Abstract: 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.

Abstract: The condition of a tyre (5) on a wheel (2) is assessed while the wheel (2) is mounted on a vehicle (1) and while the vehicle (1) is moving. As the vehicle (1) moves, the tyre (5) rotates and moves longitudinally along a path of movement. An imaging device (3, 4) captures images of a plurality of different portions (7) of the periphery of the tyre (5), which has tread portions (10) separated by tread gaps (11), whilst the tyre (5) revolves. While the images are being captured, longitudinally spaced flash units (F1, F2, F3, F4) are activated to illuminate portions (7) of the periphery of the tyre (5). The flash units (F1, F2, F3, F4) are positioned to one side of the path of movement of the tyre (5) and direct light at an acute angle to the path of movement of the tyre (5) so that the light causes shadows to be cast in the tread gaps (11) between tread portions (10).

Abstract: A sensor array (13) for checking the pressure of a vehicle tyre whilst being moved over the array comprises two sets (14) and (19) of aligned, facing sensor members. The first set (14) of sensor members is formed by slits (15) cut into a plate of metal to form first fingers (16) connected in cantilevered fashion to a first base portion (17), which extend in the direction of intended vehicle movement to free ends (18). The second set (19) of sensor members is formed by slits (20) cut into a plate of metal to form second fingers (21) connected in cantilevered fashion to a second base portion (22), which extend in the reverse of the direction of intended vehicle movement to free ends (23). The fingers of the two sets are aligned and the free ends (18) and (23) are closely adjacent. Each finger is provided with a load sensing system (28, 29) which provides an indication of the load on the finger as the tyre moves over the finger.

Abstract: Apparatus (4; 5) for checking the inflation pressure of a tyre (3) of a vehicle (2) whilst the tyre is being moved over the apparatus in a direction of travel (A). The apparatus comprises a base (7), a platform (8) which is mounted over the base, a first load sensor system (9) arranged between the platform and the base, and a second load sensor system (12) mounted on an upper surface of the platform and comprising a linear array of high resolution sensors (13, 25) extending across the platform. A data processing unit (6) processes data obtained by sampling the outputs of the first and second sensor system and provides an indication of the inflation pressure of the tyre. The data obtained by sampling the output of the first sensor system may be used to determine the total load borne by the platform, and/or the direction of travel of the tyre over the platform, and/or the speed of travel of the tyre over the platform and/or the tracking angle of the vehicle tyre.