Tire and wheel rim assemblies

A tire wheel rim assembly capable of operation in a substantially deflated condition without the tire being dislodged from its position on the rim comprising:

• (a) a one-piece wheel rim having in cross-section a pair of radially outwardly extending flanges, a pair of bead seats immediately adjacent the flanges, each bead seat being tapered at an angle of about 10.degree. in an axially and radially outwards direction with respect to the rotational axis of the rim and a radially inwardly extending open well located between said bead seats so that a tire can be mounted on the rim by use of the well,
• (b) a tire mounted on said rim and defining therewith a chamber for inflation, said tire having a tread portion connected at each edge to a respective one of a pair of sidewalls each terminating in a respective annular tire bead fitting upon an associated rim bead seat, each tire bead having a substantially inextensible annular bead reinforcement embedded therein,
• (c) means on said rim to prevent at least one of the tire beads from being dislodged from its associated rim bead seat into the open well under the action of road generated forces with the tire in a deflated condition but permitting the tire to be mounted on the rim bead seats by inflation pressure and demounted therefrom by exerting an axially directed force against the tire bead, said means comprising a substantially continuous circumferential abutment on the rim in the area between said open well and the toe of said tire bead fitted on its associated bead seat, said abutment having a height of at least 3 mm and a maximum diameter not greater than the minimum diameter of the bead reinforcement of said tire bead and a generally radially extending axially outwardly directed abutment face, said rim bead seat being substantially straight in the area between the adjacent rim flange and said abutment and said abutment face having a radial dimension with respect to the width and taper angle of said bead seat such that when an axially inwardly directed force at said tread portion is applied to said tire bead by the tire sidewall in the ground contacting portion of the tire circumference, engagement of the toe of said tire bead with said abutment face generates at the bead reinforcement a substantial radially and axially outwardly directed force at the bead reinforcement, tightening the bead reinforcement and retaining said tire bead at its bead seat.

A tire and wheel rim assembly capable of operation in a substantially deflated condition without the tire being dislodged from its position on the rim comprising:

• (a) a one-piece wheel rim having in cross-section a pair of radially outwardly extending flanges, a pair of bead seats immediately adjacent the flanges, each bead seat being tapered in an axially and radially outwards direction with respect to the rotational axis of the rim and a radially inwardly extending open well located between said bead seats so that a tire can be mounted on the rim by use of the well,
• (b) a tire mounted on said rim and defining therewith a chamber for inflation, said tire having a tread portion connected at each edge to a respective one of a pair of sidewalls each terminating in a respective annular tire bead fitted upon an associated rim bead seat, each tire bead having a substantially inextensible annular bead reinforcement embedded therein,
• (c) means on said rim to prevent at least one of the tire beads from being dislodged from its associated rim bead seat into the open well under the action of road generated forces with the tire in a deflated condition but permitting the tire to be mounted on the rim bead seats by inflation pressure and demounted therefrom by exerting an axially directed force against the tire bead, said means comprising a substantially continuous circumferential abutment on the rim in the area between said open well and the toe of said tire bead fitted on its associated bead seat, said abutment having a height of at least 2.2 mm and a maximum diameter not greater than the minimum diameter of the bead reinforcement of said tire bead and a generally radially extending axially outwardly directed abutment face, said rim bead seat being substantially straight in the area between the adjacent rim flange and said abutment and, the toe of said tire bead being of a hardness of at least 60 Shore A and having sufficient form integrity in a plane through the tip of said toe and the center of the beads reinforcement such that when an axially inwardly directed force at said tread portion is applied to said tire bead by the tire sidewall in the ground contacting portion of the tire circumference, engagement of the toe of said tire bead with said abutment face generates at the bead reinforcement a substantial force acting in said plane to tighten the bead reinforcement and retain said tire bead at its bead seat.