Captive fasteners with multiple retaining functionality

Abstract

Captive panel fasteners are configured to be held captive on a panel by multiple retaining elements. The fasteners include longitudinal grooves along a cylindrical portion of the fastener, a retaining ring over the cylindrical portion, a primary structure for retaining the retaining ring on the cylindrical portion, and secondary structure for retaining the cylindrical portion within a bore of the panel. The retaining ring includes radially inwardly extending opposing prongs that fit into the longitudinally extending grooves. A stop point may be provided in the longitudinally extending grooves, or an end of the fastener may be flared, to retain the retaining ring on the fastener. The prongs may also be slightly flexible and flared to grip the longitudinally extending grooves. The secondary structure can include one or more spring loaded pins in the fastener extending externally outward.

1 . A captive panel fastener assembly to be installed in a bore of a panel, comprising:
 a fastener including a head attached to a cylindrical member, said cylindrical member including a first end portion connected to said head, a second end portion located opposite the first end portion, and an externally threaded portion between said first end portion and said second end portion;   a plurality of longitudinally extending grooves defined along an external surface of the cylindrical member extending between said first end portion and said second end portion of said cylindrical member;   a retaining ring mounted over said cylindrical member, said retaining ring including at least two radially inwardly extending opposing prongs that fit into said plurality of longitudinally extending grooves of the cylindrical member, wherein said plurality of longitudinally extending grooves include radially inner surfaces separated by a first distance, and said inwardly extending opposing prongs being separated by a second distance that is less than said first distance between said radially inner surfaces of said plurality of longitudinally extending grooves;   primary means for retaining said retaining ring on said cylindrical member; and   secondary means for retaining said cylindrical member within the bore of the panel.   
     
     
         2 . The captive panel fastener assembly of  claim 1 , wherein said primary means for retaining said retaining ring on said cylindrical member comprises a stop point in said longitudinally extending grooves at or near an extreme end of said second end portion of said cylindrical member. 
     
     
         3 . The captive panel fastener assembly of  claim 1 , wherein said primary means for retaining said retaining ring on said cylindrical member comprises said at least two radially inwardly extending opposing prongs being slightly flexible and flared, and said at least two radially inwardly extending opposing prongs being biased to grip said plurality of longitudinally extending grooves and resist movement of said retaining ring along said plurality of longitudinally extending grooves along the cylindrical member. 
     
     
         4 . The captive panel fastener assembly of  claim 1 , wherein said secondary means for retaining said cylindrical member within the bore of the panel comprises at least one spring loaded pin positioned internally within said cylindrical member near the second end portion of said cylindrical member, said at least one spring loaded pin extending externally through the cylindrical member. 
     
     
         5 . The captive panel fastener assembly of  claim 4 , wherein said at least one spring loaded pin comprises a plurality of spring loaded pins. 
     
     
         6 . A captive panel fastener assembly to be installed in a bore of a panel, comprising:
 a fastener including a head attached to a cylindrical member, said cylindrical member including a first end portion connected to said head, a second end portion located opposite the first end portion, and an externally threaded portion between said first end portion and said second end portion;   at least one spring loaded pin positioned internally within said cylindrical member near the second end portion of said cylindrical member, said at least one spring loaded pin extending externally through the cylindrical member;   a plurality of longitudinally extending grooves defined along an external surface of the cylindrical member extending between said first end portion and said second end portion of said cylindrical member;   a retaining ring mounted over said cylindrical member, said retaining ring including at least two radially inwardly extending, slightly flexible, flared opposing prongs that fit into said plurality of longitudinally extending grooves of the cylindrical member, said at least two radially inwardly extending, slightly flexible, flared opposing prongs being biased to grip said plurality of longitudinally extending grooves and resist movement of said retaining ring along said plurality of longitudinally extending grooves along the cylindrical member.   
     
     
         7 . The captive panel fastener assembly of  claim 6 , wherein said at least one spring loaded pin comprises a plurality of spring loaded pins. 
     
     
         8 . A captive panel fastener assembly to be installed in a bore of a panel, comprising:
 a fastener including a head attached to a cylindrical member, said cylindrical member including a first end portion connected to said head, a second end portion located opposite the first end portion, and an externally threaded portion between said first end portion and said second end portion;   at least one spring loaded pin positioned internally within said cylindrical member near the second end portion of said cylindrical member, said at least one spring loaded pin extending externally through the cylindrical member;   a plurality of longitudinally extending grooves defined along an external surface of the cylindrical member extending between said first end portion and said second end portion of said cylindrical member, wherein said longitudinally extending grooves do not extend all the way to an extreme end of the second end or bottom end portion of said cylindrical member, but instead stop at a stop point before reaching the extreme end of the second end or bottom end portion of said cylindrical member; and   a retaining ring mounted over said cylindrical member, said retaining ring including at least two radially inwardly extending opposing prongs that fit into said plurality of longitudinally extending grooves of the cylindrical member, said plurality of longitudinally extending grooves having radially inner surfaces separated by a first distance, and said inwardly extending opposing prongs being separated by a second distance that is less than said first distance between said radially inner surfaces of said plurality of longitudinally extending grooves.