Patent ID: 7770255

Claim:
An apparatus comprising: a base having wheels, including a drive wheel, for wheeling the base over a floor; a fan in the base; a nozzle fixed to the base for the fan to draw air from the floor through the nozzle; a handle connected to the base for propelling the base by manually applying a force to the handle; a drive assist motor, not configured to drive the fan, having an output shaft coupled to the drive wheel; and a controller operative in different modes, including: a driving mode in which the controller powers the motor to rotate the drive wheel in a direction corresponding to a direction of the force applied to the handle; and a non-driving mode in which the controller refrains from powering the motor to rotate the drive wheel while a user manually applies force to the handle to propel the base over the floor while the shaft remains coupled to the drive wheel such that rotating the drive wheel causes the shaft to rotate.