Patent GB-992446-A (GB)
Title: Improvements in or relating to work supporting arrangements for machine tools
IPC: B24B41/00
Filed: 1963-11-01
Abstract: 992,446. Grinding. SHEFFIELD CORPORATION. Nov. 1, 1963 [Nov. 5, 1962], No. 43284/63. Heading B3D. A machine tool comprises a worktable composed of two inclined supporting surfaces making a predetermined angle, e.g. a right angle, therebetween, a headstock and a tailstock adjustably supported and movable on the supporting surfaces of said work-table, a plurality of relatively spaced steadyrests adjustably supported and movable on the supporting surfaces of said work-table for supporting a workpiece in co-operation with said headstock and tailstock and means for providing air bearings between each co-operating supported and supporting surfaces for adjusting in a frictionless manner with adjustable part of the machine. The base 10 of a grinding machine has surfaces 11, 12 at an angle to each other supporting a work-table 13 having surfaces 20, 21 at an angle to each other supporting a headstock 22 and a tailstock 30 having centres 37, 37 for supporting a workpiece 29; the surfaces 20, 21 also support steadyrests 39. A grinding-wheel 38 is mounted on a carriage 47 mounted on the base 10 for transverse movement by a hand wheel 87. The supported surfaces of the work-table 13 have sets 62, 63, 66 of ports connected through adjustable regulators 64, 65, 67 with an air line 58. Air is admitted to the ports by actuating an on-off control 88, and the worktable is then positioned along the base by a rack-and-pinion 70, 69 actuated by a hand wheel 51. Accurate determination of the work-table position is effected by an optical device 75 mounted on the base. Air is then cut off and the work-table secured by a tee-bolt 19 extending through a tee-slot 71 in the base. The supported surfaces of the headstock 22 have sets 77, 78 of ports connected through adjustable regulator 79 with an air line 80. Normally, the headstock remains in the same position on the work-table. If it is desired to adjust it, air is admitted to the ports by actuating on-off control 60, the headstock is moved to the desired position, air is cut off and the headstock secured by a tee-bolt 27 extending through a tee-slot 28 in the work-table. The supported surfaces of the tailstock 30 have sets 72, 73 of ports connected through adjustable regulator 74 with an air line 76. Air is admitted to the ports by actuating on-off control 52, the tailstock is moved to the desired position, air is cut off and the tailstock secured by a tee-bolt 49 extending through the tee-slot 28. The supported surfaces of each steadyrest 29 have sets 81, 82 of ports connected through adjustable regulator 83 with an air line 84. Air is admitted to the ports by actuating on-off control 53, the steadyrest is moved to the desired position, air is cut off and the steadyrest secured by a tee-bolt 57 extending through the tee-slot 28. Each steadyrest has a worksupporting member 44 adjustably mounted to take the weight of a workpiece and a worksupporting member 45 adjustably mounted to oppose the force imposed by the grinding-wheel on the centres. The work-supporting members are readily replaceable to co-operate with workpieces of different sizes and shapes. Fluid, e.g. air, for adjusting the members 44, 45, is supplied through regulator 46 from line 85; on on-off control 61 is provided. In operation, the headstock 22 is firmly attached to one end of the work-table 13.. The workpiece 29, which may be large and massive, is lowered into position. The tailstock 30 is adjusted so that the ends of the workpiece are engaged by the centres 37. The work-table 13 is adjusted with respect to the grinding-wheel. The steadyrests 29 are adjusted, and the members 44, 45 actuated. The grinding-wheel is fed in and then retracted. The work-table 13 is readjusted with respect to the grinding-wheel, the cycle being repeated until the required form is ground on the workpiece.