Abstract: A self-plugging blind rivet, of the kind comprising a tubular body having a head and a shank which is deformed by means of a headed stem which is disposed in the body and pulled so as to form a blind head and, if necessary, to cause the shank to bulb so as to grip workpieces of lesser thickness than the maximum for which the rivet is designed, is so shaped and dimensioned as to avoid the need for a crimping or hardening operation to be performed on the shank. Thus the shank is made of uniform hardness, and has a waist and a tail portion, the waist being of reduced external diameter compared with the tail portion, and the tail portion having a length B and an external diameter D which are related to satisfy the expressionB=mD+nwhereinB is the length in millimeters, of the tail portion;D is the external diameter, in millimeters, of the tail portion;n is a length, in millimeters, of from 2.15 to 2.73 millimeters, andm is a number from 0.373 to 0.527 inclusive.

Abstract: For use in a robotically operated workstation, apparatus for installing fasteners, for example tubular blind rivets, comprises a pneumatically operated fastener installation tool 16. The tool 16 has a part in the form of a headed mandrel 22 which is loaded with and carries a finite supply of the fasteners, a gripping and pulling actuator 26 and a nose assembly 21 which provides an abutment 18 for supporting successive rivets while the mandrel is pulled to draw its head through and set the rivet. For reloading the tool with further fasteners, after use, the apparatus includes a nest 96b for detaching and receiving the mandrel 22, together with the nose assembly 21, from the actuator 26, and a similar nest 96a provided with another nose assembly and another mandrel fully loaded with fasteners which it presents and attaches to the actuator 26.

Abstract: A breakstem blind rivet comprises a deformable tubular shell 11 of aluminium alloy having a bore 12 inside it. A stem 13 of low-carbon steel is a close fit within the bore, extending along the bore and having a head 14 adjacent the tail end 15 of the shell. The outside of the shell is formed with at least three zones 27, 28, 29 of modified strength spaced apart along its length, these zones being in the form of shallow grooves rolled into the surface. The spacing between each zone 27, 28, 29 and the next progressively decreases as the distance along the shell from the tail end 15 increases. Alternatively the grooves may be formed by a turning process.

Abstract: A blind rivet able to be anchored in material such as softwood, without the need to break through the blind face of the material, comprises a tubular shell and a stem which extends through the shell. The shell has a preformed heat at one end of a shank. An end portion of the shank remote from the head has a thinner wall than the main, next adjacent, portion of the shank, and is thus weakened and made more easily expandible. The stem has a plugging portion having an expander head adjacent the thin-walled end portion of the shell, a breakneck, and a pulling portion which projects from the head end of the shell. The expander head increases in diameter away from the pulling portion, and presents a plurality of longitudinal cutting elements generally towards the weakened end portion of the shell. On gripping the pulling portion and pulling the stem, the cutting elements split the end portion of the shell into a plurality of legs, while the expander head enters into the end portion and forces the legs outwardly.

Abstract: A bush for installation in easily crushed or marred work material such as apertured honeycomb sheet or fibre reinforced plastics material, enables the work material to be secured to a support, by means of a nut and bolt, without damage. The bush has a cylindrical body longer than the thickness of the work, and a flange for abutting a face of the work at one end of the body. The other end of the body has an annular boss which projects beyond the other face of the work, and, peripherally of the boss an annular skirt which during installation can be deformed to provide a retaining flange for engaging the other face of the work. A bolt can then be passed through the bush and a support, and secured with a nut. Only the bush directly engages the work.

Abstract: A threaded fastener for installation in threaded engagement with an initially unthreaded apertured workpiece and which after installation can be removed in the manner of a screw or bolt, has a shank and an enlarged head. At least part of the shank intermediate between its ends has an external screw thread having a sharp crest, and can be radially expanded to cause the thread to embed in the workpiece. A bore extends through the head and the entire shank or at least the threaded port of the shank for receiving means for expanding the shank. An end portion of the shank remote from the head may be unthreaded to avoid splitting of the shank during expansion.The method of installing the fastener involves pulling a tapered mandrel along the bore to expand the shank. The mandrel may have a key-forming head of non-circular cross-section whereby the bore of the fastener can be adopted to receive a key of non-circular cross-section for turning the fastener in the workpiece.

Abstract: A threaded fastener for installation in threaded engagement with an initially unthreaded apertured workpiece and which after installation can be removed in the manner of a screw or bolt, has a shank and an enlarged head. At least part of the shank intermediate between its ends has an external screw thread having a sharp crest, and can be radially expanded to cause the thread to embed in the workpiece. A bore extends through the head and the entire shank or at least the threaded part of the shank for receiving means for expanding the shank. An end portion of the shank remote from the head may be unthreaded to avoid splitting of the shank during expansion.The method of installing the fastener involves pulling a tapered mandrel along the bore to expand the shank. The mandrel may have a key-forming head of non-circular cross-section whereby the bore of the fastener can be adopted to receive a key of non-circular cross-section for turning the fastener in the workpiece.

Abstract: A blind, self-plugging rivet assembly for securing together two members (42, 43) is of the type comprising a tubular shell (13) with an enlarged head (14) at one end, and a stem (12) which extends through the bore (15) of the shell, the stem having an enlarged head (38) beyond the tail end (18) of the shell.The shell has a weakened zone (19) formed by three slits (22) extending along part of the shell shank and spaced apart equiangularly around it. The stem head (38) lies beyond the shell tail end, and has an underhead surface (39) which is slightly convex and is bounded by a sharp edge (40).The stem has a pulling portion (32) connected by a breakneck to a plugging portion (31) which is an interference fit in the shell bore. Adjacent the breakneck the plugging portion has a cylindrical skirt which, when the rivet has been installed, can be deformed outwardly to lock the plugging portion to the shell. A bead on the stem guides the tool for deforming the skirt.

Abstract: An anvil for a blind riveting tool comprises an annular disc 23 of resilient nylon-6 material received in a counterbore in the front of a rigid backing or mount 25. When the tool is used to place a blind rivet, the nylon disc contacts the rivet shell head to support it against the pull of the mandrel. The disc is flexible enough to conform to the shape of the rivet head, thus maximizing the contact area and minimizing the contact thrust, and is soft enough not to damage or mark the rivet head surface, which may, for example, be painted.

Abstract: A two-part fastener intended for securing, e.g., a panel 41 to a frame member 42 comprises a tubular shell 11 and a pin 12. The shell bore contains a tubular insert or slug 14 of resilient nylon material. The exterior of the pin is formed with annular barbs 30. When the pin is inserted into the shell, the barbs 30 engage in the resilient slug 14 to secure the pin and shell together. The pin includes a removable pintail 33 which protrudes beyond the shell and assists in the pulling of the pin into the shell by means of a suitable pulling tool.