Patent ID: 6577119
Filing Date: 2003-06-10
Classification: F02D,G01D,G05G,Y10T

Abstract:
A position sensor for sensing the relative position of a first and a second component, the sensor comprising:a channel having a subsidiary channel section and a main channel section at an angle to one another; a stator connected to said first component and having a surface which includes two magnetically separate regions of magnetic material separated by said channel; a magnetic unit connected to said second component such that movement of said magnetic unit is in a direction parallel to said subsidiary channel, said magnetic unit having north and south pole faces arranged relative to the surface so that when said magnetic unit is in a first position relative to said stator, at least a substantial part of one pole face lies over one of the regions of magnetic material and at least a substantial part of the other pole face lies over the other region of magnetic material, thereby producing a magnetic field across said channel, and when said magnetic unit is in a second position said north and said south pole faces of said magnetic unit lie over the same region of magnetic material such that no magnetic field is produced across said channel; and a magnetic field sensor placed in said main channel so as to produce a signal which is dependent on the magnetic field in said channel and whereby said signal has a first value when said magnetic unit is in said first position and a second value when said magnetic unit is in said second position, the value of said signal varying in a substantially linear manner between said first value and said second value in accordance with the position of said magnetic unit between said first position and said second position such that said value of said signal represents the relative position of said first and said second component, wherein said magnetic unit is arranged so that as it moves from said first position to said second position, one pole face remains over a single region of magnetic material whereas at least part of the other pole face crosses from one region of magnetic material to the other region.