GB474542A - Improvements in and relating to truing apparatus for abrasive wheels - Google Patents

Abstract

474,542. Trueing grinding-wheels. NORTON CO. Sept. 19, 1936, No. 25554. Convention date, Sept. 28, 1935. [Class 60] In a lapping-machine comprising opposed rotating laps 12, 13, the flat operative faces of the laps are trued separately, or simultaneously, by diamonds carried by an arm 54 which is swung across the laps. The laps are carried by a column 36 and are rotated by belting 41 and gearing 22 from a shaft 16, the upper lap being adjustable vertically by rack gearing 181, 182. The trueing mechanism comprises a shaft 50 rotatably mounted in bearings 51, 52 in a bracket 53 mounted on the column 36, and the shaft is located vertically by thrust collars 75, 77. The arm 54 is adjustably mounted on the shaft 50 by means of a slotted head 55 provided on the arm, and tightening screws 57, 58, and the head is located by an adjustable split collar 70 clamped on the shaft by a screw. The outer end of the arm has a head 80 in which are mounted two diamonds 81, 82 carried respectively by spindles 83, 95 adjustable by screws 86, 98 and locked in adjusted position by screws 107, 110. In order to swing the arm 54 across the laps, a hydraulic cylinder 120 is provided, pivoted at 121 to a bracket 122 on the column 36 and having therein a piston 123 which, through a rod 124, link 126, and arm 129 secured to the shaft 50, serves to oscillate the arm 54. The fluid is supplied to the cylinder from a reservoir 115 by a pump 116, and the movements of the piston are controlled by a valve 134 having three pistons 138.. 140 carried by a rod 141 moved by a knob 150, which is used to move the valve endwise to reverse the movement of the piston, and to rotate the valve to control the speed of movement by throttling both the inlet and exhaust. The throttling is produced by forming in the pistons 138, 140 four grooves 160, which, by rotation of the knob 150, are brought more or less into register with holes 159 in a sleeve 161 in the valve casing ; the valve is locked temporarily in its adjusted position by a spring plunger 156 which engages serrations 155 on the rod 141. When the two laps are to be trued simultaneously, a modified mounting for the diamond tools 81, 82 is employed as shown in Fig. 9. The tools are mounted in coaxial holders 193, 194, the holder 194 having a screwed extension 195 screwing into the holder 193, and the holders being rotatable by spiral gearing 205, 207 and 206, 208. By manipulation of the gears and clamping bushes 201 for the holders, either diamond may be adjusted.