Abstract: Fastener installation apparatus for operating cyclically so as to instal successively a plurality of fasteners includes a fastener installation head (11) having an aperture (35) in which part of a fastener is inserted, and a vacuum generator (20) for creating an airflow in through the aperture (35), along a pipe (31) and into a receptacle (15) for broken-off fastener parts. The presence of a fastener in the aperture (35) causes a change in the level of vacuum in the pipe (31) and receptacle (15). The level of vacuum is sensed by vacuum level detection means (45), which gives an electrical signal to the apparatus control unit (14a, 14b). The control unit allows the installation apparatus to continue its cyclical operation only upon the presence or absence of fastener in the aperture (35) at the appropriate points in the cycle of operation of the apparatus.

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: The rivet comprises a tubular rivet body of deformable material, and an elongate stem extending through the bore of the body. The body comprises a cylindrical shank and an enlarged rivet head at one end of the shank. The rivet head may be integral with, or separate from, the shank. The stem includes a plug, and a stem-tail connected to the plug by a frangible breakneck. The plug has a terminal head for abutting the shank, whereby the shank can be axially compressed on pulling the stem-tail and thereby deformed to form a blind head, and a locking groove circumferentially of the plug for receiving material of the rivet head which, during installation of the rivet, will be swaged radially inwardly into the locking groove to lock the plug in the body. The locking groove is of helical form, as with a screw thread, and enables the plug to be removed from the body by rotation, thus facilitating disassembly of the installed rivet and its removal from a workpiece.

Abstract: A hand-held pneumatically-powered breakstem rivet placing tool comprises a pulling head (12) driven by a pneumatic piston and cylinder device (13). The drive is transmitted by way of a chain (15), one end (45) of which is secured to the body (11) of the tool and the other end (49) of which is secured to the piston rod (35) of the pneumatic device. Between its two ends the chain forms a loop which passes over a roller (52) which is connected to the pulling head (12) by way of a link mechanism (54, 58). When the pneumatic device (13) is actuated, the movable end (49) of the chain is pulled down, thus pulling the roller (52) and driving the head (12) to place a rivet. The roller (52) is carried on the top of a plunger (56) which is continuously urged upwards by air pressure in the cylinder (63) in which it slides, thereby to return the mechanism to its original position after a rivet has been placed.

Abstract: A device for automatically replenishing and exchanging hydraulic fluid in the hydraulic system (such as that of a fastener placing tool 31) has a lower reservoir (29) for holding new hydraulic fluid (39) and an upper reservoir (28) for receiving old hydraulic fluid. The device connects with the system to be replenished by means of a single hydraulic fluid connection (17) at the bottom of the lower reservoir (29). An entry port (25) to the second reservoir is positioned opposite the connection (17) at the bottom end of a tube (23) leading to the top of the second reservoir. In use, the device is connected to the hydraulic system through the connection (17) and the system is pressurized. Old hydraulic fluid is forced up through the connection (17) at high speed and passes through the new hydraulic fluid (39) in the lower reservoir (29), through the port (25), up the tube (23) and down into the upper reservoir (28) where it is retained.

Abstract: Fastener installation apparatus for operating cylically so as to instal successively a plurality of fasteners of the type in which a portion is broken off at installation (e.g. breakstem blind rivets) comprises a fastener installation head (11) and a pipe (31) for conveying the broken-off portions away from the head to a receptacle (15). Detection device (48) is mounted adjacent the pipe (31) to detect the presence of a broken-off fastener portion at a pre-determined position (58) there along near the receptacle (15). When a portion is thus sensed, an electrical signal is sent by the detection device (48), via a relay (51), to the installation control system (14a, 14b), so as to allow cyclical operation of the system to continue.

