Caster and braking system

• US 6,321,878 B1
• Filed: 03/05/1999
• Issued: 11/27/2001
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Inventors: Mobley, Donald L., Tuttle, John, Meyer, Bruce A., Cunningham, James D., Larisey, William S. Jr., Saar, James J.
• Primary Examiner(s): Butler, Douglas C.
• Assistant Examiner(s): BARTZ, CLIFFORD T
• Application Number:
  US09/263,039
• Time in Patent Office: 998 Days
• Field of Search: 188/1.12, 188/9, 188/10, 188/16, 188/19, 188/20, 188/21, 188/106.R, 188/116, 280/87.01, 16/35.R, 551/0, 560/0
• US Class Current: 188/1.12
• CPC Class Codes: A61G 1/0243 with lockable swivel action, e.g. fixing castor in certain direction locking of castor swivel action in general B60B33/02
• CPC Class Codes: A61G 7/00 Beds specially adapted for nursing; Devices for lifting patients or disabled persons stretchers with facilities for picking up patients or disabled persons A61G1/003
• CPC Class Codes: A61G 7/0528 Steering or braking devices for castor wheels
• CPC Class Codes: B60B 33/0021 in the form of a mounting pin
• CPC Class Codes: B60B 33/0028 Construction of wheels; methods of assembling on axle
• CPC Class Codes: B60B 33/0039 Single wheels
• CPC Class Codes: B60B 33/0049 the rolling axle being horizontal
• CPC Class Codes: B60B 33/0057 the rolling axle being offset from swivel axis
• CPC Class Codes: B60B 33/0068 the swivel axis being vertical
• CPC Class Codes: B60B 33/0073 the swivel axis being symmetrical to wheel or wheels
• CPC Class Codes: B60B 33/0081 acting on tire tread
• CPC Class Codes: B60B 33/0092 actuated remotely, e.g. by cable or electrically
• CPC Class Codes: B60B 33/021 combined with braking of castor wheel
• CPC Class Codes: B60B 33/023 by using friction
• CPC Class Codes: B60B 33/025 by using form-fit, e.g. front teeth
• CPC Class Codes: B60B 33/026 being actuated remotely, e.g. by cable or electrically

Abstract

A braking system for a hospital bed having a base frame includes a plurality of caster devices rotatably coupled to the base frame. Each caster device has a wheel and a brake that inhibits rotation of the wheel. The braking system further includes a plurality of pedals configured to move the brakes between a position inhibiting movement of the wheels and a position permitting rotation of the wheels. The braking system further includes a linkage coupled to the caster devices so that movement of any one of the plurality of pedals causes movement of the brakes of the caster devices.

Claims

1. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to support the base frame on the floor, each caster device including a wheel and a brake positioned to move between a first position in which the brake inhibits rotation of the wheel and a second position in which the brake permits the wheel to rotate freely,

a plurality of pedals positioned to be moved by a user to move the brakes,

a linkage positioned to coordinate movement of all the brakes so that movement of any one of the plurality of pedals causes movement of all of the brakes, and

a plurality of caster mounting tubes having an interior configured to receive a portion of one of the plurality of caster devices, the caster mounting tubes having a rectangular outer cross-section defined by four external side walls, one of the external side walls adapted to abut the base frame, the plurality of caster mounting tubes including a weld adapted to connect the caster mounting tubes to the base frame.

2. A braking system for a hospital bed having a base frame including a first side frame member and a spaced-apart second side frame member, the braking system comprising:

a plurality of casters, each caster having a wheel and a brake, a first and second of the plurality of casters being adapted to attach to one of the first and second side frame members of the bed and a third caster adapted to attach to the other of the first and second side frame member of the bed,

a link extending between the first and second casters,

a cross shaft extending between the first side frame member and second side frame member of the bed, the link and cross shaft are arranged so that braking of any one of wheels of the first, second, or third casters induces braking of the other of the first, second, or third casters, and

a plurality of caster mounting tubes having an interior configured to receive a portion of one of the plurality of casters, the caster mounting tubes having a rectangular outer cross-section defined by four external side walls, one of the external side walls adapted to abut the base frame, the plurality of caster mounting tubes including a weld adapted to connect the caster mounting tube to the base frame.

3. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to support to the base frame, each caster device including a wheel, a brake configured to move between a first position in which the brake inhibits rotation of the wheel and a second position in which the brake permits the wheel to rotate freely, and an actuator,

a plurality of pedals positioned to provide movement of the actuator to move the brake between the first position and second position in response to movement of the pedal, and

a linkage coupled to all of the actuators of the plurality of caster devices so that movement of any one of the plurality of pedals causes movement of all of the actuators, the actuator including a cam attached to a rotatable shaft and a follower coupled to the brake, each of the plurality of caster devices including a sleeve, the cam and follower being disposed within the sleeve, and the shaft extending through the sleeve.

