EP3774178A1

EP3774178A1 - Switch for machine tool and switching logic

Info

Publication number: EP3774178A1
Application number: EP19711605.6A
Authority: EP
Inventors: Thomas Blatz
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2018-04-09
Filing date: 2019-03-20
Publication date: 2021-02-17
Anticipated expiration: 2039-03-20
Also published as: WO2019197123A1; CN111902242A; JP2021517077A; EP3774178B1; US11389941B2; JP7069339B2; EP3552760A1; US20210146523A1; CN111902242B

Abstract

A first aspect of the invention relates to a method for controlling a machine tool, the machine tool comprising a control device, a drive, a tool, an actuation switch and a locking switch. The method comprises the following method steps: - activating the actuation switch by exerting a force in the direction of the actuation switch in order to switch the machine tool from a deactivation mode to an activation mode, therefore setting the drive to a first predefined rotational speed value; - deactivating the actuation switch, therefore stopping the force in the direction on the actuation switch, the drive being set at the first predefined rotational speed value for a predefined period of time; - activating the locking switch within the first predefined period of time after the actuation switch has been deactivated, therefore setting the drive to a predefined second rotational speed value; and - activating the actuation switch by exerting a force in the direction of the actuation switch or activating the locking switch by exerting a force in the direction of the locking switch in order to switch the machine tool from the activation mode to the deactivation mode. A second aspect of the invention relates to a machine tool for performing the method.

Description

Switch for grinding device and switching logic

The present invention relates to a method for controlling a machine tool, in particular a grinding device, wherein the machine tool, a control device, a drive, a driven by the drive tool, such as an abrasive, an actuating switch and a lock switch comprises.

Furthermore, the present invention relates to a machine tool, in particular in the embodiment of a grinding device, for carrying out the method according to the invention.

Machine tools usually have an actuating switch with which the machine tool or the drive of the machine tool can be activated or deactivated. Usually, the operating switch is a pressure switch without latching function, which must be pressed permanently by a user for actuation.

However, in some machine tools, especially grinding machines, it may be desirable for the operating switch to remain permanently activated to activate the machine tool, even when no more pressure is exerted on the operating switch.

However, the devices already available on the market in order to keep the operating switch of a machine tool activated even without permanent application of pressure are problematical and often inadequate, taking into account the given safety aspects in the handling.

The object of the present invention is to solve the problem described above and to provide a method for controlling a machine tool as well as a machine tool for carrying out the method.

The object is solved by the subject matter of the independent claims. Advantageous embodiments of the subject-matter of independent claim 1 can be found in the subclaims dependent thereon.

The object is achieved by a method for controlling a machine tool, in particular a grinding device, wherein the machine tool, a control device, a Drive, a driven by the drive tool, such as an abrasive, an actuation switch and a lock switch comprises.

According to the invention, the process is characterized by the following process steps:

Activating the operation switch by applying a force in one direction (N) to the operation switch to switch the machine tool from a deactivation mode to an activation mode so that the drive is set to a first predetermined speed value;

Deactivating the actuating switch so that no more force is exerted in the direction (N) on the actuating switch, the drive being set in the first predetermined rotational speed value for a predetermined period of time;

Activating the lock switch within the first predetermined period of time after deactivating the operation switch so that the drive is set to a predetermined second speed value; and

Activating the actuation switch by applying a force in one direction to the actuation switch or activating the interlock switch by exerting a force in one direction on the interlock switch to switch the machine tool from the activation mode to the deactivation mode.

The lock switch may also be referred to as a lock switch or a lock switch. The predetermined period of time may be between 0.5 and 3 seconds and in particular one second. However, it is also possible for the time duration to be lengthened or shortened by means of a cutting edge (also called MMI-man-machine interface) on the housing of the machine tool and with the aid of the control device.

According to an advantageous embodiment of the method according to the invention, it may be possible for the first rotational speed value and the second rotational speed value to be identical.

