Motorized traction device for a patient support

1. 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.

2. The patient support of claim 1 , wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame.

3. The patient support of claim 2 , wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support.

4. The patient support of claim 3 , wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position.

5. The patient support of claim 4 , wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support.

6. The patient support of claim 5 , wherein the at least one spring is coupled to the rolling support mount.

7. The patient support of claim 1 , wherein the rolling support is at least one of a wheel, roller, track, or belt.

8. The patient support of claim 1 , comprising a user input device operably coupled to the propulsion device.

9. The patient support of claim 1 , comprising a speed controller configured to control the motor output based on user input.

10. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the at least one spring is coupled to the rolling support mount

wherein the at least one spring is coupled to the actuator by a shuttle.

11. The patient support of claim 10 , wherein the shuttle is coupled to the actuator by a linkage system.

12. The patient support of claim 11 , wherein the linkage system comprises a plurality of links.

13. The patient support of claim 12 , wherein the plurality of links comprises a first link pivotably coupled to the actuator and the frame, and a second link pivotably coupled to the first link and the shuttle.

14. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the at least one spring has a first end pivotably coupled to the shuttle and a second end coupled to the rolling support mount.

15. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mover is configured such that the actuator is in a retracted position and the spring is in a compressed position when the propulsion device is in the second position.

16. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mover is configured such that the actuator is in an extended position and the spring is in an uncompressed position when the propulsion device is in the first position.

17. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mover is configured such that the actuator is in an extended position and the spring is in an compressed position when the propulsion device is in the second position.

18. 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, and

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,

wherein the traction engagement controller comprises a rolling support mount coupled to the frame and supporting the propulsion device, and a rolling support mount mover coupled to the rolling support mount and coupled to the frame,

wherein the rolling support mount mover is configured to move the rolling support mount from the first position to the second position and to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mount mover comprises an actuator configured to move the rolling support mount from the first position to the second position,

wherein the rolling support mount mover comprises at least one spring configured to move the rolling support mount in response to the changes in elevation of the patient support,

wherein the rolling support mover is configured such that the actuator is in a retracted position and the spring is in an uncompressed position when the propulsion device is in the first position.

19. 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,

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

an external power detector operable to determine if external power is supplied to the patient support, wherein the traction engagement controller is configured to initiate movement of the propulsion device to the second position if the external power detector determines that external power is not supplied to the patient support.