EP0303651B2 - Process for interrupting the operation of a hand tool, in particular percussion and/or rotation thereof - Google Patents

Abstract

In a process for switching off a drill hammer and/or a chisel hammer during idling, a clutch (28) arranged at least in the percussion drive line is automatically released when the idling position is reached. The point at which the tool (24) reaches a position on the idling section is detected and the clutch (28) is automatically released when this position is reached and re-engaged when the tool leaves this position. To this end, an idling sensor (30) releases and re-engages the clutch (28) electromechanically through a control device. Hence, no additional manipulations or clutching-in efforts are required of the operator holding the drill hammer in order to start or stop the tool, which results in short idling periods.

Description

State of the art

The invention is based on a method for interrupting the drive activity a handheld machine tool according to the generic The preamble of claims 1 or 3. EP 150 669 A2 already states such a handheld machine tool with one accommodated in its interior Container known in which an electrically conductive, liquid mass is located. This mass is penetrated by a magnetic field, which, when the machine rotates, can be tapped off at electrodes electrical voltage induced. Measurement of inertial forces is only possible with a relatively large expenditure on equipment, moreover If the machine is intended to move, it can also trigger incorrectly the safety clutch.

It is also known from DE 24 49 191 C2, in the drive train of the Percussion mechanism a friction clutch in the form of a cone clutch to arrange, which is normally disengaged and the striking mechanism separates from the drive train. The operator presses the hand machine tool However, to the rock, it is about the tool the tool holder is moved backwards into the hand machine tool. This displacement movement is based on a displacement of the rotary drive Serving rotating sleeve for axial displacement of the driven Shaft used, whereby the non-rotatable taper coupling half axially is pressed against another cone coupling half of the striking mechanism and so now with the clutch engaged via the driven shaft the striking mechanism is driven. The clutch is thus dependent automatically engaged by a force that the operator has to be applied by firmly pressing the hand machine tool. This makes handling difficult. In addition, there are relatively large idle paths on the machine side to provide what is not only impractical for handling is, but also the axial length increased.

It is also known (DE-PS 28 20 128) as a clutch in the drive train to arrange a safety clutch that when reached of a certain transmitted torque and then separates the rotary drive. Such safety clutches are e.g. as slip clutches, friction clutches or releasable Couplings trained. Such safety clutches address depending on the force. This works well if the User of the handheld machine tool suddenly on the Blocking case occurring moment is captured and the hand machine tool in anticipation of this work disruption with the corresponding counter moment. Often, however these requirements are not met, so that e.g. twisted or even injured wrists and arms of the user hand-held machine tools of this type, in particular rotary hammers, occur again and again. As a preventive measure against it is also known the response torque of such to lower the safety couplings described, with the consequence that one can work with larger drill diameters or long drilling does not do the job Moment reached and the safety clutch continuously appeals. In a disadvantageous way, the Performance of the handheld machine tool is not full be exploited. Adjustable safety clutches too do not bring a satisfactory solution. You can work in the upper torque range, but must in Blocking case with a correspondingly larger torque surge count.

It is also known (DE-OS 35 11 437) from the above Foundations within the handheld machine tool force measuring elements to arrange that when reaching a predetermined transmitted torque react and a signal produce. This is said to be in an unresolved way of generation of control functions and serve for example to switch off the energy supply, to actuate one Clutch or brake and the like used will. Such as force measuring elements made of piezoceramic. This one too known method one is arrested in the idea that as overload sizes for automatic Disengagement e.g. a clutch like the described safety couplings force-dependent Sizes are used. This will the disadvantages described at the outset, however, are not eliminated.

In DE-A-31 28 410, in addition to the use of a Strain gauge to obtain the force signal also Possibility of using an accelerometer (Accelerometer) that records movement impulses. This protective device is intended to achieve that without an unnecessary activation for only short-term or temporary faults are nevertheless reliable in the event of danger a trigger signal is given. This will do so achieved that when irregularities occur Operation of the machine tool the trigger signal to disengage the clutch can be delivered, but not in everyone Case is passed on to the clutch. Rather is provided that such a signal when reaching a predefined measurand first over a period of time to a Integrator is created and only when the the time period set there is released. In the meantime, the measurement signal falls below the predetermined value, so the integration is immediate canceled. This has the disadvantage of being triggered the clutch detects a spin that is recognized as dangerous the machine must stop for the set period of time, which usually means that the operator Let go of the machine reflexively or tries to hold on. Both can cause injury to the operator or damage of the machine.

Advantages of the invention

The inventive method with the characteristic In contrast, features of claim 1 have the following Advantages. As the size of reaching one on the idle line located path position of the tool or a translationally moving part of the striking mechanism is detected and the clutch when this path position is reached automatically disengaged and when leaving The path position is automatically indented an automatic idle shutdown or automatic Reactivation without the user of the hand machine tool any additional operators or in particular has to apply engagement forces. Much more is the disengagement of the clutch from the displacement alone the tool forward to the idle position dependent, as well as the engagement of the clutch depends only on the fact that the tool of this Idle position to the rear in the blow mode corresponding position is shifted. The user can therefore work in a relaxed and relaxed manner without he for maintaining the percussion drive each has to constantly apply special pressure forces. The handling of the hand machine tool is thereby much simplified. It is more convenient to use achieved. Another advantage is that any other idling devices or catching devices are unnecessary and by the inventive method almost any short idling distances are possible.

