Abstract: A tubular staff is provided and includes a longitudinal slot extending therealong throughout at least a major portion of the length of the staff. A plurality of bracing structures spaced along the slotted portion of the staff internally thereof rigidly brace adjacent portions of the staff disposed on opposite sides of the slot relative to remote peripheral portions of the staff. Aligned first and second pulleys are journaled in opposite end portions of the staff for rotation about transverse axes and an endless tension member is trained over and frictionally engaged with the pulleys and includes one reach thereof extending between the pulleys spaced immediately inwardly of and extending along the slot. Follower structure is attached to the aforementioned reach of the tension member and projects through and is slidingly engaged in the slot.