EP3681677B1

EP3681677B1 - A power tool

Info

Publication number: EP3681677B1
Application number: EP18768845.2A
Authority: EP
Inventors: Carl Johan Erik Wallgren
Original assignee: Atlas Copco Industrial Technique AB
Current assignee: Atlas Copco Industrial Technique AB
Priority date: 2017-09-13
Filing date: 2018-09-07
Publication date: 2024-05-15
Anticipated expiration: 2038-09-07
Also published as: CN111065489A; EP3681677A1; WO2019052920A1

Description

TECHNICAL FIELD

The invention relates to a power tool, a tightening supervising system for a power tool, a method and a computer readable storage medium.

BACKGROUND

A problem concerned with prior art power tool application is that the operator sometimes makes the mistake to believe that he/she has properly tightened all the screw joints on the object, whereas in fact screw joints erroneously may have been left unattended or unsatisfactory tightened. This could have a serious negative effect on the function and/or durability of the object or structure being assembled by the screw joints.
Another problem inherent in prior art assembly operations is for the operator to know in which order the screw joints shall be tightened for obtaining an acceptable quality on the object being assembled. And in order not to leave anyone of the screw joints unattended during the operation. This could cause an incomplete assembly.
In order to avoid such problems prior art tightening supervising systems have some sort of display or warning light provided on a separate process control unit to alert the operator to awareness of the fact that a certain screw joint erroneously has been left unattended or unsatisfactory tightened. To find out which one of the screw joints was not properly tightened the operator had to move the power tool across the object and simultaneously look at the display or warning light on the process control unit to see in which one of the screw joint positions the alert signal was generated. This error tracing method is quite awkward and tends to prolong the assembly process unnecessarily. The operator had to remember himself which screw joint was the next to be tightened to obtain the desired assembly result.
WO 2016120125 A2 shows an example of a tightening supervise system for a power screw driver. A light emitting device is provided on the power screw driver and arranged to selectively directed a light beam onto that next screw joint in a programmed sequence. The light emitting device is also arranged to direct a light beam onto a screw joint or joints that have been left unattended or indicated as unsatisfactory tightened according to a control unit program.

SUMMARY

It is an object of the present disclosure to ensure a high and acceptable quality of an assembly process by providing a simple and time saving power tool.
This object is achieved in accordance with a power tool according to claim 1 and a method according to claim 11.
Accordingly, the screw joint tightening sequence is clearly pointed out, and the operator is quickly and easily informed which one of the screw joints has not been attended to in correct order or not been tightened properly during the assembly process. A correction of the faulty joint or joints may then be made to complete the assembly process such that the quality of the assembled object is guaranteed.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 which shows a view of a power tool according an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE SHOWN EMBODIMENT