4. The apparatus of claim 3, wherein the linkages are coupled to the shaft.

5. The apparatus of claim 4, wherein base frame has a first side frame member and a spaced-apart second side frame member and at least two of the plurality of caster devices are adapted to be attached to the first side frame member and at least one of the plurality of caster devices is adapted to be attached to the second side frame member.

6. The apparatus of claim 5, wherein the linkage includes a first side link adapted to be attached for movement relative to the first side frame member of base frame and coupling the shafts of the actuators of the caster devices adapted to be attached to the first side frame member and a cross shaft coupling the first side link to the shaft of the at least one of the caster devices adapted to be attached to the second side frame member of the base frame.

7. The apparatus of claim 6, wherein rotation of the shaft induces rotation of the cross shaft.

8. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to be rotatably coupled to the base frame, each caster device including a wheel, a brake positioned to move between a first position in which the brake inhibits rotation of the wheel and a second position in which the brake permits the wheel to rotate freely, and an actuator,

a plurality of pedals configured to move the actuators to provide movement of the brake between the first position and second position in response to movement of the pedal, and

a linkage coupled to the actuators of the plurality of caster devices so that movement of any one of the plurality of pedals causes movement of all of the actuators, at least one of the plurality of caster devices includes a steer lock, the steer lock being movable between a first state in which the caster device swivels and a second state in which the caster device does not swivel, the steer lock and brake being coupled to the actuator so that rotation of the rotatable shaft in a first direction places the brake in the first position and rotation of the rotatable shaft in a second direction places the steer lock in the first state.

9. The apparatus of claim 8, wherein base frame has a first side frame member and a spaced-apart second side frame member and at least two of the plurality of caster devices are adapted to be attached to the first side frame member and at least one of the plurality of caster devices is adapted to be attached to the second side frame member.

10. The apparatus of claim 9, wherein the linkage includes a first side link attached for movement relative to the first side frame member of base frame and coupling the shafts of the actuators of the caster devices adapted to be attached to the first side frame member and a cross shaft coupling the first side link to the shaft of the at least one of the caster devices adapted to be attached to the second side frame member of the base frame.

11. The apparatus of claim 10, wherein rotation of any one of the rotatable shafts induces rotation of the cross shaft.

12. The apparatus of claim 11, wherein the cam has a neutral surface, a brake-engaging surface, and a steer lock surface designed so that when the follower engages the neutral surface the brake is in the second position and the steer lock is in the second state.

13. The apparatus of claim 12, wherein the brake is in the first state and the steer lock is in the second state when the follower engages the brake-engaging surface of the cam.

14. The apparatus of claim 12, wherein the brake is in the second state and the steer lock is in the first state when the follower engages the steer lock surface.

15. The apparatus of claim 14, wherein the brake is in the first state and the steer lock is in the second state when the follower engages the brake-engaging surface of the cam.

16. The apparatus of claim 15, wherein the brake-engaging surface is located between 20 to 40 degrees in a first direction from the neutral surface and the steer lock surface is located between 20 to 40 degrees in a second direction from the neutral surface.

17. A braking system for a hospital bed having a base frame including a first side frame member and a spaced-apart second side frame member, the braking system comprising:

a plurality of casters, each caster having a wheel, a brake, and an actuator, a first and second of the plurality of casters being adapted to be attached to one of the first and second side frame members of the bed and a third caster being adapted to be attached to the other of the first and second side frame member of the bed,

a link extending between and coupled to the actuators of the first and second casters,

a cross shaft adapted to extend between the first side frame member and second side frame member of the bed, the cross shaft having a first end coupled to the link and a second end coupled to the actuator of the third caster, the link and cross shaft are arranged so that actuation of any one of the actuators of the first, second, or third casters induces actuation of the others of the actuators of the first, second, or third casters, the actuator including a shaft, a cam mounted on the shaft, and a follower engaging the surface of the cam at a first end and coupled to a brake at a second end, the actuator being arranged such that rotational motion of the shaft induces movement of the brake, the shaft having an axis of rotation fixed relative to the base frame, the link being pivotally coupled to the shaft by a first pivot bracket fixed to the shaft and riding on a first pivot pin having a pivot axis extending through the link, the cross shaft being mounted to the frame for rotation about an axis of rotation fixed relative to the frame, the cross shaft being pivotally coupled to the link by a second bracket fixed to the cross shaft and riding on a second pivot pin having a pivot axis extending through the link, and wherein the displacement between the axis of rotation of the shaft and the first pivot axis is substantially equal to the displacement between the axis of rotation of the cross shaft and the second pivot axis.

