The production and machining of components with intersecting axes involves high processing expenditure. These components were either processed on special machines,transfer lines or on conventional lathes in several chucking operations. Therefore, GMT developed an auto indexing chuck to meet the persistent problems in machining components with intersecting axes in a CNC Lathe.

With this chuck, it is possible to perform all the turning operations in one setup. This not only shortens cycle time and boosts productivity. Also, auto indexing chucks enhances the operational efficiency as well. Finally, GMT indexing chucks of different sizes are useful for machining typical parts like Universal joints, spider and valve bodies etc.

GMT’s Power Operated Power Indexing chucks are available with index position:
4 x 90° ,
3 x 120° ,
2 x 180°.

Indexing Accuracy

Roughing: Approx. 0.1mm at 100mm from indexing centre.
Finishing: 0.03 to 0.05 at 100mm from indexing centre.

Indexing Mechanism

You can classify the working of these chucks into two categories, indexing and clamping. The integral hydraulic cylinders performs clamping, de-clamping, indexing and locking of index drum.  The oil fed to the different cylinders through a pipe bundle running through the spindle bore. Typically, during the chuck application, the moving lower jaw clamps the component through an integral cylinder. The upper jaw is stationary. Two, four-way solenoid valves hydraulically controls the indexing of the chucks.

In addition the electrical circuit includes an adjustable time delay relay to incorporate short time lag between indexing and locking cycles. Furthermore, the chuck indexes when the main spindle is running.

Application and advantages:

  • Auto indexing chuck are useful for machining components of large batches due to their short chucking and indexing time.
  • Also, multiple machining process is possible by one operation.
  • It is possible to index automatically on the work while machine spindle is rotating.
  • High precision and accuracy can be obtained

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