Figure 1 illustrates a power tool 10 according to an exemplary embodiment of the present disclosure. The power tool 10 comprises an elongate tubular housing 12 intended to be used as a handle for manual guiding of the screw driver 10, and an output shaft 13 extending coaxially with the housing 12.
The power tool 10 is intended for tightening a number of screw joints on an object to be assembled. The screw joints are located at different positions on the object, and in order to obtain a desired clamping load on the parts of the object the screw joints may be tightened in a certain sequence.
The power tool 10 comprises a light emitting device 20 in the front part arranged to light up the screw joint. The power tool 10 is operative to retrieve a signal indicating the position of the power tool 10 in relation to a number of screw joints on an object to be assembled. The power tool 10 is further operative to provide a first type of light signal from the light emitting device 20 in case the signal indicates that the power tool 10 is positioned in relation to the screw joint next to be tighten and a second type of light signal in case the signal indicates that the power tool 10 is positioned in another position.
In order to obtain quick and easily apprehensible information on which screw joint is the next to be tightened and or which screw joint have been left unattended or improperly tightened during the assembly process the power tool 10 is operative to provide the first type of light signal from the light emitting device 20 in case the signal indicates that the power tool 10 is positioned in relation to the screw joint next to be tighten and the second type of light signal in case the signal indicates that the power tool 10 is positioned in another position.
The signal is in an exemplary embodiment received from a power tool controller (not shown). The signal is in another exemplary embodiment received from a process control unit. The signal can be received via a wire connecting the power tool 10 to the power tool controller or process control unit. In another embodiment the signal is received wirelessly. In yet another exemplary embodiment the signal is generated by the power tool 10 itself. The power tool 10 can be positioned in many different ways. How the power tool 10 is positioned is not essential to the invention and is thus not described in detail.
In one exemplary embodiment of the power tool 10 in relation to the screw joint next to be tighten means that the close to the screw joint next to be tighten. In another exemplary embodiment of the power tool 10 in relation to the screw joint next to be tighten means that power tool 10 is positioned right above the screw joint next to be tighten.
In a further exemplary embodiment of the power tool 10 in relation further comprises the power tool 10 being attached to the screw joint. In a yet further exemplary embodiment of the power tool 10 attached to comprise the power tool 10 applying the correct axial force on the screw joint.
In another exemplary embodiment of the power tool 10 the first type of light signal is a first color and the second type of light signal is another color.
The power tool is further arranged to provide a third type of light signal in case the power tool fulfills yet another condition, such as e.g. being positioned perpendicular to the object to be assembled and/or the power tool 10 applying the correct axial force on the screw joint.
According to one exemplary of the power tool 10 the light emitting device 20 is a LED, Light Emitting Diode, arranged to emit both the first color and the another color.
Another aspect of the present disclosure relates to a tightening supervising system comprising the power tool 10 according to any of the above described exemplary embodiments. The tightening supervising system further comprising a position system operative to determine the position of the power tool 10 in relation to a number of screw joints on an object to be assembled.
In one exemplary embodiment, the power tool 10 is connected to a fixed structure via a reaction support while permitting free movability of the power tool 10. And the position system includes sensors provided on the reaction support to provide signals indicating the position of the power tool 10. In one exemplary embodiment pivots on arms of the reaction support are provided with angle sensors, which are connected to the positioning system. In another exemplary embodiment the tightening supervising system comprises a process control unit connected to the position system and operative to determine the next screw joint to be tightened.
In one exemplary embodiment the process control unit is programmed with the number and the individual coordinates of the screw joints of the object, and by using the positioning system the actual position of the power tool 10 is calculated. By comparing the calculated actual position of the screw driver 10 with the screw joint coordinates it can be determined which one of the screw joints is presently attended to by the screw driver 10 and whether the screw driver 10 has attended all of the screw joints on the object. The process control unit then generate the signal indicating the position of the power tool 10 in relation to a number of screw joints on an object to be assembled.
In one exemplary embodiment the control unit is also programmable with data by which the screw joints should be tightened, and if a deviation between the programmed data and the data actually experienced during tightening of each screw joint the signal is generated. The signal is then received by the power tool 10 which is operative to provide a third type of light signal from the light emitting device 20. Such third type of light signal from the light emitting device 20 make the operator aware that a tightening error has occurred.
The process control unit may also be configured so that the signal indicates that the power tool 10 has failed to tighten the screw joint. As the signal indicates that an error has been detected the operator only has to move the screw driver 10 across the assembled object and the type of light signal from the light emitting device 20 will notify the operator that the power tool 10 has failed to tighten the screw joint.
The process control unit may also be configured to generate the signal that indicates when all joints of a work piece have been correctly tightened. The signal could also indicate when a desired target, such as a target torque has been met for the joint, or indicate if the desired target is not met. When all joints have been correctly the signal may indicate that.
The present disclosure also relates to a method, performed in the power tool 10 comprising a light emitting device 20 arranged to light up the screw joint on an object to be assembled.
In a first step the power tool 10 retrieves a signal indicating the position of the power tool 10 in relation to a number of screw joints on an object to be assembled. In a next step the electric pulse tool 10 provides a first type of light signal from the light emitting device 20 in case the signal indicates that the power tool 10 is positioned in relation to the screw joint next to be tighten and a second type of light signal in case the signal indicates that the power tool 10 is positioned in another position.
According to one exemplary embodiment of the method, the light emitting device 20 is arranged in the front part of the power tool 10. In another exemplary embodiment of the method the light emitting device 20 further comprises another light emitting device in another part of the power tool 10.
According to another exemplary embodiment, the first type of light signal is a first color and the second type of light signal is another color. According to another exemplary embodiment, the light emitting device 20 is a LED, Light Emitting Diode, arranged to emit both the first color and the another color.
The present disclosure also relates to a computer-readable storage medium, having stored there on a computer program which, when run in the power tool 10, causes the power tool 10 to perform the method as described above.
According to one exemplary embodiment, when the above-mentioned computer program code is run in a processor (not shown) of the power tool 10 it causes the power tool 10 to perform the method as described above.

