Patent GB-650129-A (GB)
Title: Improvements in the manufacture of nails, rivets or the like
IPC: B21G3/16
Filed: 1948-06-11
Abstract: 650,129. Rumbling nails. WARBURTON, J. W. June 11, 1948, Nos. 15785/48 and 13387/49. '[Class 60] A method of treating nails, rivets or the like during their manufacture includes the steps of delivering formed nails into a hopper, controlling said hopper to deposit a predetermined load automatically at given intervals into a rotary rumbling drum or agitated receptacle mounted to work in a stationary position, screening flashes, nippings or the like from the load of nails during at least one stage of the process, discharging the finished nails into one or more receptacles, and arranging the cycle of operations to be carried out automatically in correct sequence through control means. Presses or other forming machines deliver formed nails on to conveyer belts 1, Figs. 1 and 2, which deliver them into an elevated hopper 2 having a closure element, e.g. pivoted shutter 3. A predetermined load of nails is discharged from the hopper 2 under control of automatic weighing device 4 which can be set by poise 5 on graduated pivoted scale bar 6 and selected weights 7 placed on suspended pan 8, the latter rising and falling between electric switches 9, 10 controlling electric circuits for preventing further nails falling into the hopper through shoot 11 and for opening the shutter at the bottom of the hopper. The contents of the hopper are delivered through feed shoot 14 into inlet openings 15 in one end of a cylindrical rumbling drum 16 rotated about a horizontal axis by electric motor 18. The cylindrical wall of the drum is wholly or partially perforated for screening flashes or nippings, which fall through shoot 19 into sack 20. The drum is mounted in a framework 21 carried by trunnions 22 in a fixed frame 22a, the drum being tilted at predetermined intervals to discharge nails through its delivery outlet 17. One trunnion 22 carries a quadrant 23 fixed to the frame 22a and engaged by a worm 23a on shaft 24 driven by forward and reverse gear trains 25, 26 controlled by clutches 27, 28 in turn controlled by solenoids 29; a clutch knock-off mechanism 30 is provided. The drum may be constructed, mounted and controlled as described in Specification 649,837. The nails fall into a bag 33 carried by weighing means 34. The shoot 14 runs on stationary horizontal side rails 35 and has a pair of guide rolls 36 on each side engaging a guide track 37 carried by the drum framework 21 so that the shoot is caused to move away from the drum as the latter tilts. Cleaning and/or polishing medium, e.g. sawdust, escaping from the drum through the perforations is drawn into a duct 38 and passed back into the drum by a fan 39 driven by an electric motor. The arrangement may be such that sawdust is circulated back into the drum to within a given time before the drum is to be tilted; this allows all the sawdust to be screened from the drum before it tilts. At intervals the sawdust may be byepassed to waste and clean sawdust passed into the drum; this change-over may take place autcmatically. Instead of weighing the nails passing to the hopper, time control means may be used to feed batches of nails to the hopper. As the weight of finished nails may be below the required load in a bag or receptacle, nail feed means may be controlled to feed extra finished nails to said load until stopped automatically by the weighing means through an electric or mechanical control device. Electrical control means may control the rest of the apparatus so that should any one part cease to function correctly, or a filled bag of nails not be removed, either the apparatus as a whole or a particular part of parts thereof will be rendered inoperative. The rumbling drum, elevators and nail presses are started through contactors by switch means which can be maintained by a switch interlock and overload, no current and broken wire shut down switches may be employed. In a modification, the conveyer bands, which take the nails from the presses or forming machines to the hopper, are of mesh or perforated to form screens throughout their length or where receptacles are mounted. Flashes, nippings &c. fall through the bands and are caught by shoots to be collected in receptacles. To assist the removal of the nippings the bands may be vibrated or joggled at one or more places, or led through paths which impart tumbling action to the nails. The screens in the wall of the tumbling drum may be omitted. In a further modification, Fig. 4, the receptacle 43 is vibrated or joggled to discharge flashes, nippings &c. through a screen 44. The receptacle can be vibrated bodily, or with a joggling motion about its delivery end by eccentrics (or cams) 45 on a shaft 46 driven by motor 18; the receptacle is mounted in a tilting frame 47. In a further modification, nails are delivered into an inclined rumbling drum-screen which is rotated about its own axis for separating the flashes, nippings and any other surplus material from the nails; the nails are discharged with a rumbling drum which can be tilted at predetermined intervals for discharging finished nails. The drum need not have a screen or screens; the wall or end may however be perforated to ensure the separation of all flashes, nippings or sawdust from the nails.