a top plan view of the lid preform; [0019]FIG. 4 is a top plan view of the frame; [0020]FIG. 5 is a partially broken away top plan view of the shield assembly of FIG. 1; [0021]FIG. 6 is a sectional view taken, as indicated, along the line 6-6 of FIG. 5; [0022]FIG. 7 is a sectional view taken, as indicated, along the line 7-7 of FIG. 5; [0023]FIG. 8 is an enlarged view of one embodiment of an engag