According to an advantageous embodiment of the method according to the invention, it may be possible that the first rotational speed value and the second rotational speed value are different.

The first speed value can be 2625 rpm and the second speed value can be 5250 rpm.

It is preferred for the purposes of the invention that the actuating switch and the locking switch are designed as a common switch device. For example, this one switching device can be formed by two larger pressure surfaces, the individual Actuator switch and the lock switch correspond. For example, a first pressure surface can correspond to the actuating switch, while the second pressure surface corresponds to the locking switch. Preferably, the two pressure surfaces can be connected to each other by a narrower middle web. It is particularly preferred for the purposes of the invention that the common switch device is designed as a rocker or rocker switch. The rocker can be referred to in particular as a continuous rocker, since the two pressure surfaces of the central web are connected to each other and thus a common switch device has a continuous surface. Preferably, the common, continuous surface is composed of the three partial surfaces, which are associated with the two pressure surfaces and the central web. It is preferred for the purposes of the invention that the pressure surfaces can also be referred to as buttons or as buttons. The buttons are advantageously arranged to take over the functions of the operating switch and the interlock switch.

In a preferred embodiment of the invention, the proposed control method can be described by the following steps:

Activating a first pressure surface of the switch device, wherein the switch device is designed as a continuous rocker switch and wherein the machine tool is transferred from a deactivation mode into an activation mode by exerting the force on the first pressure surface,

- deactivating the first pressure surface so that no force is exerted on the first pressure surface;

- Activating a second pressure surface of the switch device within a first predetermined period of time after disabling the first pressure surface, whereby the machine tool is brought into a working mode.

A user can now work with the machine tool and perform, for example, grinding. The use of the machine tool is possible in particular in working mode.

It is preferred in the sense of the invention that the working mode as opposed to the activation mode, the continuous operation of the machine tool. Preferably, in machine mode, the machine tool is in a "momentary on" state while the machine tool is operating in a "lock on" state in continuous operation. The user can remove his finger from the second printing surface while working with the machine tool, since the machine tool advantageously also without a permanent actuation of the second printing surface in remains in working mode. It may be preferred according to the invention that the working mode of the machine tool corresponds to the predetermined second speed value. The activation mode of the machine tool preferably corresponds to the predetermined first speed value. In the deactivation mode, the machine tool is preferably switched off and the speed value is zero. It is preferred in the sense of the invention that the machine tool can be switched off or brought into the deactivation mode by actuating the first or the second pressure surface. In particular, the machine tool can be switched from the working mode to the deactivating mode by actuating the first or the second pressure surface.

For the purposes of the invention, it is preferred that the machine tool switches off automatically or brings about a deactivation mode if the second pressure surface of the rocker switch device is not actuated within a predetermined period of time after deactivation of the first pressure surface.

In a preferred embodiment, the first pressure surface of the switch device, which preferably corresponds to the actuation switch, can be designed as an "I / O button". In addition, the second pressure surface of the switch device, which preferably corresponds to the locking switch, can be designed as a "locking switch". Preferably, the first pressure surface and the second pressure surface can be combined to form a continuous rocker. The rocker may be integrated in an elastomer mat or mechanically executed. Figures 8 and 9 show an embodiment of this preferred embodiment of the invention.

It is an advantage of this invention that in the context of this embodiment of the invention, the provision of a light source between the actuation switch and the interlock switch can be dispensed with. As a result, the construction and the electronics underlying the proposed tool handle, in particular the switching electronics, can be substantially simplified. The feedback regarding the operating state of the machine tool in this embodiment of the invention preferably takes place with the aid of a second light source, which may preferably be arranged above the second pressure surface of the common rocker switch device. In particular, the second light source is arranged between the second pressure surface and the preferably adjacent third and fourth switches. The third and fourth switches of the proposed tool handle of the machine tool are preferably set up to select a gear for the operation of the machine tool. The feedback may be, for example, that the second light source flashes at regular intervals or at a certain frequency as long as the machine tool is in a temporary activation mode. This state of the machine tool is preferably referred to as the "hold to run" function or state of the first pressure surface of the switch device. The second light source can also be permanently lit as soon as the second pressure surface of the rocker switch is pressed. In the deactivation mode, the second light source is preferably switched off.

