Abstract: An arrangement is used for the efficient mass production of individual bodies for the artificial rebuilding of teeth, for example. The arrangement comprises a first pair of co-rotating elements, of which the first element (1) is so arranged as to support a replica (21) of a body which is to be produced, and the second element (2) is so arranged as to support a blank from which the body is to be produced. The replica and the blank are caused to rotate synchronously about the axis of rotation (3, 4) of the respective element. In a second pair of elements a third element supports a sensing device (31) which is capable of interacting with the external contour of the replica, and a fourth element supports a tool (52) by means of which the blank is capable of being machined. The first and second pairs of elements are capable of being displaced relative to one another.

Abstract: The piston rod of a longitudinal feed cylinder of a tracer controlled lathe is connected with the lathe carriage by means of an operative connection consisting of another hydraulic cylinder or a cam arrangement which permits the rod of the feed cylinder to continue movement in the feed direction while maintaining the carriage in a fixed position. This permits the cutting tool mounted on the cross slide to machine a sharp shoulder on the workpiece perpendicular to the axis of rotation of the lathe spindle. The circuit includes a tracer valve that is variably restricted in accordance with movement of a stylus following a contoured template. The tracer valve is conneted to a feed line from a high pressure pump which extends directly or indirectly to one side of a hydraulic cylinder for displacing the cross slide in the carriage. The opposite side of the cross slide cylinder is connected to a low pressure pump.

Abstract: A multiple-mode hydraulic tracer valve which is convertible from mode to mode by the use of a shiftable stylus and a transmission whose locus can be shifted relative to the spool valves of the tracer valve without changing the relative settings between the spools and the sleeves of the spool valves.