GB841916A - Surface grinding machine - Google Patents

Abstract

841,916. Grinding. BANKO, G. Dec. 24, 1957, No. 40021/57. Class 60. An attachment to a surface grinding machine for grinding a compound angle on a workpiece 34 comprises a sub-table 49 slidably mounted on the under side of a stationary table 15 which can be angularly adjusted about the axis of the surface grinder spindle 29 and about an axis perpendicular to the axis of the spindle, a grinding wheel 66, mounted together with a worm 64 and pulley 65 on an auxiliary spindle 62 journalled on the sub-table and connected by a belt 48 to the surface grinder spindle, and means for reciprocating the sub-table on the table 15 consisting of a connecting rod 55 pivotally connected to the stationary table and to a crank arm 53 carried by a shaft 57 journalled in the subtable and rotated by a worm-gear 59 engaging the worm on the auxiliary spindle. The table 15 is carried on a bracket 11 provided with a collar 12 which is rotatably-adjustable on the housing 67 of the spindle 29 and can be clamped in position by a bolt 14, the angular position of the table being determined by a scale 13 and index mark 35 on the column 31 of the machine. The table can also be pivotally adjusted relative to the bracket about a bolt 22, the axis of which is perpendicular to the axis of the spindle 29 ; bolts 18, 19 disposed in arcuate slots 16, 17 in the bracket secure the table in an angular position which can be determined by scales marked on the table cooperating with the sides 68 of the bracket. The sub-table 49 is slidably-mounted in guideways 23, 24 beneath the table 15 and carries, journalled in ball-bearings 63, the auxiliary spindle 62 on which are the grinding wheel 66, pulley 65 and worm 64. The worm cooperates with a worm gear 59 rotatably mounted on the shaft 57 which is disposed perpendicular to the upper face of the sub-table and carries the crank arm 53. A hand-operated nut 60 on the shaft 57 has a conical seating engaging the gear 59 to releasably-clamp the gear against a shoulder 58 on the shaft, the gear being released to stop the reciprocation of the table when it is desired to dress the grinding wheel. The crank arm 53 has a series of holes at different radial distances, any one of which can be engaged by a pin 56 on one end of the connecting rod, the other end of which is pivotally connected by a bolt 26 to the stationary table ; the length of reciprocation of the sub-table can thus be varied according to which of the holes in the crank arm is engaged by the pin 56. The auxiliary spindle is driven by the V-belt 48 from a pulley 36 mounted on the spindle 29 and constructed so that one side 42 of the V-groove is urged by a spring 44 towards the other side but can be axially displaced to permit the belt to engage the groove at different radial distances to accommodate the changes in the distance between the axes of the spindles during reciprocation of the table 49. The workpiece 34 is held by a vice 33 on the machine table 32 which is reciprocatable but held stationary while a compound angle is ground on the workpiece.