The idle travel can thus be significantly reduced, resulting in a quicker response and more direct operation of the hand tools machine leads. Depending on the construction of the hand machine tool thereby also a reduction in the axial length in the axial direction of the Tool holder possible. Furthermore, the conditions are created for to simplify the coupling if necessary, since you do not necessarily have to a cone coupling with axially pressable cone halves is.

In addition, with the method according to the invention with the characteristic Features of claims 3, 4 or 5, the following advantages can be achieved. Because as a size - here as an overload size - a movement size the hand-held hand-held power tool is detected in the room, the z. B. from a path and / or a speed and / or one Acceleration can exist, and since the clutch is exceeded a predetermined value of such a movement quantity automatically disengaged is always the same security for the user the hand machine tool, regardless of the driving torque of the Hand tool that the user applies with the holding torque. The user does not have to wait in anticipation of blocking to have a far too large holding torque as a preventive measure for most of the time. Rather, he can work relaxed and relaxed, without fear to be surprised by a sudden stall be and z. B. in a hammer drill during drilling operation by Throwing the rotary hammer around when blocking the drill, e.g. B. The drill bit gets caught in stone, concrete or the like to be injured.

The invention is based on the basic knowledge that the Blocking of a rotating tool starting swiveling movement of the Hand tool, especially a rotary hammer, even as Signal for the interruption of the drive activity, in particular rotary drive activity, and not a force-dependent one Size, e.g. B. a torque in the power flow of the rotary drive. As soon as. B. a specific one for which the hand-held machine tool is held Hand still permissible swivel movement, e.g. B. in the order of 10 ° in a maximum time, is exceeded, the clutch disengaged and the drive activity interrupted. It is irrelevant how firmly the user holds the hand machine tool and how stable he stands. The method according to the invention becomes independent of which reliably ensured that impermissible Swiveling movements of the hand tool and the one holding it Hand can be prevented with all the resulting known ones Impairment and damage.

Of course, those achieved with the means of claims 3, 4 or 5 Advantages also achieved together with the means of claim 1 will.

Due to the features contained in the further claims advantageous developments and improvements of the main claim specified procedure possible.

The invention also relates to a handheld power tool the features in the preamble of claim 11. According to the invention such a hand machine tool by the features in the labeling part of claim 11 characterized. Advantageous further training and Improvements in such a handheld power tool result from the features in claims 12-29. The handheld power tool thus designed is relatively simple in construction and inexpensive. Since she has the advantages explained at the beginning, this justifies the overall only little additional effort, also with regard to the reliable achieved Safety and easier handling for the user.

drawing

Fig. 1
einen schematischen, teilweisen axialen Längsschnitt einer Handwerkzeugmaschine, bei dem vereinfacht nur einige wichtige Teile des Antriebsstranges gezeigt sind,

Fig. 2
ein vereinfachtes schematisches Funktionsbild,

Fig. 3
eine schematische Darstellung des Translationsweges eines mittels der Handwerkzeugmaschine gemäß Fig. 1 angetriebenen Werkzeuges,

Fig. 4
ein vereinfachtes schematisches Funktionsbild.

Fig. 5
einen schematischen, teilweisen axialen Längsschnitt einer Handwerkzeugmaschine, bei dem vereinfacht nur einige wichtige Teile des Antriebsstranges gezeigt sind,

Fig. 6 und 7
jeweils vereinfachte schematische Funktionsbilder verschiedener Betriebsweisen der Handwerkzeugmaschine in Fig. 1,

Fig. 8
eine schematische Seitenansicht einer Schaltkupplung im ausgerückten Zustand,

Fig. 9 und 10
eine schematische Seitenansicht bzw. Vorderansicht der Schaltkupplung im eingerückten Zustand,

Fig. 11 und 12
zwei weitere Ausführungsbeispiele einer Handwerkzeugmaschine gem. Fig. 1.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings.
Show it:

Fig. 1
2 shows a schematic, partial axial longitudinal section of a hand power tool, in which only a few important parts of the drive train are shown in simplified form,

Fig. 2
a simplified schematic functional diagram,

Fig. 3
2 shows a schematic illustration of the translation path of a tool driven by means of the hand-held power tool according to FIG. 1,

Fig. 4
a simplified schematic functional diagram.

Fig. 5
2 shows a schematic, partial axial longitudinal section of a hand power tool, in which only a few important parts of the drive train are shown in simplified form,

6 and 7
simplified schematic functional diagrams of various modes of operation of the handheld power tool in FIG. 1,

Fig. 8
1 shows a schematic side view of a clutch in the disengaged state,

9 and 10
1 shows a schematic side view or front view of the clutch in the engaged state,

11 and 12
two further embodiments of a hand tool according to. Fig. 1.

Description of the invention

In Fig. 1, a hand tool is shown schematically, which consists of a hammer drill or the instead of a pure hammer for chisel operation can exist. Such hammers are basic known (DE-AS 12 06 817). The hammer drill shown has a housing 10 in which an electrical Drive motor 11, which is designed as a universal motor, a gear 12 and a striking mechanism 13 are also arranged are. In this respect, the hammer drill is e.g. corresponding DE-OS 28 20 128 designed to expressly here Reference is made so that special details of the Gear 12 and the striking mechanism 13 are not in detail must be explained.

