Portable sheet metal hole cutter

Claim 1

A PORTABLE CUTTER FOR CUTTING OUT A SECTION OF A SHEET COMPLETELY THEREFROM BY RELATIVE MOVEMENT BETWEEN THE CUTTER AND THE SHEET COMPRISING: (A) A U-SHAPED HANDLE MEMBER HAVING A PAIR OF VERTICALLY SPACED LEG ELEMENTS; (B) A PIVOT POST MOVABLY MOUNTED ON ONE OF SAID LEG ELEMENTS AND BEING ADAPTED TO BE INSERTED INTO A HOLE IN A PIECE OF SHEET METAL TO FUNCTION AS A PIVOT FOR SAID HANDLE MEMBER ABOUT THE HOLE; (C) A PAIR OF SPACED JOURNAL MEMBERS ONE EACH OF WHICH IS MOUNTED UPON THE OUTER END PORTION OF EACH OF SAID LEG ELEMENTS AND HAVING A COMMON JOURNAL AXIS; (D) A RIDID SLEEVE MEMBER HAVING A LENGTH SUBSTANTIALLY EQUAL TO THE SPACING BETWEEN SAID JOURNAL MEMBERS AND EXTENDING BETWEEN SAID JOURNAL MEMBERS AND ALIGNED AXIALLY THEREWITH; (E) A MILLING CUTTER EXTENDING THROUGH SAID SLEEVE AND SAID JOURNAL MEMBERS AND BEING SLIDABLE AXIALLY RELATIVE THERETO AND BEING ROTATABLY MOUNTED WITHIN SAID JOURNAL MEMBERS FOR ROTATION ABOUT ITS LONGITUDINAL AXIS; (F) SAID MILLING CUTTER HAVING ONE END PORTION ADAPTED TO BE CONNECTED IN DRIVEN RELATION TO A SOURCE OF ROTARY POWER AND HAVING HELICAL CUTTING EDGES CARRIED BY ITS OPPOSITE END PORTION EXTENDING OUTWARDLY BEYOND SAID JOURNAL MEMBERS; (G) POSITIVE ENGAGEMENT MEANS POSITIVELY ENGAGING SAID MILLING CUTTER AND SAID SLEEVE AND HOLDING SAID MILLING CUTTER AGAINST AXIAL MOVEMENT RELATIVE TO SAID SLEEVE AND SAID JOURNAL MEMBERS; (H) SAID ENGAGEMENT MEANS BEING ADJUSTABLE TO PERMIT SAID MILLING CUTTER TO BE SHIFTED AXIALLY BETWEEN FIXED AXIAL POSITIOS RELATIVE TO SAID SLEEVE AND SAID JOURNAL MEMBERS; (I) A GENERALLY U-SHAPED BRACKET CARRIED BY THE LOWER OF SAID JOURNAL MEMBERS ADJACENT THE HELICAL CUTTING EDGES OF SAID MILLING CUTTER INTERMEDIATE THE ENDS THEREOF AND HAVING A PAIR OF LEGS EXTENDING ON OPPOMAINDER OF THAT LEG AND AXIALLY OF SAID MILLING CUTTER AND GENERALLY RADIALLY THEREOF; (J) ONE OF THE LEGS OF SAID BRACKET MEMBER TERMINATING IN A STABILIZER ELEMENT EXTENDING AWAY FROM SAID JOURNAL MEMBERS AND GENERALLY NORMAL TO THE RESITE SIDES THEREOF; (K) THE OTHER LEG OF SAID BRACKET MEMBER TERMINATING IN A TERMINAL PORTION OFFSET AXIALLY OF SAID MILLING CUTTER FROM THE REMAINDER OF THAT LEG IN A DIRECTION AWAY FROM SAID JOURNAL MEMBER AND DEFINING THEREWITH A CHIP DISCHARGE AREA THROUGH WHICH THE CHIPS WILL BE DISCHARGED BY THE HELICAL CUTTING EDGES OF SAID MILLING CUTTER WHEN A SOURCE OF ROTARY POWER IS APPLIED TO THE LATTER AND SAID CUTTING EDGES OF SAID MILLING CUTTER ARE APPLIED TO SUCH A SHEET IN CUTTING RELATION; (L) SAID TERMINAL PORTION HAVING A COOPERATIVE CUTTING SURFACE COOPERATING WITH THE CUTTING EDGES OF SAID MILLING CUTTER AND BEING SPACED AXIALLY OF SAID MILLING CUTTER RELATIVE TO SAID JOURNAL MEMBERS AND BEING DISPOSED IMMEDIATELY ADJACENT TO THE HELICAL CUTTING EDGES OF SAID MILLING CUTTER INTERMEDIATE THE ENDS THEREOF AND EFFECTING THEREWITH A POSITIVE COOPERATIVE CUTTING ACTION IN A SINGLE PLANE UPON A SHEET OF SHEET METAL WHEN THE ROTATING CUTTING EDGES OF SAID MILLING CUTTER ARE APPLIED TO SUCH A SHEET.