System and method of braking for a patient support apparatus

Patent metadata

Field	Value
Publication number	US-11497664-B2
Application number	US-202117165210-A
Country	US
Kind code	B2
Filing date	Feb 2, 2021
Priority date	Jul 24, 2015
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

A patient support apparatus includes a base having a length and including a plurality of caster wheels enabling movement of the patient support apparatus across a floor surface. An auxiliary wheel support structure is secured to the base and rotatably supports at least one non-castered auxiliary wheel. A drive mechanism including a motor may be configured to drive the auxiliary wheel. A braking system including at least one brake member may be configured to apply a braking force to decelerate the auxiliary wheel and is movable between a first position wherein the at least one brake member is disengaged from the auxiliary wheel and a deployed position wherein the at least one brake member is frictionally engaged with the auxiliary wheel to restrict rotation of the auxiliary wheel. The braking system may be configured to synchronize the braking forces applied to first and second auxiliary wheels.

First claim

We claim:

1. A patient support apparatus comprising:
a base having a length and including a plurality of caster wheels enabling movement of the patient support apparatus across a floor surface;
first and second non-castered auxiliary wheels;
a braking system configured to apply a braking force to the first non-castered auxiliary wheel and/or the second non-castered auxiliary wheel; and
a control system configured to (1) synchronize the braking force when a user desires to brake the patient support apparatus in a straight path and (2) modulate the braking force wherein one auxiliary wheel of the first and second non-castered auxiliary wheels is braked at a different speed than the other auxiliary wheel of the first and second non-castered auxiliary wheels when a user desires to steer the patient support apparatus in a non-straight path.

2. The patient support apparatus of claim 1 , further comprising a sensor wherein the control system selectively actuates the braking system based on input from the sensor.

3. The patient support apparatus of claim 2 , further comprising a handle operable by a user, wherein the sensor is located at the handle.

4. The patient support apparatus of claim 2 , wherein the sensor detects the wheel speed of at least one of the auxiliary wheels.

5. The patient support apparatus of claim 1 , further comprising a handle operable by a user to push or steer the patient support apparatus and a handle sensor located at the handle, the control system configured to (1) synchronize the braking force in response to signals from said handle sensor when a user wishes to brake the patient support apparatus and (2) modulate the braking force in response to signals from said handle sensor when a user desires to steer the patient support apparatus in a non-straight path.

6. The patient support apparatus of claim 2 , wherein the sensor detects the presence of an object or person, and the control system actuating the braking system when the sensor detects the presence of the object or person to avoid a collision with the object or a person.

7. The patient support apparatus of claim 1 , wherein the braking system includes at least one brake member, the brake member is movable between a deployed position wherein the brake member brakes at least one auxiliary wheel of the first and second non-castered auxiliary wheels is braked and a non-deployed position.

8. The patient support apparatus of claim 7 , wherein the one auxiliary wheel of the first and second non-castered auxiliary wheels includes a disc, the brake member operable to frictionally engage the disc to thereby brake the one auxiliary wheel.

9. The patient support apparatus of claim 1 , further comprising a drive mechanism configured to drive the first and second non-castered auxiliary wheels, the drive mechanism comprising a motor.

10. The patient support apparatus of claim 9 , wherein the braking system uses back EMF from the motor to brake to the first non-castered auxiliary wheel and/or the second non-castered auxiliary wheel.

11. The patient support apparatus of claim 1 , wherein the braking system includes a clutch, the control system controlling the clutch to synchronize the braking force applied to the first and second non-castered auxiliary wheels.

12. The patient support apparatus of claim 11 , wherein the at least one brake member comprises a brake pad or a caliper to brake the one auxiliary wheel of the first and second non-castered auxiliary wheels, and the clutch selectively applies the braking force from the one auxiliary wheel of the first and second non-castered auxiliary wheels to the other auxiliary wheel of the first and second non-castered auxiliary wheels.

13. A method of braking or steering a patient support apparatus, the patient support apparatus having a plurality of front and rear bearings and first and second auxiliary wheels located between the front and rear bearings, said method comprising;
applying a braking force to brake the first auxiliary wheel and/or the second auxiliary wheel;
synchronizing the braking force when braking the patient support apparatus in a straight path; and
modulating the braking force wherein one auxiliary wheel of the first and second auxiliary wheels is braked at a different speed than the other auxiliary wheel of the first and second auxiliary wheels when steering the patient support apparatus in a non-straight path.

14. The method of claim 13 , further comprising monitoring input from a sensor, and synchronizing and/or modulating the braking force based on the input.

15. The method of claim 14 , wherein said monitoring includes monitoring input from a plurality of sensors.

16. The method of claim 13 , wherein the patient support apparatus includes a motor for driving the first and second auxiliary wheels, said applying the braking force includes using back EMF from the motor to apply the braking force.

17. The method of claim 13 , wherein the first and second auxiliary wheels are each mounted about a shaft, further comprising a differential joining the shafts, said applying the braking force includes applying a torque to the differential to apply the braking force to the first and second auxiliary wheels.

Assignees

• Stryker Corp

Inventors

• Childs William Dwight
• Paul Anish

Classifications

• A61G1/0237

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

• A61G7/08

  Apparatus for transporting beds · CPC title

• B60T1/065 Primary

  employing disc (B60T1/062 takes precedence) · CPC title

• A61G7/0528

  Steering or braking devices for castor wheels · CPC title

• F16D2125/60

  Cables or chains, e.g. Bowden cables · CPC title