GB553792A - Improvements relating to machines for grinding metal - Google Patents

Abstract

553,792. Gear-cutting. GILSON & CO., Ltd., D., and BANNISTER, E. Nov. 29, 1941, No. 15401. [Class 83 (iii)] [Also in Group XXIII] The leading faces 110 of the lands of a button-type screwing-die 82, or the internal teeth of annular gear-wheels, are ground in succession by turning the work holder 86 through a predetermined angle about its vertical axis while moving a tracer point 42 along a pattern 53 to cause a rotating grinding pencil 28 mounted by an adjustable bracket 79a, on a link 18 in a pantograph-mechanism to follow the desired curve. The die 82 is formed with a peripheral recess engaged by a tongue 83 on the work holder 80 and is clamped in position by a tubular member 115. The holder 80 carries a ring 101 formed with equally spaced recesses 102 corresponding in number to the number of lands or teeth. The recesses 102 are engaged in turn by a retaining tooth 104 on a spring-controlled lever 105 at the commencement of each grinding operation. The holder can be rotated in its mounting 85 by a one-way clutch comprising vertical rollers 87 mounted in wedgeshaped recesses 88 in the holder 80 and engaging a ring 86 formed with teeth engaged by a worm 92 on a spindle carrying a crank handle 94 which is movable between adjustable stops 100 on a disc 132. The mounting 85 is carried in a frame fixed to vertical pillars 56 ... 58, sliding in guides on the machine casting, the pillars 56, 57 being fitted at their lower ends with adjustable tappets 59, 60 engaging rollers 65, 66 on pivoted arms 67 engaged by cams 70 on a shaft 7. The shaft 7 may be turned to reciprocate the work holder vertically on the movement of a clutch member 8 into engagement with a hand wheel 9 or a sleeve 6 carrying an electrically driven worm-wheel 5. The clutch member 8 is operated by the transverse movements of a control lever 10 which, when rocked, operates a valve 13 to admit compressed air through a pipe 15 to a bladed wheel 26 rotating the grinding pencil spindle 27. The exhaust air passes upwardly through the spindle casing 17 and blows away any dust caused by grinding. The pantograph mechanism consists of two pairs of parallel links 18, 30 ... 32, hinged together at their comers, the link 18 which is formed with a slide 19 to receive the bracket 17a being hinged to the link 31 about a pivot 33 which is offset from the main fulcrum 34. The links 18, 30 are steadied by auxiliary links 41, 36, 37. The tracer point 42 is adjustably secured to a rod 44 rigidly fixed to the link 32. Chucks.-The work 82, Fig. 7, is clamped on a flange 81 of the rotatable work-holder 80 by a sleeve 115 having peripheral projections 116 which pass axially through slots 117 in a bush 114 attached to the holder 80, and on rotation of the sleeve by handles 118 the projections 116 pass under cams 119 in the bush to clamp the work. Annular adaptors may be used to surround work which is smaller than the bore of the holder 80.