Self-centering chuck

A self-centering chuck for accurately fixing the position of workpieces to be machined on tables, the self-centering chuck comprising:

• a basic body with guide grooves;
• a threaded spindle mounted rotatably about a longitudinal axis thereof, said threaded spindle having a right-handed external thread in a first axial area and a left-handed external thread in a second axial area, said threaded spindle being provided centrally with a circumferential groove extending around a circumference of said threaded spindle;
• a first slide screwed onto said right-handed external thread of said threaded spindle, said first slide including a clamping jaw in a head area, said first slide having sliding blocks guided in said guide grooves of said basic body and guided movably in an axial direction on said threaded spindle;
• a second slide screwed onto said left-handed external thread of said threaded spindle, said second slide including a clamping jaw in a head area, said second slide having sliding blocks guided in said guide grooves of said basic body and guided movably in an axial direction on said threaded spindle;
• a central piece arranged between said slides and against which said two slides are clamped, said threaded spindle being centered by said central piece and being fixed on said basic body by a fastening means of said central piece wherein said fastening means is guided in said groove so that rotation of said threaded spindle leads to an axial motion of said slides with said clamping jaws towards each other and away from one another, characterized in that said clamping jaws arranged on said slides on the head side have clamping surfaces on both sides for use on both sides, and said slides are screwed on both sides onto said left-handed and right-handed external threads of said threaded spindle.