In one embodiment of the invention, the machine tool may be in a first state when the machine tool is connected to a power source. In this first state, preferably neither the operation switch, nor the lock switch is pressed. If the handle of the machine tool has a common switch device, preferably neither the first pressure surface, nor the second pressure surface is pressed. In this first state, it is preferred for the purposes of the invention that the light source or the LED on the handle of the machine tool does not light up. In this first state, the machine tool is preferably in deactivation mode.

The machine tool can be brought into a second state by actuating the actuating switch or the first pressure surface of the rocker switch. In this second state, the engine of the machine tool begins to work, in which case it operates in particular in a "hold to run" state, which in the context of the invention is also referred to as "temporary operation". The light source or the LED can indicate in this second state of the machine tool by flashing that the machine tool is ready to be brought into a working mode. The flashing may be, for example, at a frequency of 1 Hz, without being limited thereto. For example, the duration of the "hold to run" state may be limited to a duration of, for example, 1 second. Preferably, the second state corresponds to the activation mode of the machine tool.

If, in this second state of the machine tool, the locking switch or the second pressure surface of the rocker switch are once briefly actuated, in particular within the specified period of 1 second after the actuating switch or the first pressure surface has been released, the machine tool preferably does not work only temporarily - ongoing, but permanent. This state is referred to as the third state of the machine tool, wherein the third state preferably corresponds to the working mode. The third state can be indicated by a permanent lighting of the light source or the LED on the handle of the machine tool. The third state may preferably be ends that either the operating switch or the interlock switch are pressed. In the event that the handle of the machine tool has a rocker switch, it may be preferred that either the first pressure surface or the second pressure surface can be pressed to end the third state - and thus the working mode. By the termination of the third state, in which the machine tool or the motor preferably work permanently, the deactivation state can be restored, which can be indicated by the fact that the light source or the LED no longer lights up.

In its embodiment with the rocker switch, the invention preferably makes it possible to provide an increased safety level, since the pressed second key particularly effectively prevents unintentional permanent switching on of the machine tool. In addition, the one light source or LED can advantageously be used to display faults and / or fault messages. Preferably, a flashing of the light source or LED indicates that the machine tool is in the "hold to run" mode, while a permanent lighting preferably stands for a continuous operation of the machine tool. In other words, within the meaning of the invention, it is preferred for the machine tool or its handle to comprise at least one light source for indicating a standby state of the machine tool. The standby states can be, for example, the first, second and third state of the machine tool or the activation mode, the deactivation mode and the working mode, wherein the activation mode preferably corresponds to the "hold to run" mode of the machine tool. A particular advantage of the invention is that the machine tool can be operated with the same switching logic, regardless of whether the machine tool has an actuating and a locking switch or a common switch device.

In addition, the object underlying the present invention is achieved by a machine tool for carrying out the method, wherein the machine tool comprises a control device, a drive, a drive-driven tool, for example an abrasive, an actuation switch and a lock switch , It is preferred in a very particularly preferred embodiment of the invention that the machine tool of the operating switch and the locking switch form a common switch device, which is preferably designed as a rocker switch. For this purpose, the actuation switch and the interlock switch can each be formed by a pressure surface, which are connected to one another via a central web. Further advantages will become apparent from the following description of the figures. In the figures, various embodiments of the present invention are shown. The figures, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

In the figures, identical and similar components are numbered with the same reference numerals. Show it:

1 shows a perspective view of a handle of a machine tool according to the invention with an actuating switch and a locking switch;

Figure 2 is a rear view of the handle of the machine tool according to the invention with the operation switch and the lock switch.

