Chair with independently pivotable seat cushion and back frame

• US 3,945,651 A
• Filed: 05/31/1974
• Issued: 03/23/1976
• Est. Priority Date: 05/31/1974
• Status: Expired due to Term

• Current Assignee: Paul Boswinkel
• Original Assignee: Paul Boswinkel
• Inventors: Boswinkel, Paul
• Primary Examiner(s): McCall, James T.
• Application Number:
  US05/474,871
• Time in Patent Office: 662 Days
• Field of Search: 297/286, 297/301, 297/311, 297/312, 297/408, 297/383, 297/329, 297/310, 297/354, 297/325, 297/326, 297/327, 297/300, 297/306, 297/291, 297/450, 297/29, 297/292, 297/293 , 297/258, 297/68, 297/270, 297/259
• US Class Current: 297/337
• CPC Class Codes: A47C 1/029 by changing the length or the inclination of the legs varying the height of a seat by inclining the legs A47C3/36
• CPC Class Codes: A47C 3/00 Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats A47C1/00, A47C4/00 take precedence

Abstract

A chair includes a lower seat cushion member which is independently pivotable about a pivot on the chair frame and a rear back cushion member which is independently pivotable about a pivot on the chair frame. The rear and lower seat cushion members are not interconnected and are independently pivotable with respect to each other. The cushion members are preferably biased toward a neutral rest position with a weak biasing force so that the occupant of the chair can easily cause the cushions to pivot so as to assume the proper support position for the occupant.

Claims

1. A chair adjustable by the occupants between seating and reclining positions responsive to forces generated by the body of an occupant, comprising:

a lower frame (1-6);

a seat cushion member (14,15) pivotally and non-lockably mounted to said lower frame and being substantially freely pivotable during occupation of the chair responsive to forces generated by an occupant of the chair;

first stop means (3) on said lower frame for defining a range of said substantially free pivotal movement of said seat cushion member;

a back frame (19-23) carrying a back cushion (18), said back frame being pivotally and non-lockably connected to said lower frame at a position on said lower frame which is spaced a substantial horizontal distance from the rearward edge of said seat cushion such that when said back frame is vertical and said seat cushion is horizontal a large gap exists therebetween, said back frame being pivotally connected at a lower portion thereof, below its center line, to said lower frame, and being substantially freely pivotable during occupation of the chair at least between first and second positions responsive to forces generated by an occupant of the chair, said first and second positions respectively corresponding to occupant-sitting and occupant-reclining positions, said back frame being independent of said seat cushion and being pivotally movable relative to said lower frame independently of said seat cushion; and

second stop means (4) on said lower frame defining a range of said substantially free pivotal movement of said back frame;

the pivotal connections to said lower frame member being located within the projection of the forward and rear extremities of said lower frame on a horizontal and being spaced from each other by a distance sufficient to permit the cushions to assume an occupant reclining position.

2. A chair according to claim 1 wherein said lower frame comprises first and second side members (1,2) and wherein said seat cushion member is interposed between said side members and is pivotally connected thereto by means of a bar means (13) extending between said side members (1,2).

3. A chair according to claim 2 wherein said bar means (13) is located rearwardly of the center line of said seat cushion member, said center line extending transversely of said seat cushion member between said side members of said lower frame.

4. A chair according to claim 1 comprising biasing (16,17) means for biasing said seat cushion member towards a rest position.

5. A chair according to claim 1 wherein said first stop means (3) limits the pivotal motion of said seat cushion member in one direction.

6. A chair according to claim 5 comprising biasing means (16,17) for biasing said seat cushion member towards said first stop means.

7. A chair according to claim 1 wherein said lower frame comprises first and second side members (1,2) and wherein said back frame is interposed between said side members and is pivotally connected thereto by means of a bar means (25) extending between said side members (1,2).

