and the cap member to stop a front planar die surface of the stamping die at the top surface of the metal panel member around the mounting through hole, and then operate the stamping press to stamp the negative mold cavity of the stamping die onto the mounting socket and the cap member, causing the front planar die surface of the stamping die around the negative mold cavity to deform a part of the metal panel member around the mounting through hole into a riveting portion and to simultaneously force the riveting portion thus formed into engagement with the annular locating groove of the mounting socket and tightly stopped between the flat bottom stop surface of the annular step and the stop flange. Thus, the deformed riveting portion of the metal panel member is wrapped about the stop flange of the mounting socket to enhance the structural strength of the connection between the mounting socket and the metal panel member. Even if the mounting socket is pulled or forced by an external force after its fixation to the metal panel member, the mounting socket will not fall out of the metal panel member, assuring a high level of structural stability and shear strength. 
     Further, when fastening the mounting head of the locking member and the mating connection portion of the cap member, insert the positioning rod of the mounting head of the locking member into the mounting hole of the mating connection portion of the cap member, and then impart a pressure to the cap member to move an engagement flange of the cap member along over a retaining flange of the mounting head of the locking member so that the engagement flange can be engaged into a position-limit groove around the positioning rod and between the retaining flange and shank of the locking member. Further, the cap member can be made from a plastic material in any desired color and shape, and configured to provide a pattern or mark. In actual application, the cap member and the locking member can be modularized for quick connection in a detachable manner, and respectively marked with a mark for installation alignment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a floating fastener mounting structure in accordance with the present invention. 
         FIG. 2  is an exploded view of the floating fastener in accordance with the present invention. 
         FIG. 3  corresponds to  FIG. 2  when viewed from another angle. 
         FIG. 4  is an exploded sectional view of the floating fastener mounting structure in accordance with the present invention. 
         FIG. 5  is a schematic sectional view illustrating the riveting process of the floating fastener mounting structure in accordance with the present invention in a stamping press (I). 
         FIG. 6  is a schematic sectional view illustrating the riveting process of the floating fastener mounting structure in accordance with the present invention in a stamping press (II) 
         FIG. 7  is a sectional view of the floating fastener mounting structure after the riveting process in accordance with the present invention. 
         FIG. 8  is sectional side view, in an enlarged scale, of a part of an alternate form of the present invention, illustrating a grip located at the operating portion of the cap member. 
         FIG. 9  is a sectional exploded view of a floating fastener mounting structure according to the prior art. 
         FIG. 10  is a sectional exploded view of another design of floating fastener mounting structure according to the prior art. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1-4 , a floating fastener mounting structure in accordance with the present invention is shown. The floating fastener mounting structure comprises a mounting socket  1 , a locking member  2 , a spring member  24 , a cap member  3 , and a metal panel member  4 . 
     The mounting socket  1  is an open-ended cylindrical member comprising a center hole  10  vertically extending through opposing top and bottom sides thereof, an annular step  11  extended around the outer perimeter thereof at a selected elevation and defining a downwardly and outwardly sloping top surface  111  and a flat bottom stop surface  112 , a stop flange  13  extended around the outer perimeter in flush with the bottom surface of the mounting socket  1 , a locating groove  12  extended around the outer perimeter between the annular step  11  and the stop flange  13 , and an annular inner top flange  14  located at a top side of the center hole  10  and defining a bottom abutment surface  141  and a center opening  140  in a concentric manner relative to the center hole  10 . The outer diameter D 1  of the stop flange  13  is larger than the outer diameter D 2  of the annular step  11 . 
     The locking member  2  comprises a shank  22  inserted through the center hole  10  and center opening  140  of the mounting socket  1 , a mounting head  21  located at a top end of the shank  22  and extended out of the top side of the mounting socket  1 , an expanded locking end tip  23  located at an opposing bottom end of the shank  22 , and a bearing step  231  defined in a top side of the expanded locking end tip  23  around the bottom end of the shank  22 . The mounting head  21  comprises a positioning rod  211 , a retaining flange  212  extending around the periphery of the positioning rod  211  and defining a chamfered edge  2121  that slopes downwardly outward, and a position-limit groove  213  extending around the positioning rod  211  between the chamfered edge  2121  of the retaining flange  212  and the shank  22 . 
     In this embodiment, the expanded locking end tip  23  is shaped like a cylindrical block. Alternatively, the expanded locking end tip  23  can be configured to provide an outer thread or retaining flange. 
     The spring member  24  is mounted around the shank  22  of the locking member  2  and stopped between the bottom abutment surface  141  of the mounting socket  1  and the bearing step  231  of the locking member  2 . 
