Vehicle Tyre Checking System
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Accused Products
Abstract
A method and apparatus for assessing the tread on a vehicle tyre, measuring tyre pressure and calculating other parameters such as vehicle weight. The vehicle is driven in a longitudinal direction so that the tyre passes over a first lateral sensor (6) that extends across the footprint of the tyre, the first sensor comprising an array of individual force sensing elements (11), which provide outputs indicative of tyre pressure at points across the footprint of the tyre. The sensing elements are sampled at intervals as the tyre moves over them, so as to build up data relating to the entire footprint of the tyre. The sensing elements are of relatively high resolution to detect areas within the tyre footprint where there is tread cut into the tyre, so that the extent of tread coverage can be assessed. Tyre pressure is also determined. The tyre then passes over a series of second lateral sensors (7) spaced at intervals to assess the tyre around its circumference. The second lateral sensors may be of low resolution, with outputs being compared with each other and with a low resolution sensor (T) adjacent the high resolution sensor to assess whether there is a difference in tyre tread quality at different positions around the tyre circumference. At least one lateral sensor may be provided with resilient portions that extend into tyre tread portions. These will engage the base of a tread portion that is below a predetermined minimum tread depth, so as to increase the area of contact and provide an indication of insufficient tread depth.
39 Citations
53 Claims
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1-25. -25. (canceled)
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26. A method for measuring characteristics of a tyre on a vehicle wheel, comprising:
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(a) moving the vehicle in a longitudinal direction so that the tyre passes over a laterally extending first measuring sensor comprising an array of individual force sensing elements which provide outputs related to contact pressure at points in a footprint of the tyre as the tyre passes over the first measuring sensor, the force sensing elements of the first measuring sensor being arranged laterally at positions across the width of the tyre as it passes over the first measuring sensor and being of sufficiently high resolution to detect positions within the tyre footprint where there is no contact between the tyre and the first measuring sensor as a result of there being a tread pattern in the surface of the tyre; (b) detecting the speed of the tyre in the longitudinal direction as it passes over the first measuring sensor; (c) sampling the outputs from the force sensing elements of the first measuring sensor at intervals as the tyre passes over, so as to provide pressure data representing the contact pressure at a number of points distributed laterally across and longitudinally along the tyre footprint that passes over the first measuring sensor; and (d) processing the pressure data representing the contact pressure and data representing the speed of the tyre in the longitudinal direction, to provide an indication representative of the extent of tread coverage over the tyre footprint that passes over the first measuring sensor. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. Apparatus for measuring characteristics of a tyre on a vehicle wheel whilst moving the vehicle in a longitudinal direction, comprising:
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(a) a laterally extending first measuring sensor arranged so that the tyre will pass over the first measuring sensor, the first measuring sensor comprising an array of individual force sensing elements arranged to provide outputs related to contact pressure at points on a footprint of the tyre as the tyre as it passes over the first measuring sensor, the force sensing elements of the first measuring sensor being arranged laterally at positions across the width of the first measuring sensor and being of sufficiently high resolution to detect, as a tyre passes over the first measuring sensor, positions within the tyre footprint where there is no contact between the tyre and the first measuring sensor as a result of there being a tread pattern in the surface of the tyre; (b) a speed detecting system for detecting the speed of the tyre in the longitudinal direction as it passes over the first measuring sensor; (c) means for sampling the outputs from the force sensing elements of the first measuring sensor at intervals as the tyre passes over, so as to provide pressure data representing the contact pressure at a number of points distributed laterally across and longitudinally along the whole of the tyre footprint that passes over the first measuring sensor; and (d) means for processing the pressure data representing the contact pressure and data representing the speed of the tyre in the longitudinal direction, to provide an indication representative of the extent of tread coverage over the tyre footprint that passes over the first measuring sensor. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A method for assessing the tread coverage on a vehicle tyre, comprising the steps of moving the vehicle in a longitudinal direction so that (a) the tyre passes over a first lateral sensor which extends across the footprint of the tyre, the first sensor comprising an array of individual force sensing elements which provide outputs indicative of tyre pressure at points across the footprint of the tyre;
- and (b) the tyre passes over a second lateral sensor, spaced longitudinally from the first sensor, which extends across the full width of the footprint of the tyre and provides an output indicative of the force imposed on the sensor by the portion of the tyre footprint over the sensor;
the method further comprising the steps of processing the output from the first and second lateral sensors, so as to provide an indication of the tyre pressure and an indication of the coverage of the tyre tread.
