Abstract: A workpiece clamping system for a measuring machine includes a rotary table disposed in a workpiece rotation axis and includes a chuck for the concentric accommodation of a workpiece, a rotary drive for the rotary table, an upper centering tip mountable or mounted on the measuring machine in the workpiece rotation axis vertically opposed to the rotary table, and a lower centering tip mountable or mounted on the rotary table in addition to the chuck for accommodating a workpiece between the centering tips instead of in the chuck, wherein the lower centering tip is provided and formed to be concentrically clamped in the chuck instead of a workpiece, and in that the workpiece clamping system is provided with a conveying device for vertically or vertically and horizontally conveying the lower centering tip into and from its clamping position in the chuck.

Abstract: A workpiece clamping systems for a measuring machine includes a rotary table disposed in a workpiece rotation axis and includes a chuck for the concentric accommodation of a workpiece, a rotary drive for the rotary table, an upper centering tip mountable or mounted on the measuring machine in the workpiece rotation axis vertically opposed to the rotary table and a lower centering tip mountable or mounted on the rotary table in addition to the chuck for accommodating a workpiece between the centering tips instead of in the chuck, wherein the lower centering tip is provided and formed to be concentrically clamped in the chuck instead of a workpiece, and in that the workpiece clamping system is provided with a conveying device for vertically or vertically and chuck.

Abstract: Isocyanates and derivatives thereof are prepared by oxidative conversion of compounds having at least one group ##STR1## wherein X represents OY or ##STR2## wherein Y is H, a metal ion or group NR.sup.3 R.sup.4 R.sup.5 R.sup.6 wherein each of R.sup.3, R.sup.4, R.sup.5 and R.sup.6 which may be the same or different, is H, alkyl or (substituted) (alk)aryl and Z is a (substituted) alkyl or aryl group. Phenyl isocyanate and derivatives thereof are preferably prepared electrochemically from the corresponding oxamides and oxanilides.