8. A chair according to claim 7 wherein said bar means (25) for pivotally connected said back frame to said lower frame is located below the center line of said back frame, said center line of said back frame extending transversely of said back frame between said side members of said lower frame.

9. A chair according to claim 2 wherein said back frame is pivotally connected to said lower frame by means of a back bar means (25) extending between said side members (1,2).

10. A chair according to claim 9 wherein said bar means (13) is located rearwardly of the center line of said seat cushion member, said center line of said seat cushion member extending transversely of said seat cushion member between said side members of said lower frame;

and wherein said back bar means extend below the transverse center line of said back frame.

11. A chair according to claim 1 comprising biasing means (27) for biasing said back frame in a direction so that the upper part of said back frame pivots away from the seat cushion member.

12. A chair according to claim 1 wherein said second stop means (4) limits the pivotal motion of said back frame to a position wherein said back frame is in a substantially horizontal position.

13. A chair according to claim 12 comprising biasing means (27) for biasing said back means towards said second stop means.

14. A chair according to claim 1 comprising a headrest (28) adjustably connected to the upper end of said back frame and above said back cushion.

15. A chair according to claim 14 wherein said headrest is rotatable about a pivot axis extending transversely of said back frame.

16. A chair according to claim 15 wherein said pivot axis of said headrest is eccentric relative to said headrest so that said headrest is adjustable in position by being rotated about said eccentric pivot axis.

17. A chair according to claim 1 wherein said seat cushion member is pivotally mounted to said lower frame at a point approximately 40% along the length of said seat cushion member beginning at the portion of said seat cushion member which is innermost of said chair;

and wherein said back frame is pivotally connected to said lower frame at a portion approximately 40% of the length thereof beginning at the lowermost part thereof.

18. A chair according to claim 1 comprising armrest means on said lower frame both forward of said back frame and rearward of the forward most portion of said back frame.

19. A chair according to claim 1 wherein said lower frame comprises first and second portions (30,32) which are movable relative to each other, said first portion (30) comprising the base and said second portion (32) carrying at least said pivotally mounted seat cushion member (35), said first and second portions of said lower frame being adjustably movable relative to each other to vary the distances between the pivots for said seat cushion and back frame to accommodate occupants of different sizes.

20. A chair according to claim 19 wherein said lower frame includes substantially vertically oriented slot means (31), and wherein said back frame is pivotally and adjustably mounted in said slot means.

21. A chair according to claim 20 wherein said second portion (32) of said lower frame has an inclined surface (38) in registration with said slot means (31), and wherein said back frame includes pivot means (39) in said slot means (31) and bearing on said inclined surface (38) whereby when the relative positions of said first and second portions of said lower frame are adjusted, said inclined surface causes the height of said pivot means and of said back frame to be varied.

22. A chair according to claim 19 comprising inclined bearing surfaces on said base portion of said lower frame, said second portion (32) of said lower frame being adjustably movable on said inclined bearing surfaces.

23. A chair according to claim 1 comprising a first pivot means (13) for pivoting said seat cushion member to said lower frame and a second pivot means (25) for pivoting said back frame to said lower frame, the vertical distance (F'"'"') between said first and second pivot means being approximately 9 inches and the horizontal distance between said first and second pivot means being approximately 17 inches.

24. A chair according to claim 5 wherein said lower frame comprises a pair of substantially vertically oriented side members (1,2) which are spaced apart in the horizontal direction;

pivot means (13) mounted to said side members and pivotally mounting said seat member thereto;

a substantially horizontally oriented member (3) extending between said side members (1,2) and below said seat cushion member forward of said pivot means, said horizontally oriented member (3) serving to retain said side members together and simultaneously serving as said first stop means.

25. A chair according to claim 24 comprising second pivot means (25) pivotally mounting said back frame to said side members (1,2);

and a second substantially horizontally oriented member (4) extending between said side members (1,2) and being located rearward of said second pivot means, said second substantially horizontally oriented member serving to retain said side members together and simultaneously serving as said second stop means.