Single-side engaging picker for data cartridges

A picker for data cartridges in a computer information storage library. The picker includes a sleeve for transporting data cartridges, a thumb that can move in one dimension relative to the sleeve, and a single pivoting finger on the thumb. The single finger has an inboard pivot point which results in a self locking action (pulling makes the finger grip tighter). The finger has an armed state for gripping and a splayed state for release. Switching between states is passive, depending only on one dimensional motion of the thumb relative to the sleeve. The finger has a post that travels in tracks in the sleeve. Switching tracks switches finger states. A spring loaded gate in the tracks enables track switching. Potential cartridge wear and binding problems during extraction are eliminated by providing sleeve guides that limit cartridge rotation, by providing a concave guide surface in storage locations, and by proper selection of materials. A corresponding drive has a handle that must be manipulated. The picker includes thumb details for manipulating the drive handle.