Natural balance active chair

Abstract

A dynamic joint, to serve as part of a chair, where the dynamic joint is disposed between, and fixedly attached to, the seat and the base of the chair. The joint is operative to enable a person sitting on the chair to tilt the seat in any direction, over a substantial angle, by appropriate force from the person's pelvis and to similarly tilt the seat from any tilted position further in any direction. The Joint comprises a pair of attachment members and an elastomer body, structurally linked with them. The elastomer body is formed so as to include the tilting axes, close to the seat, and so as to control the dynamic tilting characteristics.Also provided is a chair, comprising said joint, and an ergonomic seat for the chair, enabling the person to sit safely and comfortably while tilting the seat. Configuration of the chair as an exercise device is described.

Description

[0001]This application claims priority from US Provisional Patent Application no. 61 / 381,979, filed 11 Sep. 2010, and from PCT application no. PCT / IL2011 / 000690, filed 29 Aug. 2011, whose disclosures are incorporated herein by reference.TECHNICAL FIELD[0002]The present invention relates in general to seating devices and in particular—to tilting chairs and to fitness apparatus.BACKGROUND ART[0003]Accumulated sitting hours on chairs can cause health problems. The problems are mostly caused by technical disabilities of chairs to support adequate sitting postures for work in front of a desk or a computer, and to allow comfortable and safe body movement during long sitting periods. The term chair is to be understood hereunder to include any seating device, including a stool. With the changing industrial society and the increasing number of office jobs, where more employees transacts business while sitting for long periods of time at desk and in front of computers, resultant health proble...

AI Technical Summary

Benefits of technology

The patent describes a dynamic joint and seat that allow a user to adjust the angle between their torso and thighs for relaxing, exercising, or relieving stress. This can be done by tilting the seat using minimal effort, and the seat can be easily adapted to any existing chair. The design also includes an elastomer buffer that ensures stability and safety, and a captive linkage between rigid attachment members and the elastomer buffer to prevent failure. The seat is also designed to distribute pressure evenly over the user's buttocks and to support the person's buttocks tissue. Overall, the dynamic chair creates a "natural balance" for the user and allows them to easily achieve comfortable postures with the angle between torso and thighs over 90 degrees.

Problems solved by technology

Accumulated sitting hours on chairs can cause health problems.

The problems are mostly caused by technical disabilities of chairs to support adequate sitting postures for work in front of a desk or a computer, and to allow comfortable and safe body movement during long sitting periods.

With the changing industrial society and the increasing number of office jobs, where more employees transacts business while sitting for long periods of time at desk and in front of computers, resultant health problems have become more common.

Many past ergonomic chair designs tried to solve these problems, but the solutions were inherently limited by technologies.

Therefore such a sitting posture over long periods of time may cause discomfort and back pain.

One solution, available in many office chairs, is a back-tilting back-rest; however, the resultant posture does not allow working comfortably at a desk or in front of a computer.

Sitting on such chairs for long periods is difficult since they require much energy to maintain the upright posture, they cause pressure on the knees, as well as on the sitting bones and spine, and they are not easy to use by the common users.

The two basic solutions for the torso-thigh angle problem, discussed above, have been shown to be unsatisfactory.

They have, moreover, the disadvantage of forcing largely fixed postures, which cause additional discomfort to the user and distract from the alertness and vitality required in front of a desk or a computer.

However, since such a pivot is located far below the seat surface, the seat concurrently moves over a relatively long range, which is undesirable.

Its tilting angle and feedback pressure is a function of the user's weight; however, its pivot is far from the seat making it difficult to maintain balance.

Such a chair, moreover, requires the seat to have a shell form, limiting the possibility to shape it for ideal sitting posture.

These mechanisms have the additional disadvantages of being essentially heavy, large and expensive to produce and, moreover, cannot be produced as self-contained joint units, to be assembled with available seats and chair bases.

Such devices are limited to tilting about one axis.

Furthermore, the largest tilt angle the user can bear without siding down, or without exerting extra force, is limited, since the shape of the seat is not ideal for resisting the user from sliding down at sharp forward angles.

It is, moreover, not built to be tiltable in directions other than the combination of the two base axes, nor to maintain its natural flexibility when tilted down, to allow small movements about a tilted position.

Furthermore, it is not built to withstand constant tear forces that result from large tilt angles.

However these elastomer buffers are not designed to maintain their functionality under constant forward or backward tilting, or to insure linkage of the plates to the elastomer under aggressive or repetitive tilting, or to insure long lifetime of the buffer when used for tilt.

The motion limitations on the tilting joints disclosed in some of the last citations are also due to the manner in which the elastomer is joined to each of the plates.

In the case of large, constant or aggressive tilt angles, not only shear forces are applied to the joint, but pull forces as well, since pivoting loads cause parts of the elastomer to go into tension; such pull forces, can tear the elastomer away from the plate.

Usually elastomeric buffers are subject to compression and shear forces of vibrations, but they are not built to cope with forces caused by tilt tension, since the tensile strength of the elastomer and its merely adhesive links to the plates are not sufficient for long life time, or for such tilting angles.

Some patents cited above may suggest an implementation wherein the elastic body of the joint is fixed into a corresponding penetration or recess in the plate, to secure them together, but such an arrangement is not likely to help much.

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