Abstract: An impact-driven rotating device includes an output shaft, a hammer for rotating the output shaft by imparting an impact to the output shaft, a rotation driver for rotating the hammer, an impact detector for detecting the impact imparted by the hammer, a rotation angle detector for detecting a rotation angle of the output shaft, a rotation speed detector for detecting a rotation speed of the output shaft from the rotation angle detected by the rotation angle detector, an energy calculator for calculating energy imparted to the output shaft from the rotation speed detected by the rotation speed detector, a between-impacts rotation angle calculator for calculating a rotation angle of the output shaft rotated from when the impact detector detected the impact to when the impact detector detects an subsequent impact from the rotation angle detected by the rotation angle detector, a tightening torque calculator for calculating a tightening torque by dividing the energy calculated by the energy calculator by the rot

Abstract: A process to more accurately determine torque output of power impact tools using impulse. Also disclosed are processes for controlling power impact tools, in particular a mechanical impact wrench, by determining the impulse of the tool impacts and deriving torque values therefrom. A mechanical impact wrench having an electronic control is also disclosed.

Abstract: A method of controlling a screwing spindle comprising a fluid-fed motor and having a drive member connected to a spindle shaft to rotate it, the method comprising the step of feeding the screwing spindle under nominal conditions of pressure and flow rate that generate a required tightening torque, and a prior step during which the screwing spindle is fed under conditions that are weaker than the nominal conditions by a ratio that is sufficient to ensure that the spindle shaft has a speed of rotation that generates kinetic energy producing a torque that is less than the required tightening torque.

Abstract: A power nut runner with a torque responsive shut-off capacity comprises a housing (11, 12, 13), a rotation motor (10) connected to an output shaft (28) via a torque responsive release clutch (26) in which torque is transferred via a cam mechanism (31, 35, 36) between a driving clutch half (25) and a driven clutch half (27, 30, 39), and a spring (32) is arranged to bias and displace a first one of the clutch halves (27, 30, 39) towards the other in an engagement direction, a signal emitting release detecting sensor (46), and an activation element (40) arranged to be thrown off an abutting contact with the spring biassed clutch half (27, 30, 39) to reach an active position beyond its inactive low torque position as the spring biassed clutch half (27, 30, 39) is abruptly returned to its engagement position after an axial release movement.

Abstract: A sucker rod tool system for oil wells monitors both torque and angular displacement of a three-element sucker rod connection. The tool system engages two sucker rods that are at least partially screwed into opposite ends of a sucker rod coupling. The system, however, does not engage the coupling adjoining both rods. The system determines whether a connection has been properly tightened by sensing the torque and angular displacement of the connection as it is being tightened, and comparing the data to a stored reference set of data or curves. In some embodiments, a properly tightened connection is based upon the number of straight lines that are needed to adequately approximate a plotted curve of the sensed torque versus angular displacement. Tightness of each connection of a string of sucker rods is recorded with reference to each connection's depth within a well to later serve as an aide in diagnosing connection failures. In some cases, the energy required to unscrew a connection is also recorded.

Abstract: A rotational energy storage device or spring which includes a roller-cam assembly having a shaft, a ring rotatably disposed about the shaft, and at least one roller disposed between shaft and ring. The roller is configured such that, upon rotating the ring relative to the shaft, the roller interferes with the ring and the shaft to convert and effect storage of mechanical energy created by the relative rotation of the ring and the shaft. Preferably a plurality of spaced rollers are positioned between ring and shaft. A cam geometry which is symmetrical or asymmetrical is provided on the shaft, the ring, the roller, and combinations thereof. A rotational energy storage device having a back-up ring with alternating thin and thick cross-sectional areas is further provided which is indexed to provide regions of low and high stiffness regions against each roller.

Abstract: The screwdriving device (9) according to the invention has a control device (22) which uses a sensor system (18) to determine a characteristic variable (K) which characterizes a screwdriving moment (Mv) of the screw connection (10) and/or an emitted moment (M) of the impact screwdriver, during or after at least one pulse emission from the impact screwdriver to the screw connection, and defines a drive variable, for example a required drive speed (n) for the next impulse emission, as a function of the determined characteristic variable (Ki). In this case, the drive variable (n) is initially set to a value which corresponds to a value (K0) to be expected of the characteristic variable (K) and its magnitude is in any case less than a desired value (Kreq) for the final screw connection state. This prevents the desired screwdriving moment being exceeded even after the first impulse emission in the event of unfavorable screwdriving conditions.

Abstract: A power screwdriver has a drive unit and an input circuit for inputting screw size, material quality, pitch, and clamping length of a screw. An evaluation circuit is provided for determining a nominal prestress force based on input screw size, material quality, and clamping length, for determining a nominal torque based on the nominal prestress force and the pitch, and for determining the screw clamping angle resulting from the nominal prestress force and the pitch. A sensing device for sensing the actual torque is provided, and a further sensing device for sensing the actual screw clamping angle is present. A control and switch-off device controls further rotation of the drive unit when the actual torque coincides with the nominal torque and switches off the drive unit when the actual screw clamping angle coincides with the nominal screw clamping angle.

