Patent ID: 7475611

Claim:
A drive apparatus, comprising: an external rotary assembly having a hub ( 11 ) mounted on a central shaft ( 12 ); offset means ( 2 ) fixed within the hub, the offset means having an offset device ( 22 ′); a transmission means ( 4 ′) positioned within the hub; a drive motor ( 3 ) having an output shaft ( 31 ), the drive motor being accommodated in the offset device in drivable engagement with the hub via the output shaft and the transmission means, the output shaft being parallel to the central shaft; a movable arm ( 24 ′) pivotally attached to the offset device, the drive motor being attached to the movable arm ( 24 ′); a resilient member ( 25 ′) interposed between the movable arm and the offset device; and a torque adjustment member ( 26 ′) configured to adjust the torque between the movable arm and the offset device.