Wheelright Limited

Peter Norman Rose

Alexander Paul Codd

Syed Wajahat Ali Shah Kazmi

Paul Michael Taylor

Michael Taylor

Syed Wajahat Kazmi

A device for measuring tread depth of tyres, wherein in use a tyre can be driven over the device in a first direction, the device comprising: a light source arranged to illuminate the tyre; an obstruction extending in a second direction substantially perpendicular to the first direction and arranged to partially block the light emitted from the light source such that a shadow is cast on the tyre when the tyre is located above the device, and such that the shadow is cast on the tyre in a direction substantially perpendicular to the tread of the tyre; and a camera arranged to view an illuminated section of the tyre.

Tread line scanner

The condition of a tyre () on a wheel () is assessed while the wheel () is mounted on a vehicle () and while the vehicle () is moving. As the vehicle () moves, the tyre () rotates and moves longitudinally along a path of movement. An imaging device () captures images of a plurality of different portions () of the periphery of the tyre (), which has tread portions () separated by tread gaps (), whilst the tyre () revolves. While the images are being captured, longitudinally spaced flash units (F, F, F, F) are activated to illuminate portions () of the periphery of the tyre (). The flash units (F, F, F, F) are positioned to one side of the path of movement of the tyre () and direct light at an acute angle to the path of movement of the tyre () so that the light causes shadows to be cast in the tread gaps () between tread portions (). Each flash unit (F, F, F, F) causes a series of flashes of light to be produced when the flash unit (F, F, F, F) is activated, each flash of light in the series being separated from the next flash of light in the series by an interval. For any flash units (F, F, F, F) which are activated at the same time and illuminate overlapping portions of the periphery of tyre (), the respective series of flashes of light are out of phase so that the flashes of light from one flash unit (F, F, F, F) are emitted in the intervals between the flashes of light from the or each other flash unit (F, F, F, F). The images are analysed by data processing apparatus () to determine the extent of shadows in the tread gaps () so as to provide an indication of the depth of the tread gaps ().

Tyre condition analysis

A sensor array () for checking the pressure of a vehicle tire while being moved over the array comprises two sets () and () of aligned, facing sensor members. The first set () of sensor members is formed by slits () cut into a plate of metal to form first fingers () connected in cantilevered fashion to a first base portion (), which extend in the direction of intended vehicle movement to free ends (). The second set () of sensor members is formed by slits () cut into a plate of metal to form second fingers () connected in cantilevered fashion to a second base portion (), which extend in the reverse of the direction of intended vehicle movement to free ends (). The fingers of the two sets are aligned and the free ends () and () are closely adjacent. Each finger is provided with a load sensing system () which provides an indication of the load on the finger as the tire moves over the finger. Loads are applied to different positions along the fingers as the tire moves over the array. The sensitivity of the array increases from a minimum for a load applied where the first fingers () are attached to the first base portion (), to a maximum adjacent the free ends () of the first and second fingers () and (), and then decreases to a minimum where the second fingers () are attached to the second base portion (). The fingers may be replaced by series of individual sensing elements () arranged in groups so as to constitute sensor members, whose outputs are weighted so that the sensitivity varies in a similar manner along a sensor member.

Growing community of inventors

Oxfordshire, United Kingdom

Peter Norman Rose