Abstract: Provided are: an impact fastening tool which prevents a torque detector from missing a signal and extends service life by adopting a fixed connector that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester. Both end portions of the fixed connector are fixed, and at least two protrusion portions are formed between the both end portions. The rotating electrode is disposed between one protrusion portion and the other protrusion portion such that the rotating electrode contacts the fixed connector at two or more points or in a line form. A signal required for the torque detecting means is transmitted through the contact between the rotating electrode and the fixed connector.

Abstract: Provided are: an impact fastening tool which prevents a torque detecting means from missing a signal and extends service life by adopting a fixed connector that prevents the trouble of being instantaneously separated (bounced) from a rotating electrode by intermittent impacts and has a shape allowing the progression of friction to be delayed structurally; and a torque tester. Both end portions of the fixed connector are fixed, and at least two protrusion portions are formed between the both end portions. The rotating electrode is disposed between one protrusion portion and the other protrusion portion such that the rotating electrode contacts the fixed connector at two or more points or in a line form. A signal required for the torque detecting means is transmitted through the contact between the rotating electrode and the fixed connector.

Abstract: An electric impact tightening tool in which the rotation of an output section of an electric motor is transmitted to an impact generation section (P) and impact force generated in the impact generation section (P) causes a main shaft (107) to produce strong torque, where the electric motor is an outer rotor electric motor (M). The outer rotor electric motor (M) has low-speed, high-torque characteristics. In the tool, the impact generation section (P) and a rotor flange (61) at the forward end of the motor (M) are adapted to rotate integrally. The electric impact tightening tool is small sized and lightweight, produces low reaction force, and has durability.

Abstract: This invention relates to an impulse wrench which has two blades but generates only one impact pulse on the main shaft per one rotation of a liner. In this invention, a liner has at least four seals and a main shaft has at least two seals. And the shape of both or one of the two seals out of at least two seals of main shaft is other than a linear shape parallel to the axial center.If both of said two seals of main shaft are in said shape, two of at least four seals of liner are in the same shape. The other seals of liner are in a linear shape parallel to the axial center.If one of said two seals of main shaft is in said shape, one of at least four seals of liner is in the same shape as this. All of the other seals of liner are in a linear shape parallel to the axial center.In this way, said two seals of liner and said two seals of main shaft coincide with each other only once per one rotation of the liner.

Abstract: This invention relates to an impulse wrench which has two blades but generates only one impact pulse on the main shaft per one rotation of a liner. In this invention, a liner has at least four seals and a main shaft has at least two seals. And the shape of both or one of the two seals out of at least two seals of main shaft is other than a linear shape parallel to the axial center.If both of said two seals of main shaft are in said shape, two of at least four seals of liner are in the same shape. The other seals of liner are in a linear shape parallel to the axial center.If one of said two seals of main shaft is in said shape, one of at least four seals of liner is in the same shape as this. All of the other seals of liner are in a linear shape parallel to the axial center.In this way, said two seals of liner and said two seals of main shaft coincide with each other only once per one rotation of the liner.