405,993. Setting tubular rivets. HUCK, L. C., 541, Lincoln Road, Grosse Pointe Village, Michigan, U.S.A. Aug. 16, 1932, No. 22974. Convention date, Aug. 31, 1931. [Class 43.] A bi-part fluid-pressure-operated mechanism is adapted to engage the complementary parts of a multi-part rivet at one end thereof to effect relative movement of the parts and upsetting of the rivet. The machine comprises a plate 116 with a recess 118 for holding a tubular rivet 120 in an aperture in a structure with its head 125 resting in the recess, and gripping mechanism for pulling a headed member 126 through the rivet to upset its shank 121 against the opposite side of the structure. The gripping mechanism may be operated by a fluid-controlled piston 55 working in a cylinder 13 formed by a casing 12 and a plate 11. Fluid under pressure is supplied by a conduit 18 to an aperture 17 in a handle 15 communicating with a valve casing 19. The valve comprises a hollow plunger 36 working in a bore having enlarged ends 21, 22 and having apertures 43, 44 communicating with the end openings 21, 22. Apertures 53, 54 in the opening 21 communicate with the cylinder 13 at opposite sides of the piston and are accordingly placed in communication with the pressure supply and atmosphere by means of flanges 37, 38 on the plunger 36 as required for moving the piston. The plate 11 is fitted with a yoke 70 having straight arms 73, 74 whereto the plate 116 is secured. The piston rod 57 is accommodated within the yoke and has a reduced end bearing a second yoke 76 having legs 77 carrying blocks 84, 85 presenting inclined surfaces 89, 90 to each other. The legs 77 have inclined slots positioned so that rectangular frames may be placed adjacent the surfaces 89, 90 with legs passing through the slots. Each frame contains a pair of rollers bearing on the inclined surface. A pair of jaws 108, 109 are placed between the pairs of rollers. The jaws have semi-cylindrical recesses at the rear which slidably engage a pin 81 at the end of the piston rod 57. A spring 112 tends to push the jaws together. In use a headed tubular rivet 120, Fig. 10, is placed in apertures in a pair of plates and a headed member 126 is passed through the rivet from the opposite side. The plate 116 is presented so that the head 125 of the rivet rests in the recess 118 and the member 126 passes through an aperture therein and is inserted between the jaws. The valve is now operated to pull back the piston rod. The blocks 84, 85 are thus operated to move the frames in the slots and the rollers roll over the jaws until they grip them. The jaws thus grip the member 126 and pull it partly through the rivet to buckle the shank 121 against the opposite side of the plates as at 128, Fig. 11. The degree of movement of the piston and thus the amount whereby the member 126 is pulled may be controlled by a pressure-operated valve mounted on the cylinder or by a set screw fitted in the casing 12 and adapted to abut against the piston to limit its end position. In an alternative form, Fig. 12, the valves controlling the supply of fluid to a cylinder 152 are operated by a trigger mechanism 219. The piston rod 157 is slidably mounted in supports 161, 162 in the cylinder at each side of the piston 156 which may have cup washers. The valve mechanism comprises four passages in each of which a valve is mounted in a seating at the centre of the passage for connecting the two sides of each passage. A series of ports on each side of each passage communicate with conduits leading to the fluid supply, the atmosphere or one side or the other of the piston. Valvo stems project into a central space and are engaged by a bar 221 operated from the trigger 219 to move the valves. Each valve stem is fitted with two valve discs, one engaging the central seating and the other a seat in the first disc. Openings in this disc and the seating are progressively uncovered as the stem is moved. The rivet setting apparatus is operated from the piston rod by a lever 223 pivoted to the casing and mounted in a slot in the rod and a bearing in a reciprocatory member 230, Fig. 17, slidably mounted in a barrel 226. The barrel end carries an anvil plate 245 having a concave recess 252 for the rivet head and an opening for the headed member. The reciprocatory member terminates in a sleeve 231 formed with three semi-cylindrical sockets the axes whereof taper towards the barrel end but the crosssectional arcs whereof become less than semicircular the further awav from the end. A jaw 237 is fitted into each socket such that its outer surface fits the tapering socket and its inner surface has an axis parallel to that of the barrel. Thus as the member 230 is moved back the jaws are brought together with the axes of their gripping surfaces parallel and the surfaces in alignment with the headed member. The gripping surfaces may be grooved or threaded. The jaws are held towards the outer end by a spring-urged three-legged element. By continued pulling after the rivet is set, the shank of the headed member is broken off and the broken end is ejected through an opening in the barrel. To cushion the recoil when the shank breaks, a pin 222, Fig. 12, may be mounted on the piston and aligned with the exhaust opening so that the size of the latter is reduced as the piston approaches the breaking point and a cushion of fluid is retained in front of the piston. The recoil also causes the jaws to open and release the broken part. For riveting with elongated headed members and in narrow and deep openings, a tapering anvil attachment may be fitted on the end of the barrel. The bulging of the tubular rivet may be effected in two stages by forming the shank with two portions of differing thickness which thus form two bulges. The machine is particularly useful for setting rivets of the character described in Specification 402,813.