Indexing plungers GN 817.3 realize a reasonable priced precision locating when guide bushings DIN 179
For this purpose a guide bushing DIN 179
is used as guide, whereby the dimension l3
of the plunger determines the length of the bushing.
The precise location is, therefore, not dependent on the guide pin in the plunger, but on the accuracy of the guide bush (bore tolerance F7) and the plunger (tolerance h7). Both components are hardened and ground. It goes without saying that the bush length also influences the accuracy of the positioning.
Type C is used for such applications where the plunger has to stay in its retracted position. To achieve this, the knob is rotated by 90° degrees after being retracted. A notch keeps the plunger in this position.