Dual purpose mechanism for expanding baskets

Abstract

An improved stone basket is disclosed which comprises a handle having a slide and a piston movably mounted to it. In a first embodiment the distal end of a sheath is attached to the slide, and the distal end of a control wire is attached to the piston. A basket shaft is fixedly mounted to the handle. Initial rearward movement of the slide causes the sheath to retract over the fixed basket shaft, exposing a basket member at the forward end of the basket shaft and permitting it to open. Further rearward movement of the slide by the physician brings the slide into driving engagment with the piston. Thereafter, subsequent movement of the slide displaces the piston to exert a tension on the control wire to expand the basket member. In a second embodiment the sheath is fixedly mounted to the forward end of the handle. The rearward end of the basket shaft is mounted to the thumb slide, and the rearward end of the control wire is attached to the piston. A spring operatively associated with the slide and the piston biases the piston forward as the thumb slide is advanced and permits limited forward movement of the thumb slide after the piston reaches the forward extent of its movement. Thereafter the thumb slide can be advanced without advancing the piston, thus extending the basket shaft toward the tip of the basket assembly and expanding the basket.