Patent ID: 7500285

Claim:
An articulated caster for attachment to a frame operable to support a load above a surface, comprising: a base assembly including a base and at least three caster wheels attached to the base so that the base assembly is self-supporting; a pivot arm connectable to the frame, said base assembly being pivotally connected to the pivot arm at a first pivotal joint for permitting the base assembly to pivot relative to the pivot arm about at least one axis, a pair of said caster wheels being spaced oppositely from the first pivotal joint so that the base assembly operates as a walking beam, said pivot arm extending laterally from the base assembly and at least partially forming a second pivotal joint for coupling to the frame, said second pivotal joint being spaced laterally from the first pivotal joint so that the base assembly is operable to translate vertically relative to the second pivotal joint about at least one axis; and a second base assembly spaced from the first-mentioned base assembly, said second base assembly including a second base and at least three caster wheels attached to the second base so that the second base assembly is self-supporting, said second base assembly being pivotally connected to the pivot arm at a third pivotal joint for permitting the base assembly to pivot relative to the pivot arm about at least one axis, a second pair of sad caster wheels associated with the second base assembly being spaced oppositely from the third pivotal joint so that the second base assembly operates as a walking beam, said pivot arm extending laterally between the base assemblies and being configured to thereby support the load.