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: The method includes sliding a first shim onto the support shaft until it abuts a shoulder. The first shim has a predetermined thickness. A bearing is then slid onto the tapered surface and a lock nut is tightened onto the threaded portion of the shaft. As the lock nut contacts the inner race of the bearing it causes the inner race to contact the first shim and also to radially expand outwardly, thereby preloading the bearing. The outer race of the bearing is then connected to a motor and the motor is operated at a predetermined, constant speed. The torque required to rotate the outer race of the bearing is measured and compared to a predetermine torque range to determine if the bearing is precisely preloaded.

Abstract: A basic method is provided for determining the installed torque in a screw joint which is being tightened by a series of repeated torque impulses, wherein the rotational movement of the screw joint is detected during each impulse, the point in which the screw joint ceases to rotate is detected. And the actually applied torque is indicated at the very instant the screw joint ceases to rotate. In a tightening process control application of the above described basic method, the per impulse increasing value of the installed torque is compared to a predetermined target value in a way known per se, and the tightening process is interrupted as the target value is reached. In a tightening process quality check application of the above described basic method, the accomplished angular displacements of the joint at repeated impulses are indicated and added, and high and low limit values for the final installed torque and the total angle of rotation are provided and compared to the actually obtained values.

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 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 variable rate test joint comprises a housing and a shaft mounted within the housing. A hexagonal head is provided for coupling a tool to be tested to the shaft. In use a frictional braking torque is applied to the shaft. A computer controls the magnitude of the braking torque applied to the shaft as a function of time.

Abstract: A system by which the torque applied to a fastener such as a bolt or nut may be measured simply and accurately. More particularly, the invention relates to apparatus and methods by which the torque applied to a fastener by a socket wrench can be measured through a simplified extension element accurately and displayed quickly so that the placement of possibly damaging excessive amounts of pressure on the fastener can be avoided.

Abstract: A torque wrench is provided with an electronic evaluation device for obtaining values measured by sensors in order to detect the torque and an angle of rotation. An acceleration sensor detects the acceleration of the angle of rotation (&agr;) whose measured values are chronologically integrated twice by an evaluation device in order to determine the angle of rotation (&agr;). The angle determination begins upon the reaching of a starting value of torque.