Dynamically balanced seat assembly having independently and arcuately movable seat and backrest and method

• US 20030230918A1
• Filed: 06/18/2002
• Published: 12/18/2003
• Est. Priority Date: 06/18/2002
• Status: Active Grant

• Current Assignee: Hector Serber
• Original Assignee: Hector Serber
• Inventors: Serber, Hector
• Granted Patent: US 7,234,775 B2
• Time in Patent Office: Days
• US Class Current: 297/313
• CPC Class Codes: A47C 1/022 having independently-adjustable supporting parts
• CPC Class Codes: A47C 1/03 the parts being arm-rests conversion into a bed A47C17/12

Abstract

A seat assembly (21) including a seat (22), a backrest (23) and a mounting assembly (24) mounting the seat (22) in a near horizontal orientation for movement along an upwardly concaved arcuate seat path having a center of curvature (37) proximate the center of mass (39) of a person seated on the seat, and the mounting assembly (24) further mounting the backrest (23) in a near vertical orientation for movement independently of the seat along a forwardly concaved arcuate path having a center curvature (37) proximate the center of mass (39) of the person. An adjustment assembly (61) is provided for adjusting the radius of curvature of the path of motion of the backrest (23). Also provided are a backrest tilt adjustment assembly (71), an armrest adjustment assembly (90), a seat biasing assembly (110) and a seat motion latching assembly (111). A method of self-adjusting support and alignment of a backrest also is disclosed.

Claims

1. A seat assembly comprising:

(a) a seat;

(b) a backrest; and

(c) a mounting assembly mounting said seat in a near horizontal orientation for movement along an upwardly concaved arcuate seat path having a center of curvature proximate the center of mass of a person seated on said seat, said mounting assembly further mounting said backrest in a near vertical orientation for movement independently of said seat along a forwardly concaved arcuate back path having a center of curvature proximate the center of mass of the person seated on said seat.

2. The seat assembly as defined in claim 1 wherein,

the center of curvature of the path of the seat and the center of curvature of the path of the backrest are concentric.

3. The seat assembly as defined in claim 1, and

an adjustment assembly provided on said mounting assembly and formed to enable adjustment of the radius of curvature of the path of motion of the backrest without changing the relative positions of the centers of curvature of the seat and the backrest.

4. The seat assembly as defined in claim 1 wherein,

said mounting assembly includes a pedestal, a U-shaped frame mounted to the pedestal with a pair of upwardly extending frame arms, a U-shaped seat support cradle pivotally mounted between said frame arms from proximate a top of said frame arms and downwardly depending therefrom, said seat being carried by said seat cradle for pivotal movement relative to said frame arms, and

said mounting assembly further including a U-shaped back support assembly pivotal mounted to said frame arms and extending rearwardly thereof, a biasing assembly biasing the back support assembly to a near horizontal orientation, said backrest being mounted to said back support assembly.

5. The seat assembly as defined in claim 4 wherein,

said back support assembly includes an adjustment assembly formed for adjustment of the length of the back support assembly between said backrest and the pivotal mount to said frame arms.

6. The seat assembly as defined in claim 5 wherein,

said back support assembly includes a pair of stub arms pivoted at one end to said frame arms and attached at the other end to the sleeve, said back support assembly including a back strap member having an end telescoped relative to said sleeve;

and

said adjustment assembly includes a rack provided in said back strap member with a plurality of side-by-side pockets and a rotatable member having a plurality of pins thereon dimensioned to be received in said pockets, said rotatable member being mounted to said sleeve and including a manually engageable handle thereon for rotation of said rotatable member to walk said pins along said rack and thereby displace back strap relative to said stub arms.

7. The seat assembly as defined in claim 4 wherein,

said biasing assembly is adjustable as to the force upwardly biasing said seat support assembly.

8. The seat assembly as defined in claim 7 wherein,

said biasing assembly includes a pair of compression springs each coupled at one end to said frame arms and coupled at the other end to said back support assembly, said biasing assembly further including a pair of cams mounted for displacement of the compression springs to increase and decrease the force applied to the back support assembly, and manually engageable knobs coupled to said cams and mounted for gripping and rotation by the user to displace the cams in a manner producing at least one of increased and decreased upward biasing of the back support assembly.

