Surgical instrument comprising an instrument handle and zero point adjustment
View Patent ↗relates to a surgical instrument comprising an instrument handle ( 1 ) linked to a proximal end portion of a tube shaft ( 2 ) to the distal end portion of which an instrument head ( 4 ) is linked so as to be bendable, in which instrument head an effector ( 3 ) including at least one pivotal engaging element ( 30 ) is rotatably supported. The instrument handle ( 1 ) has a number of manipulators and/or operating mechanisms for operating the instrument head ( 4 ) and/or the effector ( 3 ) via gear trains. According to the invention, a clutch ( 37 ) which permits a zero point adjustment individual at least over a predetermined pivoting range of the instrument handle ( 1 ) is interposed in the gear train effecting the bending motion of the instrument head ( 4 ). The zero point is defined as a relative position of the instrument handle ( 1 ) with respect to the tube shaft ( 2 ) in which the instrument head ( 4 ) adopts a predetermined bending position with respect to the tube shaft ( 2 ).
1. A surgical instrument comprising an instrument handle linked to a proximal end portion of a tube shaft, and at a distal end portion of the tube shaft, an instrument head linked so as to be bendable, the instrument head having an effector including at least one pivotal engaging element that is rotatably supported, wherein said instrument handle has a number of at least one selected from the group consisting of manipulators and operating mechanisms for operating at least one selected from the group consisting of said instrument head and said effector via gear trains, wherein
a clutch which permits an individual zero point adjustment at least over a predetermined pivoting range of said instrument handle is interposed in a gear train effecting the bending motion of said instrument head, wherein the zero point is a relative position of said instrument handle with respect to said tube shaft in which said instrument head adopts a predetermined bending position with respect to said tube shaft,
said clutch being arranged in the linking area between said instrument handle and said tube shaft, and
said clutch comprising a connecting piece fixedly arranged at said instrument handle and a rotary shaft rotatably held at the tube shaft for the transmission of a bending motion to said instrument head, said rotary shaft being connected to said connecting piece via frictional engagement.
2. A surgical instrument according to claim 1 , characterized in that said rotary shaft and said connecting piece are fitted into each other at least in portions, wherein a frictional member is disposed between said rotary shaft and said connecting piece.
3. A surgical instrument according to claim 2 , characterized in that said frictional member is an open lock washer placed under a bias upon an inner and/or outer circumferential sliding face provided at said rotary shaft and/or said connecting piece and thus enters into frictional engagement with said rotary shaft and/or said connecting piece for transmission of a torque predetermined by a spring biasing force.
4. A surgical instrument according to claim 3 , characterized by a driving pin that is radially inserted either in said rotary shaft or in said connecting piece and projects into a radial gap formed by said open lock washer.