Hi-shear Corporation

Air Industries LLC

Herman L Williamson

Edwin E Hatter

Michael M Schuster

Gerhart Hufnagl

An installation tool for use with locking fasteners which reduces cam off during use. The tool comprises a cylindrical socket wrench having a central axial bore which defines a recess on one end for attachment to a socket driver and an elliptical cavity on the opposite end for engaging the collar of the locking fastener. The installation tool further comprises one or more pockets positioned on the wrenching portion of the cavity. The pockets provide space in which collar mass is deformed. As the collar is deformed to lock the collar and bolt together, collar mass is deformed into the pockets on the tool. The deformed collar mass retains the tool and collar in an engaged position until the collar is completely deformed and the fastener is locked.

Installation tool for locking fasteners and method of use

A blind fastener having an internally threaded sleeve with a head at one end and a taper at the other. A mandrel is threaded into and through the sleeve, and has a head that bears against a collar which it pushes onto the tapered end of the sleeve. A nut is threaded onto the mandrel to be turned against the head of the sleeve. In turn, the nut is restrained against rotation by a torque tool, and the mandrel is engaged by the tool to turn them counter-rotatively to set the fastener. The nut has a face that faces toward the head of the sleeve that is adapted to make at least a partially conforming engagement with recesses in the head of the sleeve.

Blind fastener

A fastener and a joint including the fastener, wherein the material in which the fastener is set is a composite. The fastener has a shank with an external helical rib that makes a slightly tighter than net to a moderate interference fit in a cylindrical wall of the hole. The rib has a form whose maximum radial protrusion is flat or convex, and which extends away from its maximum protrusion as a convex curve, devoid of sharp cutting edges. Voids between the convolutions of the rib are adequate to receive displaced material of the hole wall.

Eastener for structures made of composite materials

A torque limited threaded locking fastener and a method for setting it to form an assembly. The fastener comprises an externally threaded shank and an internally threaded collar. At least one convolution of the threads on the shank is non-circular. The collar has a nut section and a drive section. The drive section is shaped to be engaged by a driver. Between these sections there is formed a shear section having the least torque resistance of the sections. The shear section fractures when a predetermined torque is exerted between the two sections. The nut section has an internal thread engageable to the shank thread, and an external rib engageable by a swaging tool. The swaging tool radially inwardly deforms and displaces the rib so as to displace nut section material at the non-circular convolution whereby to lock the nut to the shank after, but only after, the drive section is torqued off. The rib is proportioned and arranged so that the swaging of the rib to a lesser radial dimension does not change the torque level which was applied when the drive section was torqued off.

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Seal Beach, CA, United States of America

Herman L Williamson