Linkage position sensor having a magnet with two ramped sections for providing variable magnetic field
First Claim
1. A sensor for detecting the position of a mechanical linkage relative to a reference point, comprising:
- a pair of magnets, each magnet having a surface including at least a first and a second ramp section;
a magnetically permeable bracket interconnecting said pair of magnets in spaced-apart relationship and opposite each other to define a longitudinally extending air gap therebetween with said magnets facing each other across said air gap and with said magnets aligned in a manner such that the surface including the first and second ramp sections of one of the magnets faces the surface including the first and second ramp sections of the other of the magnets so that the first ends of said magnets are positioned opposite each other and the second ends of said magnets are positioned opposite each other and so that said air gap between said magnets varies in dimension longitudinally over a distance corresponding to at least a portion of the surface of the first and second ramp sections of the magnets;
said pair of magnets and said magnetically permeable bracket being mounted relative to a mechanical linkage in a manner such that movement of said mechanical linkage causes movement of said magnets and said bracket;
said pair of magnets and said magnetically permeable bracket forming a continuous magnetic circuit and producing a magnetic field coupled between said pair of magnets, said magnetic field having linearly varying strength lengthwise of said longitudinally extending air gap over the distance corresponding to at least a portion of the surface of the first and second ramp sections of the magnets; and
at least one detector fixedly mounted within said air gap intermediate said pair of magnets and positioned to detect said strength of said magnetic field between said magnets and to generate an output representative of the strength of said magnetic field.
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Accused Products
Abstract
An extremely reliable and effective position sensor is provided at low cost for determining the relative position of a mechanical linkage with respect to a reference point. The position sensor includes a rotor or bracket which is mechanically coupled to the linkage and contains at least two magnets on opposite walls adjacent a channel opening. The opposing magnets are formed with first and second sloped or ramped sections which produce produce variable magnetic fields as determined by the geometric profile of the magnets. One or more detectors are positioned in the air gap between the opposing magnets. As the linkage is moved, the rotor or bracket moves with respect to the detector causing a change in the strength of the magnetic field detected by the detector, whereby the detector determines the position of the movable linkage.
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Citations
33 Claims
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1. A sensor for detecting the position of a mechanical linkage relative to a reference point, comprising:
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a pair of magnets, each magnet having a surface including at least a first and a second ramp section; a magnetically permeable bracket interconnecting said pair of magnets in spaced-apart relationship and opposite each other to define a longitudinally extending air gap therebetween with said magnets facing each other across said air gap and with said magnets aligned in a manner such that the surface including the first and second ramp sections of one of the magnets faces the surface including the first and second ramp sections of the other of the magnets so that the first ends of said magnets are positioned opposite each other and the second ends of said magnets are positioned opposite each other and so that said air gap between said magnets varies in dimension longitudinally over a distance corresponding to at least a portion of the surface of the first and second ramp sections of the magnets; said pair of magnets and said magnetically permeable bracket being mounted relative to a mechanical linkage in a manner such that movement of said mechanical linkage causes movement of said magnets and said bracket; said pair of magnets and said magnetically permeable bracket forming a continuous magnetic circuit and producing a magnetic field coupled between said pair of magnets, said magnetic field having linearly varying strength lengthwise of said longitudinally extending air gap over the distance corresponding to at least a portion of the surface of the first and second ramp sections of the magnets; and at least one detector fixedly mounted within said air gap intermediate said pair of magnets and positioned to detect said strength of said magnetic field between said magnets and to generate an output representative of the strength of said magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 26)
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18. An automotive linkage position sensor, comprising in combination:
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a mechanically actuated linkage member movable between first and second positions; first and second magnets each having a surface including at least a first and a second ramp section, said first and second magnets being interconnected by a magnetically permeable bracket and being positioned opposite each other to define an air gap therebetween with said magnets facing each other across said air gap and with the surface including the first and second ramp sections of the first magnet being aligned to face the surface including the first and second ramp sections of the second magnet, said interconnected first and second magnets and said magnetically permeable bracket forming a continuous magnetic circuit and producing a magnetic field having linearly varying strength over a distance corresponding to at least a portion of the surface of the first and second ramp sections of the magnets; said interconnected magnets being mounted relative to said mechanically actuated linkage member in a manner such that movement of said mechanical linkage member causes movement of said magnets; and at least one detector received within said air gap substantially midway between said first and second magnets to detect said magnetic field, said at least one detector fixed with respect to said movable mechanically actuated linkage member. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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27. A sensor for detecting a position of a movable piece, comprising:
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a) a bracket, coupled to the movable piece and being magnetically permeable, having a first and second parallel flange; b) a first and second magnet coupled to the first and second flange respectively, the first and second magnets having; 1) opposing first ramp sections and opposing second ramp section; 2) the first ramp section of each magnet having a first slope that is relative to the first flange; and 3) the second ramp section of each magnet having a second slope that is relative to the first flange, wherein the second slope is different from the first slope; c) a magnetic field coupled between the first and second magnets, having a linearly varying flux strength determined by varying distances between the opposing first and second magnets; d) a continuous magnetic circuit formed from the bracket, the first and second magnets and the magnetic field; and e) a detector positioned between the first and second magnets for determining the position of the moveable piece. - View Dependent Claims (28, 29, 30, 31, 32, 33)
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Specification