     The cap member  3  comprises an accommodation chamber  30  for accommodating a part of the mounting socket  1  and a part of the locking member  2 , a mating connection portion  31  located in a top side of the accommodation chamber  30  for securing the mounting head  21 , a mounting hole  311  vertically cut through the center of the mating connection portion  31  in communication with the accommodation chamber  30 , an engagement flange  312  located in the mating connection portion  31  and projecting into the mounting hole  311 , a sloping guide surface  3121  located at a bottom side of the engagement flange  312 , and an operating portion  32  extending around the mating connection portion  31 , and a plurality of grooves  321  located in and spaced around the operating portion  32 . Further, the outer diameter D 3  of the cap member  3  is not larger than (i.e., equal to or smaller than) the outer diameter D 2  of the annular step  11 . 
     The metal panel member  4  comprises at least one mounting through hole  40 . The inner diameter D of the at least one mounting through hole  40  of the metal panel member  4  is in the range between the outer diameter D 1  of the stop flange  13  and the outer diameter D 2  of the annular step  11 . In this embodiment, the inner diameter D of the at least one mounting through hole  40  is slightly larger than the outer diameter D 2  of the annular step  11  and smaller than the outer diameter D 1  of the stop flange  13 . 
     During installation, sleeve the spring member  24  onto the shank  22  of the locking member  2 , and then insert the mounting head  21  upwardly through the center hole  10  of the mounting socket  1  and the center opening  140  of the annular inner top flange  14  to let one end of the spring member  24  stopped at the bottom abutment surface  141  of the annular inner top flange  14  and the other end of the spring member  24  stopped at the bearing step  231  of the expanded locking end tip  23 , and then insert the positioning rod  211  of the mounting head  21  upwardly into the accommodation chamber  30  of the cap member  3  and the mounting hole  311  of the mating connection portion  31  to abut the chamfered edge  2121  of the retaining flange  212  against the sloping guide surface  3121  of the engagement flange  312 , and then impart a downward pressure to the cap member  3  to force the engagement flange  312  against the retaining flange  212  and to further elastically deform the engagement flange  312  and move the engagement flange  312  along the chamfered edge  2121  over the retaining flange  212  so that the engagement flange  312  can be engaged into the position-limit groove  213  after restoration to its original shape. At this time, the elastic restoring force of the spring member  24  is transferred to the bearing step  231  of the expanded locking end tip  23  to force the expanded locking end tip  23  to move to the outside of the stop flange  13  of the mounting socket  1 . When the expanded locking end tip  23  is forced to move to the outside of the stop flange  13  of the mounting socket  1 , the cap member  3  is moved downwards with the mounting head  21  of the locking member  2  to stop at the mounting socket  1 , and thus, the mounting socket  1 , the locking member  2  and the cap member  3  are floatably fastened together. Further, the cap member  3  can be made from a plastic material in any desired color and shape, and configured to provide a pattern or mark. In actual application, the cap member  3  and the locking member  2  can be modularized for quick connection in a detachable manner, and respectively marked with a mark for installation alignment. 
     Referring to  FIGS. 5-8 , when mounting the mounting socket  1  in the metal panel member  4 , insert the mounting socket  1  upwardly into the mounting through hole  40  of the metal panel member  4 . Because the outer diameter D 3  of the cap member  3  and the outer diameter D 2  of the annular step  11  of the mounting socket  1  are equal to or smaller than the inner diameter D of the mounting through hole  40 , the cap member  3  can move through the mounting through hole  40  smoothly. Further, because the outer diameter D 1  of the stop flange  13  is larger than the outer diameter D 2  of the annular step  11  and the inner diameter D of the mounting through hole  40 , the mounting through hole  40  of the metal panel member  4  can be moved downwardly along the outwardly sloping top surface  111  of the annular step  11  and temporarily stopped at the stop flange  13 . Therefore, the mounting socket  1  and the metal panel member  4  are placed on a worktable  5  of a stamping press for the implementation of a stamping process. 
