The ornamental design for a pistoncooling apparatus, as shown and described.
FIG. 1 is a front elevation view of a design for a piston cooling apparatus including a mounting fixture.
FIG. 2 is a left side elevation view of the piston cooling apparatus of FIG. 1.
FIG. 3 is a back elevation view of the piston cooling apparatus of FIG. 1.
FIG. 4 is a right side elevation view of the piston cooling apparatus of FIG. 1.
FIG. 5 is a top plan view of the piston cooling apparatus of FIG. 1.
FIG. 6 is a bottom plan view of the piston cooling apparatus of FIG. 1; and,
FIG. 7 is a front-right perspective view of the piston cooling apparatus of FIG. 1.
The broken lines in the drawing views are included for the purpose of illustrating portions of the piston cooling apparatus that form no part of the claimed design. For purposes of clarity, FIGS. 1-7 show the piston cooling apparatus with the mounting fixture in environment. The mounting fixture is shown for illustrative purposes and forms no part of the claimed design.