Method of Peening and Portable Peening Gun

Author:  Vincent P. Caruso, Elbert J. Minter
Source:  US Patent 3,937,055
Doc ID:  1974026
Year of Publication:  1974
Abstract:  
An improved portable peening gun characterized by a pneumatic motor, an axially reciprocable hammer supported to be driven by the motor from an initial position along a linear path, and an improved peening head including an axially reciprocable rod bundle coaxially aligned with the hammer and disposed within the path therof. The improved head includes a plurality of peening rods, each being characterized by an anvil defined at one end of a configuration substantially conforming to a segment of a sphere having a radius substantially equal to one-half the thickness of the rod, a barrel for supporting the rod bundle for axial reciprocation, and a helical spring disposed within the barrel for urging the bundle in displacement towards its initial position.