Socket for a power tool, method for controlling a power tool, control system and power tool

Abstract

A socket (28) for a power tool (10), the socket being arranged to rotate about a socket axis (32) and including a cylindrical portion (82) having an end face (86), a plurality of engagement faces (88) parallel to the socket axis on the inner side of the cylindrical portion; an inner portion (84) radially located inside the cylindrical portion relative to the socket axis and having a stop face (90) offset relative to the end face such that the engagement faces are located between the stop face and the end face; and a socket opening (30) extending radially relative to the socket axis through the cylindrical portion and the inner portion; wherein the cylindrical portion includes at least one inner inclined surface (126) extending away from the stop face on the inner side of the cylindrical portion. Also provided are a method, a control system (40) and a power tool (10).

Description

Technical Field

[0001] The present invention generally relates to power tools. Specifically, provided is a socket for a power tool including at least one inner bevel, a method of controlling a power tool including such a socket, a control system for controlling a power tool including such a socket, a method of controlling a power tool including an inspection operation, a control system for controlling a power tool to perform an inspection operation, and a power tool. Background Art

[0002] An end-opening power tool may include a socket that can rotate about a socket axis and has a socket opening for receiving a bolt or a shaft along a radial direction relative to the socket axis. For example, if a bolt surrounding a shaft is to be screwed onto a coupling on the shaft, the socket is positioned in the open position and the power tool is moved relative to the shaft so that the shaft is radially received through the socket opening. Then, the power tool and / or the bolt may be moved axially along the shaft so that the bolt is received in the socket. The bolt can then be tightened onto the coupling using the power tool.

[0003] For some prior art power tools, the operator must perform the following steps after each tightening operation: loosen the actuating element, lift the power tool from the bolt, press and hold the actuating element again to control the socket to move back to the open position, and move the power tool away from the shaft. In such power tools, the socket can rotate in an alternating direction each time the actuating element is actuated. Summary of the Invention

[0004] An object of the present invention is to provide an improved socket for a power tool.

[0005] Another object of the present invention is to provide a socket for a power tool that can position the socket in the open position more quickly.

[0006] Another object of the present invention is to provide a socket for a power tool that makes it easier to move the power tool away after tightening the joint.

[0007] Another object of the present invention is to provide a socket for a power tool that solves several or all of the foregoing objects.

[0008] Another object of the present invention is to provide a method of controlling a power tool that solves one, several, or all of the foregoing objects.

[0009] Another object of the present invention is to provide a control system for controlling a power tool that solves one, several, or all of the foregoing objects.

[0010] A further object of the present invention is to provide a power tool that solves one, several or all of the foregoing objects.

[0011] According to a first aspect, there is provided a socket for a power tool, the socket being arranged to rotate about a socket axis and comprising a cylindrical portion, an inner portion and a socket opening. The cylindrical portion has an end face and a plurality of engagement faces parallel to the socket axis on the inner side of the cylindrical portion. The inner portion is radially located inside the cylindrical portion relative to the socket axis and has a stop face offset relative to the end face such that the engagement faces are located between the stop face and the end face. The socket opening extends radially relative to the socket axis through the cylindrical portion and the inner portion. Wherein, the cylindrical portion includes at least one inner inclined surface that extends away from the stop face on the inner side of the cylindrical portion.

[0012] Since the socket opening is included, the socket is an end-opening socket. A power tool including such a socket may be referred to as an end-opening power tool.

[0013] During the tightening operation of the joint, the engagement faces can engage with the engagable faces of the bolt, and the socket can rotate in the tightening direction. When the tightening operation is completed, the socket can rotate in the loosening direction opposite to the tightening direction. For example, after the tightening operation is completed, the socket can immediately and automatically rotate in the loosening direction. When the socket rotates in the loosening direction, each inner inclined surface engages the angle between the engagable faces on the bolt. This causes the socket to move away from the bolt along the socket axis while the angle moves along the inner inclined surface until the socket slides off the bolt. Therefore, by rotating the socket in the loosening direction, the socket can be quickly and easily separated from the tightened joint.

[0014] When the socket is separated from the joint, the socket can continue to rotate in the loosening direction to an open position where the socket opening is aligned with the base opening of the base element. Thus, the socket can be quickly and easily positioned in the open position. The socket can automatically position the socket in the open position immediately after the tightening operation is completed. Therefore, the operator does not have to lift the power tool from the bolt and run a separate positioning procedure to position the socket in the open position.

[0015] The socket can be configured to tighten the bolt in a conventional manner by rotating in the tightening direction. In the case of a socket including at least one inner inclined surface, the power tool can be any type described herein.

[0016] Due to the presence of the socket opening, the cylindrical portion does not completely surround the socket axis. The socket opening can extend through the entire socket in a direction parallel to the socket axis.

[0017] The mating surface can be positioned between the stop surface and the end surface in a direction parallel to the socket axis. The mating surface can be configured to mate with a mating surface on a bolt to be tightened. The cylindrical portion can include, for example, at least four mating surfaces, such as six mating surfaces.

[0018] The inner side is the side facing the socket axis. The at least one inner inclined surface can be positioned between the end surface and the stop surface, as seen in a plane transverse to the socket axis. Each inner inclined surface can extend from the stop surface. Each of the end surface and the stop surface can be flat and perpendicular to the socket axis.

