Protective Helmet Back Plate

FIG. 1 is a front perspective view of a protective helmet back plate showing our new design. FIG. 2 is a back perspective view of the protective helmet back plate of FIG. 1 . FIG. 3 is a front view of the protective helmet back plate of FIG. 1 . FIG. 4 is a back view of the protective helmet back plate of FIG. 1 . FIG. 5 is a first side view of the protective helmet back plate of FIG. 1 . FIG. 6 is a second side view of the protective helmet back plate of FIG. 1 . FIG. 7 is a top view of the protective helmet back plate of FIG. 1 ; and, FIG. 8 is a bottom view of the protective helmet back plate of FIG. 1 . The broken lines shown in the drawings depict portions of the protective helmet back plate that form no part of the claimed design.