| CPC A61G 5/14 (2013.01) [A61G 5/1059 (2013.01)] | 8 Claims |

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1. An adjustable lifting mechanism comprising:
a fixed base;
a parallelogram structure having four pivotally connected links having four pivots, the parallelogram connected at two of the four pivots to the base;
a spring pivotably extending from a first link of the parallelogram, with one end connected pivotably to a point on the first link and an opposite end pivotably connected to an adjustable termination point on a second of the four pivotally connected links of the parallelogram to form a lifting triangle, wherein the spring termination point is displaced from a main pivot of the parallelogram;
an extension in fixed relation to the second link of the four pivotally connected links forms a seat, wherein angles of the parallelogram are varied upon raising or lowering the lifting mechanism between a sitting mode and a standing mode;
a height adjustment sleeve associated with the second link, the height adjustment sleeve configured to slideably move up and down between the sitting mode and the standing mode, along a bar fixedly attached to the base, and
a lifting power adjustment mechanism configured to adjust the position of the spring termination point with respect to the main pivot.
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