Patent ID: 7175236

Claim:
A hammer for use on steel reinforced concrete comprising: a hammer mass having two spaced parallel arms connected by a header block at the top and a foot at the bottom, the two spaced parallel arms, header block and foot form a rectangular opening, the arms having angled inside corner faces on the rectangular opening, a front guide plate and rear guide plate each having angled corner edges for slidingly engaging the angled inside corner faces on the rectangular opening of the arms, the front and rear guide plates attach to each other though the rectangular opening, and slid up and down along the arms of the hammer mass, a hammer mounting frame, the rear guide plate pivotally attached to the hammer mounting frame near the base of the rear guide plate, for pivotally holding the hammer assembly, an hydraulic cylinder centered in the width of the hammer mass rectangular opening and attached to the guide plate, a piston containing the hydraulic cylinder and connected to the foot of the hammer such that the hydraulic cylinder moving in the piston moves the hammer mass relative to the guide plate, a rod attached to the rear of the rear guide plate for pivoting the rear guide plate on the pivot connection to the frame, thereby angling the hammer foot relative to an object being hammered, an anvil proximate the base of the foot of the hammer when the hydraulic cylinder is extended from the piston to place reinforced concrete on to subject the concrete to hammer blows.