System and method of braking for a patient support apparatus

Patent metadata

Field	Value
Publication number	US-10912685-B2
Application number	US-201615201689-A
Country	US
Kind code	B2
Filing date	Jul 5, 2016
Priority date	Jul 24, 2015
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

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

What is claimed is:

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, and the length having a midpoint;
first and second non-castered auxiliary wheels;
a support structure secured to the base configured to rotatably support the first and second non-castered auxiliary wheels about a first axis transverse to the length of the base and spaced from the midpoint for engagement with the floor surface and to pivotally support the first and second non-castered wheels about a second axis transverse to the length of the base of the floor surface wherein said first and second non-castered wheels move in an arcuate path when being raised or lowered; and
a braking system including at least one brake member configured to apply a braking force to the first and second non-castered auxiliary wheels; and
a control system configured to (1) synchronize the braking force applied by the at least one brake member when a user desires to brake the patient support apparatus in a straight path and (2) modulate the braking force applied by the at least one brake member 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 , wherein at least one brake member is movable between a first position wherein the at least one brake member is disengaged from the one auxiliary wheel of the first and second non-castered auxiliary wheels and a deployed position wherein the at least one brake member is frictionally engaged with the one auxiliary wheel to restrict rotation of the one auxiliary wheel.

3. The patient support apparatus of claim 2 , wherein the one auxiliary wheel includes a disc, the at least one brake member operable to frictionally engage the disc to thereby brake the one auxiliary wheel.

4. 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.

5. The patient support apparatus of claim 4 , wherein the braking system limits rotation of the first and second non-castered auxiliary wheels by frictionally engaging the drive mechanism to brake the first and second non-castered auxiliary wheels.

6. The patient support apparatus of claim 1 , wherein the brake system comprises a hydraulic brake system.

7. The patient support apparatus of claim 1 , wherein the braking system includes a clutch, including a mechanically driven clutch, an electrically driven clutch, or a hydraulically driven clutch, controlled by said control system to synchronize the braking force applied to the first and second non-castered auxiliary wheels.

8. The patient support apparatus of claim 7 , 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.

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

10. The patient support apparatus of claim 1 , further comprising a manually operable control, said manually operable control including a handle or a pedal, mounted at the patient support apparatus, and the braking system being coupled to the manually operable control for manual activation of the braking system.

11. The patient support apparatus of claim 1 , wherein the braking system includes a motor for driving the first and second non-castered auxiliary wheels and a controller, the controller configured to use back EMF from the motor to brake the first and second non-castered auxiliary wheels.

12. 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;
a first auxiliary wheel;
a second auxiliary wheel spaced apart from the first auxiliary wheel;
a shaft extending between and rotatably connecting the first and second auxiliary wheels;
a support structure secured to the base configured to rotatably support the first and second auxiliary wheels about an axis transverse to the length of the base for engagement with the floor surface;
a drive mechanism including a motor configured to drive the first and second auxiliary wheels;

a braking system including at least one brake member configured to apply a braking force to decelerate the first and second auxiliary wheels; and
a control system configured to (1) synchronize the braking force applied by the at least one brake member to brake the patient support apparatus in a straight path and (2) modulate the braking force applied by the at least one brake member 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 a user desires to steer the patient support apparatus in a non-straight path.

13. The patient support apparatus of claim 12 , further comprising a disc associated with the first and second auxiliary wheels, the at least one brake member operable to frictionally engage the disc to thereby brake the first and second auxiliary wheels.

14. The patient support apparatus of claim 12 , wherein the braking system selectively limits rotation of the first and second auxiliary wheels by frictionally engaging the shaft extending between and connecting the first and second auxiliary wheels.

15. The patient support apparatus of claim 12 , wherein the braking system includes a clutch, including a mechanically driven clutch, an electrically driven clutch, or a hydraulically driven clutch, controlled by said control system to synchronize or modulate the braking force applied to the first and second auxiliary wheels.

16. The patient support apparatus of claim 12 , wherein said control system controls the braking system based on input from a sensor.

17. The patient support apparatus of claim 12 , wherein the braking system includes a motor for driving the first and second auxiliary wheels, the control system configured to use back EMF from the motor to brake the first and second auxiliary wheels and thereby form the at least one brake member with the motor.

18. The patient support apparatus of claim 12 , wherein the first and second auxiliary wheels are each mounted about a shaft, the braking system including a differential rotatable joining the shafts, and the braking system selectively applying a torque to the differential to apply a braking force to the first and second auxiliary wheels.

Assignees

• Stryker Corp

Inventors

• Childs William Dwight
• Paul Anish

Classifications

• B60T1/065 Primary

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

• B60T11/046

  Using cables (B60T11/043 takes precedence) · CPC title

• B60T7/102

  by means of a tilting lever · CPC title

• F16D2125/60

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

• B60T7/22

  initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle {, or by means of contactless obstacle detectors mounted on the vehicle} · CPC title