Method for operating a driving-in device

A method for operating a driving-in device for fastening elements comprises a motor operating according to a particular pattern when there are no more fastening elements in a magazine of the driving-in device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is the U.S. National Stage of International Patent Application No. PCT/EP2018/056805, filed Mar. 19, 2018, which claims the benefit of European Patent Application No. 17161823.4, filed Mar. 20, 2017, which are each incorporated by reference.

TECHNICAL FIELD

The application relates to a method for operating a drive-in device for fastening elements.

BACKGROUND OF THE INVENTION

Devices of this kind generally comprise a drive-in element for driving in a fastening element that is arranged in a drive-in channel, and a drive means for the drive-in element. In the case of devices comprising a magazine, the fastening elements are successively transported into the drive-in channel, using a transport means. When all the fastening elements in the magazine are used up without a user of the drive-in device being aware of this, the user will initially attempt to perform a drive-in procedure, and will reload further fastening elements only after identifying the empty magazine. It is therefore desirable to operate a drive-in device such that the time required for unsuccessful drive-in attempts of this kind is reduced.

BRIEF SUMMARY OF THE INVENTION

In the case of a method for operating a drive-in device for fastening elements comprising a drive-in channel, a drive-in element which is intended for driving a fastening element arranged in the drive-in channel into a substrate, a drive means which is intended for driving the drive-in element onto the fastening element arranged in the drive-in channel, the drive means comprising a motor, a magazine for fastening elements, a transport means which is intended for successively transporting fastening elements, provided in the magazine, into the drive-in channel, and a detection means for querying whether and/or how many fastening elements are present in the magazine, the object is achieved in that the motor is operated in accordance with a standard mode if the detection means detects a specified minimum number of fastening elements in the magazine, and in that the motor is operated in accordance with a deviating, special mode if the detection means does not detect any fastening elements in the magazine or detects a number of fastening elements in the magazine that is below the specified minimum number.

Owing to the deviation of the special mode from the standard mode, a user of the drive-in device immediately identifies that the fastening elements are immediately used up or will be used up following the next drive-in process, and the magazine has to be filled. The user preferably identifies this acoustically and/or haptically.

According to an advantageous embodiment, the special mode differs from the standard mode by a temporal spacing following an event that triggers the operation of the motor. The event triggering the operation of the motor is preferably a conclusion of a drive-in process of the drive-in device, activation of the drive-in device, or raising of the drive-in device from a substrate.

According to an advantageous embodiment, the special mode differs from the standard mode by a temporal duration of the operation of the motor, by a speed of the motor, and/or by a deviating sequence of individual operating phases having a different temporal spacing and/or different duration and/or different speed of the motor.

According to an advantageous embodiment, the drive-in device comprises a contact means for querying whether the work tool is in contact with a substrate, the contact means being located in a contact position when the work tool is in contact with a substrate. The contact means preferably permits driving of the drive-in element onto the fastening element only in the contact position.

According to an advantageous embodiment, the motor is operated in order to transfer the drive means into a state ready for drive-in operations, proceeding from which state the drive-in element is driven towards the fastening element. The drive-in device preferably comprises a mechanical energy storage means, the motor being operated in order to charge the mechanical energy storage means.

According to an advantageous embodiment, the motor is operated in order to drive the drive-in element towards the fastening element.

According to an advantageous embodiment, the motor is an electric motor that is supplied with electrical energy from an electrochemical energy storage means.

According to an advantageous embodiment, the detection means detects the presence of a fastening element at a specified location in the magazine or the drive-in channel.

According to an advantageous embodiment, the transport means comprises a slide for the fastening elements in the magazine, the detection means detecting a position of the slide.

According to an advantageous embodiment, the detection means performs the query regarding whether and/or how many fastening elements are present in the magazine in a capacitive, inductive, magnetic, optical, acoustic or electromechanical manner.

DETAILED DESCRIPTION OF THE INVENTION

FIG.1is a schematic view of a drive-in device10. The drive-in device10comprises a housing20in which a drive-in element100, designed as a piston, and a drive means for the drive-in element100, are accommodated. The drive means comprises a coupling means150that is held closed by means of a retaining element designed as a detent800, a spring200comprising a front spring element210and a rear spring element220, a pulley block260comprising a force deflector designed as a belt270, a front pulley bracket281and a rear pulley bracket282, a spindle drive300comprising a spindle310and a spindle nut320, a transmission400, a motor480, and a control means500.

