Patent GB-355650-A (GB)
Title: Improvements in grinding or abrading machines
IPC: B24B47/06
Filed: 1930-02-25
Abstract: 355,650. Grinding crankshafts &c. NORTON CO., New Bond Street, Worcester, Massachusetts, U.S.A. Feb. 25, 1930, No. 6210. Convention date, April 8, 1929. [Class 60.] Disc apparatus; trueing rotating tools.-In a machine for grinding crankshafts &c., hydraulically operated mechanism is employed for feeding the wheel to, and for withdrawing it from the work and for traversing the work, each mechanism being under the control of a main control valve so that admission of fluid is allowed to operate one mechanism only at a time; means also are provided for changing from a rapid traversing speed for positioning the work to a slow uniform speed for trueing the wheel. The machine comprises a base 11 carrying on ways 13, 14 a work table 12, and on ways 17, 18 a transversely moveable grinding- wheel 16. The grinding-wheel 16 is fed towards and from the work by a piston 26 movable in a fixed cylinder 25 provided with inlets and pipes 48, 49, the flow of fluid to and from the ends of the cylinder being controlled by a reversing-valve 30 comprising pistons 31, 32 on a rod 33, which is movable by a lever 40, the fluid being admitted to the valve 30 by a conduit 35 ; the valve may occupy a neutral position with the supply of fluid cut off from the cylinder 25. The table is traversed in either direction by a piston 61 in a fixed cylinder 60, movement being controlled by a reversing-valve 65 similar to the valve 30 and operated by a lever 73, fluid being admitted to the valve by a pipe 69 ; the exhaust from the cylinders is led to a reservoir 54. In order that either the wheel feed or the table traverse only may be operated at one time, a main control valve 93 is provided, fed from a pump 97 and a pipe 99 and consisting of two pistons 94, 95 mounted on a rod 96 having a T slot connection 104, 105 with a lever 102 movable about and along a stud 103. The valve 93 opens either the conduit 35, or the pipe 69 to the fluid supply, and a further pipe 108 may be provided for supplying fluid to a third mechanism, for example a work rotating and clamping mechanism; an exhaust connection 109 to the valve is provided, and when the valve is in neutral position, fluid passes directly from the pipe 99 to the reservoir. In order to obtain a slow traverse of the table at a uniform speed for trueing the grinding-wheel, by means of a tool mounted on a table, a throttlevalve 115 is provided, having therein a piston 116 adapted to uncover, more or less, a V-shaped port 118 whereby the rate of flow of exhaust fluid from the valve 65 controlling the table traverse is varied, the fluid passing from the port 118 to a pipe 119 leading to the reservior. The stem 117 of the valve is normally pressed outwards by a spring 120 and is moved inwards by a bell-crank lever 130 operated by sliding the lever 102 along the stud 103, when in the outwards position 102a, which opens the valve 93, to engage an adjustable screw 131 in the lever 130. In order to permit of the adjustment of the grinding-wheel relatively to the fluid pressure feeding mechanism for setting up the machine or for compensation for wear of the wheel, the rod 27 carrying the piston 26 is connected to the wheel slide 15 through a screw 136 rotatably connected to the rod 27 and engaging a nut 135 depending from the slide, the screw being rotatable, through gearing 140, 141, by a hand wheel 138.