[0019] The at least one inner inclined surface can include a plurality of inner inclined surfaces. One inner inclined surface can be associated with each of at least four mating surfaces. Thus, the socket can include at least four inner inclined surfaces.

[0020] Each inner inclined surface can be straight. Alternatively or additionally, each inner inclined surface can extend from the stop surface to the end surface.

[0021] The cylindrical portion can include a circular drive profile that is concentric with the socket axis on the outer side of the cylindrical portion for being drivingly engaged by a wheel. The outer side is the side facing away from the socket axis. The drive profile can include teeth or friction surfaces.

[0022] According to a second aspect, there is provided a method of controlling a power tool for tightening a joint, the power tool including a base element having a base opening, a socket according to the first aspect, a motor arranged to drive the socket, and a control system configured to control the motor, wherein the socket can be rotated about a socket axis from an open position where the socket opening is aligned with the base opening, the method including commanding, by the control system, a tightening operation to be performed through the socket to tighten the joint; and after performing the tightening operation, commanding, by the control system, a loosening operation to be performed through the socket.

[0023] The loosening operation can be automatically performed immediately after the tightening operation is completed. Thus, the method can start the loosening operation immediately after the tightening operation is completed, rather than performing the loosening operation as a separate task, for example, in response to a command from an operator. Alternatively, the loosening operation can be initiated by the operator, for example, by actuating an actuating element of the power tool.

[0024] During the tightening operation, the socket rotates about the socket axis in a tightening direction. When the target torque has been applied to the joint, the tightening operation can be considered to be completed. The loosening operation can include rotating the socket about the socket axis in a loosening direction opposite to the tightening direction.

[0025] According to a third aspect, there is provided a control system for a power tool for tightening a joint, the power tool comprising a base element having a base opening, a socket according to the first aspect, a motor arranged to drive the socket, and a control system configured to control the motor, wherein the socket is rotatable about a socket axis from an open position where the socket opening is aligned with the base opening, the control system comprising at least one data processing device and at least one memory, on which at least one computer program is stored, the at least one computer program comprising program code which, when executed by the at least one data processing device, causes the at least one data processing device to perform the following steps: commanding the socket to perform a tightening operation to tighten the joint; and after performing the tightening operation, commanding the socket to perform a loosening operation.

[0026] According to a fourth aspect, there is provided a method of controlling a power tool for tightening a joint, the power tool comprising a base element having a base opening, a socket having a socket opening, a motor arranged to drive the socket, and a control system configured to control the motor, wherein the socket is rotatable about a socket axis from an open position where the socket opening is aligned with the base opening, the method comprising commanding, by the control system, the socket to perform a tightening operation to tighten the joint; after performing the tightening operation, commanding, by the control system, the socket to perform an inspection operation; monitoring, by the control system, a response of the inspection operation to at least one parameter associated with the socket; determining, by the control system, based on the response whether the socket is engaged with the joint; and when it is determined that the socket is not engaged with the joint, commanding, by the control system, the socket to be positioned in the open position.

[0027] The inspection operation can be automatically performed immediately after the tightening operation is completed. Once it is determined that the socket is no longer engaged with the joint, the socket can be automatically positioned in the open position. Thus, the operator can directly move the power tool away from the joint instead of lifting the power tool from the joint and then manually commanding the socket to move to the open position. Then, the method automatically determines that the socket has disengaged from the bolt and automatically rotates the socket to the open position. When it is determined that the socket is not engaged with the joint, the rotational speed of the socket can be increased.

[0028] By evaluating the response to the inspection operation, it is possible to automatically sense the separation of the socket from the joint. Thus, the method is capable of performing the tightening operation and positioning the socket in the open position in a single sequence. The method enables the socket to automatically return to the open position after the tightening operation. In some applications, the method can save approximately one second of time for each tightening cycle.

[0029] The determination of whether the socket is engaged with the joint can be accomplished in various ways. According to one example, when the socket has rotated about the socket axis by more than a threshold angular distance, such as 20 degrees to 30 degrees, it is determined that the socket is rotating freely.

[0030] The checking operation may include rotating the socket or the command socket about the socket axis in the tightening direction or in the loosening direction. However, the socket should apply only a relatively small torque such that if the socket does not separate from the joint, the tightening torque in the joint achieved by the tightening operation does not change. That is, the checking operation should not cause the joint to be further tightened or loosened.

[0031] The power tool may include a socket according to the first aspect. In this case, the checking operation may include a loosening operation according to the second or third aspect. The loosening operation may be used to cause the power tool to separate from the joint and to determine when such separation has occurred. Alternatively, the power tool may include a socket that does not include an inner bevel.

[0032] The checking operation may include controlling the socket based on the rotational position, rotational speed, rotational acceleration, torque, and / or current.

[0033] The checking operation may include controlling the socket based on a torque that is less than the maximum torque during the tightening operation. The maximum torque during the checking operation may be less than 30%, for example less than 20%, of the maximum torque during the tightening operation.

[0034] The checking operation may include controlling the socket based on a current that is less than the maximum current during the tightening operation.

