The entire range of ITI-ExactTM Standard Automatic Indexing Tables incorporate a non-lifting tabletop positioned by a three-piece Hirth coupling.
CHARACTERISTICS:
1) High accuracy within +/- 3 seconds of arc as standard and the accuracy actually improves with use.
2) Robust clamping system ensures maximum rigidity, even during extreme cutting loads.
3) Non-lifting tabletop ensures that the table assembly is 100% sealed from contamination.

FUNCTION PRINCIPLES OF ITI-EXACT NON-LIFTING INDEXING TABLES

As illustrated in Sketch A, there are three components in the Hirth coupling assembly. Hirth Gear #1 is attached to rotating tabletop. #2 is rigidly mounted into the table housing and #3 raises and lowers internally under hydraulic pressure to lock/unlock the assembly.
In Sketch B, when the Hirth gear #3 lowers, the table is unlocked and can be rotated via the rack and pinion or worm drive depending upon table model.
When the table has indexed to the required location, Hirth Gear #1 lines up with Hirth Gear #2 in the table housing, then connecting Hirth Gear #3 is raised, accurately lines up and rigidly locks the three components of the Hirth coupling assembly together.