18. The apparatus of claim 17, wherein the link includes a vertical offset bracket through which one of the first and second pivot pins passes so that the axis of rotation of the shaft and the axis of rotation of the cross shaft are in different vertical planes.

19. The apparatus of claim 18, wherein the base frame includes a cross member extending between the first and second side frame members, the axis of rotation of the shaft is adapted to be fixed relative to the first and second side frame members, and the cross shaft is adapted to be rotatably mounted to the cross member so that the axis of rotation of the cross shaft is fixed relative to axis of rotation of the shaft.

20. A patient support apparatus comprising:

a base frame;

a hex shaft;

a caster mounting tube attached to the base frame, the caster mounting tube being formed to include a shaft hole through which the hex shaft extends;

a caster having a wheel rotatably mounted to a caster fork, a hollow sleeve having a top surface and a bottom surface and being swivably connected to the caster fork at the bottom surface, a cam disposed within the interior of the hollow sleeve, a follower engaging the cam at a first end and extending through the caster fork at a second end, a hex shaft-receiving hole formed in the hollow sleeve adjacent the cam, the hex shaft-receiving hole being closer to the bottom surface than to the top surface, and

a brake pad attached to the second end of the follower;

wherein the hex shaft extends through the hex shaft-receiving hole in the hollow sleeve, the cam is received on the hex shaft, and rotation of hex shaft induces rotation of cam which displaces follower until brake pad engages wheel thereby inhibiting rotation of wheel with respect to caster fork.

21. The apparatus of claim 20, and further comprising a second wheel and an axle, wherein the axle is attached to the caster fork and the first and second wheel are spaced apart and rotatably mounted on the axle.

22. The apparatus of claim 21, wherein rotation of the hex shaft induces brake pad to engage both wheels inhibiting rotation of the wheels and swiveling of the sleeve relative to the caster fork.

23. The apparatus of claim 20, and further comprising a set screw wherein the sleeve is formed to include a set screw hole between the hex shaft-receiving hole and the top surface, the caster mounting tube is formed to include a set screw hole above the shaft hole, and the set screw extends through the set screw hole and is received in the set screw-receiving hole.

24. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to support the base frame on the floor, the caster devices having a wheel, a brake positioned to move between a first position in which the brake inhibits rotation of the wheel and a second position in which the brake permits the wheel to rotate freely, and an actuator positioned to move the brake between the first and second positions,

a plurality of pedals coupled to the actuators of the plurality of caster devices to move the brakes between the first position and second position in response to movement of the pedal, and

a linkage coupled to the actuators of the plurality of caster devices so that movement of any one of the plurality of pedals causes movement of all of the actuators, the actuators being positioned between the pedals and the linkage.

25. The braking system of claim 24, wherein each actuator includes a shaft coupled to the linkage.

26. The braking system of claim 25, wherein the plurality of pedals are coupled to the shafts of the actuators.

27. The braking system of claim 25, wherein each actuator further includes a pair of arms coupling a pair of the plurality of pedals to the shaft.

28. The braking system of claim, 24, wherein the plurality of caster devices includes at least four caster devices and the plurality of pedals includes at least two pedals for each of the four caster devices.

29. The braking system of claim 24, wherein the pedals are coupled to the actuators of the plurality of caster devices.

30. The braking system of claim 24, wherein the linkage includes a pair of spaced-apart links extending between and coupled to the actuators and a cross shaft extending between and coupled to the spaced-apart links.

31. The braking system of claim 24, wherein the caster device further includes a steer lock configured to inhibit swiveling of the wheel when in a first state and permit swivelling of the wheel when in a second state, movement of the pedal in a first direction by the users moves the brake of the plurality of caster devices and movement of the pedal in a second direction moves the steer lock.

32. The braking system of claim 31, wherein the pedal is configured to move between a brake position with the brakes in the first position, a steer lock position with the steer lock in the first state, and a neutral position with the brakes in the second position and the steer lock in the second state, and the neutral position is between the brake and steer lock positions.

33. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to movably support the base frame on the floor, the caster devices including a wheel in contact with the floor and a brake configured to move between a first position in which the brake inhibits movement of the base frame relative to the floor and a second position in which the brake permits movement of the base frame relative to the floor, and an actuator positioned to move the brake,

a plurality pedals adapted to receive force from a user, each of the plurality of pedals being coupled to one of the actuators of the plurality of caster devices to transfer said force applied to said pedal to said actuator and move the brake, and

a linkage coupled to the actuators of the plurality of caster devices to receive the force transferred to said actuator and transfer said force to the other of the plurality of actuators so that movement of any one of the plurality of pedals causes movement of all of the actuators.

34. The braking system of claim 33, wherein each actuator includes a shaft coupled to the linkage, the plurality of pedals are coupled to the shafts of the actuators, and each actuator further includes a pair of arms coupling a pair of the plurality of pedals to the shaft.

35. The braking system of claim 33, wherein the plurality of caster devices includes at least four caster devices and the plurality of pedals includes at least two pedals for each of the four caster devices.

36. The braking system of claim 33, wherein the linkage includes a pair of spaced-apart links extending between and coupled to the actuators and a cross shaft extending between and coupled to the spaced-apart links.

37. The braking system of claim 33, wherein the caster device further includes a steer lock configured to inhibit swiveling of the wheel when in a first state and permit swivelling of the wheel when in a second state, movement of the pedal in a first direction by the users moves the brake of the plurality of caster devices and movement of the pedal in a second direction moves the steer lock, the pedal is configured to move between a brake position with the brakes in the first position, a steer lock position with the steer lock in the first state, and a neutral position with the brakes in the second position and the steer lock in the second state, and the neutral position is between the brake and steer lock positions.

38. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to movably support the base frame on the floor, the caster devices including a wheel in contact with the floor and a brake configured to move between a first position in which the brake inhibits movement of the base frame relative to the floor and a second position in which the brake permits movement of the base frame relative to the floor,

a plurality pedals adapted to receive force from a user to move the brakes, and

a linkage configured to distribute the force from the pedals to the brakes so that movement of any one of the plurality of pedals causes movement of all of the brakes, the linkage including a shaft connecting at least two of the plurality of casters to coordinate movement of the brakes, the shaft rotating about a horizontal axis of rotation during distribution of the force.

39. The brake system of claim 38, wherein the linkage further includes a pair of spaced-apart links, each link extending between at least two of the plurality of caster devices, and the shaft extends between the pair of spaced-apart links.

40. The brake system of claim 39, wherein the linkage further a pair of arms pivotably coupled to the links and rigidly coupled to the shaft.

41. The brake system of claim 39, wherein the linkage further includes another shaft extending between the pair of spaced-apart links.

42. The brake system of claim 38, wherein the shaft includes first and second spaced-apart ends that are adapted to be pivotably coupled to the base frame.

43. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to movably support the base frame on the floor, each caster device including a wheel in contact with the floor and a brake movable between a first position in which the brake inhibits movement of the base frame and a second position in which the brake permits the base frame to move, at least one of the plurality of caster devices includes a steer lock movable between a first state in which the caster device does not swivel and a second state in which the caster device swivels,

a pedal adapted to be moved by a user, and

a linkage coupled to the plurality of caster devices so that movement of the pedal in a first direction by the users moves the brake of the plurality of caster devices and movement of the pedal in a second direction moves the steer lock.

44. The brake system of claim 43, wherein the pedal includes a brake position when the brake is in the first position, a steer lock position when the steer lock is in the first state, and a neutral position when the brake is in the second position and the steer lock is in the second state, and the neutral position is between the brake and steer lock positions.

45. The brake system of claim 43, wherein the linkage includes a pair of spaced-apart links that couple the caster devices together, the links are movable between a first position with the brake in the first position and a second position with the steer lock in the first state.

46. The brake system of claim 45, wherein the linkage further includes a cross bar extending between the spaced-apart links to coordinate movement of the links between the first and second positions.

47. A braking system for a hospital bed having a base frame, the system comprising

a plurality of caster devices adapted to be rotatably coupled to the base frame, each caster device having a caster frame, a wheel rotatably attached to the caster frame, a brake attached for movement with respect to the caster frame between a first position in which the brake inhibits rotation of the wheel and a second position in which the brake permits the wheel to rotate freely, and an actuator,

a plurality of pedals each adjacent to a different one of the plurality of caster devices and coupled to the actuator for movement of the brake between the first position and second position in response to movement of the pedal, and

a linkage coupled to all of the actuators of the plurality of caster devices so that movement of any one of the plurality of pedals causes movement of all of the actuators, at least one of the pedals being configured so that the movement of the at least one pedal causes movement of the adjacent caster device separate from the linkage.

48. The apparatus of claim 47, wherein the actuator includes a cam attached to a rotatable shaft and a follower coupled to the brake.