Patent ID: 8499864

Claim:
A wheel, comprising an endless annular member, and a plurality of free rollers mounted on the annular member so as to be each rotatable around a tangential axial line of the annular member, wherein: the annular member comprises an arcuate main body and a complementary member configured to define an endless annular shape jointly with the main body; a joint between the main body and the complementary member includes mating surfaces that are non-perpendicular to a cross sectional center line of the annular member; and the joint is configured to be changeable between an open state where the complimentary member is removed from the main body to define a working space for enabling the free rollers to be fitted on the annular member, and a closed state where the complementary member is fixedly joined to the main body by using a fastener that joins the mating surfaces to close the working space.