The ornamental design for a drillchuck, as shown and described.
FIG. 1 is a perspective view of a drill chuck showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a cross-sectional view thereof taken along line A-A in FIG. 4; and
FIG. 8 is an enlarged sectional view thereof taken along line C-C in FIG. 2 of portion B-B in FIG. 4; and,
FIG. 9 is an enlarged cross-sectional view thereof taken along line A-A in FIG. 4 that shows a length and depth of the grooves shown in FIGS. 1-3, 6, and 8.
Portions shown with broken lines form no part of the claimed design.