GB1246466A - Sizing device - Google Patents

Abstract

1,246,466. Grinding. TOYODA KOKI K.K. 4 Dec., 1968 [15 Dec., 1967; 4 Nov., 1968], No. 57615/68. Heading B3D. [Also in Division G1] A sizing device for monitoring the section of a workpiece W, e.g. during numerically controlled grinding, comprises one or more feelers 3, Fig. 1, supported by a sizing head 1 for engagement with the workpiece W, and displaceable as the workpiece diameter changes, a detector A responding to the feeler displacement to actuate a switch in a control circuit (45), Fig. 8 (not shown) on reaching a set feeler displacement, and means 6-18 for positioning the feeler 3 and displacement detector A relative to the axis of the workpiece W so that the switch may be actuated when the workpiece W has been ground to a required diameter. In a first embodiment, Fig. 1, a main supporter 9 is positionable relative to the workpiece W by means of a piston/cylinder arrangement 21, 22, and mounts the sizing head 1 by way of a spring 10, a transducer G governed by the spring deflection providing a control signal to limit the pressure of the head 1 against the workpiece W. The detector A bearing the feeler 3 may be positioned axially of the head 1 by a motor 13 acting through a differential nut 7 on a screwed rod attached to a displacement detector support 4, a spring 8 preventing backlash of the' nut 7, while a spherical coupling member 18 allows for floating of the sizing head 1 on the spring 10. The detector A comprises an iron core 24 attached to the feeler 3 and movable within a transformer 23 against a spring 25 to produce a variation in transformer output which actuates the control circuit switch on reaching a preset value to halt advance of a grinding wheel 50. To set the device to a required workpiece radius R 1 , the control circuit (45) is set to stop the grinding wheel advance at a specific output signal of the detector A corresponding to a master radius R 0 , the device then being adjusted to R 1 by moving the feeler through an increment R 1 -R 0 by means of the motor 13. In an alternative embodiment, Fig. 4, a sizing head 83 is pivoted on a pin 87 to an adjustable bracket 86, and supports two feelers 108, 109 of which the latter is connected to a displacement detector 118. The feeler spacing is adjustable by means of a motor 105 which drives a rod 97 through a gear train 98-104, alternate gears 98, 101, 103 being of compound form, Fig. 7 (not shown), to prevent backlash. Opposite-handed screw portions 97R, 97L of the rod 97 co-operate with threaded members 116, 117 attached to supports 110, 111 on which the feelers 108, 109 are adjustably locked to shift the feelers through opposed vertical increments. In a further embodiment, Figs. 2-3 (not shown), on alternative arrangement of vertically adjustable feelers is employed, and the application of the sizing device to a grinding operation numerically controlled by a programme tape is outlined with reference to Fig. 8 (not shown).