Person support apparatus power drive system
View Patent ↗A person support apparatus comprises a lower frame, an upper frame, a drive structure, and a control system. The upper frame is movably supported above the lower frame. The drive structure is coupled to the upper frame and configured to selectively engage a surface to, when activated, propel the person support apparatus along the surface. The control system is configured to determine an engagement status of the drive structure with the surface and trigger a response based on the engagement status.
1. A person support apparatus, comprising:
a lower frame;
an upper frame movably supported above the lower frame by a lift system;
a weigh scale operable to weigh a person supported by the upper frame;
a drive structure coupled to the upper frame and movable with the upper frame as the upper frame is moved by the lift system with respect to the lower frame, the drive structure being configured to selectively engage a surface when the upper frame is in a lowered position to, when activated, propel the person support apparatus along the surface; and
a control system configured to determine whether the drive structure engages the surface and trigger a response as a function of such determination, wherein the weigh scale is prevented by the control system from weighing the person if the drive structure is engaging the surface.
2. The person support apparatus of claim 1 , wherein the response includes the control system causing the upper frame to move to a predetermined position with respect to the lower frame so that the drive structure engages the surface.
3. The person support apparatus of claim 1 , wherein the response includes the control system communicating whether the drive structure engages the surface to a user.
4. The person support apparatus of claim 1 , wherein the control system causes a light to be illuminated to indicate that the drive structure engages the surface.
5. The person support apparatus of claim 1 , wherein the control system causes a light to be illuminated to indicate that the upper frame must be lowered.
6. The person support apparatus of claim 5 , wherein the light flashes until the drive structure engages the surface.
7. The person support apparatus of claim 1 , wherein the drive structure is movable with respect to the upper frame to maintain engagement of the drive structure with the surface as the drive structure moves along the surface, wherein the surface is a non-uniform surface.
8. The person support apparatus of claim 1 , wherein the control system determines whether the drive structure engages the surface when the control system receives an input indicative of a user's desire to activate the drive structure.
9. The person support apparatus of claim 1 , wherein the engagement of the drive structure with the surface is determined as a function of the position of the upper frame with respect to a reference.
10. The person support apparatus of claim 9 , wherein the reference includes a surface of the lower frame.
11. The person support apparatus of claim 9 , wherein the reference includes a floor surface.
12. The person support apparatus of claim 9 , wherein the control system alerts a user that the drive structure system does not engage the surface when the distance between the upper frame and the reference exceeds a predetermined distance.
13. The person support apparatus of claim 12 , wherein the predetermined distance includes the distance between the upper frame and the lower frame when the upper frame is in its lowest position with respect to the lower frame.
14. The person support apparatus of claim 9 , wherein the control system includes a sensing element configured to sense the distance between the upper frame and the reference surface.
15. The person support apparatus of claim 14 , wherein the sensing element includes a hall effect sensor.
16. The person support apparatus of claim 14 , wherein the sensing element includes a limit switch.
17. The person support apparatus of claim 14 , wherein the sensing element includes an ultrasonic sensing mechanism.
18. The person support apparatus of claim 1 , wherein the response includes the control system causing the upper frame to move to a predetermined position with respect to the lower frame so that the drive structure is disengaged from the surface.
19. The person support apparatus of claim 1 , wherein the response includes the control system communicating a status of the weigh scale to a user.
20. The person support apparatus of claim 1 , wherein the response includes the control system causing a light to be illuminated to indicate that a person supported on the person support apparatus is able to be weighed when the drive structure is disengaged from the surface.
21. The person support apparatus of claim 1 , wherein the response includes the control system causing a light to be illuminated to indicate that the upper frame must be raised.
22. The person support apparatus of claim 21 , wherein the light flashes until the drive structure is disengaged from the surface.
23. The person support apparatus of claim 1 , wherein the control system includes a limit switch that is in a first state when the drive structure engages the surface and is in a second state when the drive structure is disengaged from the surface.
24. The person support apparatus of claim 1 , wherein the control system determines whether the drive structure engages the surface when the control system receives an input indicative of a user's desire to weigh a person.
25. The person support apparatus of claim 1 , wherein the control system includes a sensor configured to sense when the drive structure engages the surface.
26. The person support apparatus of claim 1 , wherein the drive structure is pivotably connected to the upper frame at a first joint and pivotably connected to the upper frame via a biasing element at a second joint, wherein the biasing element biases the drive structure toward engagement with the surface.
27. The person support apparatus of claim 26 , wherein the control system includes a sensor coupled to the biasing element and configured to sense a characteristic of the biasing element indicative of whether the drive structure engages the surface.