Abstract: A threaded fastener, inserted into a hole in materials to be joined, receives a free-running collar (nut) with out-of-round duplex barrels. Spring-loaded twin sockets cradle the barrels and a restraining polygon key extends through the sockets and into a recess in the small face on the pin tail. Installation advances in tandem sequence; tightening before swaging. A machined groove with flat bottom and side rising at about 20 degrees from axial forms a boundary and partly reshapes crests from parallel to angular. Such inclination keeps the collar connected to the cavity of the larger of twin sockets throughout tangential tightening, rise of torque, displacement of crest material, recoil of the smaller socket on the end barrel, cessation of collar rotation and plunging torque. When recoil ends, radial torque on the smaller socket crushes and locks barrel material into underlying left hand helical troughs that interrupt the last few pin threads.

Abstract: A left hand helical flute crosses right hand threads on a pin inserted into a hole in materials to be joined. A nut smoothly cooperating with the pin threads has a top portion that has three convex, equilateral sides meeting at apices capping their deformable crests. To work the nut, three irregular faces of six within a socket first apply tangential torque at locations near the nut apices. Tightening develops resistance and as the rotating nut slows down, the socket's irregular faces displace nut crest material circumferentially. Torque rises and demand reaches maximum when the socket faces coincide with the nut apices. Thereafter, the nut stops rotating, and the working surfaces move toward disengagement. Torque dips, but rises again when three flat faces of the socket take a second pass at residual nut crest material.

Abstract: An improved deformable locking fastener system comprises a fastener, a deformable collar and a dedicated installation tool. The fastener has a threaded exterior defining a plurality of axial flutes which are configured to prevent the collar from prematurely capturing the fastener during installation. The collar comprises a cylindrical forward portion, a central portion having an elliptical cross-sectional shape and a rearward portion having an elliptical cross-sectional shape. The collar portions have axial heights selected to maximize the strength of the collar and to minimize the weight of the collar. The installation tool contacts the collar along driving ridges which reduces the radial compression of the collar and increases the tangential driving force turning the collar during installation.

Abstract: A torque measuring device is described that measures forces occurring during the interconnection of a nut to a bolt. The device has particular application with bolts having a key aperture in the tail end thereof and with nuts having a swaged exterior surface. A matching swage socket is used to limit the torque applied to the nut as material from the nut is swaged into fluted surfaces of the bolt. The torque measuring device is responsive to the torque applied to the nut, the reaction torque generated by the bolt and the compressive force between the nut and the bolt. The torques and the compressive force can be simultaneously measured and displayed so that an active force profile can be provided.

Abstract: A blind fastener is disclosed. The fastener comprises a tubular nut, a buckling sleeve and a mandrel. The buckling sleeve on one of its ends has a bearing face radially overhanging a facing restraint face of the tubular nut, and a tapered surface which deforms upon threaded drawing of the mandrel through the nut to approach the shape of a plane normal to the axis of the fastener.

Abstract: A blind fastener with an axially extending sleeve having an axially extending internally threaded passage therethrough. A head at one end has an axially facing surface thereon with a periphery which is centered on its axis. A mandrel includes an axially extending threaded shank that is threaded into and through the passage. A torque-off groove is formed on the shank. Torque tool engaging surfaces are accessible at the head end of the sleeve, and blind upsetting structure is axially movable by rotating the mandrel to form an enlarged body at the unheaded end of the sleeve. A nut is threaded to the mandrel with a bearing face facing toward the surface of the head of the sleeve. The bearing face of the nut is concavely shaped so as to make contact with and thereby to make a retention engagement with at least some points around the periphery to hold the sleeve against rotation relative to the nut when the mandrel is drawn into the sleeve with the nut pressed against the head.

Abstract: A blind rivet assembly is disclosed. The rivet assembly comprises a mandrel, a rivet body, a buckle sleeve, an expanding wrinkle sleeve, a pressure sleeve and a locking collar. The sleeves, rivet body and collar are slideably disposed about the mandrel with said buckle sleeve disposed adjacent one end of the body, and the mandrel extending through the body and beyond the other end thereof. The buckle sleeve has a generally cylindrical configuration such that when subjected to a pulling force, the sleeve buckles outwardly from the mandrel, slides about the rivet body and engages a workpiece. The wrinkle sleeve has a generally cylindrical, but longitudinally corrugated configuration, such that as the mandrel proceeds through the rivet body, the wrinkle sleeve expands radially and helps create an interference fit between the rivet body and an opening in the workpiece.

Abstract: A pull-type blind fastener assembly includes a mandrel, expander, sleeve and lock collar. The expander extends through aligned holes in at least two workpieces, that are to be joined and has an enlarged head and a shank portion with a pair of conical tapered surfaces separated by a constant diameter surface thereon, adjacent the blindside end thereof. The tubular sleeve has a maximum thickness portion adjacent one end, an intermediate portion of medium radial thickness and a minimum radial thickness portion adjacent the other end. When an axial force is exerted on the mandrel by means of a conventional pulling tool, the minimum sleeve thickness portion is forced successively over the first and second conical expander surfaces where it is expanded, and a radially outwardly extending bulb begins to form at approximately the intersection between the minimum and medium thickness portion adjacent the other end.

Abstract: A blind rivet assembly is disclosed. The rivet assembly comprises a mandrel, a rivet body, a buckling sleeve and a locking collar. The sleeve, rivet body and collar are slideably disposed about the mandrel with said buckle sleeve disposed adjacent one end of the body and the mandrel extending through the body and beyond the other end of the body. The buckle sleeve has a generally cylindrical configuration such that when subjected to a pulling force, the sleeve buckles outwardly from the mandrel, slides about the rivet body and engages a work piece.

Abstract: In this blind rivet, the sleeve is counterbored from the rear end, and has interior axial splines forward of the counterbore. The bulb-forming lugs project laterally from a shoulder portion of the mandrel that has a diameter sufficiently great to collapse the sleeve splines during rivet installation. Between the bulb-forming lugs and the mandrel blind end are a set of annular flutes in the mandrel. During rivet installation these flutes urge radial expansion of the sleeve counterbore region to assist hole filling. The sleeve may include a lock-collar-guiding counterbore having an annular convex region providing a locking collar entry resistance surface effective during the initial phase of rivet installation.