Patent ID: 7481138

Claim:
An arrangement used for rotating screws and bolts, comprising: an adjustable bit array having a longitudinal axis around which an array of concentric bit elements are cascaded in nested relationship with a central bit element being sequentially connected to successively larger bit elements; an operating rod coupled to the central bit element for translating the central bit element to successively position individual bit elements for use in rotating screws and bolts; wherein the operating rod is rotatable with respect to the subsequent bit elements and has outwardly extending projections; wherein the successively larger bit elements each include an annular internal disc having radially extending slots through which the projections on the rod can pass when aligned with the slots; and wherein as the operating rod is retracted the successive bit elements are sequentially exposed so that a selected bit element is exposed for use, and a locking arrangement for locking the operating rod at locking stations to prevent the selected bit element from retracting further.