     In the stamping process to affix the mounting socket  1  and the metal panel member  4  together, attach a negative mold cavity  510  of a stamping die  51  to the annular step  11  of the mounting socket  1  and the cap member  3  to stop a front planar die surface  511  of the stamping die  51  around the negative mold cavity  510  at the top surface of the metal panel member  4  around the mounting through hole  40 , and then operate the stamping press to stamp the negative mold cavity  510  of the stamping die  31  onto the mounting socket  1  and the cap member  3 , causing the front planar die surface  511  of the stamping die  51  around the negative mold cavity  510  to deform a part of the metal panel member  4  around the mounting through hole  40  into a riveting portion  41  and to simultaneously force the riveting portion  41  thus formed into engagement with the annular locating groove  12  of the mounting socket  1  and tightly stopped between the flat bottom stop surface  112  of the annular step  11  and the stop flange  131 . Thus, the deformed riveting portion  41  of the metal panel member  4  is wrapped about the stop flange  13  of the mounting socket  1  to enhance the structural strength of the connection between the mounting socket  1  and the metal panel member  4 . Further, because the outer diameter D 1  of the stop flange  13  is larger than the outer diameter D 2  of the annular step  11 , the metal panel member  4  and the mounting socket  1  are firmly secured together and prohibited from separation. Even if the mounting socket  1  is pulled or forced by an external force, the mounting socket  1  will not fall out of the metal panel member  4 , assuring a high level of structural stability and shear strength. 
     Further, by means of the grooves  321  in the operating portion  32  of the cap member  3 , the cap member  3  can be conveniently and positively pulled to lift the locking member  2 , retracting the expanded locking end tip  23  into the inside of the center hole  10  of the mounting socket  1  and forcing the bearing step  231  of the expanded locking end tip  23  to compress the spring member  24 . At this time, the metal panel member  4  can be attached to a second metal panel member (not shown) to keep the mounting through hole  40  in vertical alignment with a locating hole in the second metal panel member, and then release the pulling force from the operating portion  32  of the cap member  3 , enabling the locking member  2  to be forced by the elastic restoring force of the spring member  24  out of the mounting socket  1  and the mounting through hole  40  of the metal panel member  4  to engage the expanded locking end tip  23  into the locating hole of the second metal panel member, and thus, the metal panel member  4  is locked to the second metal panel member. Further, the user can pull the cap member  3  to lift the locking member  2 , moving the expanded locking end tip  23  upwardly to unlock the metal panel member  4  from the second metal panel member. Further, the structure of the operating portion  32  of the cap member  3  can be variously designed. For example, a grip  322  of diameter smaller than the outer diameter D 3  of the cap member  3  can be made at the operating portion  32 . 
     In conclusion, the invention provides a floating fastener mounting structure that comprises a metal panel member  4 , a mounting socket  1  affixed to the metal panel member  4 , a spring member  24 , a locking member  2  supported on the spring member  24  in the mounting socket  1  and adapted for locking the metal panel member  4  to an external metal panel member, and a cap member  3  capped on the top end of the locking member  2  and disposed at the top side relative to the mounting socket  1 , wherein the mounting socket  1  is configured to provide a center hole  10 , an annular inner top flange  14 , an annular step  11  of relatively smaller outer diameter extended around the outer perimeter thereof, a stop flange  13  of relatively larger outer diameter extended around the outer perimeter in flush with the bottom surface of the mounting socket  1 , and a locating groove  12  extended around the outer perimeter between the annular step  11  and the stop flange  13 ; the locking member  2  comprises a shank  22  inserted through the center hole  10  of the mounting socket  1 , a mounting head  21  located at a top end of the shank  22  and extended out of the top side of the mounting socket  1  and affixed to the cap member  3 , an expanded locking end tip  23  located at an opposing bottom end of the shank  22 , and a bearing step  231  defined in a top side of the expanded locking end tip  23  around the bottom end of the shank  22 ; the spring member  24  is mounted around the shank  22  of the locking member  2  and stopped between the bearing step  231  of the locking member  2  and the annular inner top flange  14  of the mounting socket  1 . The mounting socket  1  is upwardly inserted with the cap member  3  through a mounting through hole  40  of the metal panel member  4  to let the stop flange  13  be stopped at the bottom wall of the metal panel member  4 , and then the metal panel member  4  with the mounting socket  1  and the cap member  3  are stamped in a stamping press, causing a part of the metal panel member  4  around the mounting through hole  40  to be elastically deformed. Thus, the peripheral wall of the mounting through hole  40  is deformed to provide a riveting portion  41  that is forced into engagement with the annular locating groove  12  of the mounting socket  1  and tightly stopped between the flat bottom stop surface  112  of the annular step  11  and the stop flange  131 . Thus, the metal panel member  4  and the mounting socket  1  are firmly secured together and prohibited from separation. Even if the mounting socket  1  is pulled or forced by an external force, the mounting socket  1  will not fall out of the metal panel member  4 , assuring a high level of structural stability and shear strength. 
     Although a particular embodiment of the invention has 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.