The drive motor 11 carries on the motor shaft 14 Motor pinion 15, which is in engagement with a gear 16 stands, which is rotatably held on a shaft 17. On the shaft 17 is rotatably seated a drum 18 as part a striking mechanism 13, the driving pin fixed to it 19 with play in a transverse bore of a pivot pin 20 intervenes, which in turn in a fork-shaped End of a drive piston 21 is supported. The drive piston 21 is designed and acted upon as a hollow piston an air cushion to move one inside mounted racket 22. The drum 18 axially back and forth driven drive piston 21 of the Percussion mechanism 13 drives the racket via the air cushion 22, who uses his impact energy e.g. about one not further shown strikers or directly on one in one Tool holder 23 delivers inserted tool 24. The Tool 24 is e.g. from a drill. Also different All types of tools can be accommodated in the tool holder 23 will.

The tool 24 is only indicated schematically Rotating sleeve 25 of the gear 12 can be driven in rotation. For this purpose, the rotary sleeve 25 carries a non-rotatable one Gear 26 meshing with a pinion 27 stands that is rotationally fixed or via a special safety coupling is coupled to the shaft 17. Such Safety clutch in one embodiment is e.g. in the DE-OS 28 20 128 described, to which reference is made here can be.

There is one in the drive train from the engine 11 to the tool 24 special clutch 28 arranged here only is shown schematically. This clutch is in the rotary drive drivetrain before the branch of the striking mechanism 13 arranged. It is namely the one shown Embodiment between the driven by the motor pinion 15 Gear part in the form of the gear 16 and Shaft 17 on the one hand and the one driving the striking mechanism 13 Gear train, on the other hand, to which the shaft 17 e.g. non-rotatable drum 18 and those driven by it Parts of the striking mechanism 13 belong, which are explained at the beginning are.

In another embodiment, not shown the clutch 28 is instead behind the shown branch where it is in the pure percussion drive branch is arranged, e.g. between the shaft 17 on the one hand and the drum 18 on the other hand, so that when disengaged Coupling 28 of the drive of the drum 18 interrupted is and thus the striking mechanism 13 stands still, even if the one with the shaft still driven and rotating 17 rotary drive driven above it not interrupted is, but is still effective.

The clutch 28 is a function of a size automatically disengaged with an interruption of the drive activity at least the striking mechanism 13. In this case becomes the one on the left of the coupling 28 in FIG. 1 Gearbox complex not driven, so in this Case in addition to the striking mechanism 13, which stands still, then also the rotating sleeve 25 and the tool 24 Drive also stops. Is the clutch 28 instead, between shaft 17 and drum 18 arranged, is only when clutch 28 disengaged Schlagwerk 13 silent. The clutch 28 is here as a clutch educated. It consists in particular of one non-positive clutch, e.g. from a friction clutch. The clutch 28 is a servo clutch trained by means of the existing, from the drive motor 11 diverted energy, e.g. by means of electrical or electromechanical energy, is controllable.

In another embodiment, the clutch 28 may also be designed as a positive coupling, e.g. as a claw coupling. Then the clutch 28 should the branch of the striking mechanism 13 and be arranged 1 shows, so that additionally when the clutch is disengaged the rotary drive to the striking mechanism 13 is also stopped is. It is also recommended that you then disengage the clutch 28 also turn off the drive motor 11 and stop, so that later when you re-engage the clutch 28 engages again at a standstill can be done.

As shown in the drawings in connection with the Coupling 28 is only indicated, this has at least one preloaded in the engaged state and locked release spring 29 on the release actuation the clutch 28 this automatically under relaxation disengages. When clutch 28 is engaged the release spring 29 can be tensioned and locked again be. Thus, the force to separate the two halves the clutch 28 supplied by the release spring 29.

The handheld power tool also contains one only schematically indicated sensor 30, which is inside the housing 10 is fixed. The sensor 30 is in particular as electrical sensor trained. But it can also take place its as a mechanical or electromechanical sensor be designed. The sensor 30 stands with the clutch 28 in operative connection and acts on the clutch 28 as soon as he responds. In the embodiment shown the sensor 30 is designed as an idle sensor, the size of reaching one on the idle line (Fig. 3) located position of the tool 24 or a translationally moving part of the striking mechanism 13 detected and then the clutch 28 for automatic Disengagement applied. Furthermore, the idle sensor is in able to leave this path position in the direction To record the stroke position automatically and then the clutch 28 for automatic re-engagement to act upon. In the embodiment shown, at which the clutch 28 before the branch of the striking mechanism 13 sits in the drivetrain, when disengaging the Clutch 28 not only the hammer mechanism 13 stopped, so that the tool 24 is in the front area, namely idle area, stops its translation path, but at the same time the rotary drive is switched off, so that the tool 24 is not about the rotary drive axis 31 rotates.