3 shows a sectional view along the section line A - A according to FIG. 2;

4 is a first diagram to illustrate a first aspect of the invention

process;

Fig. 5 is a second diagram illustrating a second aspect of the invention

process;

Fig. 6 is a third graph showing a third aspect of the invention

process; and

Fig. 7 is a fourth diagram illustrating a fourth aspect of the invention

Process.

Fig. 8 representation of a preferred embodiment of the machine tool, in particular the Flandgriffes the machine tool

Fig. 9 representation of a preferred embodiment of the machine tool, in particular the Flandgriffes the machine tool EXEMPLARY EMBODIMENTS:

Figures 1 and 2 show a portion of a machine tool 1 in the embodiment of a grinder. However, it is also possible that the machine tool 1 is designed as a drill, saw or the like.

The machine tool 1 essentially comprises a housing 2, a drive, a gear, a drive shaft, a tool holder, a power source and a control device.

The drive can be configured for example in the form of a brushless electric motor. In the housing 2, the drive is positioned so that a torque generated by the drive via the drive shaft and the tool holder is transferred to the tool. The control device controls or regulates all functions of the machine tool 1 and in particular the functions of the drive. The energy source serves to supply the electrical consumers of the machine tool 1 with an electrical energy. An electrical consumer is in particular the drive. In this case, the energy source can be configured in the form of a rechargeable battery (also called rechargeable battery). The designed as an accumulator power source is connected to the housing 2 of the machine tool 1. Alternatively, the power source may also be realized as a power cable for releasably connecting the machine tool 1 to a mains power connector (i.e., power outlet).

In particular, the control device controls and regulates the supply of electrical energy to the drive, i. with electric current, whereby specifically the speed of the drive designed as an electric motor is controlled or regulated.

The drive, the transmission, the drive shaft, the tool holder, the power source, the control device and the tool are not shown in the figures.

The partial area shown in FIGS. 1 and 2 is a rear part of the housing 2 of the machine tool 1 and, in particular, one of the handles of the machine tool 1 designed as a grinding device. The handle is used to hold and guide the machine tool 1. It is usually still another handle on a front portion of the grinder designed as a machine tool 1 is provided.

As can be seen in FIG. 1, a first, second, third and fourth switch 3, 4, 5, 6 are positioned on the handle of the machine tool 1. The first, second, third and fourth switches 3, 4, 5, 6 are each designed as a pressure switch. In addition, a multi-level scale S is provided on the handle. The first switch 3 is an actuating switch 7, by means of which the machine tool 1 is selectively and reversibly placed in an activation or deactivation mode. The operation switch 7 may also be referred to as an "I / O button". When the machine tool 1 is put into the activation mode, a corresponding signal is sent from the operation switch 7 to the control device. The controller provides for the drive to be activated by the supply of electrical energy (ie, supply of power) from the power source, thereby producing torque from the drive. In other words, in the activation mode, the machine tool 1 is turned on, so that can be done with this work. Preferably, the actuation switch 7 can be formed by a first pressure surface 13 when the functions of the actuation switch 7 and the interlock switch 8 are taken over by a common switch device 11, which is preferably formed by a rocker switch.

On the other hand, when the machine tool 1 is set in the deactivation mode, a corresponding signal is sent from the operation switch 7 to the control device. The control device ensures that-advantageously after a predefined delay time, such as, for example, 1 second for moving the thumb-no electrical energy (= current) is conducted from the energy source to the drive. In other words, in the deactivation mode, the machine tool 1 is switched off, so that no more work can be done with it. The control device is still active for a certain time, even if the drive has already been shut down.

