Patent GB-567267-A (GB)
Title: An improved apparatus for slotting self-locking or "stiff" nuts
IPC: B23G9/00
Filed: 1943-07-09
Abstract: 567,267. Making self-locking nuts. DUNDAS, Ltd., R. K., KING, R. D., and WOOD, N. F. July 9, 1943, No. 11168. [Classes 83 (ii), 83 (iii) and 83 (iv)] In a machine for making slotted self-locking nuts of the character described in Specification 561,286, nuts are supplied singly from a vertical stack to holders attached to a chain which conveys them past one or more saws inclined to the path of the nuts so that a slot or slots are formed progressively transversely to the axes of the nuts, the latter then being carried by the chain under a roller which deforms them and are finally ejected from the holders. The chain 3 passing over sprockets 4, 5, of which 4 is driven by an electric motor 73 through a variable reduction gear 74, has links with upstanding portions 54, Fig. 3, on which the holders 2 are pivoted. Each holder has a hexagonal recess r for a nut formed in an upper flange 2a which rests on two longitudinal guide plates 8. The nuts are stacked in a tube 14 of hexagonal section and are pressed downwards by a rod 56 carrying a weight 57 acting through a spring 58 so as to press the lowest nut against dogs 19, Figs. 3 and 5, carried by springs 20 secured to the machine bed. As each holder 2 approaches the shoot its forward pointed end separates the dogs 19 and allows the lowest nut to rest on the top of the holder until it drops into the recess r. A cover-plate 26, pivoted to the holder at 27, then engages a fixed stop 28 and is rotated to cover the nut and position it at the bottom of the recess as it is carried between the saws 6, Fig. 7, which are vertically movable on pivots at the front end and are tensioned by springs 12 at the rear end. The saws are guided vertically by slots 2b in the holders 2 and are backed by inclined members 13 laterally adjustable in the machine frame by screws 53 and locked by studs 50 and slotted holes 52. A single saw may be used for cutting a slot at one side only, or a succession of progressively acting cutters may be used at one or both sides. After leaving the saws, each holder passes under a roller 7 which depresses a loose pin 29 in the cover-plate 26 to deform the nut against the base of its recess. The roller is mounted in bearings 67 pressed upwardly in fixed supports 68 by springs 69 and adjusted vertically by screws 70 acting through rubber blocks 71. The cover-plate 26 is then swung aside by a fixed stop 32 engaging the pin 29 and a spring 39 on the machine frame is depressed by the holder until a recess in the bottom of the holder allows it to shoot upwards and strike a member 36, Fig. 3, in a transverse aperture 35 in the holder. The member 36 carries a pin 33 lying in a hole at the bottom of the nut recess r which is thus shot upwards to eject the finished nut from the holder. Turrets.-Several vertical shoots 14 for holding blanks are carried by spiders 16, 17 pivoted on a pillar 18 attached to the machine frame and are indexed so that one shoot will extend over the line of travel of the chain 3 to deliver blanks to the holders 2 whilst the other shoots are filled by hand. A spring- pressed bolt 22 on a stationary arm 65 engages one of a number of recesses 21 in the spider 17 to index it, and for rotation of the spiders to replace an empty shoot at the working position by a full one a nut 24 is released by hand to allow a spring 23 on the pillar 18 to raise the spiders until the lower one 17 engages a shoulder 18<1> on the pillar and the recess 21 is almost clear of the bolt 22. The spiders may then be rotated by hand until the bolt 22 snaps into the next recess and the nut 24 is then tightened. The nuts are retained in each shoot by a stirrup 15, Fig. 4, pivoted thereon at 59 and having a portion 15<1> to support the lowest nut when in a vertical position, the stirrup being swung to the release position shown when in the delivery position. The stirrup is maintained in the released or operative positions by a spring 60 having a toggle action. Cuttings, catching and removing.-Cuttings are removed from the work-holding recess r as each holder 2 approaches the feeding shoot 14 by means of a pulse of compressed air delivered automatically by a pipe 41, Fig. 1B, under which the holders pass in succession. Beds and framings.-All parts of the machine are attached to an H-section beam having outside vertical flanges 42 and a horizontal web 43 which is cut away at the ends to accommodate the sprockets 4, 5. The Provisional Specification refers to Specification 551,534, [Group XXV].