Patent GB-903500-A (GB)
Title: Rivet feeding apparatus
IPC: B21J15/34
Filed: 1960-01-20
Abstract: 903,500. Riveting. BREWER, C. E. Jan. 19, 1961 [Jan. 20, 1960; March 31, 1960], Nos. 2095/60 and 11407/60. Class 83 (4). A riveting apparatus comprises a rotor adapted to carry a plurality of angularly spaced chucks 12, each chuck being capable of receiving a rivet mandrel, means for imparting a step-by-step motion to said rotor whereby said chucks will move successively from a rivet feed position A to an operative position B and then to a mandrel discharge position C and means adapted, when each chuck is in the operative position to impart a movement to the chuck to move the mandrel in a rivet setting direction. Rivet setting means.-The apparatus comprises a rotor 10 which carries four equally spaced chucks 20 and which is freely mounted on a shaft 11. Each chuck assembly comprises a body 21 which slides in a radial slot in the rotor 10 and is urged outwardly by a spring 22, and which has a transverse pin 28 therein which carries a roller 29 at each end. Within the body slides a gripper which comprises a sleeve 23 and resilient jaws 24 and which is acted on by a light spring 25. The assembly is completed by a retaining cap 26 and a threaded bush 27. On each side of the rotor is a disc 30, 31, each of which is fixed on the shaft 11 and has an internal cam 32. The disc 30 has teeth to mesh with a rack 19 which is reciprocated by a double-acting fluid pressure cylinder assembly 18. When the rack moves upwards (Fig. 4), the shoulder 33 engages the rollers 29 and rotates the rotor 10 in an anti-clockwise direction, and when the rack moves down the cam surface 32 engages the rollers 29 of the chuck at position B, causes retraction of the body 21 and hence of the gripper jaws 24 which withdraw the mandrel from rivet. The mandrel falls out of the chuck when it is rotated to position C. Reverse rotation of the rotor is prevented by a spring-loaded stop 34 and overrunning by a resilient stop 35 attached to, and reciprocating with the rack 19. Rivet feeding mechanism.-Rivets from a magazine 42 pass down a feedway 43 which is controlled at its lower end by a sliding gate 44. The gate is attached to one end of a bar 45 which has at the other end a lug 46 adapted to co-operate with a cam 39 formed on a bar 37 connected to the rack 19. The opposite face of the bar bears a cam 38 which co-operates with a lug 51 on one end of a second slide bar 52 which carries at its other end a block 53. The two slide bars are held against the cam surfaces by a pair of connecting tension springs 48. When the rack 19 is in the uppermost position the gate 44 is drawn clear of the feedway and the leading rivet is supported by the block 53. As the rack moves downwards the block 53 is withdrawn, the gate 44 advances and the rivet and mandrel eventually fall clear of the block 53 so that the mandrel enters the gripper means of the chuck at position A. The rivet is then supported by a lip on the gate 44. On the next upward movement of the rack there will be initially no movement of the bars 45 and 52 due to the position of the cams 38 and 39, but the rotor will turn and carry the chuck containing the rivet to the operative position B. As the rack continues to rise the gate 44 will be retracted to allow the passage of another rivet and the block 53 will advance to support it. An alternative feed mechanism comprises a feed drum rotatable about a vertical axis and formed at its periphery with rivet receiving pockets. Pawl-and-ratchet means associated with the rotor drive the drum and rotor in step. Rivets are fed to the drum by an inclined guide the outlet of which is controlled by a reciprocating separator blade arranged so that when the rack is in the uppermost position the separator is retracted and a rivet is allowed to enter a pocket in the drum. At each movement of the drum a rivet is brought to the feed position and falls into the chuck which is at position A.