[0035] The socket may be commanded to perform the checking operation in a pulsed manner. The socket may be controlled based on a relatively large torque during the pulse and based on a relatively small, zero, or negative torque between the pulses. Alternatively or additionally, the socket may be controlled based on a relatively large current during the pulse and based on a relatively small, zero, or negative current between the pulses. In any case, the pulse may have a frequency of at least 5 Hz (e.g., 10 Hz).

[0036] As an alternative to the pulse, the checking operation may include controlling the socket based on a constant torque. Then the constant torque may be set small enough so that the power tool can separate from the joint. When the power tool separates from the joint, the constant torque will cause the socket to start rotating. Based on this rotation, it can be determined that the power tool has separated from the joint.

[0037] The at least one parameter may include rotational position, rotational speed, rotational acceleration, torque, and / or current.

[0038] The method may further include determining whether the tightening operation is successful and, when it is determined that the tightening operation is successful, commanding the checking operation to be performed. In the case where the tightening operation is not successful, a warning may be issued to the operator. If the tightening operation is not successful, the socket may be prevented from returning to the open position.

[0039] The power tool may include an actuating element for actuation by a human operator. In this case, the method may include commanding the execution of a tightening operation and an inspection operation regardless of whether the actuating element is actuated. After the tightening operation is completed, the operator can directly move the power tool away from the joint without releasing the actuating element. Once the socket disengages from the joint, the socket is automatically brought back to the open position.

[0040] According to a fifth aspect, there is provided a control system for controlling a power tool for tightening a joint, the power tool including a base element having a base opening, a socket having a socket opening, a motor arranged to drive the socket, and a control system configured to control the motor, wherein the socket is rotatable about a socket axis from an open position where the socket opening is aligned with the base opening, the control system including at least one data processing device and at least one memory having stored thereon at least one computer program, the at least one computer program including program code which, when executed by the at least one data processing device, causes the at least one data processing device to perform the following steps: commanding the execution of a tightening operation through the socket; after executing the tightening operation, commanding the execution of an inspection operation through the socket; monitoring a response of the inspection operation to at least one parameter associated with the socket; determining based on the response whether the socket is free to rotate; and commanding the socket to be positioned in the open position when it is determined that the socket is free to rotate.

[0041] The at least one computer program may include program code which, when executed by the at least one data processing device, causes the at least one data processing device to perform any of the steps according to the fourth aspect.

[0042] According to a sixth aspect, there is provided a power tool including the socket according to the first aspect, the control system according to the third aspect, and / or the control system according to the fifth aspect. The power tool may be used to transmit torque to a joint. The power tool may be handheld. Description of the Drawings

[0043] From the following description in conjunction with the drawings, further details, advantages and aspects of the present invention will become apparent, in which:

[0044] Figure 1a : schematically shows a side view of the power tool;

[0045] Figure 1b : schematically shows a top view of the power tool;

[0046] Figure 2 : schematically shows a partial cross-sectional side view of the power tool when the tool head is removed from the body;

[0047] Figure 3a : A schematic cross-sectional side view showing a tool head;

[0048] Figure 3b : A schematic top view showing the components of a tool head;

[0049] Figure 4 : A schematic perspective view showing the socket of a power tool;

[0050] Figure 5a : A schematic top view showing the socket including a positioning device;

[0051] Figure 5b : A schematic top view showing another example of the socket including a positioning device;

[0052] Figure 6a : A schematic side view showing an unassembled joint including a coupling and a bolt;

[0053] Figure 6b : A schematic side view showing the joint when assembling the bolt into the coupling using a power tool;

[0054] Figure 6c : A schematic side view showing the joint when the power tool is removed from the joint;

[0055] Figure 7a : A schematic graph showing the variation of the current flowing to the motor over time during an inspection operation;

[0056] Figure 7b : A schematic graph showing the variation of the rotational position over time during an inspection operation;

[0057] Figure 7c : A schematic graph showing the variation of the rotational speed over time during an inspection operation;

[0058] Figure 7d : A schematic graph showing the variation of the rotational acceleration over time during an inspection operation;

[0059] Figure 7e : A schematic graph showing the variation of the torque over time during an inspection operation;

[0060] Figure 8a : A schematic perspective view showing another example of the socket of a power tool;

[0061] Figure 8b : Schematically showing Figure 8a the side view of the socket in

[0062] Figure 8c: schematically show Figure 8a and Figure 8b a top view of the socket in

[0063] Figure 9a : schematically show Figures 8a to 8c a top view of the socket in

[0064] Figure 9b : schematically show the Figure 9a socket and the connector in

[0065] Figure 9c : schematically show the Figure 9a socket and the connector in

[0066] Figure 10a : schematically show Figure 9a a side view of the socket and the connector in

[0067] Figure 10b : schematically show the Figure 9c socket and the connector in DETAILED DESCRIPTION

[0068] In the following, a socket for a power tool including at least one inner bevel, a method for controlling a power tool including such a socket, a control system for controlling a power tool including such a socket, a method for controlling a power tool including an inspection operation, a control system for controlling a power tool to perform an inspection operation, and a power tool will be described. The same or similar reference numerals will be used to denote the same or similar structural features.

[0069] Figure 1a Schematically show a side view of the power tool 10, Figure 1b schematically show a top view of the power tool 10. With joint reference Figure 1a and Figure 1b , the power tool 10 includes a main body 12 and a tool head 14. In this example, the tool head 14 is detachably attached to the main body 12. The main body 12 is taken as a housing here.

[0070] The power tool 10 of this example is a hand-held end-opening power tool for tightening. The power tool 10 can be driven by electricity, for example. As Figure 1b shown, the power tool 10 can be used, for example, to tighten the bolt 16 on the threaded connector 18. The connector 18 can in turn surround the pipe fitting 20.

[0071] The power tool 10 of this example further includes an actuating element 22. The actuating element 22 is exemplified herein as a rod that can be rotated relative to the body 12 by manual actuation.

[0072] The tool head 14 includes a base element 24. The base element 24 includes a base opening 26 at its distal end.

[0073] The tool head 14 further includes a socket 28a having a socket opening 30. Thus, the socket 28a is an end-opening socket and the power tool 10 is an end-opening power tool. The socket 28a can be rotated relative to the base element 24 about a socket axis 32. In Figure 1a and Figure 1b , the socket 28a is in an open position 34. In the open position 34, the socket opening 30 is aligned with the base opening 26, whereby the pipe fitting 20 can be received in the radial direction relative to the socket axis 32. Then, the power tool 10 can be axially moved along the pipe fitting 20 to axially accommodate the bolt 16 in the socket opening 30.

[0074] Figure 2 Schematically shows a partial cross-sectional side view of the power tool 10. The tool head 14 is removed from the body 12 here. As Figure 2 shown, the body 12 of this example includes a drive shaft 36. The drive shaft 36 can rotate about a drive axis 38. In this example, when the tool head 14 is attached to the body 12, the drive axis 38 is parallel to the socket axis 32.

[0075] The power tool 10 of this example further includes a control system 40. The control system 40 is provided in the body 12 here. The control system 40 includes a data processing device 42 and a memory 44. A computer program is stored on the memory 44. The computer program includes program code that, when executed by the data processing device 42, causes the data processing device 42 to perform or command the performance of the various steps described herein.

[0076] The power tool 10 of this example further includes an electric motor 46 encapsulated within the body 12. The motor 46 rotationally drives a motor shaft 48. The control system 40 communicates signals with the motor 46 and controls the operation of the motor 46 here by sending an electric current 50 to the motor 46.

[0077] The power tool 10 of this example further includes a reduction gear 52 and an intermediate shaft 54. The reduction gear 52 is configured to transmit the rotation of the motor shaft 48 at a first rotational speed to the rotation of the intermediate shaft 54 at a second rotational speed lower than the first rotational speed. The rotation of the intermediate shaft 54 is transmitted to the rotation of the drive shaft 36 via bevel gears 56. In this way, the power tool 10 is configured to transmit the rotation of the motor shaft 48 to the rotation of the drive shaft 36. The reduction gear 52, the intermediate shaft 54, and the bevel gears 56 constitute one of many examples of a motor transmission 58 configured to transmit the rotation of the motor 46 to the rotation of the drive shaft 36.

[0078] The power tool 10 further includes a position sensor 60. The position sensor 60 is arranged to measure the position of the motor shaft 48, here the rotational position 62.

[0079] The power tool 10 further includes a torque sensor 64. The torque sensor 64 is arranged to measure the torque 66, here taking the input torque to the reduction gear 52 as an example.

[0080] Figure 3a A sectional side view schematically showing the tool head 14 Figure 3b A top view schematically showing the components of the tool head 14. With common reference Figure 3a and Figure 3b , the tool head 14 of this example includes a drive member 68. The drive member 68 can rotate relative to the base element 24 about a drive axis 38. The drive member 68 is here exemplified by a hollow shaft arranged to receive the drive shaft 36 and thus be driven.

[0081] The tool head 14 further includes a drive transmission 70. The drive transmission 70 is configured to transmit the rotation of the drive member 68 about the drive axis 38 to the rotation of the socket 28a about the socket axis 32. In this example, the ratio between the drive member 68 and the socket 28a is 1:1. The drive transmission 70 of this specific example includes a first gear 72 meshingly engaged with the tooth portion of the drive member 68, a second gear 74 meshingly engaged with the first gear 72, a third gear 76 meshingly engaged with the second gear 74, a main fourth gear 78a meshingly engaged with each of the third gear 76 and the tooth-shaped drive profile 80 of the socket 28a, and a secondary fourth gear 78b meshingly engaged with each of the third gear 76 and the drive profile 80 of the socket 28a. The drive profile 80 is thus drivingly engaged by the fourth gears 78a and 78b. By means of the motor transmission 58 and the drive transmission 70, the power tool 10 is configured to transmit the rotation of the motor shaft 48 to the rotation of the socket 28a.

[0082] The rotational position of the socket 28a can be determined based on the rotational position of the motor shaft 48. Additionally, the torque at the socket 28a can be determined based on the torque 66 at the reduction gear 52.

[0083] Figure 4 A perspective view schematically showing the socket 28a. The socket 28a includes a cylindrical portion 82 and an inner portion 84. The inner portion 84 is radially located inside the cylindrical portion 82 with respect to the socket axis 32. As shown, a drive profile 80 is provided on the outer side of the cylindrical portion 82.

