Patent GB-1287572-A (GB)
Title: Blind riveting apparatus
Inventor: PROSSER PAUL EDWARD
IPC: B21J15/28
Filed: 1968-09-16
Abstract: 1287572 Blind riveting AVDEL Ltd 3 Oct 1969 [16 Sept 1968] 43859/68 Heading B3U A blind riveting apparatus comprises grippers 79, 81 and 85, 86 for gripping the mandrel 40 at spaced apart positions, so that a tubular rivet may be fed on to the mandrel past the gripping position of each gripper whilst it is retracted, the mandrel being gripped at any one instant by at least one gripper. In operation, the cycle of operations is controlled automatically by a pneumatic circuit (Fig. 20, not shown) the cycle being initiated by a start button to cause highpressure air to flow through a conduit 35 above a stationary piston 65 thereby raising a mandrel gripping jaw carrier 61. The mandrel head 48 of the mandrel 40 (Fig. 10, not shown) is thus pulled through a rivet positioned in a workpiece to set it. At the start of a cycle, a rivet is positioned in a pocket (163) (Fig. 12, not shown) of a nose 162 of a transporter arm 161 pivoted at 167 to a plunger 153. As the jaw carrier 61 is raised, inclined faces 74 of the upper jaws 79, 81 engage inclined faces 165 of the transporter nose 162 and push the arm 161 upwards against the action of a spring 155 until the plunger 153 contacts a shoulder 150. As the jaw carrier 61 is further raised, the upper jaws 79, 81 are forced apart by the nose 162 so that the spring 155 is released and the arm 161 moved down to its lowermost position feeding the rivet on to the mandrel 40, the spring loaded upper jaws 79, 81 closing behind the transporter nose 162. As the jaw carrier 61 continues to move upwards, the nose 162 is engaged by the lower jaws 85, 86 and is again raised. During the movement of the jaw carrier 61, a pawl 129, Fig. 5, of a mechanism 130 connected to the carrier 61, is moved out of a bore 126 and rides up a ramp 142 allowing a spring-urged shutter 121 to move outwardly and a further rivet to fall from a feed tube 28 connected to a vibratory hopper. When the uppermost position of the carrier 61 is reached, high-pressure air is fed through a conduit 36 to lower a piston 98 and allow the spring-urged lower jaws 85, 86 to open, which causes the arm 161 to move downwardly moving the rivet therein down the mandrel 40. Thereupon high-pressure air is supplied through a conduit 37 to close the lower jaws 85, 86, after which the jaw carrier 61 is lowered by supplying air through a conduit 34. The lower faces of the lower jaws 85, 86 are thereby engaged by a curved portion (164) of the transporter arm nose 162 so that the arm 161 is forced aside by pivoting about the pivot 167. The rivet is thus left at the top of the column of rivets on the mandrel 40 and is contacted by the descending lower jaws 85, 86 to cause the lowermost rivet to be forced through the spring-biased riveting jaws 56, 57 ready for the next cycle. When the jaw carrier 61 reaches its lowermost position, the pawl 129 which has been moving down the ramp 142, is urged into the bore 126 to force the shutter 121 inwards to transfer a rivet into the pocket (163) of the arm 161. The initial positioning of the mandrel 40 is facilitated by a movable plunger 185 having a recess 186 to accommodate the top of the mandrel. In a modification (Fig. 21, not shown), the upper (201a) and lower jaws (208) are moved into and out of engagement with the mandrel by a double slope cam (206).