As shearing blades of a first jaw portion, a shearing machines includes: a tip blade; a pair of first parallel shearing blades bent at an obtuse angle to the biting direction of the tip blade and disposed both sides of the blade width; and a pair of second parallel shearing blades bent at an obtuse angle to an attaching portion of the first parallel shearing blades and disposed on both sides of the blade width. As a tip blade, the shearing machine includes: a point blade a pair of tip tapered blades disposed on both sides of an end portion and whose blade width is increased toward the rear end; and a pair of tapered blades bent at an obtuse angle to an attaching portion of the rear end portion of the tip tapered blades and disposed toward the first parallel shearing blades.

A cutting head for a power tool. The cutting head includes a first jaw having a first blade mounting surface and a second jaw having a second blade mounting surface. The second jaw is rotatably coupled to the first jaw. The cutting head also includes a first blade removably coupled to the first blade mounting surface of the first jaw and a second blade removably coupled to the second blade mounting surface of the second jaw. A first cutting edge of the first blade is substantially co-planar with a second cutting edge of the second blade. During a cutting action, the first jaw and the second jaw rotate with respect to one another to bring the first cutting edge closer to the second cutting edge.

A cutting head for a power tool. The cutting head comprises a pivot pin, and a first jaw and a second jaw each disposed for rotation about an axis defined by the pivot pin. The first jaw comprises a first blade mounting surface and a first ear having a first ear surface. The second jaw comprises a second blade mounting surface and a second ear having a second ear surface for rotational engagement with the first ear surface. The cutting head further comprises a first blade mounted on the first blade mounting surface and a second blade mounted on the second blade mounting surface. The first blade mounting surface, the second blade mounting surface, the first ear surface, and the second ear surface are substantially co-planar, and during a cutting action, the jaws rotate about the axis.

The application relates to a double acting demolition device according to one embodiment for demolishing structures. The device includes a first crushing jaw for crushing operation, a first cutting jaw for cutting operation, and a combination jaw. The first jaws are separate jaws. The combination jaw is attachable to the first cutting jaw for constructing a second crushing jaw and to the first crushing jaw for constructing a second cutting jaw. The second crushing jaw is used jointly with the first crushing jaw in crushing operation and the second cutting jaw is used jointly with the first cutting jaw in cutting operation. In crushing operation, the first crushing jaw rotates around a fulcrum other than that of the second cutting jaw in cutting operation.

The application relates to a double acting demolition device according to one embodiment for demolishing structures. The device includes a first crushing jaw for crushing operation, a first cutting jaw for cutting operation, and a combination jaw. The first jaws are separate jaws. The combination jaw is attachable to the first cutting jaw for constructing a second crushing jaw and to the first crushing jaw for constructing a second cutting jaw. The second crushing jaw is used jointly with the first crushing jaw in crushing operation and the second cutting jaw is used jointly with the first cutting jaw in cutting operation. In crushing operation, the first crushing jaw rotates around a fulcrum other than that of the second cutting jaw in cutting operation.

A cutting head for a hydraulic power tool includes a first jaw that includes a first ear configured with a slot for receiving a corresponding ear. The second jaw includes a second ear with a third ear bore that aligns in between a first ear bore and to a second ear bore of the first ear when the second ear is coupled in the slot of the first ear. The cutting head further includes a spring-biased flange coupled to a blade mounted to the first jaw and a retained coupled at a fixed position to a blade mounted to the second jaw. The retainer is configured to receive the flange during a cutting action such that the flange prevents the blades from shifting out of alignment during the cutting action.

A throttle valve device includes a shaft in a cylindrical passage, a slit passing through the shaft from one lateral side to another lateral side of the shaft, a pair of bearings on both sides of the cylindrical passage and rotatably supporting one end part and another end part of the shaft, and a circular-plate valve inserted into the slit of the shaft and rotatable to open and close the cylindrical passage. A length of the slit on the one lateral side of the shaft is, in an axial direction of the shaft, longer than a length of the slit on the other lateral side of the shaft. A round end hole is formed at an end of the slit in the one end part of the shaft on the one lateral side of the shaft.

A throttle valve device includes a shaft in a cylindrical passage, a slit passing through the shaft from one lateral side to another lateral side of the shaft, a pair of bearings on both sides of the cylindrical passage and rotatably supporting one end part and another end part of the shaft, and a circular-plate valve inserted into the slit of the shaft and rotatable to open and close the cylindrical passage. A length of the slit on the one lateral side of the shaft is, in an axial direction of the shaft, longer than a length of the slit on the other lateral side of the shaft. A round end hole is formed at an end of the slit in the one end part of the shaft on the one lateral side of the shaft.

Shear tools are described. In one version, the shear tools include a pair of pivotally movable jaws positioned between sideplates. Various shearing dies are also described. Also described are systems and related methods utilizing the shear tools and dies which enable convenient shearing or severing of workpieces such as threaded rods.

The application relates to a demolition device for demolishing a concrete structure according to one embodiment. The device has a crushing blade for crushing concrete, and a cutting blade for cutting metal or a pulverizing blade for grinding concrete, and a combination blade. The device can be attached to a utility machine in a detachable manner. The crushing and cutting/pulverizing blade are separate blades from each other. The combination blade is adapted to be used for crushing concrete with the crushing blade. The combination blade is adapted to be used for cutting metal with the cutting blade or for grinding concrete with the pulverizing blade. The combination blade has abutment surface parts for the crushing and cutting/pulverizing blade. The abutment surface part for the cutting/pulverizing blade makes possible a power transmission between the cutting/pulverizing and combination blade when using the combination blade for crushing concrete. The abutment surface part for the crushing blade makes possible a power transmission between the crushing and combination blade when using the combination blade for cutting metal or grinding concrete.