Laproscopic instrument depth stop

Abstract

Disclosed is an infinitely adjustable depth stop for a laparoscopic instrument having a shaft. The depth stop includes a first component having a first annular space adapted to allow the shaft to be fitted therethrough. The first annular space has a reducible diameter and an interference surface against which the shaft may be fitted. Upon reduction of the reducible diameter, the interference surface frictionally engages the shaft to arrest relative movement of the depth stop along the shaft. The frictional engagement may be along a curve, a spiral curve, or an area.

What is claimed is: 
     
         1 . A depth stop for a laparoscopic instrument having a shaft, where the depth stop comprises:
 a first component having a first annular space adapted to allow the shaft to be fitted therethrough;   a second component adapted to be connected to the first component, the second component having a second annular space adapted to allow the shaft to be fitted therethrough;   the first annular space and the second annular space forming a combined annular space having a first cross sectional area;   wherein when the first component is moved relative to the second component the combined annular space reduces to a second cross sectional area less than the first cross sectional area to impart a force on the shaft, the force capable of arresting relative movement of the depth stop along the shaft;   wherein the reduction in annular space is created by tapering of the first annular space.   
     
     
         2 . The depth stop of  claim 1 , wherein the first component comprises a tapered section and the second component comprises a collet that conforms to the geometry of the tapered section. 
     
     
         3 . The depth stop of  claim 2 , wherein the first component and the second component are threaded together with threads, whereby rotation of the first component and second component relative to each other moves the collet with respect to the tapered section. 
     
     
         4 . The depth stop of  claim 1 , wherein the reduction in annular space is created by rotation of a stop lever about a point outside the cross sectional area of the shaft. 
     
     
         5 . The depth stop of  claim 4 , further comprising a spring, said spring imparting a force on said stop lever. 
     
     
         6 . The depth stop of  claim 5 , wherein said stop lever includes a cylindrical section between a first tab and second tab. 
     
     
         7 . The depth stop of  claim 1 , wherein said second component is a helical coil. 
     
     
         8 . The depth stop of  claim 7 , wherein said first component further comprises a series of recesses;
 said depth stop further comprising a third component, said third component including a ramp adapted to ratchet with said series of recesses.   
     
     
         9 . The depth stop of  claim 8 , further comprising a release button adapted to release said ramp from said series of recesses. 
     
     
         10 . A depth stop for a laparoscopic instrument having a shaft, where the depth stop comprises:
 a first component having a first annular space with a first cross sectional area adapted to allow the shaft to be fitted therethrough;   a second component adapted to be fitted over portions of the first component to reduce the first annular space to a second cross sectional area less than the first cross sectional area, wherein the second component is fitted over the first component by moving the second component a direction perpendicular to the longitudinal axis of the shaft.   
     
     
         11 . The depth stop of  claim 10 , wherein the second component is a clip having first and second legs connected by a connector member. 
     
     
         12 . A depth stop for a laparoscopic instrument having a shaft, where the depth stop comprises:
 a first component having a first annular space adapted to allow the shaft to be fitted therethrough;   the first annular space having a reducible diameter and an interference surface against which the shaft may be fitted;   wherein, upon reduction of the reducible diameter, the interference surface frictionally engages the shaft to arrest relative movement of the depth stop along the shaft;   wherein the frictional engagement is along a spiral curve.   
     
     
         13 . The depth stop of  claim 12 , wherein the frictional engagement forms an area.