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 This application claims the benefit of U.S. Provisional Application No. 60/188,406 filed Mar. 10, 2000, entitled “Floating Captive Screw.”
 1. Field of the Invention
 The present invention relates generally to captive screws.
 2. Brief Description of the Prior Art
 Captive screws are screws which are “captivated” or held within a collar or ferrule. The ferrule is mounted in a first panel or like object. The screw portion is captivated so that it can be moved perpendicular to the first panel and the screw's threads can engage a corresponding aperture in a second panel, so that the first and second panels can be secured together. However, when the panels are unscrewed and disengage, the screw is retained in the first panel. Captive screws are useful in applications where it is important to avoid dropping or losing screws during assembly or repair, such electronic devices, where lost screw can cause catastrophic electrical shorts damaging equipment.
 The present invention provides a captive screw including a ferrule, a screw, and a spring. The screw has a head, a shank adapted to pass through the ferrule, a threaded portion at the end of the shank opposite the head, and a collar formed on the shank proximate the threaded portion. The screw is captivated on the ferrule between the head and the collar. The spring extends on the shank of the screw between the head and the ferrule. Preferably, the ferrule has a generally cylindrical exterior surface having a plurality of knurls for securing the captive screw in a preformed aperture in a first structure, such as a lever. Is also preferred that the ferrule be formed with an annular collapsible ring section formed on the bottom having a generally circular opening large enough to permit the threads collar the screw to pass through but not large enough to permit the spring to pass through. When the captive screw is assembled, the annular ring section is bent upwardly to captivate the screw on the ferrule. Preferably, the ferrule has an annular lip formed on the exterior cylindrical surface proximate the top of the ferrule for limiting the penetration of the ferrule in the preformed aperture in the first structure, as well as an annular circumferential groove formed in the exterior cylindrical surface of the ferrule immediately adjacent and below the annular lip for receiving the plastic flow of material when the ferrule is pressed into the preformed aperture.
 The present invention provides a captive screw for slideably securing a first structure such as a lever to a second structure such as a door frame or panel.
 Referring now to the drawings in detail, wherein like reference numerals indicate like elements throughout the several views, there is shown in
 As can be seen in FIGS.
 As can be seen in the FIGS.
 The ferrule
 Various other modifications can be made in the details of the various embodiments of the apparatus of the present invention, all within the scope and spirit of the invention and defined by the appended claims.