Sensoreinrichtung zur Positionserkennung eines Kolbens

摘要

A sensor device for a cylinder 12 containing a moving piston 11 comprises a permanent magnet 13 or 13a on the piston 11 or on an element connected with the piston, and at least one magnetic field responsive device 15 or 15a, having a preferential direction, arranged on the cylinder 12 and responsive to the approach of the permanent magnet The permanent magnet 13 or 13a and the at least one device 15 or 15a are so aligned that on mutual passage the magnetic field 14 or 14a of the permanent magnet at spatially consecutive points acts substantially parallel to the preferential direction of the sensor 15 or 15a but in opposite directions and thus causes different sensor reactions, means being provided for the storage of such sensor reactions. Accordingly it is possible not only to ascertain the exact current position of the piston 11 on passing the device 15 or 15a but furthermore information is always available as to whether the piston is to the left or to the right of the field responsive device. <IMAGE>