Chairs and seats – Movable bottom – Tiltable
Patent
1991-08-29
1993-10-12
Dorner, Kenneth J.
Chairs and seats
Movable bottom
Tiltable
297322, A47C 102
Patent
active
052519589
DESCRIPTION:
BRIEF SUMMARY
STATE OF THE ART
The invention starts from a synchronous adjusting device for office chairs, seat furniture or the like.
Where office chairs are concerned, the term "synchronous mechanism" means the arrangement of a combined or dependent back adjustment and seat adjustment, that is to say the adjustment of the back inclination fundamentally also results in an adjustment of the sitting surface.
Known office chairs have a relatively complicated mechanical construction which is distinguished by a multiplicity of articulation points for the purpose of coordinating the cycle of movement between the seat part and back part. Thus, the adjustment of the inclination of the back part should take place in such a way that a counterpressure or a corresponding counter moment rising with an increasing inclination is generated. The synchronous, that is to say simultaneous adjustment of the seat part, serves for adapting the chair to the physical characteristics of the user. For the adjustment, pressure units are usually employed additionally for influencing and damping the individual movements.
A particular problem of known office chairs is that they generally have to be adjusted to the weight or size of the user. A large heavy user exerts a substantially higher force on the back part than a lighter and smaller user. The same applies to the load on the seat part, the movement of which is associated with the movement of the back part.
ADVANTAGES OF THE INVENTION
The object on which the invention is based is to avoid the disadvantages described in relation to the state of the art and to propose a chair mechanism as a synchronous mechanism which is of extremely simple and effective construction, that is to say has few mechanical means and, if appropriate, can do without additional force accumulators and pressure units.
A further object of the invention is to equip such an office chair with a convenient adjusting mechanism which allows damped movements and retentions in any position without catching.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the chair includes a carrier structure of fixed location, having front and rear regions and a back part having first and second locations of articulation disposed below one another. The first location of articulation of the back part is pivotally jointed to the rear region of the carrier structure, whereby upon pivotal movement of the back part, the second location of articulation moves along a circular path about the first location of articulation. The chair further has a seat part having front and rear regions. The rear region of the seat part is pivotally jointed to the second location of articulation of the back part. A single coupling component connects the front region of the seat part with the front region of the carrier structure. An arrangement compels an end of the single coupling component to travel in a circularly arcuate path having a center of curvature which is fixed relative to the carrier structure. The travelling end of the single coupling component is situated at all times at a height level which is below the second location of articulation of the back part.
Further advantageous and expedient developments of the invention for achieving the object according to the invention are contained in the subclaims.
The invention is based on the principal idea that, during the adjustment of the backrest, a restoring movement of the back part must take place as a function of the weight of the user. At the same time, the restoring moment must rise automatically with the increase in the inclination, since the lever arm for the torque increases constantly with the increase in inclination. Consequently, the counter moment must also increase constantly with an increase in the inclination of the back part.
According to the invention, such a counter moment or restoring moment during the adjustment of the back inclination is obtained, in the first place, in that the back part is mount
REFERENCES:
patent: 1888471 (1932-11-01), Robbins
patent: 2679285 (1954-05-01), Luckhardt
patent: 2679286 (1954-05-01), Luckhardt
patent: 2730164 (1956-01-01), Higley et al.
patent: 4768829 (1988-09-01), Goldman
patent: 4877291 (1989-10-01), Taylor
patent: 4988145 (1991-01-01), Engel
Biggel Franz
Fleischmann Horst
Roericht Hans
Schmitz Burkhard
Dorner Kenneth J.
Gardner James M.
Wilkhahn Wilkening & Hahne GmbH & Co.
LandOfFree
Synchronous adjusting device for office chairs or the like does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Synchronous adjusting device for office chairs or the like, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Synchronous adjusting device for office chairs or the like will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1900002