Abstract: Disclosed is a crushing equipment for crushing a pillar or beam of concrete structures through opening and closing movement of a pair of arms while clamping the pillar or beam by a pair of crushing blades provided on the ends of the arms. A hydraulic cylinder 1 for opening and closing the arms comprises a second cylinder including a couple of cylinders 3' and 3", and a pair of first cylinders fitted into the cylinders 3' and 3", respectively, and each having a cylinder bottom serving as a piston 9. When a hydraulic oil is introduced through a fifth oil port 18 provided in the second cylinder on the side of the cylinder bottom, the first cylinders 2 are forwardly displaced. When the first cylinders 2 reach their stroke ends, pistons of the first cylinders are forwardly moved to close the arms for crushing the concrete structure. When the hydraulic oil is introduced through fourth oil ports 16, the pistons 5 are retracted by way of second oil ports 10 and oil passages 11.

Abstract: A working machine comprises a machine body provided with a pair of arms which are arranged for movement toward and away from each other. The machine body is disposed for rotation, relative to a bracket mounted on the machine body, about an axis. A hydraulic cylinder assembly has a single cylinder defining therein a hydraulic chamber, and a single piston mounted to a piston rod extending through the hydraulic chamber, the piston rod having opposite ends thereof, which extend respectively from opposite ends of the hydraulic chamber, and which are fixedly connected to the bracket. Upon introduction of hydraulic fluid into the hydraulic chamber, the cylinder and a rack fixedly mounted to the outside of the cylinder are moved in the direction perpendicular to the axis, so as to cause a pinion meshing with the rack and the machine body connected with the pinion to rotate about the axis, thereby changing the direction of the plane in which the arms mounted on the machine body are moved.