Patent GB-262039-A (GB)
IPC: B24B5/35
Abstract: 262,039. Detroit Machine Tool Co., (Assignees of Holmes, H. W.). Nov. 25, 1925, [Convention date]. Centreless grinding; spindle mountings; guides and rests.-In a centreless grinding-machine for grinding shouldered or flanged cylindrical work, the grinding-wheel is moved towards and from a regulating-wheel to allow of the automatic feeding of the work, to grind the work to size, and to allow discharge of the work from the machine. An automatic stop motion also may be employed to stop the machine after each piece of work has been ground to size. The machine consists of a slowly rotating regulating wheel 21 adjustably carried by a column 15 which is movable vertically by a screw 18 in the machine frame 10, the wheel-bearing member 23 being turnable about a pivot 24; the wheel is surrounded by a water pan 39. The grinding-wheel 12 is mounted on a shaft 11 carried by bearings 42, 55, Fig. 8, eccentrically placed in a trunnion 43, which is oscillated in the frame 10, to move the wheel to and from the work, by a cam 52 carried by a shaft 53 and levers 44, 46, a weight 54 keeping the gear in engagement. The cam 52 gives a quick lift to the grinding-wheel, then a slow descent, followed by a dwell, during which dwell the wheel is reciprocated axially to remove scratches from the work, the reciprocation being produced by a cam 65 having a rise which, through an arm 63, moves a yoke engaging a collar 60 on the shaft 11. The work W is located in position by an adjustable blade 31 and by a movable blade 74 carried by the work feeding means. This work feeding means comprises an arm 67 pivoted at 68 to the pan 39 and oscillated, through a rod 81 and levers 79, 76 carried by a shaft 77, by a cam 75 on the shaft 53. The arm carries a slidable tray 70 upon which a piece of work is fed from a magazine 85, the tray having a lug which engages fixed stops 71, 72 at the ends of its movements. When the lug engages the stop 72, the tray is withdrawn from under the work. which rolls on to the regulating wheel, the further movement of the arm 67 then bringing up the blade 74, which is spring pressed to locate the work. Upon completion of the grinding the arm 67 is retracted, and the work rolls off the regulating wheel, and upon further movement of the arm the lug on the tray engages the stop 71 to re-position the tray to receive a piece of work. The arm 67 carries a cam 87 which moves an arm 89 to carry fingers 90 thereon through an aperture in the magazine to retain the work therein after one piece has been deposited on the tray, and a ridge 91 engages the shoulder on the work to prevent endwise displacement thereof. The cam shaft 53 is driven through worm gearing 95, 97 from a shaft 96 driven by a pulley 99, which is clutched to the shaft by an automatically operated hand controlled clutch 107. The clutch is moved by a fork 117 carried by the shaft 77, and links 119 are pivoted to the fork and supported near the other end by a bell-crank lever 120, while at the ends the links have a pin slidable in a slot 123 in a rod 122 having thereon a projection 134. A cam 136 on the shaft 53 has a projection 135, which, when the rod 122 is lowered engages the projection 134 and moves the links 119, whereby the fork 117 uncouples the clutch, stopping the rotation of the camshaft 53. The rod 122 is raised or lowered by a hand lever 127 adapted to be locked in position by a plunger 130 and holes 131 in a plate 132; by raising the rod 122, the top of this engages the lever 120 to throw in the clutch; the machine then continues to operate automatically until the rod is lowered when the cam 136 stops the operation of the cam shaft. Cone pulleys 105, 106 are employed to obtain various speeds of operation of the machine.