In the embodiment shown, the sensor 30 is e.g. designed as an electrical limit switch. Furthermore, in the handheld power tool also has a control device 34, e.g. a switching logic, with which the sensor 30 is connected, the sensor 30 when activated the control device 34 can activate. The sensor 30 can e.g. designed as an electromagnetic sensor be the control device when said path position is reached 34 activated. The control device 34 stands in turn with the clutch 28 to disengage it and re-engagement in operative connection (Fig. 2, 4). If the sensor 30 responds, the control device is activated 34 activated, which in turn the clutch 28 electrical or electromechanical, e.g. electromagnetic, disengages. Once the tool 24 or a translational reciprocating part of the striking mechanism 13, which is monitored by the sensor 30 from the idle position 3 to the right on the translation path into the area a stroke position is shifted, this will detected by sensor 30 and control device 34 above it also activated, which is now the clutch 28 in Controlled in the sense of an engagement.

With the handheld machine tool designed in this way, it is possible that reaching the sensor 30 as a variable a path position on the idle line of the tool 24 or a part moved in translation the striking mechanism 13 is detected and when reached this position the clutch 28 disengaged automatically and when leaving this path position the Clutch 28 is automatically engaged again. This is illustrated with the aid of FIG. 3 Impact operation of the tool's translation path 24 - or e.g. of the reciprocating drive piston 21 - corresponds to a distance considerably Length, which is only about 22 mm for example can. When the striking mechanism 13 is switched on, this is Tool 24 in impact operation in one on this route in FIG right shift position. Because of the acting The tool 24 carries out an oscillating movement from that over a distance of 1/3 of the total Translation path is performed. The sensor 30 is e.g. B. not placed in this area, but, in Fig.3 seen from right to left, at least in the second or better still in the third third and thus in one area the tool 24 or a reciprocatingly driven one Part of the striking mechanism 13 only in the idle position reached. The sensor 30 is on this idle distance e.g. placed so that it from the idle position going tool 24 is passed and in the idle position the end of the tool 24 left and there is at a distance from the sensor 30 so that the sensor 30 this as a criterion for idle operation and loading the clutch 28 is detected for disengagement. Then the sensor 30 could e.g. in the middle third of Translation path of the tool 24 or even further be placed to the right of it. It depends on the training of the sensor 30 from where it is ultimately arranged. Does the sensor 30 respond when the tool e.g. in Overlap is so that the sensor 30 is reliable placed at a suitable point on the idle path, e.g. in the last third, as in Fig. 3 with solid Lines is shown. Does the sensor 30 respond if it was overrun by tool 24 and no overlap in the idle position, the sensor 30 e.g. in the middle position, as dashed in Fig. 3 is indicated to be arranged.

In everything, the core idea is that in the field operation the idle position of the tool 24 or one back and forth part of the striking mechanism 13 from Sensor 30 is detected and then the clutch 28th is controlled so that it disengages. Once the tool 24 or said part of the striking mechanism 13 of this idle position by moving in Fig. 1, 3 after is shifted to the right in the striking position, this will also detected by sensor 30 and clutch 28 pressured to re-engage. It doesn't come with everything on any to be applied by the user of the hand machine tool Force to indent for the field operation the clutch and automatically when idling To disengage the clutch. Rather, it is one reliable and high quality idle shutdown created, no additional operators for the user or engaging forces. Special idling facilities or catching devices or the like are in such Handheld machine tools are therefore unnecessary. Advantageous is also possible that almost any short idling distances are that can be used.

In Fig. 2 and in particular 4 is indicated how the sensor 30 indirectly applied to the clutch 28. If the sensor 30 responds when the idle position is reached, the sensor 30 thus activates the control device 34, in particular Switching logic, which in turn is a control pulse in terms of disengaging the clutch on an electromechanical, e.g. electrical, actuator, in particular Release actuator 35, which then leads to the Clutch 28 engages to disengage them. After this the tool 24 from the idle position to the striking position postponed, so there will be an indentation the clutch 28 also from the sensor 30 via the control device 34 causes, which in turn one Control pulse e.g. to an actuator in the form of a Engagement actuator 36 leads to the clutch 28th attacks to engage them. Just like the release actuator 35 can also the engagement actuator 36 of the Controller 34 e.g. electromechanical, in particular electromagnetic, operated.

In the following description of FIGS. 5 to 10, the same parts have the same reference numbers as in the previous one Description.

5 a hand-held power tool is shown schematically, which consists of a hammer drill here. The hammer drill has a housing 10 in which an electrical Drive motor 11, which is designed as a universal motor, a gear 12 and a striking mechanism 13 are also arranged are. In this respect, the hammer drill is e.g. corresponding DE-OS 28 20 128 designed to expressly here Reference is made so that special details of the transmission 12 and the striking mechanism 13 are not explained have to.

The drive motor 11 carries on the motor shaft 14 Motor pinion 15, which is in engagement with a gear 16 stands, which is rotatably held on a shaft 17. A drum 18 sits on the shaft 17 in a rotationally fixed manner as part of the striking mechanism 13, the driver pin attached to it 19 with play in a transverse bore of a pivot pin 20 intervenes, which in turn in a fork-shaped End of a drive piston 21 is supported. The drive piston 21 is designed and acted upon as a hollow piston an air cushion to move one inside mounted racket 22. The drum 18 axially reciprocating driven piston 21 of the Percussion mechanism 13 drives the racket via the air cushion 22, who hits his energy directly into one Tool holder 23 delivers inserted tool 24. The tool 24 is e.g. from a drill. Also different All types of tools can be accommodated in the tool holder 23 become.