[0084] The cylindrical portion 82 includes an end face 86 and a plurality of engagement faces 88. Each engagement face 88 is provided on the inner side of the cylindrical portion 82. Additionally, each engagement face 88 is parallel to the socket axis 32. In this example, the cylindrical portion 82 includes four full - size engagement faces 88 and two smaller engagement faces 88 defined by the socket opening 30. As Figure 4 shown, the socket opening 30 extends radially with respect to the socket axis 32 through the cylindrical portion 82 and the inner portion 84.

[0085] The inner portion 84 includes a stop face 90. The stop face 90 and the end face 86 are offset from each other in a direction parallel to the socket axis 32. In this example, each of the end face 86 and the stop face 90 is a plane and perpendicular to the socket axis 32. In Figure 4 it, the stop face 90 is located below the end face 86. The engagement faces 88 are positioned between the end face 86 and the stop face 90 in a direction parallel to the socket axis 32.

[0086] Figure 5a A top view schematically showing the socket 28a. The socket 28a of this example includes a positioning device 92a. The positioning device 92a of this example includes a positioning base 94, a spring 96, and a stopper 98. The positioning device 92a further includes a notch 100 in the socket 28a, for example, in the cylindrical portion 82 offset from the drive profile 80. The positioning base 94 can be fixed to the base element 24.

[0087] As Figure 5a shown, when the socket 28a rotates in the counter - clockwise direction, the notch 100 can pass through the stopper 98. Thus, Figure 5a the socket 28a in Figure 5a can rotate continuously in the counter - clockwise direction. When the socket 28a rotates in the clockwise direction in

[0088] Figure 5b Figure 5a and the notch 100 reaches the stopper 98, the spring 96 will push the stopper 98 into the notch 100 and the socket 28a will stop at the open position 34.

[0088] Figure 5bA top view schematically showing socket 28a. Socket 28a includes another example of positioning device 92b. Positioning device 92b can be positioned in a direction parallel to socket axis 32 at a cylindrical portion 82 offset relative to drive profile 80.

[0089] The positioning device 92b of this example is a sensor including an active component 102 and a passive component 104. In this example, the active component 102 is a Hall effect sensor fixed to base element 24, and the passive component 104 is a magnet fixed to socket 28a (e.g., fixed to cylindrical portion 82 offset relative to drive profile 80). The active component 102 communicates signals with control system 40. When socket 28a is in open position 34, the active component 102 detects the proximity of the passive component 104.

[0090] Figure 6a A side view schematically showing unassembled joint 106. The joint 106 of this specific example includes pipe fitting 20, coupling 18, and bolt 16 as Figure 1b already shown. Coupling 18 includes external threads 108. In Figure 6a , bolt 16 surrounds pipe fitting 20 but does not threadedly engage with external threads 108.

[0091] The bolt 16 of this example includes six engagable surfaces 110 and twelve corners 112 between the engagable surfaces 110. Six corners 112 are located at one end of bolt 16 ( Figure 6a the left end in Figure 6a ), and six corners 112 are located at the opposite end (

[0092] the right end in Figure 6a ). When socket 28a is positioned in open position 34, power tool 10 can move relative to socket axis 32 in a radial direction to receive pipe fitting 20 through socket opening 30. Then, power tool 10 can move axially along pipe fitting 20 to accommodate bolt 16 in socket 28a. When bolt 16 is accommodated in socket 28a, each engagement surface 88 is parallel to the associated engagable surface 110 of bolt 16. In addition, power tool 10 can move axially relative to bolt 16 (to the right in Figure 6a ) until bolt 16 abuts against stop surface 90 within socket 28a.

[0093] Figure 6bA side view of the joint 106 is schematically shown when the power tool 10 is used to assemble the bolt 16 to the connector 18. Now, the tightening operation of the joint 106 is performed. In this example, the control system 40 commands the motor 46 to perform the tightening operation in response to the actuation of the actuating element 22. During the tightening operation, the socket 28a rotates the bolt 16 along the tightening direction 114 to tighten the joint 106. During the tightening operation, the socket 28a is initially controlled at a constant rotational speed until the torque threshold is reached. Then, the rotational speed can be decreased until the target torque in the joint 106 is reached. When the tightening operation is successful, a green light can be displayed. If the tightening operation is not successful, a red light can be displayed. When the tightening operation is completed, the control system 40 immediately commands the execution of an inspection operation, such as as Figures 7a to 7e described. The inspection operation can be conditional on a successful tightening operation.

[0094] Figure 6c A side view of the joint 106 is schematically shown when the power tool 10 is removed from the joint 106. The operator can remove the power tool 10 from the joint 106 immediately after the tightening operation is completed. The removal of the power tool 10 from the joint 106 can be detected by the inspection operation.

[0095] Figure 7a A graph is schematically shown that depicts the variation of the current 50 flowing to the motor 46 over time t during the inspection operation. As shown, during the inspection operation, the control system 40 sends pulses 116a - 116c of the current 50 to the motor 46. The current 50 is an example of a parameter associated with the socket 28a. A first pulse 116a is sent at time t1, a second pulse 116b is sent at time t2, and a third pulse 116c is sent at time t3. In this example, between the pulses 116a - 116c, the current 50 is zero. The time step between the pulses 116a - 116c can be, for example, 0.1 s. At times t1 and t2, the socket 28a engages with the bolt 16. At time t3, the socket 28a disengages from the bolt 16.

