GB1292986A - Grinder and method of grinding - Google Patents

Abstract

1292986 Grinding MURRAY-WAY CORP & NORTON CO 10 Oct 1969 [13 Nov 1968] 50007/69 Heading B3D [Also in Division B8] A method of grinding a generally flat workpiece comprises passing the workpiece W, Fig. 1.1, along a predetermined pass line past an abrasive grinding device 12 to grind one substantially vertical surface of the workpiece, rotating the workpiece about a vertical axis whereby the opposite surface of the workpiece can be presented to the device 12, and grinding the opposite surface as the workpiece returns past the device. In apparatus for carrying out the method, identical feed sections 14, 16 are located one on each side of the grinding device, and guide sections 18, 20 are located adjacent the feed sections, guide section 18 being stationary and guide section 20 being rotatable through 180 degrees. The guide section 18 has a plurality of roll . support assemblies 22a ... 22e, each of which has a horizontal roll 24a ... 24e, Fig. 1.3, driven by gearing from a shaft 28 connected to an hydraulic motor 29. The rolls are vertically adjustable by hydraulically actuated screw jacks 83 so that the centre line of the workpiece, such as a slab, sheet, billet or coil material, supported on one edge, is aligned with the central height of the grinding device. The guide section also has a plurality of guide roll assemblies 30a ... 30c, each of which has a roll sub-assembly 32a ... 32c located at one side of the path of the workpiece and a respective slave roll sub-assembly 34a ... 34c located on the opposite side. The roll sub-assemblies 32a ... 32c have a frame 84a, Fig. 1.4, slidably supporting a slide 88a carrying a support 90a on a horizontal pivot, the support mounting a guide roll 36a. The support 90a is biased to a central position by springs 94a to permit the roll to move from its vertical position and follow the surface of the workpiece. The slide can be moved to position the roll by an hydraulic piston 110a. The slave assembly 34a is similar in construction but its piston 210a is connected to a pressure relief mechanism so that it applies a preselected force on the workpiece. The feed section 14 has pinch rolls 40a, 40b, Fig. 1.8, on one side of the path of the workpiece carried by upper and lower slides movable along guides by upper and lower pistons 312a, 314a to vary the position of the rolls. Rolls 42a, 42b on the other side of the path are similarly movable but are also mounted on secondary slides so as to be able to float to accommodate variation in the thickness of the workpiece. The rolls are driven by universal joint assemblies from an hydraulic motor. The feed section 16 is similar to feed section 14, and the guide section 20 is similar to guide section 18 with the exception that it is mounted on a turntable 74, Fig. 1.1, so that when the workpiece has been fed from guide section 18 by the feed sections 14, 16 through the grinding device 14 and back past the device a sufficient number of times that one side is satisfactorily ground, the guide section can be rotated with the workpiece through 180 degrees for the other side to be ground by the device 12. The grinding device consists of a contact roll 44, Fig. 1.12, which is belt driven from an electric motor 46 and over which runs an abrasive belt guided over an idler roller 60. The roller 60 is acted upon by an hydraulic cylinder 602 to maintain tension in the abrasive belt and by an oscillating assembly 605 which pivots the roller 60 to cause the abrasive belt to move in a selected axial direction. The depth of cut of the abrasive belt is determined by the position of control rolls 62, 66 movable by hydraulicallyoperated screw jack mechanisms. A billy roll 64 is disposed opposite the contact roll 44 and is rotatable by high or low speed motors. The billy roll is positioned by an hydraulically operated screw jack but can be quickly retracted by a fluid motor if a device senses breakage of the abrasive belt, which device also activates fluid motors for operating the control rolls 62, 66 to move the workpiece away from the contact roll.