Patent GB-829364-A (GB)
Title: Improvements in and relating to grinding machines
Inventor: MALUGANI GEORGE
IPC: B24B47/06
Filed: 1957-02-13
Abstract: 829,364. Grinding. HOBSON Ltd., H. M. March 7, 1958 [Feb. 13, 1957], No. 4925/57.. Class 60. A method of grinding a profile on a cylindrical workpiece 17 comprises effecting relative rectilinear movement between the workpiece and a crush formed grinding wheel 12, both of which are rotating in the same direction but at different peripheral speeds about parallel axes normal to the direction of relative motion, so that the workpiece and wheel meet tangentially and separate after the workpiece has been ground to a pre-set depth. The grinding wheel is crush formed by a method comprising replacing the workpiece with a crush roller which is then rotated in order to drive the grinding wheel when in contact therewith, the relative movement between the roller and grinding wheel being similar to that required for grinding the workpiece. In a machine for carrying out the methods, the grinding wheel, which is belt-driven from an electric motor 13, is mounted on a slide 11 reciprocably mounted on a base 10 by a hydraulic jack 20. The workpiece or crushing roller 17 is also belt-driven from an electric motor 18 and mounted on a slide 16 vertically adjustable on an upstanding member 15 on the base 10. When the machine is used for grinding, the slide 16 is adjusted so that the workpiece is positioned so that the lowest portion of its finished size will be in the same horizontal plane as the uppermost portion of the periphery of the grinding wheel. The wheel is fed towards the workpiece manually or by operation of a reversing valve 22 which supplies pressure fluid to the left-hand end of the jack 20 ; the fluid from the other end of the jack is unrestricted until shortly before grinding commences, the movement of the slide 11 causes a cam 33 to actuate a valve 31 and the fluid to be by-passed through a restricted control orifice 35 and thereby reduce the rate of feed of the grinding wheel until the workpiece has been ground to the required diameter and the grinding wheel has moved past the workpiece. The rate of feed may be adjusted so as to increase as the depth of cut increases by a wedgeshaped cam operating a hydraulic bleed circuit. After the wheel has moved past the workpiece, the reversing valve 22 is operated to supply fluid to the right-hand end of the jack 20 through a valve 36 which permits a rapid return of the slide 11 to its initial position. A motor 26 is automatically controlled to maintain the fluid in accumulators 21 at a desired pressure. The workpiece is replaced by the crushing roller in order to crush from the grinding wheel and its height is set in a similar manner to that of the workpiece. The drive to the grinding wheel is disconnected so that when the wheel is fed into contact with the crushing roller it is driven by contact therewith ; the rate of feed during crush forming may be reduced by adjustment of the control orifice 35. The grinding wheel is arranged so as to be replaceable with others of different profile by removing bolts 39, Fig. 4, which connect the wheel and its arbor 37 to a supporting member 38 on the grinding wheel shaft 40 and by removing the upper portions 43 of the shaft housing 42 to enable the shaft and its bearings 136 to be removed therefrom. In an alternative embodiment, the grinding wheel is mounted on a vertical slide and the crusher or workpiece on a horizontal slide.