A vascular intervention device delivery system, such as for implanting a self expanding stent, includes a thumbwheel rotatably mounted in a handle. The thumbwheel includes a radially outward thumb surface. A catheter has a proximal end attached to the handle, and a distal carrier segment for mounting a vascular intervention device thereon. A retractable sheath is movable from a first position covering the distal carrier segment to a second position retracted proximally uncovering the distal carrier segment. A pull extends between the thumbwheel and the retractable sheath. A holding mechanism is operably positioned between the handle and the thumbwheel, and includes a wedge pin trapped to move in a wedge shaped cavity between a wedged position that prevents the thumb wheel from rotating, and an unwedged position that permits the thumbwheel to rotate to facilitate deployment of a self-expanding stent.