Browse Prior Art Database

Structural Captive Fastener Device

IP.com Disclosure Number: IPCOM000052587D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 3 page(s) / 92K

Publishing Venue

IBM

Related People

Veals, ER: AUTHOR [+2]

Abstract

A screw captivating device is disclosed which is a hollow, cylindrical sleeve with a flange having an inner threaded surface to threadably engage a screw used to fasten a panel to a supporting structure.

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Structural Captive Fastener Device

A screw captivating device is disclosed which is a hollow, cylindrical sleeve with a flange having an inner threaded surface to threadably engage a screw used to fasten a panel to a supporting structure.

Prior-art captive fasteners are typified by that shown in Fig. 1 wherein the panel 1 is attached by means of the screw 2 to the structural number 3 by virtue of the threaded engagement of the threads 4 of the screw 2 with the tapped threads or threaded insert 5 in the structure 3. When the threads for the screw 2 are disengaged from the threads 5 of the structure 3, it is the function of the captive fastener to not fall backwardly through the hole 7 in the panel 1 but to remain intact in the panel 1 to avoid loss. This is achieved by reducing the diameter of the shank portion 6 of the screw 2 to a lesser diameter than that of the threaded portion 4 and then threading the internal diameter of the hole 7 so that its internal diameter is less than the outer diameter of the threaded end portion 4 of the screw 2. There are several problems associated with this type of captive fastener. The tensile strength and shear strength of the shank portion 6 of the screw 2 is reduced by virtue of its reduced diameter. Furthermore, additional work is required to tap the threads in the hole 7 of the panel 1.

An improved captive fastener device is disclosed in Figs. 2 and 3 which obviates the need for tapping threads into the hole 7 and which furthermore increases the shear strength and tensile strength of the shank portion 6 of the screw 2. This device gives any standard threaded fastener the ability to be used as a captive fastener in any application.

As is shown in Fig. 2, the screw 2' maintains its shank portion 6' at the same diameter as the end portion 4 and the entire shank portion 6' remains in threaded engagement with threads of the same diameter as that of the end portion 4. The threade...