Abstract: The object of the invention is to provide an attachment heavy duty shear of reduced weight. This shear has a single-row upper jaw and a single-row lower jaw, with the upper jaw being driven by a built-in hydraulic cylinder to open and close with respect to the lower jaw. The forward end of the lower jaw has a 7-configured guide member for precluding a lateral displacement of the upper jaw in shearing. This construction provides for reduced overall weight and positive grip and shearing.

Abstract: The present invention provides a concrete crusher comprising an upper jaw and a lower jaw which are connected to each other through a pivot pin and adapted to be opened and closed by a hydraulic cylinder, the lower jaw having a plurality of longitudinal cutters extending perpendicular to the pivot pin and arranged in the form of a fork, the upper jaw having a large rough cutter extending perpendicular to the pivot pin, the lower jaw further having a plurality of cross cutter bars arranged in a grate-like pattern avoiding the position of descent of the large rough cutter, the upper jaw further having a surfacing plate member facing the lower jaw and having a plurality of cross cutter bars corresponding to the cross cutter bars of the lower jaw, with the large rough cutter interposed between rows of the cross cutter bars of the upper jaw.

Abstract: The present invention provides a scissor-action reinforcement cutter comprising a lower jaw and an upper jaw which is of smaller profile than the lower jaw, a first and a second shearing cutter means dismountably secured to each of opposed inner lateral surfaces of the upper and lower jaws in a bent formation in the longitudinal direction of the jaw, and a hydraulic cylinder operatively associated with the jaws, the lower jaw being provided with a through-opening in a forward part thereof to accept a foreard end portion of the upper jaw in such a manner that the first shearing cutter means of the upper and upper jaws intersect each other to grip a work to be cut, the lower jaw being provided with a land series configured generally in the shape of the capital letter L around the through-opening, the shearing cutter means being disposed along the long lateral side of the land series, and a clearance being provided between the short side of the land series which is opposite to the side of the lower jaw on which