Apparatus for determining the speed, angular position and direction of rotation of a rotatable shaft
First Claim
1. An apparatus (10) for determining a direction of rotation of a rotatable shaft (15), comprising:
- a disk (14) rotatable in synchronization with the rotatable shaft (15) having a plurality of contiguous zones (16a-16x), each zone having first and second areas (18a-18x, 20a-20x), wherein the zones are divided into a first set (16c-16t, 16v-16x) and a second set (16a16b, 16u), each of the first areas of the zones of the first set having a first angular extent and each of the first areas of the zones of the second set having a second angular extent different than the first angular extent and wherein the first and second sets of zones form a first repeating zone pattern when the disk rotates in a first direction and a second repeating zone pattern different from the first pattern when the disk rotates in a second direction opposite the first direction;
a sensor (24) disposed adjacent the disk for developing a sensor signal in response to the passing of the zones as the disk rotates; and
means coupled to the sensor for determining the direction of rotation of the disk in response to the sensor signal.
1 Assignment
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Accused Products
Abstract
An apparatus (10) for use on electronically controlled fuel injection systems senses speed, angular position, and direction of rotation using only a single Hall effect type sensor (24). A disk element (14) is fixedly connected to and rotatable with the camshaft of an internal combustion engine. The disk element (14) includes a plurality of circumferential zones (16a-16x) of substantially identical length with each zone (16a-16x) having first (18a-18x) and second (20a-20x) areas. A first portion 16c-16t, 16v-16x) of these circumferential zones (16a-16x) have first (18c-18t, 18v-18x) and second areas (20c-20t, 20v-20x) which are substantially different in length than the first (18a, 18b, 18u) and second areas (20a, 20b, 20u) of a second portion ( 16a, 16b, 16u) of the circumferential zones (16a-16x). Accordingly, the sensor (24) delivers a signal which has a frequency directly related to the instantaneous velocity of the disk element (14), but varies in pulse width in response to the first (16c-16t, 16v-16x) and second (16a, 16b, 16u) portions of the circumferential zones (16a-16x). A microprocessor (46) operating under software control detects the instantaneous angular position and direction of rotation of the disk element (14) by locating the second portion (16a, 16b, 16u) of the circumferential zones (16a-16x) and the order in which they are received.
56 Citations
17 Claims
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1. An apparatus (10) for determining a direction of rotation of a rotatable shaft (15), comprising:
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a disk (14) rotatable in synchronization with the rotatable shaft (15) having a plurality of contiguous zones (16a-16x), each zone having first and second areas (18a-18x, 20a-20x), wherein the zones are divided into a first set (16c-16t, 16v-16x) and a second set (16a16b, 16u), each of the first areas of the zones of the first set having a first angular extent and each of the first areas of the zones of the second set having a second angular extent different than the first angular extent and wherein the first and second sets of zones form a first repeating zone pattern when the disk rotates in a first direction and a second repeating zone pattern different from the first pattern when the disk rotates in a second direction opposite the first direction; a sensor (24) disposed adjacent the disk for developing a sensor signal in response to the passing of the zones as the disk rotates; and means coupled to the sensor for determining the direction of rotation of the disk in response to the sensor signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus (10) for determining a direction of rotation of a rotatable shaft (15), comprising:
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a disk (14) rotatable in synchronization with the rotatable shaft (15) having a plurality of contiguous circumferential zones (16a-16x), each zone having a tooth (18a-18x) and a notch (20a-20x) wherein the zones are divided into a first set (16c-16t, 16v-16x) and a second set (16a, 16b, 16u), each of the teeth of the zones of the first set having a first angular extent and each of the teeth of the zones of the second set having a second angular extent different than the first angular extent and wherein the first and second sets of zones form a first repeating zone pattern when the disk rotates in a first direction and a second repeating zone pattern different from the first pattern when the disk rotates in a second direction opposite the first direction; a sensor (24) disposed adjacent the disk for developing a sensor signal in response to the passing of the zones as the disk rotates; first means coupled to the sensor for determining the direction of rotation of the disk in response to the sensor signal; second means coupled to the sensor for determining the speed of rotation of the disk responsive to the sensor signal; and third means coupled to the sensor for determining the angular position of the disk responsive to the sensor signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification