Fastening device and tool for surgical holding systems

Abstract

A fastening device for surgical holding systems includes a holding element and a fastening element with a ball joint, which can be locked by way of rotating an eccentric ring in the holding element. The joint socket defines a joint inner surface of the ball joint and the joint head a joint outer surface of the ball joint. When the eccentric ring clamps the joint head with respect to the joint socket, the position of three contact locations of the ball joint which lock the ball joint are unambiguously defined due to the shape of at least one of the three elements: joint socket, joint head and eccentric ring.

What is claimed is: 
     
         1 . A tool, for fixing, locking and releasing a fastening device for surgical holding systems, comprising
 an inner shank with an inner tool tip,   an outer shank with an outer tool tip,   
       wherein the inner shank is arranged within the outer shank and is displaceable with respect to the outer shank along a longitudinal axis of the two shanks. 
     
     
         2 . The tool according to  claim 1 , wherein, in a first displacement position the outer shank is retracted, so that the inner tool tip can be used and in a second displacement position, the outer shank is extended, so that the outer tool tip can be used. 
     
     
         3 . The tool according to  claim 1 , wherein a locking element is provided for locking the position in the two displacement positions, and a release element is provided which can be actuated by way of a release button for releasing the locking. 
     
     
         4 . The tool according to  claim 3 , wherein if this release is effected in the first displacement position, thus with a retracted outer shank, then the telescopic sleeve together with the outer shank is pushed forwards by a spring. 
     
     
         5 . The tool according to  claim 4 , comprising a brake that limits the movement of the outer shank. 
     
     
         6 . The tool according to  claim 1 , wherein when working with the tool a torque is transmitted from the hand grip on the respectively active tool tip, that is, the inner tool tip or the outer tool tip. 
     
     
         7 . The tool according to  claim 1 , wherein the inner shank is designed for screwing in or screwing out a screw. 
     
     
         8 . The tool according to  claim 1 , wherein the outer shank is designed for rotating a clamping element. 
     
     
         9 . The tool according to  claim 1 , which is designed to be disassembled in a tool-free manner into at least two units, by way of at least the inner shank and further parts connected thereto, constituting a first unit, being able to be separated from the outer shank and further parts connected thereto, constituting a second unit, and to be connected to the second unit again, in a tool-free manner. 
     
     
         10 . The tool according to  claim 9 , which is designed to be disassembled by way of the two units being separable from one another by way of the two units firstly being brought into a certain position by way of displacement along a longitudinal axis of the tool, and then the two units being able to be pulled from one another after rotation about the longitudinal axis. 
     
     
         11 . The tool according to  claim 1 , wherein one of the tool tips is designed in order to hook with an element to be rotated therewith, and wherein the shank corresponding to the tool tip is designed in a flexible and rotationally stiff manner. 
     
     
         12 . The tool according to  claim 1 , wherein the outer tool tip is designed to hook with an element to be rotated therewith, and wherein the outer shank in an elastic region is designed in a flexible and rotationally stiff manner. 
     
     
         13 . The tool according to  claim 12 , wherein the inner shank has a tapering at the location of this elastic region when the outer shank is in the working position. 
     
     
         14 . The tool according to  claim 1 , wherein the outer shank comprises two elements that are designed to hook with an element to be rotated therewith. 
     
     
         15 . The tool according to  claim 1 , comprising an asymmetrically acting torque limiter. 
     
     
         16 . The tool according to  claim 1 , comprising an asymmetrically acting torque limiter for the outer shank. 
     
     
         17 . The tool according to  claim 15 , wherein a maximal torque for locking the fastening device, by way of rotation in the clockwise direction, is smaller than a maximal torque for unlocking.