GB572420A - Improvements in and relating to an apparatus for truing a grinding wheel intended for dressing high-pitch screw threads - Google Patents

Abstract

572,420. Trueing grinding-wheels. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. July 13, 1943, No. 11376. Convention date, Oct. 2, 1942. [Class 60] Apparatus for trueing a grinding- wheel for high-pitch screw threads comprises a rotating and sliding shaft the axis of which occupies the same position relative to the grinding-wheel as the axis of the work-piece and on which a diamond is mounted so as to slide parallel with the operative faces of the wheel, an adjustable supporting plane surface disposed transversely to the axes of the shaft, and a stopping device which moves along the supporting surface so that the diamond describes a portion of a helix corresponding to that part of the thread to be dressed which comes in contact with the grinding-wheel, the pitch of the helix being determined by the inclination of the supporting plane surface. The apparatus comprises a casing 77 mounted on the work-table of the grinding-machine with its axis XX in line with the axis of the work to be ground, the table being moved up to a stop to position the trueing diamond 2 opposite the grinding-wheel 1. The diamond is carried by a slider 5 movable axially in a turret 12 by a rack 8 cut on the slider and a pinion 9 rotated by handles on the ends of the pinion spindle ; the turret 12 is adjustable angularly to suit the wheel 1 in a bearing on a shaft 22 rotatable in a support 23 and fixable in two positions at 180 degrees by a spring pin 25 on the shaft and recesses 26 in the support 23, so that both sides of the wheel may be treated. The support 23 is adjustable by a screw 29 in a slideway 27 in an arm 28 to suit the diameter of the work to be ground, the arm 28 being secured on the end of a shaft 31 mounted in bearings 32, 33 in the casing 77 and pressed axially by a spring 34. The shaft 31 carries a gear 37 engaging a pinion 38 mounted on a spindle 39 supported at one end by a part 40 fixed to the casing and at the other end by a ring 41 secured to bosses 43, 44, 45, Fig. 4, on the part 40; the pinion engages a rack on a slider 47 guided in slides in bosses and has thereon forks 53, 54 and 55, 56 in which slide hubs 57, 571 carrying a shaft 58. The shaft can move in the forks under the action of ballbearings 60, 60<1> thereon or inclines 59, 59<1>, and the shaft also carries a ball-bearing 61 engaging the rectangular head 62 of a pin mounted in the shaft 31. The inclines 59, 59<1> are provided on a member 64 pivoted at 65 in the part 40 and adjustable angularly by a block 67 which engages the forked end of the member 64 and is adjustable by a screw 71 with a graduated head. A ring 74 is mounted on the casing 77 and is adjustable, by a screw 73 engaging a fixed surface, so that a roller 79 carried by an arm 80 on the ring and engaging a under rib 28<1> of the arm 28 can set the arm to an angle to the horizontal ; this angular movement is transmitted to the shaft 31 and through the gearing 37 &c. and inclines 59, 591 causes an axial movement of the shaft and all parts carried thereby depending on the angular setting of the inclines.