The drive-in device10further comprises a drive-in channel700for the fastening elements, and a contact means750. The contact means permits driving of the drive-in element100onto the fastening element only in the contact position. The drive-in device10further comprises a magazine40for fastening elements and a transport means which is intended for successively transporting fastening elements, present in the magazine40, into the drive-in channel700. Furthermore, the housing20comprises a handle30on which a manual switch35is arranged. The control means500communicates with the manual switch35and with a plurality of sensors990,992,994,996,998,1000in order to detect the operating state of the drive-in device10. The sensors990,992,994,996,998,1000each comprise a Hall probe which detects the movement of a magnet armature (not shown) that is arranged on, in particular fastened to, the element to be detected in each case.

The guide channel sensor990detects a forwards movement of the contact means750which indicates that the guide channel700has been removed from the drive-in device10. The contact sensor992detects a backwards movement of the contact means750which indicates that the drive-in device10is in contact with a substrate. The pulley bracket sensor detects a movement of the front pulley bracket281which indicates whether the spring200is pre-tensioned. The detent sensor996detects a movement of the detent800which indicates whether the coupling means150is held in the closed state thereof. The spindle sensor998detects whether the spindle nut320or a return rod, fastened to the spindle nut320, is in the rearmost position thereof. Finally, a detection means1000designed as a slide sensor detects whether a slide, arranged in the magazine40, is in the uppermost position thereof inFIG.1, in which position no fastening elements are arranged in the magazine.

After a fastening element has been driven forwards, i.e. towards the left in the drawing, into a substrate by means of the drive-in element100, the drive-in element100is located in the drive-in position thereof. The front spring element210and the rear spring element220are in the slackened state, in which they do in fact still have some residual tension. The front pulley bracket281is in the frontmost position thereof in the operating procedure, and the rear pulley bracket282is in the rearmost position thereof in the operating procedure. The spindle nut320is located at the front end of the spindle310. Owing to the spring elements210,220that may be slackened to a residual tension, the belt270is substantially unloaded.

As soon as the control means500had identified, by means of a sensor, that the drive-in element100is in the setting position thereof, the control means500triggers a return process in which the drive-in element100is conveyed into the starting position thereof. For this purpose, the motor480rotates the spindle310in a first rotation direction, by means of the transmission400, such that the rotation-resistant spindle nut320is moved backwards.

In this case, the return rods engage in the return studs of the drive-in element100and thus likewise convey the drive-in element100backwards. In this case, the drive-in element100carries along the belt270, as a result of which the spring elements210,220are not tensioned, however, because the spindle nut320likewise carries along the belt270towards the rear, and in this case releases the same amount of belt length over the pulleys of the rear pulley bracket282as the piston draws in between the pulleys of the front pulley bracket281. The belt270thus remains substantially unloaded during the return process.

The drive-in element100is then located in the starting position thereof, and the coupling plug-in portion thereof is coupled with the coupling means150. The front spring element210and the rear spring element220are still in the respective slackened states thereof, the front pulley bracket281is in the frontmost position thereof, and the rear pulley bracket282is in the rearmost position thereof. The spindle nut320is located at the rear end of the spindle310. Owing to the slackened spring elements210,220, the belt270is still substantially unloaded.

If the drive-in device is now raised from the substrate, such that the contact means750is shifted forwards relative to the drive-in channel700, the control means500triggers a tensioning process in which the spring elements210,220are tensioned. For this purpose, the motor rotates the spindle310in a second rotation direction that opposes the first rotation direction, by means of the transmission400, such that the rotation-resistant spindle nut320is moved forwards. In this case, the coupling means150retains the coupling plug-in portion of the drive-in element100, such that the belt length that is drawn in between the rear pulleys by means of the spindle nut320cannot be released by the piston. The pulley brackets281,282are therefore moved towards one another and the spring elements210,220are tensioned.