Claims

A power tool (10) comprising a light emitting device (20) arranged to light up a screw joint on an object to be assembled, whereby the power tool (10) is operative to:
- retrieve a signal indicating the position of the power tool (10) in relation to a number of screw joints on an object to be assembled;

- provide a first type of light signal from the light emitting device (20) in case the signal indicates that the power tool (10) is positioned in relation to the screw joint next to be tighten,
characterized in that the power tool is further operative to provide a second type of light signal in case the signal indicates that the power tool (10) is positioned in another position, and

in that the power tool is further arranged to provide a third type of light signal in case the power tool fulfills yet another condition, such as e.g. being positioned perpendicular to the object to be assembled and/or the power tool (10) applying the correct axial force on the screw joint.
The power tool (10) according to claim 1, wherein the light emitting device (20) is arranged in the front part of the power tool (10).
The power tool (10) according to claim 2, wherein the light emitting device (20) further comprises another light emitting device in another part of the power tool (10).
The power tool (10) according to any of claims 1 to 3, wherein in relation further comprises the power tool (10) being attached to the screw joint.
The power tool (10) according to claim 4, wherein attached to comprise the power tool (10) applying the correct axial force on the screw joint.
The power tool (10) according to any of claims 1 to 5, wherein the first type of light signal is a first color and the second type of light signal is another color.
The power tool (10) according to any of the preceding claims , wherein the light emitting device (20) is a LED, Light Emitting Diode, arranged to emit both the first color and the another color.
A tightening supervising system comprising the power tool (10) according to any of claims 1 to 5, the tightening supervising system further comprising a position system operative to determine the position of the power tool (10) in relation to a number of screw joints on an object to be assembled.
The tightening supervising system according to claim 8, further comprising a process control unit connected to said position system and operative to determine the next screw joint to be tightened.
The tightening supervising system according to any of claims 8 or 9 , wherein the power tool (10) is connected to a fixed structure via a reaction support while permitting free movability of the power tool (10), and said position system includes sensors provided on the reaction support to provide signals indicating the position of the power tool (10).
A method in a power tool (10) comprising a light emitting device (20) arranged to light up the screw joint on an object to be assembled, the method comprises the steps of:
- retrieving a signal indicating the position of the power tool (10) in relation to a number of screw joints on an object to be assembled;

- providing a first type of light signal from the light emitting device (20) in case the signal indicates that the power tool (10) is positioned in relation to the screw joint next to be tighten and a second type of light signal in case the signal indicates that the power tool (10) is positioned in another position; and

- providing a third type of light signal from the light emitting device (20) in case the power tool fulfills yet another condition, such as e.g. being positioned perpendicular to the object to be assembled and/or the power tool applying the correct axial force on the screw joint.
The method according to claim 11, wherein the light emitting device (20) is arranged in the front part of the power tool (10).
The method according to claim 12, wherein the light emitting device (20) further comprises another light emitting device in another part of the power tool (10).
The method according to any of claims 11 to 13, wherein the first type of light signal is a first color and the second type of light signal is another color.
The method according to claim 14, wherein the light emitting device (20) is a LED, Light Emitting Diode, arranged to emit both the first color and the another color.
A computer-readable storage medium, having stored there on a computer program which, when run in a power tool (10) according to claim 1, causes the power tool (10) to perform the method as claimed in any of claims 11 to 15.