Patent GB-1041139-A (GB)
Title: Screw thread forming machine
IPC: B23G1/18
Filed: 1964-11-10
Abstract: 1,041,139. Tapping machine making tap drive and work guide. MAC LEAN-FOGG LOCK NUT CO. Nov. 10, 1964 [April 1, 1964], No. 45749/64. Headings B3A and B3N. [Also in Division F2] A continuous operating tapping machine 25 for tapping nuts comprises a rotary tap 26, work feeding rollers 30, 32, 33, a rotary housing 38 which carries a cranked portion 37 of the stem 36 of the tap to rotate the latter, and an electric motor 34, which rotates the housing 38 through a chain and sprocket drive 43-45, and rotates the rollers 30, 32, 33 through a gear chain 46. The means for guiding the nuts when passing along the tap, and also for driving the tap comprises a pair of hinged blocks 63, 64, Fig. 8 (not shown), which is carried in a slot 60 in the cylindrical shell 58 of housing 38, and secured to the blocks by pins 79, Fig. 5 (not shown), are segmental plates 76-78, each of which is formed with a half hexagonal, square, octagonal, or circular opening 80. The tap, along with the complete guiding means, can be removed from housing 38 by moving a handle 85 axially against springs 98, 99, to disconnect the end plate from the housing. Housing 38 is supported for rotation by a bearing 128 at its inner end, and by three bearings 137, 138, 139, Fig. 6 (not shown), which are radially adjustable. The inner end of housing 38 has a bore 162 Fig. 9 (not shown), through which the finished workpieees pass, and they are oriented to pass into hexagonal opening 80, by keys 165. Each of the feed rollers 30, 32, 33, Figs. 13, 14 (not shown), has helical convolutions 182 on its periphery for moving the nut blanks axially as the rollers rotate, and the rollers are mounted on crank type supports 192-194. Support 192 can be pivoted about a screw 220a for removal of faulty workpieces &c. by an air cylinder 245 Fig. 13 (not shown), and this movement pivots support 193 about a screw 220b due to lever 238, and pivots support 194 about screw 220 due to teeth 235, 236. Each support 192-194, along with its roller can also be moved axially when an abnormal force is exerted on the convolutions 182 by a defective workpiece. The motor 35 can be stopped when the feed rollers are moved axially, or when they are pivoted, by micro switches 252, 253, Fig. 5 (not shown). In operation, nut blanks 183 are fed from a hopper 27, Fig. 2 (not shown), along a wire 29, Fig. 4 (not shown), through a housing 28, and up to the tap 26. The rotary speed of rollers 30, 32, 33 is such that the blanks move along the tap at the required feed rate to suit the tap pitch. Lower rollers 32, 33 separate the blanks until they are engaged by the ribs of roller 30, whereupon the nuts pass through housing 38 and off the discharge end 39 of the tap. Liquid coolant is supplied by a nozzle 47. Making metal articles.-Segmental work guiding and tap driving plates 76, 77, 78 in a tapping machine, Figs. 22, 5 (not shown), are produced by turning a groove in the form of a half hexagon in a plate 292, cutting out the parts 76-78, and placing edges 294b and 295a, and also edges 295b and 294a together. The parts are then pinned to plates 63, 64, and two sets of such plates form aperture 80, Fig. 8 (not shown).