Caster Assembly with Low Friction Caster Wheel

Patent metadata

Field	Value
Publication number	US-2019337334-A1
Application number	US-201916400450-A
Country	US
Kind code	A1
Filing date	May 1, 2019
Priority date	May 2, 2018
Publication date	Nov 7, 2019
Grant date	—

Abstract

A patient transport apparatus comprises a support structure comprising a base and a patient support surface for supporting a patient and a caster assembly coupled to the base. The caster assembly comprises a wheel assembly. The wheel assembly includes a first edge, a second edge, and a center disposed between the first edge and the second edge. Each of the edges have a lower coefficient of friction than the center. The caster assembly further includes a tilt assembly coupled to the wheel assembly. The tilt assembly is configured to allow the wheel assembly to tilt relative to a floor surface such that at least one of the first and second edges contact the floor surface.

First claim

What is claimed is:

1 . A patient transport apparatus comprising:
a support structure comprising a base and a patient support surface for supporting a patient; a caster assembly coupled to the base, the caster assembly comprising a wheel assembly including a first edge, a second edge, and a center disposed between the first edge and the second edge, each of the edges having a lower coefficient of friction than the center; and a tilt assembly coupled to the wheel assembly and configured to allow the wheel assembly to tilt relative to a floor surface such that at least one of the first and second edges contact the floor surface.

2 . The patient transport apparatus of claim 1 , wherein the first and second edges of the wheel assembly are formed of a first material and the center of the wheel assembly is formed of a second material which is different than the first material.

3 . The patient transport apparatus of claim 2 , wherein the hardness of the center is less than the hardness of the first and second edges, when tested in accordance with ASTM D2240.

4 . The patient transport apparatus of claim 2 , wherein the first material comprises a thermoplastic.

5 . The patient transport apparatus of claim 2 , wherein the second material comprises elastomer or rubber.

6 . The patient transport apparatus of claim 1 , wherein the caster assembly comprises a stem supported by the base and a wheel support rotatably supporting the wheel assembly.

7 . The patient transport apparatus of claim 6 , wherein the tilt assembly comprises a biasing device operatively acting between the stem and the wheel support to bias the wheel assembly toward a first position.

8 . The patient transport apparatus of claim 7 , wherein the tilt assembly is configured such that the wheel assembly is oriented vertically relative to the floor surface and the center of the wheel assembly is in contact with the floor surface in the first position.

9 . The patient transport apparatus of claim 8 , wherein the tilt assembly is configured to allow the wheel assembly to move to a second position, where the wheel assembly is tilted at an acute angle relative to the floor surface such that one of the first edge or the second edge of the wheel assembly is in contact with the floor surface.

10 . The patient transport apparatus of claim 1 , wherein the center has a first texture to increase coefficient of friction, and the first and second edges have a second texture to decrease coefficient of friction.

11 . A caster assembly comprising:
a wheel assembly including a first edge, a second edge, and a center disposed between the first edge and the second edge, each of the edges having a lower coefficient of friction than the center; and a tilt assembly coupled to the wheel assembly and configured to allow the wheel assembly to tilt relative to a floor surface such that at least one of the first and second edges contact the floor surface.

12 . The caster assembly of claim 11 , wherein the first and second edges of the wheel assembly are formed of a first material and the center of the wheel assembly is formed of a second material which is different than the first material.

13 . The caster assembly of claim 12 , wherein the hardness of the center is less than the hardness of the first and second edges, when tested in accordance with ASTM D2240.

14 . The caster assembly of claim 12 , wherein the first material comprises thermoplastic.

15 . The caster assembly of claim 12 , wherein the second material comprises elastomer or rubber.

16 . The caster assembly of claim 11 , wherein the caster assembly comprises a stem and a wheel support rotatably supporting the wheel assembly.

17 . The caster assembly of claim 16 , wherein the tilt assembly comprises a biasing device operatively acting between the stem and the wheel support to bias the wheel assembly toward a first position.

18 . The caster assembly of claim 17 , wherein the tilt assembly is configured such that the wheel assembly is oriented vertically relative to the floor surface and the center of the wheel assembly is in contact with the floor surface in the first position.

19 . The caster assembly of claim 18 , wherein the tilt assembly is configured to allow the wheel assembly to move to a second position, where the wheel assembly is tilted at an acute angle relative to the floor surface such that one of the first edge or the second edge of the wheel assembly is in contact with the floor surface.

20 . The caster assembly of claim 11 , wherein the center has a first texture to increase coefficient of friction, and the first and second edges have a second texture to decrease coefficient of friction.

Assignees

• Stryker Corp

Inventors

• Patmore Kevin Mark

Classifications

• A61G7/05

  Parts, details or accessories of beds (devices for prevention against falling out A47C21/08, A47D7/00 {; mattresses A47C27/00}) · CPC title

• B60B33/045

  mounted resiliently, by means of dampers · CPC title

• B60B2200/242

  Hospital beds · CPC title

• B60B33/0055

  the rolling axle intersects swivel axis · CPC title

• A61G7/1046

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