Stapler and multi-inclined anvil structure thereof

A stapler having:

• a base having a clinching end;
• an arm assembly pivotally mounted on the base;
• a magazine assembly pivotally mounted on the base and located between the arm assembly and the base;
• and
• a multi-inclined anvil structure disposed on the clinching end of the base and having
• a body having
• a horizontal imaginary plane;
• a first side;
• a second side opposite to the first side;
• and
• a top facing toward the arm assembly;
• an operating portion formed in the body and located between the first side and the second side, the operating portion being recessed downward in the top of the body to form a recess and having a bottom surface, and the operating portion having a projection plane cut along the horizontal imaginary plane, wherein a part of the projection plane adjacent to the first side is narrower than a part of the projection plane adjacent to the second side;
• and
• a flattening surface formed in the bottom surface of the operating portion and having two inclined bottom portions being inclined relative to the horizontal imaginary plane, wherein each inclined bottom portion has a first end, a second end, and an inclined state, the first end of the inclined bottom portion is defined as an end of the inclined bottom portion adjacent to the first side of the body, the second end of the inclined bottom portion is defined as an end of the inclined bottom portion adjacent to the second side of the body, the inclined state of each inclined bottom portion is that a position of the inclined bottom portion at the first end of the inclined bottom portion is higher than a position of the inclined bottom portion at the second end of the inclined bottom portion, and an inclined bottom angle is formed between an extension direction of the inclined bottom portions and an extension direction of the horizontal imaginary plane.