[0096] In this example, each of the pulses 116a - 116c is positive to command the socket 28a to rotate along the loosening direction opposite to the tightening direction 114. However, the pulses 116a - 116c can be negative to command the socket 28a to rotate along the tightening direction 114, or alternately command rotation along the loosening direction and the tightening direction 114.

[0097] Figure 7bSchematically shows a graph depicting the variation of the rotational position 62 over time t during the inspection operation. There is a linear relationship between the rotational position 62 measured by the position sensor 60 and the rotational position of the socket 28a. Thus, the position 62 is another example of a parameter associated with the socket 28a. The control system 40 monitors the response of the rotational position 62 to the pulses 116a - 116c.

[0098] At time t1, the socket 28a rotates slightly from the starting position within the gap between the mating surface 88 of the socket 28a and the engagable surface 110 of the bolt 16. Then, the socket 28a stops shortly after time t1. The control system 40 can thereby conclude that the socket 28a is engaged with the joint 106.

[0099] At time t2, the rotational position 62 does not change. The control system 40 can thereby conclude that the socket 28a remains engaged with the joint 106.

[0100] At time t3, the socket 28a rotates beyond the threshold angular distance 118. Based on this, the control system 40 can conclude that the socket 28a is now not engaged with the joint 106. The threshold angular distance 118 can be, for example, 20 degrees to 30 degrees.

[0101] Figure 7c Schematically shows a graph depicting the variation of the rotational speed 120 of the socket 28a over time t during the inspection operation. The control system 40 determines the rotational speed 120 based on the measured rotational position 62. There is a linear relationship between the rotational speed 120 determined based on the rotational position 62 and the rotational speed of the socket 28a. Thus, the rotational speed 120 is another example of a parameter associated with the socket 28a. The control system 40 monitors the response of the rotational speed 120 to the pulses 116a - 116c. At time t1, the rotational speed 120 increases slightly within a short time period. At time t2, the rotational speed 120 is zero. At time t3, the rotational speed 120 increases more, indicating that the socket 28a has moved away from the bolt 16.

[0102] Figure 7d Schematically shows a graph depicting the variation of the rotational acceleration 122 of the socket 28a over time t during the inspection operation. The control system 40 determines the rotational acceleration 122 based on the measured rotational position 62. There is a linear relationship between the rotational acceleration 122 and the rotational acceleration of the socket 28a. Thus, the rotational acceleration 122 is another example of a parameter associated with the socket 28a. The control system 40 monitors the response of the rotational acceleration 122 to the pulses 116a - 116c. At time t1, there is a small rotational acceleration 122 within a short time period. At time t2, the rotational acceleration 122 is zero. At time t3, the rotational acceleration 122 increases, indicating that the socket 28a has moved away from the bolt 16.

[0103] Figure 7e Schematically shows a graph of the torque 66 of the socket 28a varying with time t during the inspection operation. The torque on the socket 28a can be determined based on the torque 66 measured by the torque sensor 64. Thus, the torque 66 is another example of a parameter associated with the socket 28a. The control system 40 monitors the response of the torque 66 to the pulses 116a - 116c. Shortly after the moment t1, the torque 66 increases until it reaches the torque threshold 124. The torque threshold 124 is substantially lower than the tightening torque and can be, for example, 1 Nm. When the torque 66 reaches the torque threshold 124, the pulse 116a stops. At the moment t2, the torque 66 increases again until it reaches the torque threshold 124, and the pulse 116b stops. However, at the moment t3, the torque 66 does not increase. After the moment t3, the socket 28a rotates from the starting position by more than the threshold angular distance 118, while the torque 66 does not reach the torque threshold 124. This particularly indicates that the power tool 10 has separated from the joint 106.

[0104] In this specific example, when the torque 66 reaches the torque threshold 124, each of the pulses 116a - 116c stops, and then the socket 28a remains in that position until the next pulse 116a - 116c. Optionally, the socket 28a can return to the starting position after each pulse 116a - 116c.

[0105] When the control system 40 has determined that the socket 28a is not engaged with the joint 106, the control system 40 immediately and automatically commands the socket 28a to be positioned in the open position 34, in this example, regardless of how or whether the actuating element 22 is actuated. In the case where it is determined that the power tool 10 has left the joint 106, when the socket 28a is positioned in the open position 34, the rotational speed 120 can be increased. Thus, the operator can directly remove the power tool 10 from the joint 106 and from the pipe fitting 20 when the tightening operation is completed. The power tool 10 will automatically be responsible for positioning the socket 28a in the open position 34 without the need for a further command from the operator for this purpose. This can save a significant amount of time.

