Self-centering holder for objects of various sizes

In apparatus for centering and releasably holding predetermined objects of various sizes, the improvement comprising in combination:

• a holder member having an annulus and three flexible fingers distributed equally inside of, and projecting inwardly from, said annulus for centering and releasably holding any of said objects inside said annulus, said flexible fingers being of one piece with said annulus;
• said flexible fingers emerge gradually from said annulus in progressively divergent relationship to said annulus at an inside thereof;
• each of said flexible fingers has a stop at a free end threreof for holding said object against axial displacement;
• said apparatus includes an annular structure bearing actuator members projecting from, and of one piece with, said annular structure to engage said flexible fingers for selectively moving said fingers relative to said annulus for an accommodation of any of said objects, said annular structure being concentric with, and rotatable relative to, said annulus;
• and
• detent means between said annular structure and said annulus for releasably retaining said annular structure in any of several angular positions relative to said annulus.