Jeffrey A Christensen

US Patent:

51996278, Apr 6, 1993

Filed:

Mar 29, 1991

Appl. No.:

7/678534

Inventors:

Jeffrey M. Christensen - Tujunga CA

International Classification:

B27F 709

US Classification:

227130

Abstract:

A hammer including a magazine for holding and feeding fasteners such as nails including hydraulic means for driving the fasteners. The hammer head is movable to the rearward with respect to the body and the handle upon impacting a work surface driving one or more pistons rearwardly. Cylinders for the pistons surround a single fastener driver cylinder and piston of smaller surface area than rearward traveling piston or pistons. Hydraulic fluid flows from the large or multiple piston(s) through a manifold to the rear of the fastener drive cylinder piston. Rapid forward movement of the fastener drive piston sets the fastener. Forward movement of the movable head by a return spring opens a chamber for the next fastener to be placed by spring action in front of the fastener drive blade, ready for the next fastener placement. The body of the hammer is secured to the handle at an angle A which is between 95. degree. and 116. degree. and the center of gravity of the hammer is located between at handle location. +-.