GB227902A - Improvements in grinding machines - Google Patents

Abstract

227,902. Kessel, H. Oct. 20, 1923. Hollow-grinding razor and like blades; cutting-edges shaping and treating; wheels. - In a grinding- machine, more particularly for grinding knife blades, of the kind in which the work-piece is carried in a holder slidable between a pair of grinding-wheels set at an angle to one another and adjustable horizontally, the wheels 16 have rounded grinding-faces and are carried in bearing members 15 mounted on horizontal axes or pivots 14 so as to be rocked both towards or away from the work; work-pieces can thus be ground with straight or convex or straight and convex sides. The pivots 14 are carried by intermediate plates 9 pivoted at 8 to main plates 3 which are pivoted at 2 to the machine bed and carry adjustable screws 5 contacting with a verticallyadjustable cone 7 by which the horizontal adjustment of the wheels is obtained. The bearing members 15 are balanced by tension springs 17 and rest on the ends of vertical rods 18 supported by horizontal levers 19 resting at their free ends on arms 20 carried by an horizontal shaft 21. The length or leverage of the arms 20 can be varied and a lever 24, which has a forked end pivotally engaging a projection in the shaft 21, can be moved by a handle 25 to place its free end in contact with any one of a series of cams 23 in the driving shaft 22, to vary the extent of the flat surface to be produced. To produce a convex surface, or a flat and a convex surface, the wheels are rocked about the pivots 2 in synchronism with the rocking about the pivot 14 by moving a lever 6 connected to the cone 7. To produce a longitudinal taper in the blade, the wheels are also rocked by moving the intermediate plates 9 on their pivots 8 by means of a treadle 11 connected by cords 12 to the plates; the grinding-faces of the wheels are curved about the pivots 8 as centres. A work-holder for a pair of blades, one side of each of which can be ground simultaneously, comprises a pair of blades 33 connected by springs 34 with bolts 35 carrying a pivoted traversing lever 32. The holder, with the work-pieces held against the outsides of the blades 33 in any suitable manner, is guided on a rail 31 and the blades 33 are forced apart by a tongue 36 to press the work-pieces against the grinding-wheels; a lateral grinding- arrangement comprising adjustable rods 38 carried by the blade 33 and contacting with adjustable inclined guide-rails 40, may be used to twist the blades 33 and give the longitudinal taper to the work-pieces, the blades being held in their movement by guide rollers 37, a flange 44 on the tongue 36 and the bolts 35. The blades 33 may be slightly recessed at the place where the manufacturer's mark is stamped on the workpiece so that the pieces can give, a little to preserve the mark.