Abstract: A self-plugging blind fastener of the break-stem type, is suitable for fastening apertured sheets together, and comprises a headed tubular body and an elongate stem disposed in the bore of the body. The stem comprises a plug, and a stem-tail connected to the plug by a breakneck which is concealed by overlapping lips. The plug has a stop face, and an annular locking groove between the breakneck and the stop face. The body has a deformable locking collar upstanding above an adjacent region of the upper surface of the head. The diameter of the bore reduces, to provide a stop face and a locking region of smaller diameter, within the head. The fastener is set by pulling the plug into the bore until the stop faces meet, to form a blind head, and then deforming the collar to force the body to bulge into the locking groove of the plug.

Abstract: In a blind fastener (20) of the kind comprising a tubular nut (22) having shank (28) with a head (30) at one end and a tapered nose (32) at the other end, a headed bolt (24) threadedly engaged in the bore (34) of the nut (22), and an expansible sleeve (26) which, by rotating the bolt (24), can be forced on to the nose (32) to form a blind head, a section of the shank (28) of the nut (22) is formed with a single protuberance (42) which protrudes resiliently into the bore (34) sufficiently to interfere with and restrain rotation of the bolt in the nut, and thus render the fastener self-locking. The shank (28) may have more than one section provided with a single such protuberance (42), the effect of several protuberances being additive. Each protuberance (42) lies entirely within a minor sector of its section of the shank, and presents either a flat or a curved threaded surface traversed by the thread (38). Protuberances may be in different sectors if spaced longitudinally of the shank.

Abstract: Apparatus for automatically installing blind rivets includes structure for automatically feeding new rivets one at a time to the front of the rivet installation head. Each rivet is supported in the appropriate position by a pair of support fingers (36,36) whilst the installation head (19) advances towards the rivet. The rivet feeding structure is provided with rivet guiding fingers (51,51) which guide the rivet stem (41) into the approaching anvil aperture (48) in the installation head. As the installation head continues to advance, it pushes out of the way first the guiding fingers (51,51) and then the support fingers (36,36) so that the rivet can reach the workpiece and be installed in it.

Abstract: A headed steel pin for a multi-grip fastener of the pin and swageable collar type has a homogeneous microstructure, and consists substantially entirely of sorbitic tempered martensite. Suitable coarse-grained medium carbon steel is shaped to form a headed pin having a plurality of identical, regularly spaced, annular, combination grooves each able to function alternatively as a locking groove, a pulling groove, or a breaker groove. The shaped pin is heat treated, the steel rendered homogeneously martensitic and then tempered at a temperature approaching as closely as practicable to the lower critical temperature of the steel, to convert the martensitic steel entirely to sorbite. The finished pin has a suitable balance of brittleness, toughness, ductility and impact strength, and tends to break cleanly and reliably at a selected one of the combination grooves when the fastener is installed in a workpiece.

Abstract: A breakstem rivet installation tool includes an airflow ejector for ejecting broken-off stems through a rear pipe (23) mounted on the tool housing (11). The ejector is provided by the annular gap (28) between the front-end of the rear pipe (23) and the rear-end part (26) of an extension pipe (25) mounted on the reciprocable stem-pulling draw rod (13). In order to adjust the rate of air-flow through the ejector, the rear pipe (23) is axially adjustable to vary the size of the annular gap (28). To this end, the pipe (23) is screw-threaded into the housing, and its position can be locked by a lock nut (62). The range of adjustment of the ejector flow includes complete shutting off the air flow.

Abstract: A nosepiece for temporarily supporting a fastener in front of a fastener installation tool is disclosed. The nosepiece comprises a split support provided by a plurality of support members which define between them a cavity which receives the fastener. The fastener is supported peripherally by the support members which can move to allow a fastener to move through said members in a forwards direction, from the back to the front of the nosepiece to allow installation of the fastener. The support members also restrain undesired movement of the fastener in the cavity in the reverse direction (i.e. from the front to the back of the nosepiece) as well as undesired movement in the forwards direction.

