Patent GB-691579-A (GB)
Title: Improvements in or relating to machines for assembling nuts on bolts
IPC: B23P19/00
Filed: 1951-10-17
Abstract: 691,579. Screwing - up nuts; chucks. NATIONAL BOLTS & RIVETS, Ltd. Oct. 17, 1951 [Oct. 21, 1950]. No. 24281/51. Class 83 (iii). A machine for assembling nuts on bolts for dispatch to the user comprises means for holding the bolts against rotation and a hopper 3 from which the nuts are fed in a continuous stream, flat-to-flat, to a hollow chuck 5 through which each nut is pushed to be gripped and spun on to a bolt. In the fully automatic machine shown in Fig. 1, the nuts and bolts are respectively contained in hoppers 3, 6 fitted with agitating devices, the nuts being fed down a shoot 4 to the chuck 5 and the bolts being fed down a shoot 7 to a turret 8 above the chuck. The bolts A, held in the notches 9 by a band 8a and preferably also having their heads in shaped recesses are first presented above the chuck, where they are held against rotation by a radially-advanced clamp 11 while the nut is spun on, and then moved round to a position A<SP>1</SP> where they fall into a collecting box or, if necessary are raised from the notches by a lever 13 and swept off the turret by an arm 13a. The nuts B are pushed from the shoot 4 into the bore of the chuck 5 by a rod 14, Fig. 7, until they are gripped by two or more spring-pressed pivoted jaws 12 and the whole chuck, which is rotated by a belt drive 19, is then moved axially to present each nut to a bolt. The case-hardened gripping surfaces of the jaws are smooth so that the nut can slip off them as it is screwed on the bolt and be carried fully on to the bolt thread under its own momentum. The hopper agitators, the nut-feeding rod 14, the axial movement of the chuck, the clamp 11, the bolt-removing devices 13 and 13a and the indexing and locking of the turret are operated from a camshaft by lever systems and, in the case of the turret, by pawl and ratchet mechanisms. To protect the lever systems against damage, they may be provided with spring links as shown at 18, Fig. 4. The stroke of the nut-feeding rod 14 is sufficient to eject the nut from the chuck into a collecting box if a bolt is not correctly presented over it and means may be provided to prevent delivery of bolts without a nut screwed on them or to prevent operation of the machine if a fault arises; for example, the clamp 11 may act to stop indexing of the turret if the bolts are incorrectly positioned in it or if the notches are empty. In a modification, Figs. 15 and 19, the bolts are placed by hand in a slidable holder 50 which is advanced to present the bolt to a nut in the horizontallymounted chuck 5 by a pedal-operated lever system also connected to the nut-feeding rod 14. A plunger 48, acting through a spring 51, advances the holder 50 until it meets a plate 53 and pushes it forward against springs 52. In a limiting position, the plunger follows through and pushes the bolt through a downward-facing notch 53a in the plate 53 until the bolt head is held against rotation in a complementary portion 50b while a nut is spun on. When the operating pedal is released and the plunger and holder are withdrawn, the bolt falls out through the notch 53a.