| abstract |
ABSTRACT OF THE DISCLOSURE A bent wire spring unit for interposition between a grid frame and base frame comprising upper and lower attaching elements and intervening spaced, parallel, oppositely-facing supports yieldably connecting the top and bottom attaching elements, said supports comprising first legs inclined upwardly in opposite directions from the bottom attaching elements at a predetermined angle, second legs inclined downwardly in opposite directions from the top attaching element at a sharper angle than the angle of inclination of the first legs relative to the bottom attaching element and spaced, parrallel third legs connected at their upper and lower ends to the distal ends of the downwardly and upwardly-facing first and second legs, said third legs being concavely bent intermediate their ends in directions toward each other. |