[0106] Figure 8a Schematic perspective view showing another example of the socket 28b of the power tool 10. Figure 8b Schematically shows a side view of the socket 28b, Figure 8c Schematically shows a top view of the socket 28b. With common reference Figures 8a to 8c , different from the socket 28a, the socket 28b further includes an inner inclined surface 126. The socket 28b of this example includes four inner inclined surfaces 126. The inner inclined surfaces 126 are located inside the cylindrical portion 82. Here, each inner inclined surface 126 is formed by a cut in the corresponding engaging surface 88. As shown, each inner inclined surface 126 of this example is straight and extends from the stop surface 90 to the end surface 86. AsFigure 8c As specifically shown, each inner inclined surface 126 is located between the end surface 86 and the stop surface 90, as seen in a plane transverse to the socket axis 32.

[0107] Figure 9a A top view schematically showing the socket 28b accommodating the joint 106, Figure 10a A side view schematically showing the socket 28b and the joint 106. In Figure 9a and Figure 10a the socket 28b is in the same position relative to the bolt 16 as in Figure 6b As Figure 9a shown, each engaging surface 88 is aligned with the unique engagable surface 110 of the bolt 16.

[0108] Figure 9b A top view schematically showing the socket 28b and the joint 106. The socket 28b is rotated in the tightening direction 114, causing the bolt 16 to rotate as shown by the arrow 128. It can be seen that the socket 28b is configured to tighten the bolt 16 in a conventional manner by rotating in the tightening direction 114.

[0109] Figure 9c A top view schematically showing the socket 28b and the joint 106, Figure 10b A side view schematically showing the socket 28b and the joint 106 when the socket 28b is rotated in the loosening direction 130 opposite to the tightening direction 114. This causes the socket 28b to rotate about the socket axis 32 relative to the bolt 16 which remains stationary. The rotation of the socket 28b in the loosening direction 130 causes the corners 112 of the bolt 16 (here the four corners 112 of the bolt 16) to move along the corresponding inner inclined surfaces 126. This causes the power tool 10 to move axially away from the joint 106 relative to the socket axis 32, as shown by the arrow 132.

[0110] Similarly, when the power tool 10 includes the socket 28b, an inspection operation can be performed immediately after the tightening operation is completed. In this case, the inspection operation can alternatively include a loosening operation which includes rotating the socket 28b in the loosening direction 130. In this way, the operator does not have to lift the power tool 10 from the bolt 16. Also, in this example, the control system 40 can detect when the socket 28b is not engaged with the joint 106, such as when the torque 66 decreases. The loosening operation does not have to be performed in the pulses 116a - 116c. When the socket 28b has disengaged from the bolt 16, the rotational speed 120 can be increased until the socket 28b reaches the open position 34.

[0111] In the case where the inspection operation includes applying torque along the release direction 130 to the socket 28b, the same software can be used in the power tool 10 for working with the socket 28a and the socket 28b. The torque can be small enough so as not to loosen the joint 106 when using the socket 28a, and large enough so that the socket 28b can be separated by the engagement between the inner bevel 126 and the corner 112.

[0112] Although the invention has been described with reference to exemplary embodiments, it will be understood that the invention is not limited to what has been described above. For example, it will be understood that the dimensions of the components can vary as needed. Thus, the invention is intended to be limited only by the scope of the appended claims.

Claims

1. A socket (28b) for a power tool (10), the socket (28b) being arranged to rotate about a socket axis (32) and comprising: - a cylindrical portion (82) having an end face (86) and a plurality of engagement faces (88) parallel to the socket axis (32) on the inner side of the cylindrical portion (82); - an inner portion (84) located radially inside the cylindrical portion (82) relative to the socket axis (32) and having a stop face (90) offset relative to the end face (86) such that the engagement faces (88) are located between the stop face (90) and the end face (86); - a socket opening (30) extending radially relative to the socket axis (32) through the cylindrical portion (82) and the inner portion (84); and - a positioning device for stopping the socket in an open position; wherein the cylindrical portion (82) includes at least one inner inclined surface (126) formed by a cut in a corresponding engagement face (88) and extending away from the stop face (90) on the inner side of the cylindrical portion (82); wherein the inner inclined surface (126) extends from the stop face (90) to the end face (86).

2. The socket (28b) according to claim 1, wherein the at least one inner inclined surface (126) includes a plurality of inner inclined surfaces (126).

3. The socket (28b) according to any one of the preceding claims, wherein the inner inclined surface (126) is straight.

4. The socket (28b) according to claim 1, wherein the cylindrical portion (82) includes a circular drive profile (80) on the outer side of the cylindrical portion (82) and concentric with the socket axis (32) for driving engagement by wheels (78a, 78b).

5. A method of controlling a power tool (10) for tightening a joint (106), the power tool (10) including a base element (24) having a base opening (26), a socket (28b) according to any one of the preceding claims, a motor (46) arranged to drive the socket (28b), and a control system (40) configured to control the motor (46), wherein the socket (28b) is rotatable about the socket axis (32) from an open position (34) where the socket opening (30) is aligned with the base opening (26), the method comprising: - commanding by the control system (40) a tightening operation to be performed through the socket (28b) to tighten the joint (106); and - automatically and immediately after performing the tightening operation, commanding by the control system (40) a loosening operation to be performed through the socket (28b).