- and (b) the tyre passes over a second lateral sensor, spaced longitudinally from the first sensor, which extends across the full width of the footprint of the tyre and provides an output indicative of the force imposed on the sensor by the portion of the tyre footprint over the sensor;
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49. A method for assessing the tread depth of a tyre on a vehicle, comprising the steps of moving the vehicle in a longitudinal direction so that the tyre passes over a laterally extending force sensor which extends across the footprint of the tyre, the output of the force sensor varying in accordance with the area of contact of the tyre with the sensor, wherein the force sensor is provided with resilient portions in contact with the tyre, the resilient portions extending into tread portions on the tyre, so as to contact the base of tread portions whose depth is below a specified limit and thus increase the area of contact between the tyre and the force sensor.
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50. Apparatus for measuring characteristics of a tyre on a vehicle wheel, comprising a lateral sensor over which a tyre is to pass in a longitudinal direction, the lateral sensor comprising an array of individual force sensing elements which provide outputs related to contact pressure at points on a footprint of the tyre as the tyre passes over the lateral sensor;
- wherein the force sensing elements are arranged laterally so as to be at positions across the entire footprint of the tyre as it passes over the lateral sensor;
means are provided for sampling the outputs from the force sensing elements at intervals as the tyre passes over, so as to provide data representing the outputs at a number of points distributed over the whole of the tyre footprint that has passed over the lateral sensor;
wherein the force sensing elements are of sufficiently high resolution to detect positions within a tyre footprint where there is no contact between the tyre and the lateral sensor as a result of there being a tread pattern in the surface of the tyre; and
means are provided for processing the data to provide an indication representative of the proportion of the footprint area of the tyre over which there is a tread pattern.
- wherein the force sensing elements are arranged laterally so as to be at positions across the entire footprint of the tyre as it passes over the lateral sensor;
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51. Apparatus for measuring the tyre pressure of a vehicle tyre and for assessing the tread coverage on the tyre, whilst the vehicle is being moved in a longitudinal direction over sensors, the apparatus comprising a first laterally extending sensor comprising an array of individual force sensing elements which provide outputs indicative of tyre pressure at points across the footprint of the tyre;
- a second laterally extending sensor, spaced longitudinally from the first sensor, which provides a signal indicative of the force on the sensor;
means for processing the signals from the sensing elements of the first sensor, so as to provide the tyre pressure of the tyre; and
means for processing the signal from the second sensor, and the signals from the sensing elements of the first sensor, so as to provide a measure of the quality of the tyre tread.
- a second laterally extending sensor, spaced longitudinally from the first sensor, which provides a signal indicative of the force on the sensor;
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52. A linearly extending sensor for use in the assessment of the tyre tread quality of a vehicle tyre whilst the tyre is moved over the sensor, with the sensor extending laterally across the tyre, the sensor providing an electrical output which depends on the area of contact between the vehicle tyre and the sensor, wherein the sensor is provided with resilient portions adapted to extend into tread portions of the tyre and to engage the base of tread portions whose depth is less than a predetermined minimum, so as to increase the area of contact between the vehicle tyre and the sensor if there are tread portions whose depth is less than the predetermined minimum.
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53. A linearly extending sensor for use in the assessment of the tyre tread quality of a vehicle tyre whilst the tyre is moved over the sensor, with the sensor extending laterally across the tyre, the sensor comprising an array of individual force sensing elements arranged along the linear extent of the sensor to provide outputs related to contact pressure at points on the tyre as it passes over the sensor, the force sensing elements of the sensor being of sufficiently high resolution to detect, as a tyre passes over the sensor, positions within the tyre footprint where there is no contact between the tyre and the first measuring sensor as a result of there being a tread pattern in the surface of the tyre, wherein the sensor is provided with resilient portions adapted to extend into tread portions of the tyre and to engage the base of tread portions whose depth is less than a predetermined minimum, so as to increase the area of contact between the vehicle tyre and the sensor if there are tread portions whose depth is less than a predetermined minimum.
Specification