Patent ID: 7815638

Claim:
An applicator for an electrosurgical instrument, comprising: a gas and high frequency current terminal at a first end of said applicator; a cutting electrode at a second end of said applicator, opposite said first end; a gas and high frequency current supply pipe formed of an electrically conductive material and attached to said cutting electrode, said pipe forming a passage that communicates a gas from said gas and high frequency current terminal to a location proximate to said cutting electrode, said electrically conductive material of said pipe conducting a high frequency current that drives said cutting electrode from said gas and high frequency current terminal to said cutting electrode; an insulating cap having a cylindrical inner recess configured to detachably fasten the applicator on a handle of the instrument, the insulating cap having an annular protrusion that contacts a portion of the supply pipe to secure the supply pipe to the insulating cap, the insulating cap further having a proximal extension that surrounds the supply pipe, the extension extending away from the annular protrusion toward the second end of the applicator terminating with an inwardly projecting edge; an insulating casing tube surrounding a portion of the supply pipe and partially within the cap, the tube extending from the annular protrusion of the cap past the inwardly projecting edge of the cap, the tube having a collar on a tube end proximate to the annular protrusion, the tube displaceable along a longitudinal axis of the applicator, a path of displacement of the tube end with the collar being only between the annular protrusion of the cap and the inwardly projecting edge of the cap, so that the insulating tube can expose or cover the cutting electrode; and at least one radially surrounding gas-sealing inhibiting device arranged between an inside of the casing tube and an outside of the gas and high frequency current supply pipe, wherein the inhibiting device allows that a respective position be frictionally fixed at any location of the path of displacement of the casing tube, wherein said inhibiting device is adapted and arranged to prevent leakage of gas.