Pull wire and spool for vascular intervention device delivery system

A vascular intervention device delivery system comprising:

• a handle;
• a thumbwheel rotatably mounted in the handle for rotation about an axis of rotation, and having a radially outward thumb surface and a spool with a collection surface;
• a catheter with a proximal end attached to the handle, and a distal carrier segment for mounting a vascular intervention device thereon;
• a retractable sheath movable from a first position covering the distal carrier segment to second position retracted proximally uncovering the distal carrier segment;
• a pull extending between the thumbwheel and the retractable sheath, and including a distal segment extending distally beyond a distal end of the handle;
• the retractable sheath moving responsive to rotation of the thumbwheel in a first direction;
• wherein the pull is wound at least once completely around the collection surface when the retractable sheath is at the first position;
• wherein the pull is metallic and has a proximal end bent back on itself into a T-shaped integral anchor;
• wherein the spool has an inner surface separated from the collection surface by a cylindrically shaped wall;
• the integral anchor is in contact with the inner surface;
• wherein the collection surface has a circular cross section;
• wherein the handle includes a hub at a fixed location that defines the axis of rotation;
• wherein the integral anchor is received in a slot defined by the thumbwheel that opens in a direction parallel to the axis of rotation;
• the slot is closer to the axis of rotation than the collection surface is to the axis of rotation;
• wherein the collection surface is bound on one side by a rim having a rim radius that is greater than a radius of the collection surface;
• wherein the pull is a thin band of spring steel with a curved cross section;
• and
• wherein the integral anchor includes a concave portion that matches an outer radius of an outer surface of the hub.