This invention relates to a mechanism for a reclining chair, useful for a wide variety of seating applications.
The basic requirements of the ideal reclining mechanism are as follows:
a. There should be zero-shear movement between the person's body and the chair, such that there is no sliding between the body and the chair in any position;
b. There should be zero shear force between the body and the chair. The recline of the back support must be in an exact ratio to the incline of the seat support. Again, there should be no sliding or sense of sliding between the body and the chair;
c. The center of gravity for the body and the chair should stay in one location for any chair position (no vertical or horizontal movement of the gravity center from sitting to fully reclined), since any movement of the center of gravity vertically would require outside forces (springs, motors, etc.) to compensate for the different reclining positions, and any horizontal movement of the center of gravity requires an extension of the length of the support base;
d. The body and the chair parts should be in balance with each other, in any position.
The ideal solution to these requirements should result in a reclining chair design with a minimum number of actual parts, regardless of the complexity of the design theory.