Portable drum opener

A portable drum opener for tracking around a cover rim of a drum while cutting through an outer lip of said cover rim, said opener including a drive wheel for engaging a radially inward facing surface of said cover rim and advancing said opener around said cover rim, and said opener comprising:

• a. a pivot vertically and laterally spaced from said drive wheel;
• b. an assembly including a guide roller bracket, a spring support element, and a generally vertically oriented idler shaft mounted on said pivot for generally horizontal movement;
• c. a cutter wheel mounted on said idler shaft to be pivotally movable toward and away from said outer lip of said cover rim;
• d. means for moving said idler shaft to press said cutter wheel against said outer lip in a region opposite said drive wheel;
• e. a pair of guide rollers arranged on generally vertical axes on said guide roller bracket for rolling against said outer lip on opposite sides of said drive wheel and said cutter wheel to support said opener in tracking around said cover rim;
• f. spring means arranged between said guide roller bracket and said spring support element for biasing said guide rollers against said outer lip;
• and
• g. a lost motion coupling between said idler shaft and said guide roller bracket for moving said guide rollers away from said outer lip against the bias of said spring means when said idler shaft is pivoted away from said outer lip and for releasing said spring means for biasing said guide rollers against said outer lip when said idler shaft pivots toward said outer lip.