GB1334172A - Guard system for high speed grinding machines - Google Patents

Abstract

1334172 Grinding CINCINNATI MILACRON Inc 27 May 1971 [31 Aug 1970] 17408/71 Heading B3D [Also in Division F2] A guard system for a high speed grinding machine has a shield movable from a grinding position where it prevents grinding wheel fragments escaping upwards to a retracted position towards the wheel in its withdrawn workpiece changing position. A grinding wheel 14 is mounted on a slide for movement from a position, Fig. 3, engaging a workpiece 22 to a withdrawn position, Fig. 4, which allows access to the workpiece and protection is by a guard 15 having a plastic impact absorbing lining 16. A shield 26 is pivotally mounted at 31 and comprises a thick front plate 32 and sheet metal members 33 forming a chamber 34 to conduct coolant to the workpiece which also provides a liquid cushion. A second shield 60 is pivotable on arms 61 from a splash preventing working position, Fig. 3, to a position between the workpiece and the shield 26, Fig. 4, when the wheel 14 is withdrawn. The front is enclosed by a coolant shield 49 and a deflector 38 to provide protection if the workpiece is displaced by fragments of an exploding wheel 14. A circuit for the control of an automatic grinding cycle is shown, by which from the position of Fig. 4 a workpiece 22 is first clamped between head and tail stacks, the shield 60 is retracted to its splash preventing position, Fig. 3, the shield 26 is moved to its operative position by an hydraulic piston cylinder 28, 29, coolant is started and the wheel 14 is rapidly advanced to engage the workpiece. Grinding is controlled by a gauge head and upon indication that work is completed the parts are returned to the Fig. 4 position, the coolant stopped and the workpiece released. If the wheel 14 explodes in the Fig. 4 position it may force the shield 26 forward but the movement is stopped by catches 67 locking the shield 60 in position. If the pivots of the arms 61 shear, wedges continue to support them in the operative position. If an automatic workpiece replacement mechanism is used the shields 49, 60 and the deflector 38 are omitted and a wall of the guard is reduced in height to allow the operation of the mechanism.