Patent ID: 8267206

Claim:
A patient support, comprising: a frame configured to support a person in at least a horizontal position, a motor, a propulsion device coupled to the motor and coupled to the frame, the propulsion device including a rolling support to propel the patient support from one location to another location in response to output from the motor, a traction engagement controller coupled to the propulsion device and coupled to the frame, configured to: move the propulsion device from a first position in which the propulsion device is unable to propel the patent support to a second position in which the propulsion device is able to propel the patient support in response to user input, and move the propulsion device toward or away from the floor to compensate for changes in elevation of the patient support and allow the propulsion device to remain in contact with the floor as the patient support is propelled by the propulsion device over the changes in elevation, and a plurality of casters supporting the frame and a caster mode detector operable to detect a mode of operation of the casters, wherein the traction engagement controller is configured to initiate movement of the propulsion device to the second position if the caster mode detector determines that the casters are in a steer mode.