Socket construction for torsion member

Claim 1

In a variable tension device comprising an elongated torsion member and a socket member having a body with an aperture of significant depth extending to a mouth and defined by walls at least some of which are shaped and oriented to engage sides of said torsion member when a portion of said torsion member is received within said aperture with another portion of said torsion member extending out beyond the mouth of said aperture, thereby to non-rotatably engage said torsion member in said socket member, said wall-side engagement producing the rotative stress between said torsion member and socket member when said other portion of said torsion member is twisted; the improvement which comprises said torsion member sides and said socket aperture walls engaging one another, when said torsion member is in an initial twist condition, at a first location relatively remote from the mouth of said aperture, said torsion member sides and aperture walls diverging from one another to a limited degree from said first location toward the mouth of said aperture, whereby said torsion member sides and aperture walls do not engage at locations closer to said aperture mouth than said first location when said torsion member is in its said initial twist condition, the degree of the divergence from one another of said torsion member sides relative to said aperture walls being such that as said torsion member is further twisted from said initial twist position, at least some of said torsion member sides engage the aperture walls corresponding thereto at second locations closer to the mouth of said aperture than said first location while continuing such engagement essentially at said first location and at points between said first and second locations, thereby to progressively increase the area of engagement as said torsion member is increasingly twisted.