Ergonomic chair

Abstract

An ergonomic chair provides continuous support to the seated user throughout a broad range of postures by pivoting both the seat and back supporting cushions about a first or common axis disposed above the seat support cushion and in front of the back support cushion. The back supporting portion also independently pivots about a second horizontal axis proximate the lumbar region in a manner that allows the back supporting cushion to assume an angle that provides permanent contact with the seated user's back when said user is leaning back against the back support cushion. The springs that otherwise oppose the free rotation about the first and second axis are balanced such that the force inherently exerted by the user during movement through a range of seated postures is sufficient to initiate the coordinated rotation of the seat and back supporting element. No additional exertion is required once the user has reached the desired inclination, as the return springs are selected to counterbalance the redistributed weight of the user. Thus, full contact of the back supporting portion with the user's back is achieved over a full range of postures to provide proper ergonomic support, allowing the user to stay at task. In combination with such motion, which maintains the head at a level and angle such that the eyes can remain focused on their primary visual target without need to adjust the height, depth or angle of the target. The chair can offer armrests that support the forearms of the seated user to reduce the load carried by the arms, shoulders, neck and back and cooperate with the motion of the seat and back supporting elements to maintain ergonomically correct orientation of the hands to the keyboard or work surface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority to the provisional application having Ser. No. 60 / 617,540 entitled “Ergonomic Chair” filed on Oct. 8, 2004, which is incorporated herein by reference.BACKGROUND OF INVENTION [0002] The present invention relates to improved seating, and in particular improved task seating. [0003] Numerous improvements and innovations have been made to conventional chairs for the purposes of providing more comfortable and ergonomically correct seating for office and factory workers, as well as others required to sit for long periods of time. [0004] However, despite these improvements seated workers are subject to repetitive strain injuries to extremities, discomfort and stiffness because, in part their posture is either incorrect or limited. While many modern office chairs provide for adjustability of the seat height, back support tilt, seat tilt and armrests the inherent complexity in these mechanisms dissuades the...

AI Technical Summary

Benefits of technology

[0007] It is an additional object of the invention to provide an ergonomically improved chair that allows unrestricted movement through a greater range of ergonomically correct postures.

[0008] It is another object of the invention to provide an ergonomically improved chair that allows a user to stay at task through a greater range of postures.

[0009] In the present invention, the first object of improved worker / user comfort and reduced ergonomic hazards is achieved by providing a chair comprising a frame supported on a surface, the frame having a forked armature extending upward there from, a seat support mounted in suspension about a first rotary axis from the forks of said frame, a U-shaped mounting bracket having a left and right terminus, each of which is disposed in rotary connection about the forks of the armature and in substantial coincidence with the first rotary axis, and a back support cushion disposed between the left and right terminals of said U-shaped back support, being mounted to pivot thereon about a second rotary that is located behind the back support cushion and proximate the lumbar spine region of the seated user. The rotation of seat support and back cushion support about the first and second axis enable the seated user's unrestricted movement to any posture within the range of seated postures recommended by the American National Standards Institute and the Human Factors and Ergonomics Society. Further, the user is free to stretch and flex yet is stably supported without the need to operate controls.

[0010] Another object of the invention that reduces the ergonomic hazards thought to increase the risk of injury is that at any posture the user assumes (and at any point in the movement between those postures) the back support cushion maintains permanent contact with the seated user's back and especially the lumbar spine.

[0011] The additional object of the invention of reducing the risk of ergonomic hazards is achieved by keeping the seated user's hands in proper orientation to their task during movement by means of an armrest that maintains the user's hands in an ergonomically correct orientation to the tool or work surface, that is, the armrest does not change its position as the user moves through the range of available postures. This is further improved by utilizing a double pivot freely rotating armrest to increase the horizontal range of the arm support. This aspect is further achieved in preferred embodiments by providing at least one auxiliary support surface disposable within an ergonomic position by rotation about the vertical arm rest support, the support surface being suitable for support of a keyboard, mouse, trackball, microscope or other requisite tool, and the like.

[0012] Further, the primary visual target does not need to be repositioned as the head only moves a small distance by the allowed pivotal rotation between inclined and reclined postures.

Problems solved by technology

However, despite these improvements seated workers are subject to repetitive strain injuries to extremities, discomfort and stiffness because, in part their posture is either incorrect or limited.

While many modern office chairs provide for adjustability of the seat height, back support tilt, seat tilt and armrests the inherent complexity in these mechanisms dissuades their deployment to the user's full benefit.

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