| 摘要 |
AN ELECTRIC DRILL APPARATUS HAVING A LOW PROFILE IS PROVIDED WHICH COMPRISES AN ANNULAR CUTTER, A MOTOR (12) FOR ROTATING THE ANNULAR CUTTER, A ROTARY SHAFT ASSEMBLY (18) FOR ROTATING THE ANNULAR CUTTER ATTACHED TO ITS LEADING END ABOUT A ROTATING, A ROTATION REDUCTION MECHANISM DISPOSED BETWEEN THE MOTOR (12) AND ROTARY SHAFT ASSEMBLY (18) FOR TRANSMITTING A DRIVING FORCE OF THE MOTOR (12) TO THE ANNULAR CUTTER THROUGH THE ROTARY SHAFT ASSEMBLY (18), A FEED MECHANISM (20) RESPONSIVE TO AN OPERATION OF A MANUAL HANDLE (39, 42), FOR MOVING THE ROTARY SHAFT ASSEMBLY (18) ALONG WITH A STRAIGHT LINE TO ADVANCE OR RETRACT THE ANNULAR CUTTER ATTACHED TO THE ROTARY SHAFT ASSEMBLY (18) WITH RESPECT TO A WORKPIECE, AND AN ADHESION BASE FOR SECURING THE ELECTRIC DRILL APPARATUS TO THE WORKPIECE. THE ANNULAR CUTTER HAS A PLURALITY OF CUTTING BLADES COMPRISED OF CEMENTED CARBIDE TIPS FIXED ON ITS LOWER END, THEREBY IT IS CAPABLE OF ROTATING AT A HIGH SPEED. THE ROTARY SHAFT ASSEMBLY (18) HAS A ROTATING SHAFT (22, 24, 26) WHICH ROTATES IN A DIRECTION DIFFERENT FROM THAT OF A ROTATING SHAFT (22, 24, 26) OF THE MOTOR (12), THEREBY THE DRILL APPARATUS HAS A LOW PROFILE.(FIG 1) |