Abstract: A universal torque power tool has a housing having a motor, a driving mechanism being operatively connected with the motor, the driving mechanism including a drive having an axis and being engageable with a nut to be turned, first and second transfer members to apply a reaction force substantially coaxial with the axis of the drive and spaced from one another in direction of the axis, the drive being formed to transfer an action force from the motor to a nut to be turned, the transfer members being formed to engage a stationary object and to transfer a reaction force to the stationary object, so that when the stationary object is engageable outside of the nut engagement the first transfer member transfer the reaction force to the stationary object, and when the stationary object is engageable inside the nut engagement the second transfer member transfer the reaction force to the stationary object.

Abstract: This counting apparatus is a tool monitor and assembly qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. When used in conjunction with a pressure tool, proper fastener torque and count can be verified. The device monitors internal tool pressures and has the ability to "learn" the pressure characteristics of the tool during the assembly process. This assembly qualifier is a device that monitors either the pressure of an air tool, the current of an electrical tool or the torque of a mechanical wrench to determine if the tool shut off at a target torque. The qualifier also determines if some unknown means shuts off the tool.

Abstract: This counting apparatus is a tool monitor and assembly qualifier that verifies that the correct number of fasteners have been properly installed into an assembly. When used in conjunction with a pressure tool, proper fastener torque and count can be verified. The device monitors internal tool pressures and has the ability to "learn" the pressure characteristics of the tool during the assembly process. This assembly qualifier is a device that monitors either the pressure of an air tool, the current of an electrical tool or the torque of a mechanical wrench to determine if the tool shut off at a target torque. The qualifier also determines if some unknown means shuts off the tool.

Abstract: A cable connector for assembly and mounting on a front section of a housing of a power wrench is arranged to connect at least one operation parameter sensor of the power tool to a multi-core cable. The cable connector includes a multi-contact cable connector plug carried on the multi-core cable, and a one-piece mounting member which is made of an elastically resilient material and which is secured to the front section of the housing and supports a multi-contact jack. The multi-contact cable connector plug includes a coupling sleeve formed with an internal thread, and the mounting member includes an open ring portion to be mounted around the front section of the housing and a tubular coupling portion extending laterally from the ring portion.

Abstract: A device for signal transmission between components supported so as to be movable relative to one another is proposed. A first conductor is partly accommodated in a first component, while a second conductor is partly disposed in a second component, which is supported rotatably relative to the first component via a bearing. The bearing (21) is electrically insulated from the components by means of an insulating body and an insulating sheath. The first conductor and the second conductor are electrically conductively connected to one another via the bearing. In this way, an interruption-free contact between the first conductor and the second conductor (15) is assured.

Abstract: Disclosed is a low reaction oscillating mass-based torquing tool wherein an oscillating mass is excited into near resonant oscillation by reversing pulses resulting in increased energy stored in oscillation about a dual stiffness spring which develops a higher torque output with the stiffer spring action in the tightening direction and hence tightens the fastener.

Abstract: Disclosed is a low reaction oscillating mass-based torquing tool wherein an oscillating mass is excited into near resonant oscillation by reversing pulses resulting in increased oscillation about a torsion spring to the point where the torque associated with the energy stored in the torsion spring exceeds the torque required to further tighten a fastener and the torque released from the torsion spring tightens the fastener while a biasing torque assures application of the released torque in the tightening direction only.

Abstract: A production assembly tool for securing fasteners to a workpiece such as an automobile body. The production assembly tool of the present invention includes a housing which encases a motor, a transmission, a clutch mechanism and a control module. The control module controls the running and braking of the motor and prevents both over and under securing of a fastener caused by falsely detected tool clutch conditions. An improved clutch sensor switch is operatively associated with the control module for detecting clutch disengagement. The clutch mechanism is designed to drive the fastener until the clutch sensor switch detects clutch disengagement and signals the control circuit to stop drive and start braking. The production assembly tool further includes a system for ensuring accurate placement of the power tool motor in the power tool housing subsequent to motor servicing or repair.

Abstract: An impact screw-tightening apparatus is comprised of a main body and a controller. The main body includes a motor outputting pulsed drive output, a main shaft driven by the drive and connected to a screw to be tightened, and a torque detector detecting a change of torque applied to the main shaft. The controller includes a calculating section and a control section. The calculating section obtains frequency of impacts generated from a time that a bearing surface of the screw is in contact with a tightened object, on the basis of the signal from the torque detector. The control section cuts off a motive power source of the drive at a time that the frequency of the impacts becomes a predetermined value. Therefore, even if impact operation is executed prior to the contact of the bearing surface, the tightening force is accurately calculated by a rapid and brief calculation and control logic, and the dispersion of the tightening force at the cut-off time is decreased.

