Abstract: An oil-pressure cylinder in a crushing device is connected to a crushing jaw via a pivot shaft so that the crushing jaw can open and close. The extension of oil-pressure cylinder causes the crushing jaw to close and crush the object to be crushed. Oil-pressure cylinder has a piston with a greater pressure-receiving area on the head side than on the rod side. An acceleration valve serves to switch the extension/retraction operations of the oil-pressure cylinder. During a rod unloaded interval, beginning when the crushing jaw starts to close and ending when the crushing jaw comes into contact with the object to be crushed, the acceleration valve makes communication between a head-side port and a rod-side port in the cylinder continuous, while the oil path from the rod side to a tank is blocked. The oil from the rod side is made to flow to the head side.

Abstract: A shearing machine includes a sickle shaped upper jaw interacting scissors fashion with a generally linear lower jaw. The distal ends of the sickle shape begin shearing from opposite ends of a plate-type object at about the same time, with shearing progressing toward a central point. A transverse member and a return leg form, with the lower jaw, a J-shaped device. The upper jaw slides within the return of the J during the entire cutting operation, thereby overcoming any tendency for jaw spreading between the linear and sickle shaped cutters. A front cutting insert in the transverse member and a return cutting insert in the return leg, interact with a tip of the upper jaw to pierce, and then cut, a plate which is longer than the throat of the shearing machine, thereby enabling shearing of large plates. The initial piercing takes place simultaneously at the tip of the upper jaw and at an upward-directed point on the front cutting insert.

Abstract: A cutting/crushing device for the demolition of buildings has a pair of jaws that pivot on frame. The jaws are constrained to pivot in synchrony because each jaw remains engaged with a guide pin which substantially prevents relative movement of the two jaws. The guide pin is guided by a slot in the frame, aligned with a plane of symmetry between the two jaws, to prevent it from moving toward or away from either jaw. By guiding the guide pin in this way, frictional binding and wear of the guide pin are minimized. In addition, the shape of the recesses into which the guide pin fits can have smaller tolerances reducing play between the two jaws. Stoppers on the frame press against the rotatable jaws when they are filly opened to prevent any play.

Abstract: A concrete crusher has a crushing surface 1a on a stationary lower jaw 1 and it is formed so that its axial cross-section is V-shaped. A main crushing blade 5 is installed on a crushing surface 2a of a movable upper jaw 2 pivoted to the lower jaw and is opposite the lowermost portion of stationary crushing surface 1a. Supporting crushing blades 6 are installed on the upper jaw at opposite sides of the main crushing blade 5 and have shorter blade heights than main crushing blade 5.

Abstract: The shearing machine is designed to surely shear an object to be sheared with less amount of power without causing slips. A plurality of lower shear blades mounted on a lower jaw member are arranged such that the arrangement of the cutting edges forms a convexity curved downward. The front edge portion of each shear blade inwardly protrudes from an adjacent rear edge portion of each forward adjacent shear blade. A plurality of upper shear blades mounted on an upper jaw member are arranged such that the arrangement of the cutting edges forms a convexity curved upward. The front edge portion of each shear blade inwardly protrudes from an adjacent rear edge portion of each forward adjacent shear blade.

Abstract: A double scissors cutter for cutting a workpiece into substantially rectangular pieces is provided which comprises a pair of jaw members adapted to be opened and closed about a pivot shaft. Each of the jaw members includes, attached thereto, a cutting blade on an abutting surface thereof, the cutting blades being of a substantially U-shaped configuration. The cutting blades are arranged to be inter-engaged with each other with one of the cutting blades being positioned within the other of the cutting blades, so that a workpiece positioned between the cutting blades may be cut in a scissors cutting movement of the jaw members to form cutout pieces of a substantially rectangular configuration. Protuberant structure is carried on one of the jaw members and extends beyond a plane in which the cutting edge of the associated cutting blade lies.

Abstract: A universal breaking machine is provided which comprising a pair of movable arms pivotably connected to a support frame for open-close movement, and a hydraulic cylinder for causing the open-close movement of the pair of movable arms. The pair of movable arms are adapted to secure detachably, at the opposite, forward end surfaces thereof, a set of or a pair of tool rests for long cutter having a long cutter thereon, tool rests for short cutter having, at the rearward end thereof, a short cutter of a length smaller than that of the long cutter, and having a crusher at the forward end thereof, or smashing blocks having a plurality of large protrusions. A secondary breaking attachment having a plurality of small protrusions thereon may be removably attached, as desired, to the opposite, forward-most surfaces of the pair of movable arms.

Abstract: Breaking equipment comprising a mounting bracket that is attached to an arm of a power shovel for vertical pivotal movement, a holder frame mounted on the mounting bracket for swivel movement, a hydraulic motor attached to the mounting bracket for rotatably and reversibly driving the holder frame or a swivel break mechanism which is used in place of the hydraulic motor for restricting swivel movement of the holder frame, a pair of pivot arms of a symmetrically L-shaped configuration attached at their mid points to the holder frame by means of pivot axes, the pivot axes being separated apart a predetermined distance H from one another so as to satisfy the equations; a=<b and H=<2h, wherein, a is a distance from the pivot point to the forward end of each of the pivot arms, b is a distances from the pivot point to the rearward end of each of the pivot arms, and h is a distance from the blade edge vertically to the line connecting the pivot point and the forward point of the application, a hydraulic cylinde

Abstract: A lower jaw 4 is tiltably connected to the front end of a swing arm 3, an upper jaw 6 openably and closably connected to the lower jaw 4, a hydraulic cylinder 8 interposed between the upper and lower jaws to open and close the jaws, and a protective cover 11 connected to the lower jaw 4 by a link 12 and to the upper jaw 6 by a pin and adapted to follow the opening and closing movement of the upper jaw 6 by a pin while covering the piston rod 10 of the hydraulic cylinder 8. A plurality of straight lower cutting blades are formed on the upper surface of the front end of the lower jaw 4 and a plurality of pointed upper cutting blades 7 are formed on the lower surface of the front end of the upper jaw 6. These upper and lower cutting blades are disposed to mesh with each other in zigzags as viewed from the side. When the upper and lower jaws are closed, concrete is finely broken in the clearances between the upper and lower cutting blades.