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 method for installing a captive panel fastener in a bore of a panel, comprising:
 providing a panel including a bore therethrough;   providing a captive panel 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;   providing a retaining ring configured to be mounted over said cylindrical member, said retaining ring including at least two radially inwardly extending, slightly flexible, flared opposing prongs configured to 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;   inserting said captive panel fastener into said bore of said panel;   mounting said retaining ring over said cylindrical member with said at least two radially inwardly extending, slightly flexible, flared opposing prongs inserted into said plurality of longitudinally extending grooves, and positioning said retaining ring on a side of the panel to prevent said captive panel fastener from out of said bore of said panel;   pulling said captive panel fastener through said bore of said panel; and   positioning said at least one spring loaded pin within said bore of said panel to depress said at least one spring loaded pin within said bore of said panel, to thereby hold said captive panel fastener within said bore of said panel.   
     
     
         2 . A method for installing a fastener in a bore of a panel, comprising:
 providing a panel including a bore therethrough;   providing a captive panel 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;   providing 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;   providing an installation tool for installing said retaining ring over said second end portion of said cylindrical member, said installation tool including a tool end portion having a beveled portion on one side of said tool end portion and a slot on an opposing side of said tool end portion;   inserting said captive panel fastener into said bore of said panel;   inserting a first one of said prongs of the retaining ring into a first one of said plurality of longitudinally extending grooves;   positioning said installation tool such that a second one of said prongs of the retaining ring is disposed inside said slot of said installation tool;   pulling the retaining ring with said installation tool so that said second of said prongs are inserted into a second of said longitudinally extending grooves;   pulling said captive panel fastener through said bore of said panel;   positioning said at least one spring loaded pin near said second end portion of said cylindrical member within said bore of said panel to depress said at least one spring loaded pin within said bore of said panel, to thereby hold said captive panel fastener within said bore of said panel; and   positioning said retaining ring on a side of the panel to prevent said captive panel fastener from out of said bore of said panel.