Abstract: A method for determining the quality of a screw joint tightening process performed by means of a torque impulse wrench, comprising clamp load determination via calculation of the time of flight for ultra sonic waves induced into the screw joint, and comparing of a total rotation movement of the screw joint with predetermined angle limit values as a target axial load level has been indicated by the time of flight of ultra sonic waves induced in the screw joint. Occurring discrepancies between the obtained total rotation movement of the screw joint and the angle limit values would indicate a faulty screw joint and/or a malfunctioning ultra sonic wave flight time measurement, which means an unacceptable tightening process quality.

Abstract: A method for determining the quality of a screw joint tightening process performed by means of a torque impulse wrench, comprising clamp load determination via calculation of the time of flight for ultra sonic waves induced into the screw joint, and comparing of a total rotation movement of the screw joint with predetermined angle limit values as a target axial load level has been indicated by the time of flight of ultra sonic waves induced in the screw joint. Occurring discrepancies between the obtained total rotation movement of the screw joint and the angle limit values would indicate a faulty screw joint and/or a malfunctioning ultra sonic wave flight time measurement, which means an unacceptable tightening process quality.

Abstract: A portable power tool is provided which includes a housing having an angle drive chamber, a rotation motor, an output spindle, and a grease lubricated angle drive that is located in the angle drive chamber and that includes a drive pinion connected to the motor and a bevel gear connected to the output spindle. The portable power tool also includes an output spindle arresting device which includes a number of recesses in the bevel gear and a latch pawl movably supported in the housing for movement between an inactive position and an active position to engage the recesses in the bevel gear, wherein a grease moving element is connected to the latch pawl to be moved and displace grease from one part of the angle drive chamber to another as the latch pawl is shifted from its inactive position to its active position.

Abstract: A portable power tool having a housing (10, 11) with an angle drive chamber (30), a rotation motor, an output spindle (18) and a grease lubricated angle drive (15) located in the angle drive chamber (30) and including a drive pinion (16) connected to the motor and a bevel gear (17) connected to the output spindle (18), and an output spindle (18) arresting device (24) comprising a number of recesses (25) in the bevel gear (17) and a latch pawl (26) movably supported in the housing (10, 11) for movement between an inactive position and an active position to engage the recesses (25) in the bevel gear (17), wherein a grease moving element (32) is connected to the latch pawl (26) to be moved and displace grease from one part of the angle drive chamber (30) to another as the latch pawl (26) is shifted from its inactive position to its active position.

Abstract: A method for determining the axial load in a threaded fastener when tightened above its yield point by using the variation in travel time (&Dgr;t) for ultrasonic waves induced in the fastener to determine the axial load (N) in the fastener, both in the yield point and at the final pretension state of the fastener. The yield point of the fastener is detected by indicating a significant change in the growth of the momentary transferred torque per angle unit of rotation, and comparing the actual travel time (&Dgr;t) for ultrasonic waves in the fastener to a pre-tightening determined relationship between the axial load (N), the rotation angle (&PHgr;) and the ultrasonic wave travel time (&Dgr;t) for the actual type of fastener.