The ornamental design for a dispensinghead for a tire sealing apparatus, as shown and described.
FIG. 1. is a front-right side perspective view of a dispensing head for a tire sealing apparatus having our new design; the broken lines which define the boundary of the claimed design form no part thereof and the broken lines which depict environment similarity form no part of the claimed design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a rear elevation view thereof;
FIG. 6 is a right side elevation view thereof; and,