Patent ID: 7191854

Claim:
A modular drive unit for propelling a gurney across a supporting surface comprising: a control/handle module, a cord charger module, a drive module, and a chassis assembly for mounting the drive module under a chassis of the gurney, said drive module comprising: a drive wheel connected to an electric motor for rotating the wheel, said drive wheel mounted for rotation between pivot arms attached to the chassis assembly, said pivot arms resiliently biased by a spring such that the drive wheel is out of contact with the supporting surface, an air bag for selectively biasing the pivot arms against the resistance of the spring such that the drive wheel is in contact with the supporting surface, said air bag connected to an air compressor under control of an air pressure switch for controlling the air pressure in the air bag whereby the gurney is propelled across the supporting surface by the drive wheel when the drive wheel is in contact with the supporting surface.