| 摘要 |
Apparatus for monitoring the actuation of a piston and cylinder unit according to the invention comprises a position measuring device (15) incorporated in the unit (7). The position measuring device comprises two relatively movable electrically cooperating elements (16, 18) mounted within the piston rod (6), one element (16) being fixed to the cylinder and the other element (18) being fixed to the piston. The two elements may comprise a hollow, cylindrical induction coil device (16) with exciter coil 29 and receiver coils 28, 30 and a permanent magnet (18) movable within and longitudinally of the device. Relative movement of the elements generates an output signal representative of the relative position of the piston and cylinder. The position measuring device may be calibrated by relative movement of the elements. The apparatus can be used in conjunction with vertical electric control means for the piston and cylinder unit. <IMAGE> |
