Abstract: A switching mechanism switches on and off transmission of a striking force to a working tool, and switches on and off transmission of a rotational force to the working tool, thereby switching operation modes among at least a rotation and strike mode, a strike only mode, and a neutral mode. A rotation locking mechanism engages a cylinder during the strike only mode, thereby locking rotation of the cylinder. During the neutral mode, the transmission of the striking force, the transmission of the rotational force, and the locking of rotation of the cylinder are all turned off.

Abstract: An air chamber is formed in a cylinder between a piston and a striking member. The cylinder is formed with at least one through-hole for providing fluid communication between the air chamber and an outside of the cylinder. A switching mechanism switches operation modes between a first operation mode and a second operation mode. In the first operation mode, the at least one through-hole is closed when the working tool is moved toward the another end and, when the at least one through-hole is closed, reciprocating motion of the piston generates pressure changes in the air chamber, allowing the striking member to transmit a striking force to a working tool. In the second operation mode, the at least one through-hole is constantly open, prohibiting the striking member from transmitting a striking force to the working tool.

Abstract: A switching mechanism switches on and off transmission of a striking force to a working tool, and switches on and off transmission of a rotational force to the working tool, thereby switching operation modes among at least a rotation and strike mode, a strike only mode, and a neutral mode. A rotation locking mechanism engages a cylinder during the strike only mode, thereby locking rotation of the cylinder. During the neutral mode, the transmission of the striking force, the transmission of the rotational force, and the locking of rotation of the cylinder are all turned off.

Abstract: An air chamber is formed in a cylinder between a piston and a striking member. The cylinder is formed with at least one through-hole for providing fluid communication between the air chamber and an outside of the cylinder. A switching mechanism switches operation modes between a first operation mode and a second operation mode. In the first operation mode, the at least one through-hole is closed when the working tool is moved toward the another end and, when the at least one through-hole is closed, reciprocating motion of the piston generates pressure changes in the air chamber, allowing the striking member to transmit a striking force to a working tool. In the second operation mode, the at least one through-hole is constantly open, prohibiting the striking member from transmitting a striking force to the working tool.

Abstract: A polycarbonate resin of a copolymer of diethyleneglycol bis(allyl carbonate) with one of glycidyl acrylate and glycidyl methacrylate, its homopolymer and its copolymer, and further occasionally a copolymerizable compound can be easily modified with active amine at its surface, and the surface-modified copolymer of diethylene glycol bis(allyl carbonate) with glycidyl acrylate or methacrylate can be easily dyed with acid dye in a sharp color tone and can be used in an optical instrument demanded to have a high vividness of color.

Abstract: A polycarbonate resin of a copolymer of diethyleneglycol bis(allyl carbonate) with one of glycidyl acrylate and glycidyl methacrylate, its homopolymer and its copolymer, and further occasionally a copolymerizable compound can be easily modified with active amine at its surface, and the surface-modified copolymer of diethylene glycol bis(allyl carbonate) with glycidyl acrylate or methacrylate can be easily dyed with acid dye in a sharp color tone and can be used in an optical instrument demanded to have a high vividness of color.

Abstract: A lubricating oil composition for metal rolling is described, comprising (a) an oily component comprising one or more of fats and oils, mineral oils, and fatty acid esters, and (b) a dispersant comprising one or more of polyethyleneimine/epoxy compound adducts, polyethylene polyamine/epoxy compound adducts, fatty acid esters of the adducts, and salts of the adducts and the fatty acid esters. This composition is useful for rolling metals under high shear and high rolling speed conditions.

Abstract: A method for preparing a coal-water slurry is described, comprising the divided addition of dispersing agent or multi-step addition of dispersing agent during grinding in a process for preparing a coal-water slurry by the wet grinding of coal in water.

Abstract: The cold flow of fuel oils is improved by adding esters of addition products of epoxides of specifically limited nitrogen-containing compounds with linear saturated fatty acids or a combination of the esters and polymers of one or more monomers selected from the group consisting of olefins, alkyl esters of ethylenically unsaturated carboxylic acids and vinyl esters of saturated fatty acids to fuel oils.

Abstract: The cold flow of fuel oils is improved by adding esters of nitrogen-containing compounds having polyhydroxyl groups with linear saturated fatty acids or a combination of said esters and polymers of one or more monomers selected from the group consisting of olefins, alkyl esters of ethylenically unsaturated carboxylic acids and vinyl esters of saturated fatty acids to fuel oils.