Abstract: In a blind fastener (20) of the kind comprising a tubular nut (22) having a shank (28) with a head (30) at one end and a tapered nose (32) at the other end, a headed bolt (24) threadedly engaged in the bore (34) of the nut (22), and an expansible sleeve (26) which, by rotating the bolt (24), can be forced on to the nose (32) to form a blind head, a section of the shank (28) of the nut (22) is formed with a single protuberance (42) which protrudes resiliently into the bore (34) sufficiently to interfere with and restrain rotation of the bolt in the nut, and thus render the fastener self-locking. The shank (28) may have more than one section each provided with a single such protuberance (42), the effect of several protuberances being additive. Each protuberance (42) lies entirely within a minor sector of its section of the shank, and presents either a flat or a curved threaded surface traversed by the thread (38). Protuberances may be in different sectors if spaced longitudinally of the shank.

Abstract: A pin for a pin and swaged tubular member type of fastener has a shank (14) provided along nearly all of its length with identical combination locking, breakneck and pulling grooves (20). Each groove is provided on at least one sidewall with a discontinuity, and in a preferred embodiment both sidewalls of each groove are provided with discontinuity in the form of a displacement across the width of the groove and along the length of the pin. Alternatively the discontinuity may take the form of a change in inclination of the groove wall, or a combination of both such displacement and change in inclination.

Abstract: A hand-held rivet installation tool is provided with an airflow ejector (23, 26, 28) to eject broken off rivet stems. The tool has a base (71) on which it can stand on a level surface. A valve (73) is provided with its actuating plunger (75) protruding from the base. When the tool is standing on its base, the plunger (75) is pushed in and the valve (73) shuts off the air supply to the ejector. When the tool is picked up again the valve (73) stays in the off position until the tool-actuating trigger (31) is operated again. Thus needless waste of air through the ejector, when the tool is not being used, is eliminated.

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: The rivet comprises a tubular body 12 having a shank 14 having a rivet head at one end and an end portion 32 of which is tapered externally and internally towards the other (tail) end 20. A stem 10, disposed in the bore 18 of the body, has a stem-tail 22 which projects from the head end and breaks off when the rivet is set, a plug 24 in the bore 18, and a terminal head 28 abutting the tail-end 20. The diameter of the plug is reduced progressively and stepwise towards the terminal head, providing an abutment 50 and an annular groove 29 between the terminal head 28 and the abutment 50. Material of the end portion 20 extends into the groove to maintain the body and stem assembled, and enters further into the groove during setting of the rivet.The rivet is set by pulling the stem tail while supporting the body, causing the shank to collapse into a bulge which provides a blind head.The external tapering of the portion 32 promotes bulging at a lower applied force than would otherwise be required.

Abstract: A three piece blind fastener of the kind comprising a tubular nut having a head at one end and a tapered nose at the other end, an expansible sleeve, and a headed bolt threadedly engaged with the nut for forcing the sleeve on to the nose of the nut to form a blind head, has the thread of the nut provided with a locking zone in which the bore of the nut is constricted and, in cross sectional shape, a closed non-reentrant non-circular curve so that the nut resiliently interferes with the bolt.A die, and a method of providing the nut with the locking zone by means of the die are disclosed. The die has a tapered aperture having a cross sectional shape corresponding to the desired shape of the locking zone, and the method involves forcing the tapered nose of the nut into the aperture so as to constrict the bore, in a zone spaced from its ends, to the desired extent and impose the non-circular cross sectional shape on the constricted zone.

Abstract: An anchor nut fastener device is of the type comprising a tubular body portion (11) and a nut portion (12) which tapers externally, whereby when the body portion is inserted in a suitable hole in a workpiece and the nut portion (12) is forced into the body portion (11), the taper on the nut portion (12) both radially expands the body portion into engagement with the wall of the workpiece hole and also engages the nut portion in the body portion, thereby to provide an anchor nut in the workpiece. The external taper on the nut portion (12) comprises a first, relatively long, part (24) of a relatively shallow taper and a second, relatively short, part (26) of relatively steep taper further away from the body portion than is the first part and extending radially outwardly of the first part. The end of the body portion (11) is enlarged to provide a head (10), and a countersink (14) into which the leading end of the nut can be enlarged.