Chair control mechanism
First Claim
Patent Images
1. A chair comprising:
- a base including a vertically extending support column;
a seat including a back portion and a bottom portion with a front edge, said seat capable of being positioned in an upright position and a plurality of tilted positions;
a tilt control assembly including a main pivot, a base plate, and a seat plate, said base plate and said seat plate being operatively connected by said main pivot, said main pivot being generally horizontally disposed in the vicinity of said front edge, said base plate attached to said column, and said seat plate attached to said seat;
first spring means operatively connected between said base plate and said seat plate for uniformly resisting tilting by said seat;
second spring means operatively connected between said base plate and said seat plate for variably resisting tilting by said seat including means for providing a relatively high initial resistance against tilting said seat in said upright position and providing a relatively low resistance against tilting said seat in said tilted positions; and
adjustment means for adjusting the resistance of said first spring means, said adjustment means including a screw, a tension arm having a pivot and a spring engagement portion, and means for threadedly connecting said screw and said tension arm, said tension arm pivot engaged with one of said plates of said tilt control assembly, said first spring means extending between the other of said plates and engaging said spring engaging portion of said tension arm, said screw threadedly engaged with said tension arm whereby rotation of said screw causes movement of said tension arm, with the distance from said tension arm pivot to said threaded connection means being greater than the distance from said tension arm pivot to said spring engagement portion thereby facilitating movement of said screw by the leverage of said tension arm.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention is an office chair capable of dynamically tilting to provide a desired seat inclination from an upright position to a maximum tilted position. The preloading mechanism of the spring includes an adjusting screw and a tension arm which provides leverage. The leverage of the preloading mechanism facilitates turning the adjusting screw to vary the preloaded tension of the springs. Also, a spindle cover is provided to stop movement of the seat at the maximum tilted position, and to stop movement of a toggle mechanism at the upright position.
44 Citations
18 Claims
-
1. A chair comprising:
-
a base including a vertically extending support column; a seat including a back portion and a bottom portion with a front edge, said seat capable of being positioned in an upright position and a plurality of tilted positions; a tilt control assembly including a main pivot, a base plate, and a seat plate, said base plate and said seat plate being operatively connected by said main pivot, said main pivot being generally horizontally disposed in the vicinity of said front edge, said base plate attached to said column, and said seat plate attached to said seat; first spring means operatively connected between said base plate and said seat plate for uniformly resisting tilting by said seat; second spring means operatively connected between said base plate and said seat plate for variably resisting tilting by said seat including means for providing a relatively high initial resistance against tilting said seat in said upright position and providing a relatively low resistance against tilting said seat in said tilted positions; and adjustment means for adjusting the resistance of said first spring means, said adjustment means including a screw, a tension arm having a pivot and a spring engagement portion, and means for threadedly connecting said screw and said tension arm, said tension arm pivot engaged with one of said plates of said tilt control assembly, said first spring means extending between the other of said plates and engaging said spring engaging portion of said tension arm, said screw threadedly engaged with said tension arm whereby rotation of said screw causes movement of said tension arm, with the distance from said tension arm pivot to said threaded connection means being greater than the distance from said tension arm pivot to said spring engagement portion thereby facilitating movement of said screw by the leverage of said tension arm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A chair comprising:
-
a base including a vertically extending support column having an upper end; a seat including a back portion and a bottom portion having a front edge, said seat capable of being positioned in an upright position and a plurality of tilted positions including a maximum tilted position; a tilt control assembly including a main pivot, a base plate, and a seat plate, said base plate and said seat plate being operatively connected by said main pivot, said main pivot being generally horizontally disposed in the vicinity of said front edge and below an upper planar surface of said base plate, said base plate attached to said column, and said seat plate attached to said seat and having a generally planar lower surface; spring means for resisting tilting by said seat, said spring means operatively connected between said base plate and said seat plate; cover means for limiting the tilting movement of said seat, said cover means located at said upper end of said column, said cover means including a spindle cover with a generally planar angled upper surface disposed under said seat plate such that said spindle cover stops movement of said seat at said maximum tilted position and said angled upper surface and said seat plate lower surface are substantially parallel in said maximum tilted position; and toggle means operatively connecting said seat plate and said base plate for resisting tilting of said seat, said spindle cover positioned to stop movement of said toggle means at said upright position. - View Dependent Claims (13)
-
-
14. A chair comprising:
-
a base including a vertically extending support column having an upper end; a seat including a back portion and a bottom portion having a front edge, said seat capable of being positioned in an upright position and a plurality of tilted positions including a maximum tilted position; a tilt control assembly including a main pivot, a base plate, and a seat plate, said base plate and said seat plate being operatively connected by said main pivot, said main pivot being generally horizontally disposed in the vicinity of said front edge and below an upper planar surface of said base plate, said base plate attached to said column, and said seat plate attached to said seat and being L-shaped in cross-section having a generally planar lower surface and an extension connected with said main pivot; spring means for resisting tilting by said seat, said spring means operatively connected between said base plate and said seat plate; cover means for limiting the tilting movement of said seat, said cover means located at said upper end of said column, said cover means including a spindle cover with a generally planar upper angled surface and a resilient stop cushion disposed over said spindle cover upper service, a top portion of said stop cushion being positioned such that said spindle cover stops movement of said seat at said maximum tilted position and said top portion dampens incident vibration and noise when said seat plate moves to said maximum tilted position and said angled upper surface and said seat plate lower surface are substantially parallel in said maximum tilted position; and toggle means operatively connecting said seat plate and said base plate, said toggle means for resisting tilting of said seat, said spindle cover positioned to stop movement of said toggle means at said upright position. - View Dependent Claims (15)
-
-
16. A chair comprising:
-
a base including a vertically extending support column having an upper end; a seat including a back portion and a bottom portion having a front edge, said seat capable of being positioned in an upright position and a plurality of tilted positions including a maximum tilted position; a tilt control assembly including a main pivot, a base plate, and a seat plate, said base plate and said seat plate being operatively connected by said main pivot, said main pivot being generally horizontally disposed in the vicinity of said front edge, said base plate attached to said column, and said seat plate attached to said seat; toggle means for resisting tilting by said seat, said toggle means operatively connected between said base plate and said seat plate; and cover means for limiting the tilting movement of said seat, said cover means located at said upper end of said column, said cover means including a spindle cover and a resilient stop cushion disposed over an edge of said spindle cover, a portion of said stop cushion being positioned such that said spindle cover stops movement of said toggle means at said upright position and said edge portion dampens incident vibration and noise when said seat plate moves to said upright position. - View Dependent Claims (17, 18)
-
Specification