Magnetic sensor, with sensor gap adjusting high permeable flux collecting chip, for detecting rotation

Claim 1

A magnetic sensor for detecting rotation comprising: (a) a disk-shaped sensing plate which is rotatable with an object to be sensed; (b) a sensor having a tubular portion and an end wall formed on a front end of said tubular portion, said end wall being disposed in opposed relation to an outer periphery of said sensing plate, a hole being formed through said end wall and having an axis extending in the direction of an axis of said tubular portion; (c) a magneto-electric transducer mounted in said sensor housing and disposed adjacent to said end wall of said sensor housing, said electro-magnetic transducer comprising a semi-conductor element; (d) a magnetic flux-collecting chip of a high permeability material capable of being cut, said magnetic flux-collecting chip being received in and fixed to said hole of said end wall of said sensor housing and disposed forwardly of said electro-magnetic transducer, and said magnetic flux-collecting chip having an exposed front face which is directed away from said electro-electric transducer and faces said outer periphery of said sensing plate; and (e) positioning means for positioning said sensor housing; wherein said front face of said magnetic flux-collecting chip is so cut that a magnetic gap between said outer periphery of said sensing plate and said front face of said magnetic flux-collecting chip is equal to a predetermined optimum value.