GB1098730A - An improved grinding machine - Google Patents

Abstract

1,098,730. Grinding. H. M. HOBSON Ltd. Dec. 21, 1966 [Nov. 5, 1965], No. 47052/65. Heading B3D. [Also in Division B8] A machine for grinding fuel cans 14 having ribs 14A for nuclear fuel elements comprises a profiled grinding wheel 10, Fig. 2, a workpiece carrier 12 for mounting a workpiece 14 with its axis extending parallel to that of the grinding wheel, mechanism 18 for rocking the carrier in relation to a support member 13 about an axis parallel to the axis of rotation of the grinding wheel and so traversing the workpiece past the grinding wheel in an arcuate path, mechanism for rotating the grinding wheel and workpiece in the same direction, and mechanism 19 for rapidly approaching the support member towards the grinding wheel preparatory to grinding to a position determined by an adjustable stop 20 and afterwards retracting it. The grinding wheel 10 is belt driven from an electric motor 11. The workpieces are succes sively fed from a shoot 50 and held between workheads 26 which are rotated by belts 15, Fig. 3, from a shaft 25 driven by a belt 2 from an electric motor 17, the workheads being mounted in the carrier 12 which is mounted on trunnions 120 on the support 13. The support is advanced by a pair of air motors 19 but is guided at one end only by a tongue 95 and slot 96, the extent of the movement of the ends of the support being determined by stops 20. The workheads are provided with spigots 32 for engaging the inside of the tubular workpieces and are connected by right- and left-handed portions of a shaft 28 to an air motor 29 for movement towards and away from each other to engage the workpiece, the movement towards each other first being at a fast pace until a switch SW4 is actuated, and then at a slow pace until a stop is engaged. Each workhead has a collet 33 which is movable by a piston for gripping the workpiece. In order to form the thin lands 14A on the workpiece by the profiled grinding wheel, the workpiece is reciprocated during grinding, a toothed belt 88, driven from the shaft 25 rotating through gearing a cam 39, Fig. 10, on a shaft 40, coupled to the shaft 28 carrying the workheads 26. The cam engages an adjustably fixed ball 42 which determines both the position and degree of reciprocation. A steady supports the workpieee during grinding and has two fixed lower jaws 44, Fig. 14, which support the complete length of the workpiece, and two upper jaws 45 movable by motors 118, the upper jaws being connected to quadrants 125 engaging racks 122 on the rods of pistons 123. The rocking of the carrier 12 to traverse the workpiece in an upward direction past the grinding wheel is effected by the motors 18, Fig. 2, which abut a roller 135 on the carrier and are supplied with fluid from a pipe 134, Fig. 15, connected to a cylinder 49 having a piston 132 which is moved by engagement of a follower 131 with a cam 48 rotated by reduction gearing from an electric motor 47. The rate of movement of the carrier is decreased as the wall of the workpiece gets thinner. The return movement of the carrier downwardly is effected by gravity. The workpieces are automatically loaded and unloaded by movement of arms 52, Figs. 16 and 17, which carry the workpieces in succession from a shoot 50 and deposit them between the workheads 26 and, after grinding, to a tray 79. The arms are movable about the axis of a shaft 71 rotated by a quadrant 69 rocked by an air motor 67 provided with an oil damper 68 having adjustable needle valves 137. A cam 72 is mounted on shaft 71 and actuates a rod 73 connected to a lever 74 which moves the shoot 50 from a stop 51 to allow a bottom workpiece to fall into sockets 53 in the arms 52 on their return stroke and actuates a valve V3 controlling a motor 77 for rocking the tray 79 so that a finished workpiece in the sockets 53 is lifted therefrom and rolls to a collection receptacle. A circuit is described which controls the machine so that all the operations are controlled automatically.