The tool 24 is only indicated schematically Rotating sleeve 25 of the gear 12 can be driven in rotation. For this purpose, the rotary sleeve 25 carries a non-rotatable one Gear 26, which is in engagement with a pinion 27, that is fixed against rotation or via a special safety coupling is coupled to the shaft 17. Such a safety clutch is also described in DE-OS 28 20 128 referred to.

In the drive train from the drive motor 11 to the tool 14 a special clutch 28 is arranged, which here only is shown schematically. This clutch 28 is in Rotary drive drive train in front of the branch of the striking mechanism 13 arranged. It is between the gear part driven by the motor pinion 15 in Shape of the gear 16 and the shaft 17 on the one hand and the gear train driving the striking mechanism 13, on the other hand, in the form of the drum 18 which is rotatably fixed to the shaft 17 and the driven parts of the striking mechanism 13, as explained at the beginning.

In another embodiment, not shown the clutch 28 behind the shown Branch in the pure rotary drive branch, e.g. on the Shaft 17 or between the pinion 27 and its drive from the shaft 17.

The clutch 28 is dependent on an overload size automatically disengaged with an interruption of the drive activity. In this case, the one in Fig. 5 becomes left not the clutch 28 adjoining gear complex driven, so that in this case both the striking mechanism 13 stands still as well as the rotating sleeve 25 and that Tool 24 rotating drive. The clutch 28 is here designed as a clutch. This can e.g. as positive coupling designed, in this case e.g. as a claw coupling. Then it is advisable to This clutch 28 also disengages the drive motor 11 turn off and shut down, so later when you re-engage the clutch 28 in the manner described Can be re-engaged at a standstill. Instead can, as shown, the clutch 28 as a frictional Clutch may be formed, e.g. as a friction clutch. The clutch 28 is designed as a servo clutch, by means of the existing drive motor 11 diverted energy, e.g. by means of electrical or electro-mechanical energy, is controllable.

As shown in Figs. 5-10 in connection with that shown Coupling 28 is indicated, this has at least one preloaded and locked in the engaged state Release spring 29 on when the clutch is actuated 28 this automatically releases with relaxation.

When the clutch 28 is actuated, the release spring is 29 can be tightened and locked again. Thus the force to separate the two halves of the clutch 28 delivered by the release spring 29.

The handheld power tool also has one only schematically indicated sensor 130, which is firmly connected to the housing 10, expediently is located inside the housing 10. Of the Sensor 130 is an electrical or mechanical or electromechanical sensor trained. The sensor 130 is in operative connection with the clutch 28 (Fig. 6-10) and acts on the clutch 28 Exceeding a movement size of the hand-held Hand tool. In the embodiment shown is the sensor 130 formed as a twist sensor, which as Movement size the way and / or the speed and / or the acceleration of an external pivotal movement of the hand-held hand tool in the room around a rotary drive axis 31 of the driven tool 24 is detected.

The hand tool also has one from the machine exterior accessible, in particular manually operated, Engagement adjuster 32, which e.g. from an operating button consists. The clutch 28 is disengaged has been activated by means of the engagement adjuster 32 directly or indirectly and mechanically, electrically or be re-engaged electromagnetically.

In the embodiment shown in Figs. 8-10 the sensor 130 is designed as a mechanical inertia switch and mechanically with an indicated lever 33 the clutch 28 coupled to disengage them. Of the at the end the lever 30 carrying the sensor 30 is about one schematically indicated pivot axis 38, which is approximately parallel runs to the central axis of the clutch 28 in the housing 10 freely pivoted, with an approximately U-shaped Claw dimensioned and designed at the end of the lever 33 is that the clutch 28 in the engaged state 9 and 10 in this engaged state can. The claw is e.g. approximately radially from the outside both compressed coupling halves brought up, which are attacked together by the claw so that the release spring 29 remains in the compressed state and the clutch 28 can not disengage. In Fig. 10, the direction of rotation of the drive is schematically indicated by arrow 41 symbolizes the tool 24. If the tool 24 e.g. blocked in the rock, the hand machine tool hurled around in the direction of arrow 40. The sensor 30 responds, which in this exemplary embodiment then as a mechanical inertia switch together with the lever 33 and the one engaging on the clutch 28 Claw about the pivot axis 38 in the direction of the arrow 39 and is pivoted so that the claw at the end of the lever 33 releases both coupling halves of the clutch 28, so that the compressed release spring 29 the Clutch 28 automatically in the disengaged position 8 can transfer.

8 shows an engagement actuator 32 schematically, the mechanically via a separate lever 37 with the clutch 28 is coupled to their engagement. Should the Clutch 28, starting from the disengaged position 8 are indented again, so the The engaging button 32 is pressed mechanically via the lever 37 the left half in FIG. 8 by compressing the Release spring 29 pushes against the right coupling half, until the indented position according to FIG. 9 is reached, in which the claw then automatically at the end of the lever 33 over both compressed coupling halves of the clutch 28 takes hold.

In the embodiment shown in FIGS. 6 and 7 is an additional control device in the handheld power tool 34, e.g. a switching logic, with which both the sensor 130 and the engagement actuator 32 in Connection is established, each of these the control device can activate when it becomes effective. In this If the sensor 130 is designed as an electromechanical sensor, the control device 34 in the event of an overload activated. The control device 34 in turn stands with the clutch 28 to disengage and re-engage in operative connection (Fig. 6, 7). Speaks the sensor 130 on, the control device 34 is activated above it, which in turn the clutch 28 electrically or electromechanically, e.g. electromagnetic, disengages. Then from outside the engagement actuator 32 is actuated and lies there is no overload, the operation of the The engagement device 32 also the control device 34 activated, which is now the clutch 28 in the sense of a Activates again.

It is with the hand tool designed in this way possible that a via the sensor 130 as an overload variable Movement size of the hand-held hand tool in the Space is detected and when a predetermined is exceeded Value of this movement variable, the clutch 28 disengaged automatically becomes. The sensor 130 can be designed so that it as a movement quantity recorded a path that the hand machine tool goes through. The path comes e.g. the swivel angle a pivoting movement of the hand tool around Rotary drive axis 31 into consideration, the rotation sensor 30 then e.g. when exceeding a permissible swivel movement from e.g. 10 ° swivel angle and described in Disengaging the clutch 28 causes. Instead or in addition, you can use the Sensor 130 as the movement variable also the speed and / or detect acceleration with which the handheld power tool moved in space. The main idea here is the one that starts when the driven tool 24 is blocked Rotation of the housing 10 of the hand machine tool - so he is given an angular momentum - itself as a signal to use the rotary actuator if this movement size is exceeded by disengagement to turn off the clutch 28. Then the rotary drive interrupted so that the rotary actuation of the tool 24th ceases while the clutch 28 in FIG located drive part, in particular drive motor 11 with gear 15, 16, can continue to rotate freely. Only in Case of the formation of the clutch 28 as a positive Clutch is recommended when disengaging at the same time the clutch 28 also the drive motor 11 from Disconnect and switch off the mains. With everything, it is irrelevant how firm the user holds the hand machine tool holds and how stable it stands. Regardless of that, the explained overload device for that impermissible Twists of the hand machine tool and thus the hand of the user holding this with the risk associated with it Injuries can be prevented. The means of Safety guaranteed by overload device is reliable always on, regardless of the working moment of the Hand tool that the user with the holding torque applies. The user therefore does not need to wait of a possible blocking for the to have a far too large holding torque as a preventive measure most of the time. Rather, he can be relaxed and relaxed with work much less effort and yourself thereby better on the actual machining process focus. Thus, with the help of the overload device Protection with simple, inexpensive means of the person working with the hand machine tool against injuries caused by hurling the handheld power tool when blocking the rotating tool 24 created, especially protection against hurling around the hand machine tool e.g. then if that Tool 24 in the workpiece, e.g. in stone, concrete or the like, should get caught. So it becomes the way as a movement quantity and / or the speed and / or the acceleration an outer pivoting movement of the hand machine tool detected about the rotary drive axis 31. Exceed this Movement size a predetermined value, this is from Sensor 30 is detected, which then immediately (Fig. 8-10 or indirectly (Fig. 6, 7) the clutch 28 disengages. In the The clutch is disengaged immediately 28 mechanically via the lever 33. In the indirect Actuation activates the sensor 130 when the predetermined value of the movement size the control device 34, in particular switching logic, which in turn then a control pulse in the sense of disengaging the clutch to an electromechanical, e.g. electric actuator in particular disengaging actuator 35, which then engages the clutch 28 to disengage it. According to this, the specified value of the movement quantity is the has caused the clutch 28 to disengage clutch 28 is engaged again e.g. by manually pressing in the engagement adjuster 32 initiated, which then directly or indirectly and mechanically, electrically or electromechanically causes clutch 28 to re-engage. In which Embodiment according to Fig.8-10 takes place by means of Indentor 32 an immediate and mechanical Re-engagement of the clutch 28. In the embodiment 6 and 7, however, is e.g. manual Depressing the actuator 32 the control device 34, in particular switching logic, activated, which in turn a control pulse e.g. on an actuator in Form of an engagement actuator 36, which leads to the Clutch 28 engages to engage them. The engagement actuator 36 is controlled by the control device 34 e.g. electromechanical, in particular electromagnetic, operated.

It is clear that the two in Figures 1 to 4 and 5 or 10 illustrated and described embodiments of the fundamental idea of stopping the driving activity of the Hand tool when electrically exceeded to cause measured sizes, also very advantageous on one single machine can be used. Here then results another synergy effect, since the measured electrical signals processing electronics naturally builds smaller than the sum of those of the two embodiments.

FIGS. 11 and 12 show two further exemplary embodiments of the Invention shown. A drill hammer is shown in FIG which the clutch 28 is arranged behind the striking mechanism. In addition, is located in the drive train between clutch 28 and Tool 24 a holding device 50, via which the named Drive train is connectable to the housing 10 of the hammer drill. The holding device 50 is known as being electrical releasable brake executed.

If the clutch 28 is released in the manner described above, then only the drive train for rotating the tool is interrupted.

The brake 50 is actuated at the same time but ultimately the casing of the rotary hammer the tool 24 firmly connected. This can the angular momentum, for example when blocking of the drilling tool 24 in the workpiece in the housing 10 has been issued and which to trigger the Coupling 28 has to be caught. Injuries of the operator by the described This reliably prevents angular momentum.

In the embodiment described in Figure 12 the invention is the clutch 28 and the holding device (brake 50) already in the drive train between engine 11 and Percussion. In this embodiment in addition to the rotary drive, the striking mechanism stopped when the clutch 28 is triggered becomes.

Claims (29)

1. Method for interrupting the percussion-drive activity of a hand-operated machine tool in the drive train from its drive motor (11) to its percussion-and/or rotary-drivable tool (24), in which a coupling (28) arranged in the drive train is disengaged automatically when a predetermined quantity recorded by a sensor (30) is reached, the quantity being independent of the user's holding force and reproducing a movement quantity of one of the parts of the hand-operated machine tool moved in translational motion or of the tool (24), characterized in that a path position located on the idling path of a percussion-mechanism part or of the tool (24) is detected as a movement quantity, and the coupling (28) is re-engaged automatically when this path position is left, and in that, when this path position is reached, the sensor (30) activates a control device (34), especially a logical switching unit, which itself transmits a control pulse to an especially electromechanical , for example electromagnetic, actuating drive (35), especially disengagement actuating drive, which acts on the coupling (28) to disengage it.
2. Method according to Claim 1, characterized in that the sensor (30) activates the control device (34), especially the logical switching unit, when departing from the path position in the direction of the percussion position, and the control device (34) itself transmits a control pulse to an especially electromechanical, for example electromagnetic, actuating drive (36), especially engagement actuating drive, which acts on the coupling (28) to engage it.
3. Method for interrupting the rotary-drive activity of a hand-operated machine tool in the drive train from its drive motor (11) to its percussion-and/or rotary-drivable tool (24), in which a coupling arranged in the drive train is disengaged automatically in dependence on a quantity recorded by a sensor (130) when a predetermined value of the quantity is reached, the quantity being independent of the user's holding force and reproducing a movement quantity of the hand-operated machine tool as a whole or of one of its co-moved parts, characterized in that a path which the hand-operated machine tool covers is detected as a movement quantity and in that the drive train is simultaneously connected to a housing (10) of the hand-operated machine tool by a holding device (50) between the coupling (28) and the tool (24).
4. Method for interrupting the rotary-drive activity of a hand-operated machine tool in the drive train from its drive motor (11) to its percussion-and/or rotary-drivable tool (24), in which a coupling arranged in the drive train is disengaged automatically in dependence on a quantity recorded by a sensor (30) when a predetermined value of the quantity is reached, the quantity being independent of the user's holding force and reproducing a movement quantity of the hand-operated machine tool as a whole or of one of its co-moved parts characterized in that the speed with which the manually controlled hand-operated machine tool moves in space is detected as a movement quantity and in that the drive train is simultaneously connected to a housing (10) of the hand-operated machine tool by a holding device (50) between the coupling (28) and the tool (24).
5. Method for interrupting the rotary-drive activity of a hand-operated machine tool in the drive train from its drive motor (11) to its percussion- and/or rotary-drivable tool (24), in which a coupling arranged in the drive train is disengaged automatically in dependence on a quantity recorded by a sensor (30) when a predetermined value of the quantity is reached, the quantity being independent of the user's holding force and reproducing a movement quantity of the hand-operated machine tool as a whole or of one of its co-moved parts, characterized in that the acceleration with which the hand-operated machine tool moves in space is detected as a movement quantity and in that the drive train is simultaneously connected to a housing (10) of the hand-operated machine tool by a holding device (50) between the coupling (28) and the tool (24).
6. Method according to one of the preceding claims, characterized in that the sensor (30) disengages the coupling (28) directly and mechanically when the predetermined value of the movement quantity is exceeded.
7. Method according to one of the preceding Claims 3 to 5, characterized in that, when the predetermined value of the movement quantity is exceeded, the sensor (30) activates a control device (34), especially a logical switching unit, which itself transmits a control pulse to an especially electromechanical, for example electromagnetic, actuating drive (35), especially disengagement actuating drive, which acts on the coupling (28) to disengage it.
8. Method according to one of the preceding claims characterized in that, after the disengagement of the coupling (28) and after the value of the movement quantity has fallen below the predetermined value, the coupling (28) can, if required, be engaged directly or indirectly and mechanically, electrically or electromagnetically, especially by the manual actuation of an engagement actuator (32).
9. Method according to Claim 8, characterized in that the engagement actuator (32) engages the coupling (28) directly and mechanically.
10. Method according to Claim 9, characterized in that the engagement actuator (32), when actuated, activates the control device (34), especially logical switching unit, which itself transmits a control pulse to an especially electromechanical, for example electromagnetic, actuating drive (36), especially engagement actuating drive, which acts on the coupling (28) to engage it.
