Atlas Copco Industrial Technique

The present specification relates to a handheld power tool for tightening of threaded fasteners, the power tool comprising an output shaft (5) drivingly connected to a motor and having an interface arranged to receive a socket (S), wherein the output shaft further comprises a safety arrangement for preventing loss of the socket in case of damage to the interface, the safety arrangement comprising an elongated member (10), and a retaining member (3) secured to a rear portion of the output shaft, wherein a first end of the elongated member is arranged to restrict axial movement of a front portion (5a) of the output shaft and wherein the retaining member is arranged to restrict axial movement of the elongated member.

In an aspect, a method of a device (20, 35) is provided of detecting that a tightening tool (10) should be subjected to maintenance. The method comprises acquiring (S101) data indicating a tightening trace comprising torque and rotation angle values applied to a fastener being tightened during a tightening operation performed by the tightening tool (10), determining (S102) whether a selected section of the tightening trace is linear, and if so deriving (S103), from the linear section of the tightening trace, at least one value indicating the applied torque and acquiring a value indicating current consumed by the tool upon applying the torque, computing (S104) a ratio (k) between the at least one derived torque value and the value of the consumed current, comparing (S105) the computed ratio (k) with a correspondingly computed reference ratio (k_ref) of a previously performed tightening operation, and if the comparing of the ratios (k_ref - k) indicates that the consumed current is increasing above a preconfigured current threshold value (I1), determining that the tool (10) should be subjected to maintenance.

The present disclosure relates to a method of monitoring usage of a group of tightening tools (10a-10e), and a device (20, 35) performing the method. In an aspect, a method of a device (35) is provided of monitoring usage of a group of tightening tools (10a-10e). The method comprises acquiring (S101) data indicating a degree of utilization for the tools (10a-10e) over a time period, determining (S102) whether or not the acquired degree of utilization for at least one of the tools (10a) deviates from a set degree of utilization, and if so indicating (S103) a change of utilization pattern of said at least one tightening tool (10a) such that the degree of utilization of said at least one tightening tool (10a) complies with the set degree of utilization following the change.

The present disclosure relates to a method of a device (20, 35) of monitoring events of a tightening tool (10), and a device (20, 35) performing the method. The method comprises computing (S104) a second derivative of a cumulative sum of events occurring for each of a number of event types, rescaling (S105) the computed second derivative such that a more severe event type is given a higher weight than a less severe event type, computing (S107) an updated wear score, up until a set upper value, when a current value of the rescaled computed second derivate for an event exceeds a first threshold value (S106), by adding the current value of the rescaled computed second derivate to a last computed wear score, and decrementing (S110) the wear score when the current value of the rescaled computed second derivate for an event falls below a third threshold value (S108) being set to be lower than the first threshold value.

The present disclosure relates to a method of detecting that a tightening tool (10) should be subjected to maintenance, and a device (20, 35) performing the method. The method enables computing (S104) a measure (N_i) indicating total rotation angle that can be applied by a fully functioning tool before tool maintenance is required. The computed measure (N_i) enables subsequent computation of a tool wear metric for an individual tool to determine that maintenance is required for said individual tool.

In an aspect, a method of a device (20, 35) is provided of detecting that a tightening tool (10) should be subjected to maintenance. The method comprises acquiring (S101) data representing at least two selected operational parameters of the tightening tool (10), computing (S102) a tool wear indicator (w) based on a combination of the acquired parameter data, and determining (S103) that the tightening tool (10) should be subjected to maintenance in response to the tool wear indicator (w) exceeding a set maintenance threshold value (T).

A method of controlling a motor of a pulse tool is provided. The pulse tool is arranged to provide torque in pulses during a tightening operation to tighten a threaded joint. The method comprises: determining a parameter value (d) indicative of a torque and/or angle increase achieved by a just performed pulse (n); determining a motor power control parameter value (M) for the next pulse (n+1) based on said determined parameter value indicative of the torque and/or angle increase; controlling the motor according to the determined motor power control parameter value to create the next pulse; and repeating these steps until a target torque and/or angle is reached. Thereby, a control method is provided that will adjust the power (energy) of the motor during the tightening dependent on the characteristics of the joint. This enables a trade-off between speed and accuracy of the tightening that is tailored to the joint being tightened.

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Zusammenfassung wird geladen …