The actuation switch 7 is correspondingly connected to the control device for signal transmission by means of lines (not shown). For actuating the operation switch 7, a certain force or a certain pressure by a user of the machine tool 1 in the direction of arrow N on the surface of the actuating switch 7 or the first pressure surface 13 of the common switch device 1 1 exercised, so that the operation switch 7 moves in the direction of arrow N. becomes. As soon as no force is exerted on the actuation switch 7, the actuation switch 7 again moves counter to the direction of the arrow N into the initial position. For this purpose, the actuation switch 7 can be designed with a corresponding spring (not shown). Alternatively, the actuation switch 7 may also be made of an elastic material, eg rubber. An activation of the machine tool 1 is generally only given as long as the operating switch 7 or the first pressure surface 13 of the common switch device 1 1 is pressed in the direction of arrow N. The operating switch 7 is therefore not a switch with a latching function which remains in a desired (ie depressed) position by a single push. The second switch 4 is a locking switch 8 which serves to lock the machine tool 1 or the control device and the drive in the activation mode. The locking switch 8 may be formed in a preferred embodiment of the invention as a second pressure surface 14 of a rocker switch 1 1. After activation of the locking switch 8, the machine tool 1 and the control device and the drive remain in the activation mode, even if the operation switch 7 is no longer pressed or no force is exerted on the operation switch 7 in the direction of arrow N.

This constitutes a significant advantage of the invention, which achieves the object of providing a machine tool 1 that can be used by a user without requiring a permanent actuation of a pressure surface (13 or 14).

In addition, the lock switch 8 as well as the operation switch 7 can be used to move the machine tool 1 from the activation mode to the deactivation mode. In a particularly preferred embodiment of the invention, the rocker switch 11 can be used for this purpose. In other words, by actuating, for example, the interlock switch 8, the machine tool 1 is set from the activation mode to the deactivation mode. To actuate the locking switch 8, a certain force or pressure is exerted by a user of the machine tool in the direction of the arrow N on the surface of the locking switch 8, so that the locking switch 8 is moved in the direction of the arrow N.

FIGS. 4 to 7 show various modes or functions of the machine tool 1.

In Figure 4, the situation is shown using the graph that the operation switch 7 or the first pressure surface 13 of the common switch device 1 1 is pressed by the user for six seconds. For six seconds, the machine tool 1 and the control device and the drive is thus in the activation mode. Within the first second, the speed of the engine designed as an electric motor increases linearly from zero to 5250 revolutions per minute (rpm). For five seconds, the speed of the drive remains constant at 5250 rpm. From the sixth second, no force or pressure is exerted by the user on the operation switch 7. After the actuation switch 7 is no longer depressed, the speed for the drive remains at the value of 5250 rpm.

Only after one second, ie from the sixth to the seventh second, the value of the speed for the drive in a linear curve of 5250 rev / min is reduced to zero. The value zero is reached for the speed from the ninth second. When the speed for the drive has reached zero, the drive and thus the machine tool 1 is in a deactivation mode.

The graph shown with the aid of the graph in Figure 4 illustrates the situation in which the Actuate transmission switch 7 is pressed by the user only for a period of six seconds and the machine tool 1 is accordingly in a mode of activation for a total of nine seconds.

In Figure 5, a situation is shown with the aid of the graph, in which the user presses the Actuate supply switch 7 or the first pressure surface 13 of the common switch device 1 1 single Lich for 0.8 seconds or operated. The speed for the motor configured as an electric motor increases from zero to a value of 2625 rpm in the period of zero to 0.75 seconds. The speed remains for a total of one second, i. for the period of 0.75 to 1.75 seconds, constant at 2625 rpm. From 1.5 seconds, the speed value drops from 2625 rpm to zero. The drive finally stops at 2.5 seconds and the machine tool 1 and the drive change from the activation mode to the deactivation mode.

In Figure 6, a situation is shown with the aid of the graph, in which the user presses the Actuate supply switch 7 or the first pressure surface 13 of the common switch device 1 1 single Lich for 6 seconds or operated. The speed value for the drive increases linearly from zero to 5250 rpm within one second. The operation switch 7 remains pressed for a total of 6 seconds. The machine tool 1 and the control device and the drive thus change from the deactivation state into the activation mode.