11. Hand-operated machine tool, especially hammer drill, in the drive train from the drive motor (11) to the driven tool (24) of which is arranged a coupling which can be disengaged automatically in dependence on a measured quantity in order to interrupt the percussion-drive activity, especially for carrying out the method according to Claim 1, characterized in that the coupling is designed as a positive or non-positive coupling (28), and in that there is arranged in, preferably firmly connected to, the hand-operated machine tool an, in particular electrical, mechanical or electromechanical sensor (30) which, in the percussion mode, detects the idling position and which is connected operatively to the shift coupling (28) and loads the latter for automatic disengagement when the measured quantity is exceeded.
12. Hand-operated machine tool, especially hammer drill, in the drive train from the drive motor (11) to the driven tool (24) of which is arranged a coupling which can be disengaged automatically in dependence on a measured quantity in order to interrupt the rotary-drive activity, especially for carrying out the method according to Claims 3, 4 or 5, characterized in that the coupling is designed as a positive or non-positive coupling (28), and in that there is arranged in, preferably firmly connected to, the hand-operated machine tool an, in particular electrical, mechanical or electromechanical sensor (130) which is connected operatively to the shift coupling (28), in that the coupling is a wrap-spring coupling which can be actuated electromagnetically when the quantity is exceeded, and the sensor (30) loads the coupling (28) for automatic disengagement when the measured quantity is exceeded, it being possible, for rotation of the tool (24) and/or the percussion mechanism (13), to connect the drive train to a housing (10) of the hand-operated machine tool by means of a holding device (50).
13. Hand-operated machine tool according to Claim 11 or 12, characterized in that the sensor (30) is designed as a limit switch.
14. Hand-operated machine tool according to one of Claims 11 to 13, characterized in that the sensor (30) is designed as an electromechanical feeler which is connected operatively inside the hand-operated machine tool to a control device (34), especially logical switching unit, and which activates the latter when the path position is reached, and in that the control device (34) is connected operatively to the shift coupling (28) for the disengagement and re-engagement of the latter.
15. Hand-operated machine tool according to one of Claims 11 to 14, characterized in that the shift coupling (28) is designed as a servo shift coupling and can be actuated by means of electrical or electromechanical energy branched off from the drive motor (11) of the hand-operated machine tool.
16. Hand-operated machine tool according to one of Claims 11 to 15, characterized by an electromechanical, especially electromagnetic, actuating drive, especially disengagement actuating drive (35) and/or engagement actuating drive (36), of the shift coupling (28), which drive can be loaded by the control device (34).
17. Hand-operated machine tool according to one of Claims 11 to 16, characterized in that the shift-coupling (28) has at least one disengagement spring (29) which is pretensioned and locked in the engaged state and which, during the disengaging actuation of the shift coupling (28), disengages the latter automatically by relaxing and can be tensioned and locked again during the engaging actuation of the shift coupling (28).
18. Hand-operated machine tool according to one of Claims 11 to 17, characterized in that the shift coupling (28) is arranged in the percussion-mechanism drive train or especially in the rotary-drive train, preferably in front of its branch-off to the percussion drive, of the hammer drill.
19. Hand-operated machine tool according to Claim 18, characterized in that the shift coupling (28) is arranged in the drive train between the output-side gear (16, 17) driven by the motor pinion (15), on the one hand, and the gear train driving the percussion mechanism (13), on the other hand.
20. Hand-operated machine tool according to Claim 12, characterized in that the sensor (30) is designed as a rotation sensor which detects as a movement quantity the path and/or speed and/or acceleration of an external pivoting movement of the manually controlled hand-operated machine tool in space about a rotary-drive axis (31) of the driven tool (24).
21. Hand-operated machine tool according to Claim 20, characterized in that the sensor (30) is designed as a mechanical inertia switch.
22. Hand-operated machine tool according to Claim 21, characterized in that the mechanical inertia switch is coupled mechanically, via a lever (33), to the shift coupling (28) for the disengagement of the latter and acts thereon.
23. Hand-operated machine tool according to one of Claims 12, 14, 20, 21 or 22, characterized by an especially manually actuable engagement actuator (32) which can be reached from outside the machine and by means of which the shift coupling (28) can be re-engaged directly or indirectly and mechanically, electrically or electromechanically.
24. Hand-operated machine tool according to Claim 23, characterized in that the engagement actuator (32) is coupled mechanically, via a lever (37), to the shift coupling (28) for the engagement of the latter and acts thereon.
25. Hand-operated machine tool according to Claim 23, characterized in that the engagement actuator (32) is connected to the control device (34), especially logical switching unit, and, when actuated, activates the latter.
26. Hand-operated machine tool according to one of Claims 12, 17, 20 to 25, characterized in that the shift coupling (28) is arranged in the rotary-drive train in front of or after its branch-off to the switching drive of the hammer drill.
27. Hand-operated machine tool according to Claim 26, characterized in that the shift coupling (28) is arranged in the drive train between, on the one hand, the output-side gear (16, 17) driven by the motor pinion (15) and, on the other hand, the gear train driving the percussion mechanism (13).
28. Hand-operated machine tool according to one of the preceding claims, characterized in that the drive train between coupling (28) and tool (24) can be connected to the housing (10) of the hand-operated machine tool by means of a holding device (50), especially a brake, when the drive train to the motor (11) is interrupted by means of the coupling (28).
29. Hand-operated machine tool according to Claim 28, characterized in that the holding device (50) connects the drive train for the rotation of the tool (24) and/or to the percussion mechanism (13) to the housing of the hand-operated machine tool.

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