Abstract: Apparatus for checking diameters of workpieces in a broad range of operation, including two arms moving with a scissorwise movement.The two arms carry relevant measuring heads and are coupled to coaxial shafts.A rotary transducer has two moving elements coupled to the coaxial shafts. A processing and control circuit includes pre-selectors for zero-setting the apparatus with reference to different diameters to be checked. The processing and control circuit provides a measurement signal depending on the output signals of the measuring heads and of the rotary transducer.

Abstract: An apparatus for checking the dimensions of mechanical workpieces in movement with respect to the apparatus, including at least one feeler adapted to cooperate with the surface of the workpiece, or workpieces, at least one transducer connected to the feeler for providing a signal responsive to the dimensions, processing apparatus connected to the transducer for processing the signal and providing a measurement signal, the processing apparatus including a limiter circuit adapted to receive the signal responsive to the dimensions and limit it as to variations in a pre-established direction, providing a relative output signal, output apparatus connected to the processing means to receive and utilize the measurement signal and control apparatus.

Abstract: An apparatus for measuring taper on mechanical workpieces having a tapered surface, including first and second reference bodies for cooperating with the tapered surface along relevant circumferences of different diameters, a measuring transducer for providing indications responsive to the position of the first and second reference bodies, a support for the first and second reference bodies and first and second connectors connecting the first and second reference bodies, respectively, to the support. The first and second reference bodies define a first revolutionary surface and a second revolutionary surface, the revolutionary surfaces being coaxial between each other and adapted to be arranged tangent to the tapered surface and passing, respectively, through a relevant circumference of the tapered surface.