Patent ID: 7871359

Claim:
A resistance apparatus for use with exercise devices, the resistance apparatus comprising; a first resistance cartridge; at least a second resistance cartridge; and an axle; wherein the first resistance cartridge and the at least second resistance cartridge are co-axially aligned with respect to each other and are selectively engagable by the axle; and wherein the axle includes a groove along an axial direction that receives an engagement member slidably mounted within the groove, wherein the engagement member selectably engages at least one of the first resistance cartridge and the at least second resistance cartridge, wherein each of the first resistance cartridge and the second resistance cartridge comprise an outer housing and an inner housing, and wherein the inner housing is rotatably mounted inside the outer housing, wherein the inner housing of at least one of the first resistance cartridge and the second resistance cartridge comprises a set of helical grooves circumscribing an outer portion of the inner housing, wherein a rolling member is disposed between the outer housing and inner housing within the set of helical grooves, and wherein at least the set of helical grooves and rolling member define a limit of rotation of the at least one of the first resistance cartridge and the second resistance cartridge.