Abstract: An arrangement for tightening screw connections comprises a screw spindle turnable by a screw tool, at least two-stage rotary drive for the screw spindle, the drive providing a coarse driving for pre-tightening of a screw connection and a fine driving for obtaining the desired screwing condition, a measuring value pick up for obtaining measuring values which correspond to a value of an available screwing condition, a control device for providing switching signals for the rotary drive in dependence on the measuring values determined by the measuring value pick up, the screw spindle being subdivided into at least three spindle parts, including a first spindle part connected with the drive motor for providing the coarse driving, a second spindle part, and a third spindle part, and an auxiliary drive providing the fine driving and having a drive element which together with the auxiliary drive form an independently operating structural unit which forms the second spindle part and is integrated between the first sp

Abstract: An impulse wrench comprises a pneumatic rotation motor (12), a hydraulic torque impulse generator (13) provided with an impulse magnitude responsive actuator (17), a linear movement responsive electric signal producing device (25) located at the rear end of the motor (12), a movement transferring push rod (21) extending through an axial bore (22) in the motor rotor (16) and interconnecting the actuator (17) and the signal producing device (25), an electrically activated motive air shut-off valve (31) disposed concentrically with the signal producing device (25), and an external process controlling and monitoring unit (40) connected to the signal producing device (25) and the shut-off valve (31) and arranged to compute and compare received signals with predetermined values and to initiate shut-off of the power supply (31) as a desired tightening condition is reached.

Abstract: In an impact type clamping apparatus including a motor unit for generating a pulsatory driving torque, a main spindle driven by said pulsatory driving torque to rotate a fastening member, a detecting unit for detecting a pulsatory torque applied to the main spindle, a calculating circuit for calculating a clamping force in accordance with a peak value of the pulsatory torque, and a control unit for stopping the operation of said motor unit when the calculated clamping force exceeds a desired clamping force, said clamping force is calculated not only from the peak value of the pulsatory torque but also from an increasing coefficient which represents a relationship between the peak value of the pulsatory torque and an increment of the clamping force.

Abstract: A system and method for compensating for torque overshoot in a rotary power tool wherein the tool is shut off at an adjusted set point value of torque which is below the target value of torque by the amount of torque overshoot. While the tool is operated to perform a fastening job, the relationship between the torque rate in the fastening job to overshoot in the tool is determined, the torque rate in the job is monitored while the tool is setting the job, and the torque set point is adjusted while the tool is setting the job to compensate for the torque overshoot determined from the foregoing relationship.

Abstract: An automatic screw fastening machine embodied by the invention transmits the rotating force of a motor to a driver bit via a differential planetary mechanism consisting of an input disc, a plurality of planetary cones, a cam disc, and a variable-speed ring. The automatic screw fastening machine causes a resilient supporting unit to restrict the variable-speed ring from shifting itself in the axial direction. Furthermore, the machine is provided with a torque detection unit capable of detecting the torque of reaction force applied to the variable-speed ring by effect of the load applied to the driver bit. As soon as the detect-signal value correctly matches a specific value corresponding to the predetermined fastening torque, supply of power to the motor is discontinued. In consequence, when fully completing a screw fastening process, rotation of the driver bit is substantially reduced to zero so that no rotating force can be transmitted to the driver bit.

Abstract: In order to prevent a looseness of bolts after main clamping, a nut runner of the present invention comprises a torque sensor for detecting a clamping torque T of a clamping unit, and a torque comparison means for comparing the clamping torque T with a clamping completion torque ST. The nut runner further includes a torque control means which gradually reduces a rotational torque of the motor until a resilience such as a torsion accumulated in the clamping unit is entirely nullified when the clamping torque T reaches the clamping completion torque ST. This ensures an effective cancellation of an inverse torque arising from the resilience and acting in the direction loosening the bolt, thus preventing the bolt from loosening.

Abstract: An impact wrench with a torque controlling faculty including an air motor for generating a primary torque, an oil pressure pulse generating unit for converting the primary torque into a pulsatory secondary torque, a main spindle to which the pulsatory secondary torque is applied, a transducer for detecting the pulsatory secondary torque and a shut-off valve which is closed to stop a supply of a compressed air to the air motor when the secondary torque exceeds a predetermined threshold value. The main spindle is made of material having the magnetic strictive effect and the distortion of the main spindle is detected by a pair of coils arranged in opposition to the main spindle. The coils are connected into a bridge circuit together with resistors and an exciting current having a sinusoidal waveform is supplied to a first set of diagonal points of the bridge circuit.

Abstract: An automatic screw fastening machine embodied by the invention transmits the rotating force of a motor to a driver bit via a differential planetary mechanism consisting of an input disc, a plurality of planetary cones, a cam disc, and a variable-speed ring. The automatic screw fastening machine causes a resilient supporting unit to restrict the variable-speed ring from shifting itself in the axial direction. Furthermore, the machine is provided with a torque detection unit capable of detecting the torque of reaction force applied to the variable-speed ring by effect of the load applied to the driver bit. As soon as the detect-signal value correctly matches a specific value corresponding to the predetermined fastening torque, supply of power to the motor is discontinued. In consequence, when fully completing a screw fastening process, rotation of the driver bit is substantially reduced to zero so that no rotating force can be transmitted to the driver bit.