The ornamental design for a barbecuegridlifter, as shown and described.
FIG. 1 is a top perspective view of a barbecue grid lifter showing our new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a is a left side elevational view thereof, the right side being a mirror image;
FIG. 5 is rear elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken line showing of a ring in the handle of the barbecue grid lifter is for the purpose of illustrating environmental structure and forms no part of the claimed design.