GB891186A - Hone dressing apparatus - Google Patents

Abstract

891,186. Dressing gear hones. NATIONAL BROACH & MACHINE CO. Sept. 30, 1960 [Dec. 21, 1959], No. 33721/60. Class 60. Gear-like honing tools of hard but resilient resin material having abrasive material embedded in at least their working surfaces are renovated by having material removed from the teeth crests by a grinding tool comprising diamond particles embedded in a substantially rigid matrix. In a knee-type machine 10, Fig. 1, adapted for this purpose the honing tool T is motor-driven above a table 30 pivoted at 32 and provided with transversely adjustable supports 36 for the centres 38 between which the gear to be honed or the hone renovating tool is carried; a piston 40 is hydraulically operated to apply pressure to the element in contact with the hone T. The table 30 may be locked after adjustment. The hone-grinding tool 70 is a flat disc mounted on a stem 72, Fig. 3, which is carried in a support 50 having a downwardly extending member 56 to prevent rotation of the support on the centres 38. The disc 70 is of greater diameter than the width of the hone face and it preferably consists of 20/80 grit size diamonds embedded in a matrix of tungsten carbide base powder and a metal alloy, e.g. silver solder. In a modification, Fig. 5, the dressing tool 88 may be both raised towards the hone and rotated about its axis during the dressing operation by means of a manually rotatable shaft 100 and irreversible worm gear 94, 102, the stem 82 of the tool being fine-threaded at its upper end and splined to engage with the gear 94 so that rotation of the latter ensures even wear over the surface of the disc and provides a fine feed simultaneously. The disc may comprise concentric zones of graduated abrasive material, the inner having 20/40 diamond grit size, the intermediate 40/60 and the outer zone 60/80.