GB1440851A - Apparatus for operating on a workpiece having a reference surface - Google Patents

Abstract

1440851 Grinding WARNER & SWASEY CO 25 Jan 1974 [28 March 1973] 03620/74 Heading B3D An apparatus for operating on a workpiece 28 having a reference surface 52 comprises means for effecting operation of a support means 24, 26 to move the workpiece relative to a tool 34, such as a grinding wheel, in the work area 30, and sensor means 60 for detecting when the reference surface is in a predetermined position in the work area, the sensor means having a probe member 74 movable between an inactive condition and an active condition, motor means 98 for moving the probe member between the active and inactive conditions and having operating and non-operating conditions, and connection means 106 for yieldably interconnecting the probe member and motor means for enabling the probe member to move relative to the motor means when the probe member is in the active condition and the motor means is in the non- operating condition. As described, the apparatus is incorporated in a grinding machine in which the workpiece 28 is located between a headstock 24 and tailstock 26 for grinding by a wheel 34. The spindle 40 of the headstock is axially movable (to the left in Fig. 1) by a screw 190 rotated by a pinion 188 engaged by a rack movable by a hydraulic motor 182 of a mechanism 56, the tailstock spindle 46 being acted upon by a spring 48 so that the workpiece follows the axial movement of the spindle 40 until the reference surface 52 is in the predetermined position as determined by rotation of the probe member 74 about an axis 86 to operate a switch 64. The probe member 74 has opposite surfaces 76, 78 for engaging right or left reference surfaces 52, 70, respectively, and is secured to an axle 84 and actuator arm 82, the axle being supported in a slide 88 adjustable along a guideway 90. The actuator arm is located between a pair of identical springs 110, 112 which are disposed between washers 117 on a rod 116 of a piston 118 of the motor means 98. When a right reference surface 52 is to be located in a predetermined position, the motor 98 is positioned as shown in Fig. 5 so that the springs 110, 112 hold the probe initially in an inactive position. The motor is operated to move the probe to the active position shown in Fig. 6 and as the surface 52, is moved to the left by the mechanism 56 the probe rocks the axle until the arm 82 actuates the switch 64 to prevent further axial movement of the workpiece, the movement of the arm 82 being against the action of the spring 112. Similar action occurs during location of the left reference surface 70, the arm 82 acting against the spring 110. The motor 98 is controlled by a valve 126 to move the probe to inactive positions in one direction or the other according to which reference surface is to be positioned. The apparatus may be controlled so as to sequentially locate a right reference surface on a first workpiece and thereafter a left reference surface on a second workpiece.