Patent ID: 6938711
Filing Date: 2005-09-06
Classification: A61G,B62D

Abstract:
1. A freestanding self-propelled device for moving wheeled objects, the self-propelled device comprising: a chassis having oppositely-disposed fore and aft ends and oppositely-disposed lateral ends, the chassis comprising lower frame portions and upright frame portions extending upward from the lower frame portions; means coupled to the upright frame portions for gripping a wheeled object; a single drive wheel coupled to the chassis and centrally located between the lateral ends of the chassis, the drive wheel being rotatable about a horizontal axis and pivotable about a substantially vertical axis; means for causing rotation of the drive wheel; first and second sets of support wheels coupled to the lower frame portion of the chassis, the drive wheel being centrally located between the first set and the second set of support wheels and projecting below the first and second sets of support wheels so that the self-propelled device is supported by the drive wheel and by only one of each of the first and second sets of support wheels at any given time to establish a three-point contact with a surface supporting the self-propelled device; a third set of support wheels mounted to the chassis and extending aft from the aft end of the chassis so as to inhibit tipping of the self-propelled device in an aft direction of the self-propelled device; and a tiller coupled to the drive wheel to enable pivoting of the drive wheel about the vertical axis thereof, the tiller comprising means for controlling operation of the drive wheel.