The ornamental design for a gripperjoint, as shown and described.
FIG. 1 is a side view of a tool including a gripper joint;
FIG. 2 is an enlarged perspective view of the area indicated with the unevenly-spaced boundary line in FIG. 1; and,
FIG. 3 is an enlarged side view of the area indicated with the unevenly-spaced boundary line in FIG. 1.
The evenly-spaced broken lines in FIGS. 1, 2, and 3 depict unclaimed portions of the gripper joint and form no part of the claimed design. The unevenly-spaced broken line in FIG. 1 forms the boundary of the claimed design and forms no part of the claimed design.