Patient transport apparatus with auxiliary wheel system

Patent metadata

Field	Value
Publication number	US-11801174-B2
Application number	US-202318116354-A
Country	US
Kind code	B2
Filing date	Mar 2, 2023
Priority date	Nov 21, 2018
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

A patient transport apparatus transports a patient over a floor surface. The patient transport apparatus comprises a support structure and support wheels coupled to the support structure. An auxiliary wheel is coupled to the support frame to influence motion of the patient transport apparatus over a floor surface. The auxiliary wheel is movable to a deployed position with the auxiliary wheel engaging the floor surface and a stowed position with the auxiliary wheel spaced a distance from the floor surface. An actuator assembly including a lift actuator a biasing device, and a biasing load adjustment assembly. The lift actuator is operable to move the auxiliary wheel to the deployed position and to the stowed position. The biasing device configured to bias the auxiliary wheel towards the deployed position. The biasing load adjustment assembly configured to adjust a biasing force being applied by the biasing device to the auxiliary wheel.

First claim

What is claimed is:

1. A patient transport apparatus comprising:
a base arranged for movement along a floor surface;
an intermediate frame operatively attached to the base and supporting a patient support deck to support a patient;
an auxiliary wheel assembly including a wheel support frame supporting a motor and an auxiliary wheel disposed in rotational communication with the motor to influence motion of the patient transport apparatus over the floor surface, the wheel support frame being arranged for pivoting movement relative to the base to move the auxiliary wheel between:
a deployed position with the auxiliary wheel engaging the floor surface to drive along the floor surface, and
a stowed position with the auxiliary wheel spaced from the floor surface;

a lift actuator operable to move the auxiliary wheel between the deployed position and the stowed position;
a biasing device arranged to urge the wheel support frame away from the base to bias the auxiliary wheel towards the deployed position; and
a biasing load adjustment assembly for adjusting a biasing force applied by the biasing device to the auxiliary wheel.

2. The patient transport apparatus of claim 1 , wherein the biasing load adjustment assembly includes a slider block arranged for sliding movement relative to the base and disposed in contact with the biasing device to adjust a load imparted on the wheel support frame by the biasing device.

3. The patient transport apparatus of claim 2 , further including a support frame operatively attached to the base and including a first cross-member and a second cross-member spaced a distance from the first cross-member along a longitudinal axis, with the wheel support frame pivotably coupled to the first cross-member for moving the auxiliary wheel between the stowed position and the deployed position.

4. The patient transport apparatus of claim 3 , wherein the slider block is positionable along an outer surface of the first cross-member to contact the biasing device to adjust a load imparted on the wheel support frame by the biasing device.

5. The patient transport apparatus of claim 4 , wherein the biasing load adjustment assembly includes:
a positioning bracket coupled to the first cross-member; and
a positioning assembly coupled to the positioning bracket and the slider block for adjusting a position of the slider block relative to the biasing device to facilitate adjusting the load imparted on the wheel support frame by the biasing device.

6. The patient transport apparatus of claim 5 , wherein the positioning bracket includes a positioning opening extending through the positioning bracket, the positioning assembly extending through the positioning opening to contact the slider block.

7. The patient transport apparatus of claim 6 , wherein the positioning assembly includes a positioning pin inserted through the positioning opening to contact the slider block to maintain a position of the slider block with respect to the biasing device.

8. The patient transport apparatus of claim 6 , wherein the positioning assembly includes a positioning bolt extending through the positioning opening defined through the positioning bracket, the positioning bolt coupled to the slider block such that a movement of the positioning bolt causes a movement of the slider block.

9. The patient transport apparatus of claim 8 , wherein the positioning assembly includes a positioning nut rotatably coupled to the positioning bolt to adjust a position of the positioning bolt with respect to the positioning bracket.

10. The patient transport apparatus of claim 9 , wherein the positioning bolt includes a threaded outer surface, the positioning nut threadably coupled to the positioning bolt.

11. The patient transport apparatus of claim 10 , wherein a rotation of the positioning nut in a first rotational direction moves the slider block towards the biasing device and a rotation of the positioning nut in a second rotational direction moves the slider block away from the biasing device.

12. The patient transport apparatus of claim 11 , wherein the slider block is movable along an outer surface of the first cross-member in a first linear direction towards the biasing device and a second opposite linear direction away from the biasing device; and
wherein the rotation of the positioning nut in the first rotational direction moves the slider block in the first linear direction towards biasing device, and the rotation of the positioning nut in the second rotational direction moves the slider block in the second opposite linear direction away from the biasing device.

13. The patient transport apparatus of claim 1 , wherein the biasing device extends between a first end and a second end, the first end positioned in contact with the biasing load adjustment assembly and the second end positioned in contact with the wheel support frame.

14. The patient transport apparatus of claim 1 , wherein the biasing load adjustment assembly includes:
a positioning bracket operatively attached to the base; and
a positioning assembly coupled to the positioning bracket and to the wheel support frame for adjusting a position of the wheel support frame with respect to the base.

15. The patient transport apparatus of claim 14 , wherein the positioning assembly includes a positioning bolt extending through a positioning opening defined through the positioning bracket, the positioning bolt coupled to the wheel support frame such that a movement of the wheel support frame causes a movement of the positioning bolt.

16. The patient transport apparatus of claim 15 , wherein the positioning assembly includes a positioning nut rotatably coupled to the positioning bolt to adjust a position of the positioning bolt with respect to the positioning bracket.

17. The patient transport apparatus of claim 16 , wherein the positioning bolt includes a threaded outer surface, the positioning nut threadably coupled to the positioning bolt.

18. The patient transport apparatus of claim 17 , wherein a rotation of the positioning nut in a first rotational direction moves the wheel support frame towards the base and a rotation of the positioning nut in a second rotational direction moves the wheel support frame away from the base.

19. The patient transport apparatus of claim 1 , wherein the biasing load adjustment assembly includes a support bracket extending outwardly from the base towards the wheel support frame, the support bracket including a positioning opening extending therethrough; and
wherein the wheel support frame includes a positioning slot orientated with respect to the positioning opening such that a tool may be removably inserted through the positioning opening and the positioning slot to prevent a movement of the wheel support frame with respect to the base.

20. The patient transport apparatus of claim 1 , wherein the biasing device includes a torsion spring in contact with the wheel support frame to bias the wheel support frame away from the base.

Assignees

• Stryker Corp

Inventors

• Derenne Richard A
• Bartley Gary L

Classifications

• A61G1/0268 Primary

  having deployable or retractable wheels · CPC title

• A61G1/0237

  having at least one swivelling wheel, e.g. castors · CPC title

• A61G7/005

  tiltable around transverse horizontal axis, e.g. for Trendelenburg position {(rocking beds for physical therapy A61H1/003; hanging patient inclined downwardly for drawing him out A61H2203/0493)} · CPC title

• A61G7/1046

  Mobile bases, e.g. having wheels · CPC title

• B60B33/045

  mounted resiliently, by means of dampers · CPC title