Climbing toy

A string climbing device consisting of:

• a round body means having an axis of revolution passing through the center of gravity of said body means;
• first and second annular grooves circumscribing said body means and respectively describing first and second planes which are both perpendicular to said axis of revolution, said first and second planes intersecting said axis of revolution at points which are removed from said center of gravity by distances X.sub.1 and X.sub.2 respectively, said first and second grooves each having depths which are at least three times greater than their width and having respective radii R.sub.1 and R.sub.2 measured from said axis of revolution to the bottom of each groove, said radii R.sub.1 and R.sub.2 being related to the distances X.sub.1 and X.sub.2 so as to substantially satisfy the following equation:
• ##EQU3## where .DELTA.R=R.sub.2 -Rhd 1 and .DELTA.X=X.sub.2 -X.sub.1 ;
• and string means freely wound in opposite directions in each of said grooves such that tension applied to said string means causes said body means to rotate and move along said string means, and whereby any tilting moment caused by said tension is counteracted by the tilting moment caused by the offset of said center of gravity relative to the center of spacing between said first and second grooves.