After 6 seconds no pressure or no more force is exerted by the user on the Actuate supply switch 7. Within one second, ie from the seventh second, after the operation switch 7 is no longer pressed, the locking switch 8 is pressed once by the user. By pressing or pressing the locking switch 8 or the second pressure surface 14 of the common switch device 1 1 remains the machine tool 1 and the drive in the activation mode or can be transferred by the user in a working mode. In addition, the speed value for the drive remains as before at 5250 rpm. After 15 seconds or from the fifteenth second of Actuate supply switch 7 is pressed again. By re-actuating the operating switch 7, the machine tool 1 and the drive changes from the activation mode to the deactivation mode. Alternatively, instead of actuating the operation switch 7, the lock switch 8 may also be actuated to change the machine tool 1 and the drive from the activation mode to the deactivation mode. The speed value for the Drive drops linearly to zero within one second from 5250 rpm. From the seventeenth second the drive stops.

In Figure 7, a situation is shown with the aid of the graph, in which the user presses the Actuate supply switch 7 or the first pressure surface 13 of the common switch device 1 1 single Lich for 0.75 seconds or operated. The machine tool 1 and the drive change from the deactivation mode to the activation mode. The speed value only increases from zero to 2625 rpm. The speed for the drive remains at 2625 rpm for one second. Within one second, i. From 0.75 seconds after the operation switch 7 is no longer depressed, the locking switch 8 or the second pressure surface 14 of the common switch device 1 1 is pressed once by the user. By pressing or pressing the lock switch 8, the machine tool 1 and the drive remain in the activation mode. In addition, the speed value for the drive increases linearly from 2625 to 5250 rpm. As before, the operating switch 7 is pressed again after 15 seconds or from the fifteenth second. By re-actuating the operating switch 7, the machine tool 1 and the drive changes from the activation mode to the deactivation mode. Alternatively, instead of actuating the operation switch 7, the lock switch 8 may also be actuated to change the machine tool 1 and the drive from the activation mode to the deactivation mode. The speed value for the drive drops linearly to zero within 2 seconds from 5250 rpm. The drive stops at the seventeenth second.

As shown in FIG. 3, the housing 2 of the machine tool 1 is configured such that the actuation switch 7 is located in a recess 10. When the operation switch 7 and the lock switch 8 are formed by a common switch device 11, it is also preferable that the rocker switch is in a recess 12. The surface of the actuation switch 7 can be positioned lower in the direction N than the surface of the housing 2 of the machine tool 1. The distance D between the surface of the actuation switch 7 and the surface of the housing 2 of the machine tool 1 is, for example, between 5 to 20 mm. However, a depression of the actuating switch with a depth or height in a range of 1 to 15 mm is very particularly preferred. In a particularly advantageous embodiment, the distance D is a value of 10 mm. The edge surfaces 9 of the recess 10 on the surface of the machine tool 1 are chamfered and inclined to the operating switch 7. As shown in FIG. 3, the inclination of the bevelled edge surfaces is configured in such a way that a circle with the radius R at individual points of the edge surfaces and at a single point on the surface of the actuation switch 7 lies. This special design of the recess 10 of the surface of the actuating switch 7 serves to make the actuation of the actuating switch 7 more difficult and thus not accidentally actuated. A user must specifically intervene with a finger in the recess of the housing 2 in order to actuate the operating switch 7 deliberately and willingly. In addition, the recess serves to ensure that the operating switch 7 is not accidentally actuated when the machine tool 1 is placed over a head, ie on the surface of the housing 2, where the operating switch 7 is located on a substrate. Unevenness, such as stones, which are located on the ground, can not trigger the operation switch 7 due to the special depression of the operating switch.

In order to additionally prevent the machine tool 1 from being switched on inadvertently, all or individual switches-except for the recessed operating switch 7 or the first pressure surface 13 of the switch device 11-can be raised. The switches are preferably connected in such a way that the actuation switch 7 or the first pressure surface 13 of the switch device 1 1 is only active if no other switch is pressed simultaneously.

