초록 ▼

Before being coated with the magnetizable material, the substrate plates are machined on a precision turning lathe in such a way that the annular surface provided for the storage area is convexly arched on both sides of the plate. For this purpose, the substrate plate, during machining, is held on t

Before being coated with the magnetizable material, the substrate plates are machined on a precision turning lathe in such a way that the annular surface provided for the storage area is convexly arched on both sides of the plate. For this purpose, the substrate plate, during machining, is held on the chuck in a concave arch of the annular surface and machined flat with a purely radial free movement of the cutting tool, or held on a flat chuck and turned down under a feed movement of the tool, which feed movement corresponds to the required convex arching of the annular surface. In the first machining method, the elastically deformed substrate plate, after removal from the chuck, loses tension and forms a convexly arched annular surface.

대표청구항 ▼

A method of machining substrate plates for magnetic memory plates having an annular storage area, in such a way that convexly curved surfaces are formed on both sides of said substrate plate in said storage area, comprising (1) providing a chuck, driveable about an axis, and having a flat front disk

A method of machining substrate plates for magnetic memory plates having an annular storage area, in such a way that convexly curved surfaces are formed on both sides of said substrate plate in said storage area, comprising (1) providing a chuck, driveable about an axis, and having a flat front disk with vacuum connected annular grooves, a cutting tool carried by a tool slide which is movable in a direction parallel to as well as perpendicular to the chuck axis, and a regulating element interposed between said slide and said tool for displacing said tool, in a direction parallel to the chuck axis, the amount of said displacement being controllable in the micrometer range, (2) causing the substrate plate to be held flat against said disk by said vacuum, (3) driving the chuck with the substrate plate thereon and machining the exposed surface of the substrate plate by means of said cutting tool and with the aid of said regulating element, to a convexly arched surface, (4) disconnecting the vacuum to release the substrate plate, (5) reversing the substrate plate and reconnecting the vacuum to cause the substrate plate again to be driven by said chuck in its reversed condition and with the arched surface thereof held flat against said disk so that the substrate plate is convexly deformed, (6) with the substrate plate in this condition machining the now exposed surface of the substrate plate by means of said cutting tool and with the aid of said regulating element to a convexly arched shape that is twice as pronounced as that imparted on the first-mentioned surface, and then, (7) again disconnecting the vacuum and thereby allowing the substrate plate to straighten out.