Rotary chuck

A rotary chuck for machine tools with multiple clamping jaws guided in radial direction in a chuck body, said jaws being actuatable via a direction-changing drive mechanism by a drive element shiftable in axial direction by a drive so that said clamping jaws move in radial direction with the chuck body for gripping respectively releasing a workpiece, whereby said clamping jaws are subdivided into a base jaw and a top jaw for adaptation to different diameters of workpieces to be clamped therewith, said top jaw being secured interchangeably on the base jaw and also being secured therewith displaceably relative to the base jaw, and whereby the base jaw remaining in the chuck body during changing and adjustment of the top jaw cooperates with the direction-changing drive mechanism, whereby for determination of the clamping force applied to the workpiece by the clamping jaws there is provided the improvement therewith comprising:

• at least one force measuring strip arranged in the chuck body, said force measuring strip being arranged respectively in the base jaw so that for preventon of any interruption of any signal line during changing, as well as displacement of the top jaw, such that radial force introduced by the drive element via the direction-changing drive mechanism into the base jaw is determined, and accordingly the force detection occurs at a location which lies after the direction-changing drive mechanism but before a spearation point between the base jaw and the top jaw, so that the connection of said force measuring strip with the signal line is kept from being separated during a change of said top jaw;
• said direction-changing mechanism including an angle lever, and a pressure-stressed pin to which radial force is applied as introduced into said base jaw by said angle lever, said pressure-stressed pin being arranged in said base jaw and being provided with said at least one forcing measuring strip.

A rotary chuck including a body having radial guides as well as including a plurality of clamping elements provided as primary jaw parts radially adjustable in the radial guides and movable for engaging a respective workpiece, said clamping elements being adapted to be actuated by a force-operation via a direction-changing drive;

• each clamping element including a clamping element jaw part which directly engages a workpiece and is interchangeable to adapt to differently dimensioned workpieces, and a drive jaw part for operative cooperation with said clamping element jaw part, said drive jaw part remaining non-removable in said chuck during an exchange of said clamping element jaw part;
• and the improvement in combination therewith comprising:
• a clamping pressure detector provided operatively with said drive jaw part to stay in place therewith in a location considered in the direction of the force introduced from said force-operation, said clamping pressure detector specifically being subsequent to location of said direction-changing drive effective relative to said drive jaw part and located ahead of a joint face between said clamping element jaw part and said drive jaw part so that measured values of clamping pressure are obtained only indirectly via reaction force by said clamping pressure detector provided relative to said drive jaw part without being subject to interruption and disturbance during adjustment movement and interchange as well as displacement movement of said clamping element jaw part rather than directly at locations of movable clamping element jaw parts subject to frictional forces which would falsify resulting measured values as well as being subject to interchange and displacement movement although now always ready for measuring not only when the chuck is stationary but also when the chuck rotates, such that said clamping pressure detector delivers indirectly only satisfactory measured values of reaction force in every state of operation of a clamped-in workpiece and such that these measured values can be used as control and adjustment factors for determination of clamping force of the rotary chuck;
• said drive jaw part being a base jaw having a jaw body and a wedge hook;
• said clamping element jaw part being a top jaw a chuck piston operatively arranged therewith a wedge-type drive for changing the direction of force between said chuck piston and said clamping elements;
• an elongation element for mounting said wedge hook of at least one of said base jaws on the respective jaw body thereof;
• and
• strain gauges provided with said elongation element for determining clamping pressure.

A rotary chuck including a body having radial guides as well as including a plurality of clamping elements provided as primary jaw parts radially adjustable in the radial guides and movable for engaging a respective workpiece, said clamping elements being adapted to be actuated by a force-operation via a direction-changing drive;

• each clamping element including a clamping element jaw part which directly engages a workpiece and is interchangeable to adapt to differently dimensioned workpieces, and a drive jaw part for operative cooperation with said clamping element jaw part, said drive jaw part remaining non-removable in said chuck during an exchange of said clamping element jaw part;
• and the improvement in combination therewith comprising:
• a clamping pressure detector provided operatively with said drive jaw part to stay in place therewith in a location considered in the direction of the force introduced from said force-operation, said clamping pressure detector specifically being subsequent to location of said direction-changing drive effective relative to said drive jaw part and located ahead of a joint face between said clamping element jaw part and said drive jaw part so that measured values of clamping pressure are obtained only indirectly via reaction force by said clamping pressure detector provided relative to said drive jaw part without being subject to interruption and disturbance during adjustment movement and interchange as well as displacement movement of said clamping element jaw part rather than directly at locations of movable clamping element jaw parts subject to frictional forces which would falsify resulting measured values as well as being subject to interchange and displacement movement although now always ready for measuring not only when the chuck is stationary but also when the chuck rotates, such that said clamping pressure detector delivers indirectly only satisfactory measured values of reaction force in every state of operation of a clamped-in workpiece and such that these measured values can be used as control and adjustment factors for determination of clamping force of the rotary chuck;
• said drive jaw part being a base jaw having a jaw body;
• said clamping element jaw part being a top jaw
• a chuck piston operatively arranged therewith;
• a lever direction-changing drive including at least one angle lever for changing the direction of force between said chuck piston and said clamping element jaw part;
• a pressure-stressed pin arranged with said clamping element jaw part and engaged by said lever direction-changing drive;
• and
• a force-measuring member arranged on said pressure-stressed pin between at least one angle lever of said direction-changing drive, and the respective drive jaw part belonging therewith.