Patent ID: 8042403
Filing Date: 2011-10-25
Classification: F42B,Y10T

Abstract:
1. An apparatus comprising: a first, second, third, and fourth swing link; a first and second seat link, a first end of the first seat link coupled to the first swing link and a second end of the first seat link coupled to the second swing link, and a first end of the second seat link coupled to the third swing link and a second end of the second seat link coupled to the fourth swing link; a fixed link having a first end coupled to the first swing link and having a second end coupled to the fourth swing link; an input/output link having a first end coupled to the second swing link and having a second end coupled to the third swing link; a spring coupled to each of the first and second seat links; a load bearing assembly coupled to the input/output link; and a rod positioned in proximity to each spring and each of the first and second seat links; wherein a load applied to the load bearing assembly causes angles formed by the swing links, the seat links, the fixed link, and the input/output link to change in magnitude thereby varying a mechanical leverage of the apparatus and providing a linearly decreasing force in opposition to the load.