9. The seat assembly as defined in claim 1 wherein,

said backrest includes a backrest tilt adjustment assembly formed for fore-and-aft adjustment of the angle of the backrest relative to a vertical plane.

10. The seat assembly as defined in claim 4 wherein,

said backrest includes a backrest tilt adjustment assembly coupled to said back support assembly and formed for manual adjustment of the angle of coupling of said backrest relative to said back support assembly.

11. The seat assembly as defined in claim 10 wherein,

the tilt adjustment assembly includes a movable wedge secured for movement to a movable lever, said lever being pivoted to said backrest and positioned to slide against a plate carried by said back support assembly, and a flexible coupling joining said backrest to said back support assembly in a manner adapted for tilting of said backrest relative to said back support assembly.

12. The seat assembly as defined in claim 11 wherein,

said flexible coupling is provided by a pair of flexible bushings.

13. The seat assembly as defined in claim 1, and

a biasing assembly coupled assembly coupled to apply a biasing force to rearwardly pivot the seat.

14. The seat assembly as defined in claim 13 wherein,

said mounting assembly includes a U-shaped frame having upwardly extending frame arms;

said seat is pivotally mounted to said frame arms by a cradle pivoted proximate upper ends of said frame arms; and

said biasing assembly includes springs mounted between said frame arms and said cradle.

15. The seat assembly as defined in claim 1 wherein,

said mounting assembly includes a U-shaped frame having upwardly extending frame arms;

and

said seat is pivotally mounted to said frame arms by a cradle pivoted proximate upper ends of said frame arms.

16. The seat assembly as defined in claim 15 wherein,

said upper ends of said frame arms further include armrest assemblies, and

armrest adjustment assemblies carried by said arm rests and formed for adjustment of the lateral positions of said armrest assemblies relative to said frame arms.

17. The seat assembly as defined in claim 14 wherein,

said armrest adjustment assemblies are further formed for independent adjustment of the side-to-side and angular positions of said armrest assemblies relative to said frame arms.

18. The seat assembly as defined in claim 15 wherein,

said armrest adjustment assemblies each include a movable armrest element, a plate carried by a frame arm and having a rack with a plurality of teeth, a spring coupled between said movable armrest element and said plate and biasing said movable arm rest toward a latched position, and pin members positioned to releasably latch said movable armrest element in a latched condition under spring biasing of said spring.

19. The seat assembly in claim 1, and

an adjustment assembly provided on said mounting assembly and formed to enable adjustment of the radius of curvature of the path of motion of the seat without changing the relative positions of the centers of curvature of the seat and the backrest.

20. The seat assembly as defined in claim 13 wherein,

said biasing assembly is adjustable as to the force rearwardly biasing said seat.

21. The seat assembly as defined in claim 1 and,

a locking assembly coupled to said mounting assembly to lock said seat to a fixed position.

22. The seat assembly as defined in claim 21 wherein,

said mounting assembly includes a frame having upwardly extending frame arms;

said seat is pivotally mounted to said frame arms by a cradle pivoted proximate upper ends of said frame arms; and

said locking assembly includes a latch brake assembly to selectively lock the seat between said frame arms and said cradle.

23. A method of self-adjusting support and alignment of a backrest of a seating assembly and the user seated thereof, comprising the steps of:

mounting a seat to rotate about an axis positioned proximate a person'"'"'s center of mass while seated on the seat; and

mounting a backrest to rotate independently of the seat about an axis positioned proximate a person'"'"'s center of mass while seated on the seat.

24. The method as defined in claim 23 wherein,

the step of mounting a backrest is accomplished by mounting a backrest formed for selective fore-and-aft adjustment of the angle of the backrest relative to a vertical plane.

25. The method as defined in claim 23 wherein,

the step of mounting a backrest is accomplished by mounting a backrest which is biased around the axis of pivoting toward a substantially vertical orientation.