GB485611A - Improvements in or relating to grinding machine table reciprocating mechanism - Google Patents

Abstract

485,611. Grinding-machines. NORTON CO. Nov. 22, 1937, No. 32084. Convention date, Nov. 20, 1936. [Class 60] The work-carrying table 16 of a grinding- machine is reciprocated by means of a rack 61 fixed thereto and engaged by a pinion 60 driven from a shaft 20 through reversing gearing controlled by a lever 77 operated by adjustable dogs S3 and 84 on the table, electrically-controlled means operated by the lever 77 being provided to effect an adjustable period of dwell at each end of the stroke. The lever 77 is journalled on a shaft 71 and is resiliently coupled to an arm 75 secured to the shaft 71, the latter being geared to a shaft 66 carrying a fork 65 actuating the double-ended slidable clutch member 26 of the reversing gearing. A roller 100, carried by a spring-pressed sleeve 102 telescoping within an arm 103 secured to the shaft 71, co-operates with a V-shaped fixed member 101 to tend to move the member 26 to either of its engaged positions. A spring- pressed latch 24, slidable in a fixed member, co-operates with the end of an extension 120 of the arm 75. A lever 130, pivoted about a fixed point 131, passes through an aperture in the latch 124 and is linked to the armature 139 of an electromagnet 140. When the table reaches either end of its stroke, contact of the appropriate table dog 83 or 84 with a pin 82 on the lever 77 causes the arm 75 to tilt, withdrawing the member 26 from its one position of engagement. The latch 124 engages the recess 121 in the end of the arm 120 and, when the roller 100 has passed just over the apex of the member 101, prevents further movement of the shaft 71, thus maintaining the member 26 in neutral position. During the tilting of the lever 77, however, an adjustable pin 148 thereon coacts with an arm 146 to close a switch 145, which latter sets into operation, an adjustable time delay relay 151, whereby, after the predetermined time interval, the magnet 140 is energized to retract the latch 124 and permit the member 26 to complete its movement to its other position of engagement. The pin 82 is carried by a block 80 slidable on the lever 77, so that the pin can be withdrawn from the path of the dogs 83 and 84 to permit an extended movement of the table.