Compound curved spring

Claim 2

A spring comprising a body formed from a flat ribbon of unstressed metal, said spring having an initially applied concave-convex cross curvature of relatively substantial arc to render same transversely curvate throughout its length, said spring having secondarily been bent into a loosely wound coil condition providing a longitudinal stress and wherein each convolution retains the transversely curvate condition by means of the applied cross curvature, the convex side of said cross curvature being directed toward the center of such coil when said spring is either in wound or unwound condition.

Claim 3

A spring as defined in claim 1 and further characterized by the central longitudinal portion of said spring being under compression.

Claim 4

A spring as defined in claim 1 and further characterized by said spring having longitudinally spaced apart, transversely extending depressions.

Claim 5

A spring as defined in claim 2 and further characterized by said depressions being relatively deep in their central portions and shallow in their outer portions.

Claim 6

A spring as defined in claim 1 and further characterized by said ribbon having longitudinal edge portions, said edge portions being stretched beyond their elastic limit whereby when said spring is unwound from its coil condition the same will retain a concave-convex cross curvature throughout its extent.

Claim 7

A spring as defined in claim 5 and further characterized by a pair of concentric relatively rotatable drums, the normally inner end of the spring ribbon being secured to the outer face of the inner of said drums, and the normally outer end of the spring ribbon being secured to the internal sUrface of said outer drum whereby upon winding of said spring upon said inner drum said spring will retain a concave-convex curvature with the convex side therefor directed toward the center of said inner drum.

Claim 8

A spring as defined in claim 6 and further characterized by the maximum diameter of said spring in a state of repose being less than the inside diameter of the outer drum for facile disposition therein.

Claim 9

A spring motor comprising a resilient body of concave-convex cross sectional configuration and capable of maintaining a concave-convex cross section when in wound condition.

Claim 10

A spring motor comprising a resilient body of concave-convex cross sectional configuration and capable of maintaining a concave-convex cross section when in wound condition.

Claim 11

A spring comprising a resilient body formed to be in general coiled condition and in repose, said spring having an applied concave-convex cross curvature throughout its extent with the convex side being directed toward the center of the coil, said spring being capable of retaining a concave-convex cross curvature when moving from repose to wound condition.

Claim 12

A spring comprising a resilient body formed to be in general coiled condition and in repose, said spring having an applied concave-convex cross curvature throughout its extent with the convex side being directed toward the center of the coil, said spring being capable of retaining a concave-convex cross curvature when moving from repose to wound condition.

Claim 13

A spring as defined in claim 9 and further characterized by the said resilient body having longitudinal edges, said edges being stretched beyond their elastic limit whereby said edges are normally under tension and the intervening portion of said spring is under compression.

Claim 14

A spring as defined in claim 1 and further characterized by said ribbon having longitudinal edge portions, said edge portions being stretched beyond their elastic limit, the portion of said ribbon between said longitudinal edges being provided with longitudinally spaced apart depressions.

Claim 15

A spring comprising a body formed from a ribbon of unstressed metal, said ribbon having an applied concave-convex cross curvature of relatively substantial arc, said spring being formed into a coil configuration so that when said spring is in a state of repose it will be curved longitudinally and transversely throughout its extent with the convex side directed toward the center of said coil configuration, said spring having longitudinally spaced-apart transversely extending depressions.

Claim 16

A spring comprising a body formed from a ribbon of unstressed metal, said ribbon having an applied concave-convex cross curvature of relatively substantial arc, said spring being formed into a coil configuration so that when said spring is in a state of repose it will be curved longitudinally and transversely throughout its extent with the convex side directed toward the center of said coil configuration, said spring having longitudinally spaced-apart transversely extending depressions.

Claim 17

A spring as defined in claim 12 and further characterized by said depressions being relatively deep in their central portions and shallow in their outer portions.

Claim 18

A spring comprising a body formed from a ribbon of unstressed metal, said ribbon having an applied concave-convex cross curvature of relatively deep substantial arc, said spring being formed into coil configuration so that when said spring is in a state of repose it will be curved longitudinally and transversely throughout its extent with the convex side directed toward the center of said coil configuration, said ribbon having longitudinal edge portions, said edge portions being stretched beyond their elastic limit, the portion of said ribbon between said longitudinal edges being provided with longitudinally spaced apart depressions.

Claim 19

A spring comprising a body formed from a ribbon of unstressed metal, said ribbon having an applied concave-convex cross curvature of relatively deep substantial arc, said spring being formed into coil configuration so that when said spring is in a state of repose it will be curved longitudinally and transversely throughout its extent with the convex side directed toward the center of said coil configuration, said ribbon having longitudinal edge portions, said edge portions being stretched beyond their elastic limit, the portion of said ribbon between said longitudinal edges being provided with longitudinally spaced apart depressions.