6. A control system (40) for controlling a power tool (10) for tightening a joint (106), the power tool (10) including a base element (24) having a base opening (26), a socket (28b) according to any one of claims 1 to 4, a motor (46) arranged to drive the socket (28b), and a control system (40) configured to control the motor (46), wherein The socket (28b) is rotatable about a socket axis (32) from an open position (34) where the socket opening (30) is aligned with the base opening (26), and the control system (40) includes at least one data processing device (42) and at least one memory (44) having stored thereon at least one computer program including program code which, when executed by the at least one data processing device (42), causes the at least one data processing device (42) to perform the following steps: - commanding a tightening operation to be performed through the socket (28b) to tighten the joint (106); and - after performing the tightening operation, automatically and immediately commanding a loosening operation to be performed through the socket (28b).

7. A method of controlling a power tool (10) for tightening a joint (106), the power tool (10) including a base element (24) having a base opening (26), a socket (28a; 28b) according to any one of claims 1 to 4 having a socket opening (30), a motor (46) arranged to drive the socket (28a; 28b), and a control system (40) configured to control the motor (46), wherein, the socket (28a; 28b) is rotatable about a socket axis (32) from an open position (34) where the socket opening (30) is aligned with the base opening (26), and the method includes: - commanding, by the control system (40), a tightening operation to be performed through the socket (28a; 28b) to tighten the joint (106); - after performing the tightening operation, automatically and immediately commanding, by the control system (40), an inspection operation to be performed through the socket (28a; 28b); - monitoring, by the control system (40), a response of the inspection operation to at least one parameter associated with the socket (28a; 28b); - determining, by the control system (40), based on the response, whether the socket (28a; 28b) is engaged with the joint (106); and - when it is determined that the socket (28a; 28b) is not engaged with the joint (106), commanding, by the control system (40), the socket (28a; 28b) to be positioned at the open position (34), wherein the at least one parameter includes a rotational position (62), a rotational speed (120), a rotational acceleration (122), a torque (66), and / or a current (50).

8. The method according to claim 7, wherein, the inspection operation includes a loosening operation.

9. The method according to any one of claims 7 and 8, wherein, the inspection operation includes controlling the socket (28a; 28b) based on a rotational position (62), a rotational speed (120), a rotational acceleration (122), a torque (66), and / or a current (50).

10. The method according to claim 7, wherein, the inspection operation includes controlling the socket (28a; 28b) based on a torque (66) less than a maximum torque (66) during the tightening operation.

11. The method according to claim 7, wherein, The checking operation includes controlling the socket (28a; 28b) based on a current (50) that is less than the maximum current (50) during the tightening operation.

12. The method according to claim 7, wherein, the socket (28a; 28b) is commanded to perform the checking operation in the form of pulses (116a - 116c).

13. The method according to claim 12, wherein, the socket (28a; 28b) is controlled based on a relatively large torque (66) during the pulses (116a - 116c) and based on a relatively small positive, zero, or negative torque (66) between the pulses (116a - 116c).

14. The method according to claim 12 or 13, wherein, the socket (28a; 28b) is controlled based on a relatively large current (50) during the pulses (116a - 116c) and based on a relatively small positive, zero, or negative current (50) between the pulses (116a - 116c).

15. The method according to claim 12 or 13, wherein, the pulses (116a - 116c) have a frequency of at least 5 Hz.

16. The method according to claim 7, further comprising determining whether the tightening operation is successful, and commanding the execution of the checking operation when it is determined that the tightening operation is successful.

17. The method according to claim 7, wherein, the power tool (10) includes an actuating element (22) for manual actuation, and wherein the method includes commanding the execution of the tightening operation and the checking operation regardless of whether the actuating element (22) is actuated.

18. A control system (40) for controlling a power tool (10) for tightening a joint (106), the power tool (10) including a base element (24) having a base opening (26), a socket (28a; 28b) according to any one of claims 1 to 4 having a socket opening (30), a motor (46) arranged to drive the socket (28a; 28b), and a control system (40) configured to control the motor (46), wherein, the socket (28a; 28b) is rotatable about a socket axis (32) from an open position (34) where the socket opening (30) is aligned with the base opening (26), the control system (40) includes at least one data processing device (42) and at least one memory (44), and at least one computer program is stored on the memory, the at least one computer program including program code which, when executed by the at least one data processing device (42), causes the at least one data processing device (42) to perform the following steps: - Command the execution of the tightening operation through the socket (28a; 28b); - After the execution of the tightening operation, automatically and immediately command the execution of the checking operation through the socket (28a; 28b); - Monitor the response of the checking operation to at least one parameter associated with the socket (28a; 28b); - Determine whether the socket (28a; 28b) can rotate freely based on the response; and - When it is determined that the socket (28a; 28b) can rotate freely, the socket (28a; 28b) is commanded to be positioned at the open position (34). Wherein, the at least one parameter includes a rotational position (62), a rotational speed (120), a rotational acceleration (122), a torque (66) and / or a current (50).

19. The control system (40) according to claim 18, wherein, the at least one computer program includes program code which, when executed by the at least one data processing device (42), causes the at least one data processing device (42) to perform the steps according to any one of claims 7 to 17.

20. A power tool (10) comprising a socket (28b) according to any one of claims 1 to 4, a control system (40) according to claim 6 or a control system (40) according to claim 18 or 19.

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