Sp Tyres UK Limited

Mathew Simpson

Phillip N Griffiths

A tire comprising a tread portion, sidewalls and a pair of spaced-apart beads each containing a substantially enextensible annular bead core, having bead seats and an extended toe portion comprising elastomeric material extending axially and radially inwards of the bead, the toe being of a rigidity in the direction of its length so that in use of the tire on a wheel rim having a groove complementary to the toe and engaging the toe when an axially inward force is applied to the tread portion a radially and axially outwardly directed force is generated at the bead core to affect bead retention characterized by the toe being subdivided in the circumferential direction of the tire by a series of substantially radial cuts in the toe such that circumferentially adjacent portions of the toe are decoupled from one another and dislodgement or misplacement of one of said portions does not dislodge or displace an adjacent portion. Preferably the cuts are equally spaced around the tire and they are through the whole cross section of the toe.

Tire bead toe with slits

A vehicle wheel rim includes a pair of spaced-apart tire bead seats, axially outwards of each bead seat a tire retaining flange, and axially inwards but immediately adjacent thereto a circumferentially extending tire toe engaging groove. The groove is subdivided in the circumferential direction by at least three bridge members each of which is short in the circumferential direction and traverses the groove to provide a bridge surface substantially at the top of the groove such that the bridge surface may support a normal tire bead when used on the wheel or alternatively a tire with a bead retention toe may engage the toe in the groove to provide bead retention in use. Preferably four to eight bridge members are provided. The resultant wheel safely carries a normal tire or a TD type of tire with a projecting, bead retaining toe.

Growing community of inventors

Erdington, United Kingdom

Mathew Simpson