GB491666A - Improvements relating to internal grinding machines - Google Patents

Abstract

491,666. Internal - grinding machines. CHURCHILL MACHINE TOOL CO., Ltd., and ASBRIDGE, H. H. April 1, 1937, No. 9274. [Class 60] In an internal - grinding machine wherein the work head a, Fig. 1, is reciprocated and the grinding head f is given a cross-feed, a work gauge g, carried by a spindle h, secured to a cross-head i slidable on bars k on the head a, is held away from the workpiece d by a spring- loaded plunger r acting on the cross-head until the grinding operation is approaching completion, whereupon a cam 12 on the feed spindle 9 closes contacts 14, 15 so as to energize a solenoid s which retracts the plunger r and allows a spring p to move the gauge up to the work. An adjustable stop 4 coacts with the cross-head i to prevent contact of the gauge with the grinding- wheel e. The stop is constituted by a lever pivoted to the machine bed, movement of the lever towards the head a being limited by an adjustable screw while the lever can move freely in the other direction. The head a is reciprocated by an oscillating frame v. The feed of the table f carrying the grinding head is produced by a cam 8, Figs. 3 and 4, on the spindle 9 engaging a lug 7 depending from a slide 6 movable in an inclined recess 23 in the table, the lug being maintained in engagement with the cam by a balance weight 10 acting on the table. When the gauge g enters the workpiece, contacts m and n, on the crosshead i and head a respectively, close, causing energization of a solenoid o. The armature 16, Fig. 4, of the latter is thereby moved to the left, and, through a lever 17, the slide 6 is moved in the direction of the arrow 22, whereby the grinding-wheel is retracted radially from contact with the workpiece. Specification 424,261 is referred to.