Other

Hi-shear Corporation

Josef F Volkmann

Richard Ohlman

Edwin E Hatter

Dale H Hart

Michael M Schuster

There is disclosed an aerospace fastener system in which a threaded bolt fastener is secured with a free spinning threaded nut or collar and in which the engagement of the threaded members is fixedly secured by an adhesive. In this invention, the length of the bolt fastener is preselected such that when the fastener is applied in a maximum grip condition, the end of the bolt fastener does not project beyond the top surface of the nut or collar. In this invention, the bolt fastener can even be slightly shorter than the length necessary to reach the top surface of the nut or collar when the fastener still meets the tensile load requirement of the specific application. Preferably the adhesive also includes an ultra-violet light fluorescent pigment so that upon ultra-violet illumination, the correct application of the fastener can be easily observed.

Aerospace fastener with improved bonding

There is disclosed an aerospace fastener system in which a threaded bolt fastener is secured with a free spinning threaded nut or collar and in which the engagement of the threaded members is fixedly secured by an adhesive. The length of the bolt fastener is preselected such that when the fastener is applied in a maximum grip condition, the end of the bolt fastener does not project beyond the top surface of the nut or collar, or is even slightly shorter than the length necessary to reach the top surface of the nut or collar. There is also disclosed a blind fastener system in which the adhesive is applied to the threads of the core screw of the blind fastener which are engaged upon installation of the fastener.

Aerospace fastener with improved bonding relationship to other

There is disclosed a torque limiting fastener system for forged or pressed metal nuts. The stamped metal fasteners have a central, cylindrical sleeve, an annular ledge which is dependent from one end of the sleeve, and a surrounding skirt, generally with hexagonal flats, which forms an annular well about the cylindrical sleeve. The torque limiting characteristic is imparted to these fasteners by a drive member which is of approximately the same dimensions as the stamped or pressed metal fastener and which has a plurality of prongs which are received in apertures or recesses in the stamped fastener. The apertures can open into the annular well about the central sleeve of the fastener or can be placed in an annular flat base which is formed on some of the stamped metal fasteners. The drive member is formed of a suitable plastic material having a precisely controlled shear strength.

Torque limited pressed and forged metal nut members

A metallic balanced pin for a shear flow joint, and a fastener and joint including the pin. The pin has a head, a cylindrical shank and a reduced neck. The neck includes a peripheral groove, a helical thread being an example. The inherent strengths of the head and groove are substantially equal and only sufficient to resist axial tensile forces exerted by bending in a shear flow joint. The inherent strength of the shank section is sufficient to resist shear forces in the joint. Preferably the intersection of the neck and a transition section connected to the shank section is locally work-hardened to resist fatigue forces.

Balanced pin for shear flow joint, and joint including the pin

A safety bolt having a headed end, a shank, and a second end with means near the second end to hold the bolt in a hole in a workpiece. An axial passage opening into the second end intersects a laterally-extending passage spaced therefrom, and a dog fits in the laterally-extending passage wherein it is laterally reciprocable so as to be extendible beyond the maximum diameter of the shank or to be entirely retracted within it. A cam member having a pair of oppositely facing cam surfaces is axially slidable in the axial passage. A bias spring is provided to bias the cam member to a position corresponding to maximum extension of the dog. A plug is detachably attachable to the safety bolt to hold the cam member in a position respective to retraction of the dog. A projection can be provided on a nut for use with this bolt to prevent reversal of the nut, and a plurality of bias springs each with a different rate can be used.

Safety bolt

A blind fastener for fastening bodies together comprises a hollow tubular sleeve and a core bolt passing through the sleeve. The sleeve has a head at its front end to engage the front of the fastened bodies and the bolt has a head at its front end to engage the head of the sleeve. The sleeve has two sections, the first of which, adjacent to the sleeve head, has an internal diameter to fit over the core bolt, and the second of which, at the end of the sleeve remote from the sleeve head, has a larger internal diameter to leave an annular space between the core bolt and this second section. The end portion of the core bolt remote from the bolt head is threaded to engage the threads of a nut. The nut has a head rearward from the sleeve, from which there protrudes a tubular shank which extends into the annular space toward the sleeve head. The nut has an outside diameter larger than that of the nut shank but no greater than that of the sleeve. A deformable collar is positioned over the nut shank between the nut head and the end of the sleeve remote from the sleeve head. This assembly of the sleeve, bolt, nut and collar is adapted to pass through aligned holes through bodies to be fastened together, so that the sleeve head is at the front side of the bodies and the nut head, collar and rear end of the sleeve are at the rear side of the fastened bodies. When the nut is drawn toward the sleeve head, which may be done by pulling it by use of a mandrel in the absence of the core bolt, the deformable collar expands over the sleeve end and advances toward the sleeve head until it meets the rear of the fastened bodies, thereby setting the fastener. In a modification, a section of the collar nearest the sleeve head is made relatively thin as compared with the remainder of the collar so that while the nut is being drawn toward the sleeve head, the thin section first deforms outwardly until it meets the rear of the fastened bodies and then turns inwardly to meet the outer circumference of the sleeve, thereby setting the fastener. After removal of the mandrel the core bolt is torqued into the nut.

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Torrance, CA, United States of America

Josef F Volkmann