The drive-in element100is then again located in the starting position thereof, and the coupling plug-in portion thereof is coupled with the coupling means150. The front spring element210and the rear spring element220are tensioned, the front pulley bracket281is in the rearmost position thereof, and the rear pulley bracket282is in the frontmost position thereof. The spindle nut320is located at the front end of the spindle310. The belt270deflects the tensioning force of the spring elements210,220at the pulleys of the pulley brackets281,282and transfers the tensioning force to the drive-in element100which is retained by the coupling means150, against the tensioning force. The drive-in device is now ready for a drive-in process. As soon as a user pulls the trigger34, the coupling means150releases the drive-in element100, which then transmits the tensioning energy of the spring elements210,220to a fastening element and drives the fastening element into the substrate.

FIG.2is a simplified view of the control assembly of the drive-in device. A central rectangle indicates the control means1024. As is indicated by arrows, the switching and/or sensor means1031to1033deliver information or signals to the control means1024. A manual or main switch1070of the drive-in device is connected to the control means1024. A double arrow indicates that the control means1024communicates with the battery1025. Further arrows and a rectangle indicate latching1071.

Further arrows and rectangles1072and1073indicate a voltage measurement and a current measurement. A further rectangle1074indicates a disconnection means. A further rectangle indicates a B6-bridge1075. In this case, this is a 6-pulse bridge circuit comprising semiconductor elements for controlling the electric drive motor1020. This is preferably actuated by means of driver components, which are in turn preferably actuated by a controller. In addition to the appropriate actuation of the bridge, a further advantage of integrated driver components of this kind is that they bring the switching elements of the B6-bridge into a defined state in the case of an undervoltage occurring.

A further rectangle1076indicates a temperature probe which communicates with the disconnection means1074and the control means1024. A further arrow indicates that the control means1024outputs information to the display1051. A further double arrow indicates that the control means1024communicates with the interface1052and with a further service interface1077.

A further rectangle1078indicates a fixing brake which is actuated by the control means1024. The fixing brake1078is used to slow movements when relaxing the energy storage means1010and/or to keep the energy storage means in the tensioned or charged state. For this purpose, the fixing brake1078can interact with a belt drive or transmission (not shown).

A further rectangle1079indicates a detection means for querying whether and/or how many fastening elements are present in the magazine. If the detection means1079detects a specified minimum number of fastening elements in the magazine, the control means1024operates the motor in accordance with a standard mode in order to transfer the drive means into the state thereof in which it is ready for drive-in operations. For example, operation of the motor is started immediately after the drive-in device has been raised from a substrate following a drive-in process. If, in contrast, the detection means1079does not detect any fastening elements in the magazine or detects a number of fastening elements therein that is below the specified minimum number, the control means1024operates the motor in accordance with a special mode that deviates from the standard mode. For example, operation of the motor is started only following a delay, after the drive-in device has been raised from a substrate following a drive-in process. Alternatively, the motor is initially operated at an increased or reduced speed, after the drive-in device has been raised from a substrate following a drive-in process.

FIG.3shows a detail of a drive-in device410according to a further embodiment. The drive-in device comprises a magazine440and a transport means comprising a slide420for transporting fastening elements430in the magazine440in a transport direction425, and a spring element450which is designed as a scroll spring and applies a force to the slide420and thus to the fastening elements430, in the direction of a drive-in channel (not shown) of the drive-in device410.

The drive-in device410furthermore comprises a detection means460, which detects a position of the slide420. The detection means460comprises an electrical switch470which is closed by an actuation element480of the slide420when the slide420has reached the uppermost position thereof inFIG.3. This is preferably the case when the last fastening element present in the magazine440is transported into the drive-in channel.

In an embodiment that is not shown, the detection means performs the query regarding whether and/or how many fastening elements are present in the magazine in a capacitive, inductive, magnetic, optical, acoustic or electromechanical manner.

The invention has been described on the basis of the example of a spring nailer. It is noted, however, that the invention can also be implemented in other manners. In particular, gas, powder, pneumatically, hydraulically or electromagnetically operated drive-in devices can be achieved, in which a drive means comprises a motor that is operated by combustion power, pneumatically, hydraulically or electrically and which is operated within the meaning of the invention, for example in order to return a drive-in element into a starting position following a drive-in process or to drive a fan. The invention can likewise be implemented in a screwdriver, in particular a cordless screwdriver.