Patent ID: 8826547

Claim:
A reciprocating saw, comprising; a housing; a drive mechanism in said housing; a motor in the housing for driving said drive mechanism; an elongated plunger located in said housing for reciprocating motion and having a front end portion for attaching a saw blade for cutting material and a rear portion opposite said front end portion; wherein said rear end portion of said plunger is operably connected to said drive mechanism and is driven to reciprocate by said drive mechanism to produce said reciprocating motion; wherein said plunger is hollow and empty and has a cylindrical outer wall portion that extends longitudinally between said front end portion and said rear portion, said cylindrical outer wall portion has a first end permanently affixed to said front end portion and a second end permanently affixed to said rear end portion, such that said outer wall portion is driven to reciprocate by the rear end portion and the front end portion is driven to reciprocate by the outer wall portion wherein said outer wall portion defines a spiral slot that extends through said outer wall portion for multiple turns around the circumference of said outer wall portion of said plunger to form an energy absorbing compliant configuration that results in the outer wall portion having sufficient structural strength to reciprocatingly drive the front end portion of the blade with a saw blade attached thereto to perform cutting operations and that enables said outer wall portion to expand and contract in a lengthwise direction to absorb high energy impulses that can be produced by the saw blade being bound in the material being sawed during operation of the saw.