Pneumatic hammer apparatus

A pneumatic hammer for use on auto body surfaces, comprising:

• an air cylinder tube;
• a handle extending angularly from said air cylinder tube;
• a piston slidably positioned within the cylinder to subdivide same into an air chamber and a second chamber;
• a first end wall closing said second chamber;
• a compression coil spring in said second chamber trained between said first end wall and said piston for urging said piston away from said first end wall;
• a piston rod extending from said piston through said first end wall;
• said piston rod having a non-circular head adapted to interchangeably receive any one of a number of differently contoured hammering elements;
• a second end wall closing said air chamber, said second end wall threadedly received within a rear end portion of the air cylinder tube permitting volumetric adjustment of the air chamber;
• an air supply passage means extending through said handle, said air supply passage means terminating in an air pressure port in the air cylinder tube in rear proximity to said second end wall;
• and an air vent port in said air cylinder tube adjacent said second end wall;
• and a manually controlled valve carried on said handle for stopping the flow of air through said air supply passage means.