Abstract: An improved apparatus for trimming an irregular open end of a container body is disclosed. The improved trimmer cartridge includes a sealed gear housing, for retention of interior lubricant and to reduce contamination. An adjustment mechanism, accessible from the exterior of the housing, is provided to adjust a gap between two blades of the trimmer cartridge. The adjustment mechanism provides improved control over the gap width, which is between 8-25% of the can metal thickness. Additionally, a tang that is removably connected to a shaft for a first blade provides rotational power for the trimmer. The tang is replaceable without requiring the housing to be opened or requiring replacement of the blade shaft. Another blade shaft is provided for a second blade, with the two blade shafts having substantially equal mass. The trimmer also includes spur gears, which do not have the thrust load associated with prior art helical gears.

Abstract: A preferred embodiment of the disclosed can lid has a center panel having a central axis that is perpendicular to a diameter of the outer rim, or peripheral curl portion, of the can lid, an annular countersink surrounding the center panel, an arcuate chuckwall extending radially outward from the annular countersink, an arcuate step portion extending radially outward from the arcuate chuckwall, a transitional portion extending radially outward from the arcuate step portion, and a peripheral curl portion extending outwardly from the transitional portion.