A control method for tightening a threaded connection executes, in response to actuation of a pushbutton key, a sequence with consecutive phases. In a first phase, an impact mechanism of an impact wrench exerts a predefined number of rotary impacts on the threaded connection. During the first phase, a profile of a rotational angle over time is estimated. A pattern is adapted to the profile and on the basis of the pattern a setpoint torque is determined for a second phase and a final rotational angle or a final number of impacts is determined for a third phase. During the second phase, rotary impacts are exerted until an estimated torque reaches the setpoint torque. During the third phase, rotary impacts are exerted on the threaded connection until a number of rotary impacts corresponds to the final number or a rotational angle corresponds to the final rotational angle.

A method for tightening a screw for fastening a construction panel to a support of the construction panel, in which the fastening screw is screwed through the construction panel and then through at least part of the support, includes a monitoring of a change over time of a tightening torque of the fastening screw, with determination of a first maximum torque value and then of a second minimum torque value, and after determination of the second minimum torque value, a stoppage of the tightening of the fastening screw for a torque value, termed stoppage value, corresponding to a third maximum torque value or being determined after an occurrence of a third maximum torque value.

A bolt clamping force transducer for a bolt tightening operation is introduced to tighten a bolted joint by driving a torque rotating shaft in a clamping force transducer, such that a helical mechanism at one end of the torque rotating shaft generates an axial force for pressing a force sensing module and thus generates a strain value thereof. A socket is driven by the other end of the torque rotating shaft, thereby generating a clamping force under which the bolted joint of a specific specification is tightened. A parameter relation between the strain value and the clamping force is calibrated with a standard axial force gauge to facilitate calculation and control of the clamping force during the tightening process where the bolted joint fitted to any torque tool is sensed to control the precision of the clamping force being exerted on the bolted joint, thereby enhancing the quality thereof.

The disclosure relates to a method for operating a handheld power tool comprising an electric motor and the method comprising: S1 providing comparative information, comprising: S1a providing at least one model signal shape, the model signal shape being assignable to progress of work of the handheld power tool; S1b providing a threshold value of correspondence; S2 ascertaining a signal of an operating variable of the electric motor; S3 comparing the signal of the operating variable with the model signal shape and ascertaining assessment of correspondence from the comparison, the assessment of correspondence at least partially taking place on the basis of the threshold value of correspondence; S4 detecting the progress of work at least partially on the basis of the assessment of correspondence ascertained in method step S3; the providing of the comparative information at least partially taking place on the basis of a learning process.

An impact rotary tool includes: an impact mechanism that applies stroke impact to an output shaft by an output from a motor; a stroke detector that detects a stroke by the impact mechanism; a controller that stops rotation of the motor based on the detection result by the stroke detector; and a voltage detector that detects a voltage in the stroke detector. The controller determines whether the stroke detector has an abnormality based on the voltage detected by the voltage detector while the motor is not rotating. An informing unit informs a user that an abnormality is occurring when the controller determines an abnormality in the stroke detector.

An electric working machine in one aspect of the present disclosure includes a motor, a controller, and a setter. The controller is configured to change a rotational state of the motor, in response to an establishment of a condition for change after the motor is initiated, from a low speed rotation to a high speed rotation. The setter is configured to set, based on a situation in the motor in the low speed rotation, a control variable of the motor in the high speed rotation and/or the condition for change.

A control device is provided with a communication unit and a processing unit. The communication unit makes communication with a tool that is used for the work of fastening a fastener (for example, a screw) and with an image pickup unit for capturing an image of the work site where the work is being performed. The processing unit executes a determination process of determining whether or not the work is being performed normally on the basis of the fastening torque applied to the fastener by the tool and the image captured by the image pickup unit.

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.

An electric working machine in one aspect of the present disclosure includes a motor, a setter, and a controller. The setter is configured to modifiably set a change characteristic in changing a rotational state of the motor from a low speed rotation to a high speed rotation. The high speed rotation is greater than the low speed rotation in rotational frequency of the motor.

A bolt clamping force sensing washer includes a sensing washer, connection line assembly, and signal processor. The sensing washer includes a body, sensing component, and bushing. The body has an axial hole that matches outer diameter of a bolt's thread. The circumferential surface of the body has a circumferential groove for receiving the sensing component which measures a deformation signal generated by the body under an axial load. Two end surfaces of the body are perpendicular to the axial hole and each have a loosening-proof structure. The bushing is made of metal or plastic or formed by plastic insulating material casting to enclose the sensing component. The signal processor has a signal amplifier, microprocessor, pairing switch, power circuit unit, signal transmission unit, memory unit, RF antenna and alert unit. The connection line assembly is disposed at the bushing to electrically connect the sensing component and signal processor.