RATCHET LOCKING MECHANISM FOR SURGICAL INSTRUMENTS

摘要

Releasable ratchet mechanism for medical instruments such as endoscopic instruments are disclosed. The ratchet mechanism includes: a leaf spring with a locking barb which is located on a handle of the medical instrument; a ratchet on a lever arm of the medical instrument which lever arm is pivotally engaged to the handle; and a latch on the handle of the medical isntrument. The latch on the handle engages and resiliently deforms the leaf spring to cause engagement of the locking barb in a groove of the ratchet when the latch is in a first position. When in a second position, the latch releases the locking barb from the ratchet groove. Preferably, the locking barb has an extending edge surface on an axis which is substantially parallel to the pivoting axis of the handle and lever arm, and the teeth of the ratchet have extending edge surfaces on axes substantially parallel to the extending edge surface of the locking barb. Also, preferably, the edge surfaces of said teeth of the ratchet are located along an arc of a cylinder having the handle/lever arm pivot axis as its center line.