Patient Transport Apparatus With Controlled Auxiliary Wheel Speed

A patient transport apparatus comprising:

• a support structure;
• a support wheel coupled to the support structure;
• and
• an auxiliary wheel assembly including:
• an auxiliary wheel coupled to the support structure to influence motion of the patient transport apparatus over a floor surface, the auxiliary wheel assembly being positionable to a deployed position with the auxiliary wheel engaging the floor surface and to a retracted position with the auxiliary wheel spaced a distance from the floor surface;
• an auxiliary wheel drive system including:
• a motor coupled to the auxiliary wheel to rotate the auxiliary wheel relative to the support structure at a rotational speed;
• and
• a motor control circuit for transmitting power signals from a power source to the motor;
• a user interface for receiving user commands from a user to operate the auxiliary wheel drive system;
• and
• a control system coupled to the user interface and the auxiliary wheel drive system for operating the auxiliary wheel drive system based on user commands received via the user interface, the control system including a processor programmed to:
• receive a first user command to move the patient transport apparatus and operate the auxiliary wheel drive system in a drive mode with the auxiliary wheel assembly in the deployed position by operating the motor control circuit to transmit power signals to the motor to rotate the auxiliary wheel;
• and
• receive a second user command to stop the patient transport apparatus and operate the auxiliary wheel drive system to decelerate the auxiliary wheel to a stop position;
• and
• upon determining the auxiliary wheel is in the stop position, operate the auxiliary wheel drive system in one of a free wheel mode and a drag mode with the auxiliary wheel assembly in the deployed position;
• wherein the auxiliary wheel drive system operates the motor control circuit to enable the auxiliary wheel to rotate more freely in the free wheel mode than the drag mode and operates the motor control circuit to resist rotation of the auxiliary wheel in the drag mode.