US 5,176,702 AGranted

Ratchet locking mechanism for surgical instruments

AssigneeSymbiosis Corporation

InventorsThomas O. Bales, Gregory J. Murphy, Frank A. Scarfone, Charles R. Slater, Kevin W. Smith

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Abstract

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 instrument. 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.

Claims34

Dependent claims

In a medical instrument having end effectors and a handle means and a lever arm means each coupled to at least one of said end effectors, said handle means and lever arm means being pivotably fixed relative to each other by a pivot means, wherein pivoting of said lever arm means relative to said handle means around said pivot means effects relative movement between said end effectors, an improvement comprising:

a releasable ratchet mechanism having
a) a resilient member with opposite first and second opposite ends, said first end held in cantilever engagement with one of said handle means and said lever arm means, and with its second end extending away from said one of said handle means and said lever arm means with which said resilient member is in cantilever engagement toward the other of said handle means and said lever arm means, said resilient member having a locking element extending therefrom remote from its cantilevered engagement;
b) a ratchet means extending from said other of said handle means and lever arm means toward said cantilever engagement of said resilient member, said ratchet means being axially displaced relative to said locking element along an axis perpendicular to said pivot means but in closely adjacent opposed relationship to said locking element, said ratchet means having a plurality of teeth defining a plurality of grooves wherein each groove is adapted to individually receivably engage said locking element of said resilient member;
c) latching means movably coupled to said one of said handle means and lever arm means with which said resilient means is in cantilever engagement, said latching means for engaging and resiliently deforming said resilient member to cause engagement of said locking element in a groove of said ratchet means when said latching means is in a first position, and said latching means for either substantially disengaging said resilient means or for reducing the deformation of said resilient member when in a second position such that said locking means is substantially free from said ratchet means.

1 more element

A medical instrument, comprising:

a) a hollow outer tube having a proximal end, a distal end, and a longitudinal axis;
b) a push rod extending through said outer tube and having proximal and distal ends;
c) an actuating means for imparting reciprocal axial motion to said push rod relative to said outer tube, said actuating means comprising a handle means and a lever arm means, said handle means and lever arm means being coupled to each other by a pivot means, with said handle means engaging said outer tube, said lever arm means engaging said push rod;
d) end effector means coupled to said push rod at said distal end of said push rod and pivotally coupled to said outer tube, whereby pivoting of said lever arm means relative to said handle means around said pivot means is translated to pivotal movement of at least one of said end effectors;
and
e) a releasable ratchet mechanism having
a resilient member engaged with and extending from a first of said handle means and said lever arm means, said resilient member having a locking element extending therefrom,
a ratchet means extending from the other of said handle means and said lever arm means said ratchet means being axially displaced relative to said locking element along an axis perpendicular to said pivot means but in closely adjacent opposed relationship to said locking element, said ratchet means having a plurality of teeth defining a plurality of grooves wherein each groove is adapted to individually receivably engage said locking element of said resilient member, and
latching means movably coupled to said first of said handle means and lever arm means, said latching means for engaging and resiliently deforming said resilient member to cause engagement of said locking element in a groove of said ratchet means when said latching means is in a first position.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/833,840Filed 7 Feb 1992 · continuation in part
Priority: 4 Apr 1991
Granted: 5 Jan 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification27 codes

A61B 17/2909
Forceps for use in minimally invasive surgery: handles
A61B 17/29
Surgical forceps: forceps for use in minimally invasive surgery
A61B 17/320016
Surgical cutting instruments: endoscopic cutting instruments, e.g. arthroscopes, resectoscopes
A61B 18/1445
Probes having pivoting end effectors, e.g. forceps: at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod