Patent ID: 8196676
Filing Date: 2012-06-12
Classification: B25D

Abstract:
1. A pneumatically actuated recoilless hammer comprising: a first housing; a moil supported for reciprocal movement along a hammer axis by said first housing; a piston assembly disposed in an elongate tube extending from the rear of said first housing, the bore of said tube defining a first chamber having a fore end near said first housing and an oppositely disposed closed aft end, said piston assembly moveable within said first chamber such that it may strike said moil, wherein in a rest position the piston assembly is held forward against said moil by a low pressure air supply delivered from a location at or near said aft end of said first chamber, and said piston assembly is retracted to a charged position at said aft end of said first chamber by delivery of high pressure air to act on the fore portion of said piston assembly, and upon actuation of a trigger mechanism by an operator, air is vented from the fore end of said first chamber to atmosphere causing a pressure unbalance of low magnitude across said piston assembly such that it accelerates towards and strikes said moil, and wherein said first chamber is of a length to enable a high energy blow with minimal piston acceleration recoil when said hammer is manually held and operated.