The ornamental design for a drillbit, as shown and described.
FIG. 1 is a perspective view of the drill bit of the subject invention, the opposite side being a mirror image thereof.
FIG. 2 is a greatly enlarged front end view of the drill bit of FIG. 1; and,
FIG. 3 is a enlarged, partial perspective view of the tip of the drill bit of FIG. 1, it being understood that the line indicating the point at which it is broken off forms no part of the claimed design.
The broken line showing of unclaimed portions of the drill bit are for illustrative purposes only and form no part of the claimed design.
Security device comprising a stop member for drilling instrument used in particular in dental surgery and device pre-calibrating and storing drilling depth