Patent ID: 7444205

Claim:
A modular unit comprising: a central housing; a power storage unit mounted in the housing; a drive motor mounted in the housing and connected to the power storage unit; a commuting mechanism mounted in the housing for controlling the drive motor; a leg having a first end and a second end, the first end being pivotally attached to the housing, wherein the leg includes: a first tubular member having a hollow main body portion formed along a longitudinal axis with an opening situated at one longitudinal end of the main body portion; a second tubular member slidably received through the opening of the first tubular member; and an abutment for limiting sliding movement of the second tubular member within the main body portion of the first tubular member; a connecting plate attached to the second end of the leg, the connecting plate including a short-term connection element and a long-term connection element; and an electronic communication system for transmitting signals between the computing mechanism and the connecting plate through the housing and the leg.