The ornamental design for a colletchuck, as shown and described.
FIG. 1 is a perspective view of a collet chuck, showing my new design;
FIG. 2 is a front view, the rear view being a mirror image thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a plan view, the bottom view being a mirror image thereof;
FIG. 6 is a cross-sectional view thereof, taken along line 6-6 of FIG. 3; and,
FIG. 7 is a view illustrating a use of the collet chuck; the broken line showing of the billet for enlarging forms no part of the claimed design.
The claimed collet chuck has a structure in which a fore-end of a cylinder is divided into four parts and slits are formed between the divided parts. The collet chuck clamps and supports a product to be processed on the outside thereof.