Patent GB-167541-A (GB)
Title: Improvements in or relating to machines for trimming or truing stones and abrasive wheels
IPC: B24B53/02
Filed: 1920-05-03
Abstract: 167,541. Wade, H., (Norton Co.). May 3, 1920. No Patent granted (Sealing fee not paid). Shaping.-A grindstone or like trimming-machine, available for either taper or parallel-sided stones, is arranged to have an automatic increase of the length of the cutting-stroke in successive reciprocations. The feed-screw 67 is driven by a short shaft 74, which is rotated by an electromotor 66 through worm gearing 69 and reversing gearing 71. The clutch members 76, 77 are moved by arms 88 on a rock-shaft 90, which is operated by a rod 94 through a spring cylinder 93 and a spring-mounted lug 106. The rod 94 is connected to the cylinder 93 by loose collars 99, 100 held apart by a stiff spring 98, and is moved to actuate the clutch by a handle 110, connected to the rod 94 by rack-and-pinion gearing and springs, which return the handle to a central position when it is released. A rack 126 attached to the rod 94 carries an adjustable lug 128 which stops the tool as it moves to the left by means of a block 129 carried by the main slide 26. For stopping the tool as it moves to the right, a lug 131 is pivoted to a slide 130 on the rack 126, and can be locked to the rack by turning a cam 132 into the position shown in Fig. 1. A toothed segment 133 pivoted on the lug is thereby raised into engagement with the rack, the segment being locked between a nose 134 and a cross-pin 136 ordinarily placed in the lowest of a number of holes 137. A fine adjustment for the main slide comprises a hand-operated worm 145 engaging a worm-wheel 146 carried by the driving-nut on the feed-screw 67. The machine may be set either for hand control or for one of three automatic methods of working, namely; reversal of the tool carriage at the left-hand end of its travel and stoppage at the right-hand end; reversal at the right-hand end and stoppage at the left-hand end; or reversal at each end until stopped by the rotation of the rod 94, which passes through a latch plate 163 pressed down by springs 170 so as to coact with notches 174 in a fixed part 176. When the machine is under hand control only, by means of the handle 110, the plate is in the position shown in Fig. 9, its lower edge being clear of the ridge 173 between the two notches. By turning the rod 94 more or less on its axis by means of a handle 187, one or other of three cams 179, 180, 181 is brought uppermost and determines which of the three methods is employed by permitting the lower edge of the plate to co-operate with the notches 174 and bringing the spring connection 98, 99, 100 into action. When taper-sided wheels are being acted upon by the tool, the table 27 can be angularly adjusted by a partial rotation on a stud 160, which can itself occupy one of three different positions in a slot, whilst the further end of the table is locked by a bolt 163. The length of the traverse of the tool can also be caused to increase as the work proceeds by changing the pin 136 from the lowest of the holes 137 to one of the others. A certain amount of rotation of the segment 133 then takes place at each reversal, allowing a corresponding movement of the slide 130 before it is locked to the rack, the segment 133 being constantly returned to the position shown by a spring 200. A dust-collecting passage 51 is arranged in the casing with openings in its inner wall through which the dust is sucked by the usual exhaust fan. Larger chips fall into the space 58 and are shovelled out through an opening 59. Cloth sleeves 121 are arranged to keep dust from the bearings of the rod 94.