Avdel Systems Limited

Avdel Textron Limited

Neil J Sherry

Keith Denham

Jonathan L Brewer

Members of an assembly, a first of which has an aperture and a second of which is of deformable sheet-like material, are fastened together by piercing and deforming the second member using a punch and die to provide a pierced aperture having a peripheral wall of helical form analogous to a screw-thread, assembling the members together with the apertures aligned, inserting a tubular fastener having a head and a shank into the apertures so that the head abuts a face of the first member and the shank extends through the second member, and then expanding at least part of the shank within the pierced aperture of the second member and thereby causing the peripheral wall of the pierced aperture to impress a helical peripheral groove into the external surface of the shank of the fastener. The shank can be expanded by pulling a tapering mandrel head into or through it. The fastener is made to facilitate its removal by unscrewing from the fastened assembly by providing or forming wrenching surfaces in its bore or on its head for engagement with a key, screwdriver, spanner or the like.

Method of fastening members of an assembly

A method of riveting two metal sheets together including the steps of inserting the shank of a blind rivet through superposed oversized holes in the sheets, and deforming the parts of the sheets immediately surrounding the apertures by compression between the blind head and the preformed head of the rivet when the rivet is placed. The holes are oversized to allow for manufacturing and assembly tolerances, and deformation of the sheets provides interengagement between the sheets and substantially increases their resistance to slipping sideways relative to each other.

Method of securing members together

A pin-type fastener capable of dual-function includes a pin which can be used in fastening workpieces together. The pin has a pintail capable of being removed from the remainder of the pin after the pin has been installed as a fastener in a workpiece, and the pintail can then be used as a weldstud and welded to the same workpiece as the pin-type fastener, or to another workpiece. The pin-type fastener can be a two-part fastener, for example a lockbolt including a nut or swageable collar engageable with the pin. The pin may have a breakneck to facilitate removal of the pintail. The pin itself may be a weldstud. In use, the pin-type fastener is installed in a workpiece and the pintail is removed, and then the pintail is used as a weldstud, being welded to a workpiece. Electric welding is employed. The advantage of the fastener is in economy through second use of the pintail as a stud.

Dual-function fastener and method of use

A removable rivet which includes a shank and a preformed head located at at least one end of the shank, the shank being insertable through workpieces and being capable of being permanently deformed to rivet the workpieces together. The rivet includes an annular groove at the junction of the shank and the head, the annular groove extending radially inwardly of the diameter of the shank, thereby to facilitate separation of the head from the shank when a drill of diameter substantially equal to that of the shank is applied to the head of an installed rivet co-axially with the shank until the drill meets the annular groove; an annular rim carried by the head of the rivet for cooperating with a drill, thereby to locate the drill co-axially with the annular groove; and abutment faces carried by the head of the rivet for engaging dogs of a non-rotating sleeve of the drilling apparatus thereby to prevent rotation of the rivet under the influence of the rotating drill.

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Stevenage, United Kingdom

Neil J Sherry