It may be preferred for the purposes of the invention that the actuation switch 7 and the locking switch 8 are formed by a common switch device 11. The surface of this common switch device 1 1 can be flat or flat. However, it may also be preferred that the rocker switch 1 1 in the region of the first pressure surface 13 and the second pressure surface 14 recesses in the surface, which are advantageously adapted to guide the finger of a user. Preferably, the user can thereby orient themselves better on the surface of the common switch device and operate the rocker switch 11 with particular accuracy.

The third and fourth switches 5, 6 are gear selector switches with which the individual gears of the transmission of the machine tool can be selected. The selection and the insertion of the gears is preferably carried out electronically. By applying a force or a pressure in the direction of arrow N to the fourth switch 6, a higher gear is selected and inserted. By applying a force or a pressure in the direction of arrow N to the third switch 5, a lower gear is selected and engaged. The multi-level scale S consists of several light sources (for example LEDs) and indicates by analogy with the illumination of the individual light sources which gear is engaged in the gearbox or in the engine electronics.

Furthermore, it can be seen from FIG. 1 that, above the actuation switch 7, a first light source 17 in the form of an LED and above the interlock switch 8 a second light source 17 Light source 18 is positioned in the embodiment of a LED. The first light source 17 lights up when the operation switch 7 has been pressed and the machine tool 1 has been switched from the deactivation mode into the activation mode. The second light source 18 lights up when the interlock switch is pressed and the machine tool is locked in the activation mode.

The first light source 17 and the second light source 18 may optionally be used to indicate disturbances. By way of example, a temporary error of the machine tool 1 can be indicated by a blink code. For example, a temporary error can be overheating. A permanent fault can preferably be indicated by a continuous lighting of one of the two light sources 17, 18. A permanent error can be, for example, a service request. It may be preferred for the purposes of the invention that the light sources 17, 18 are made bicoloured. In the context of the invention, this means that the light sources 17, 18 are set up to emit light in at least two different colors, for example red and green. For example, the color "green" can be used for the regular display of the operating status and the color "red" for the display of faults. The two-color can be achieved either by multi-colored bulbs or by different colored, individual bulbs under a common light guide. In the preferred embodiment of the invention with a common switch device 11, the provision of the light source 17 can be dispensed with. The above is then mutatis mutandis for the sole light source 18. It is within the meaning of the invention very particularly preferred that the light sources 17, 18 of light emitting diodes (LED) are formed or include such.

As an aid to the user, the switches (3-8, 13, 14) and / or light sources 17, 18 themselves or adjacent areas may be provided with symbols or inscriptions.

FIG. 8 shows a preferred embodiment of the machine tool 1, in particular the handle (represented by the reference numeral 15 in FIG. 9) of the machine tool 1. In particular, the common switch device 1 1, which comprises a first pressure surface 13 and a second pressure surface 14, is shown. and a central web which connects the two pressure surfaces (13, 14) with each other. Preferably, the common switch device 1 1 represents a rocker switch. In the embodiment of the invention with a common switch device 1 1, the handle 15 of the machine tool 1 comprises only one light source, which may, for example, be the second light source 18. This one light source 18 can, for example, be located between the second pressure surface 14, which is preferably the locking device. tion switch 8 corresponds, and the third switch 5 and the fourth switch 6 are present.

FIG. 9 shows a side view of a preferred embodiment of the handle 15 of the machine tool 1. The light source 18, which may preferably be connected to an integrated light source 19, can be seen in particular. The integrated light sources 19 can be formed, for example, by a light emitting diode (LED). In addition, FIG. 9 shows the arrangement of the first pressure surface 13 and the second pressure surface 14 of the rocker switch 11.

The second pressure surface 14 may be connected to a second micro-switch 22, while the first pressure surface 13 of the common switch device 1 1 may be connected to a first micro-probe 20. Between the two microtasters (20, 22), the pivot point

21 of the rocker 1 1 and the rocker switch 1 1 are present. Preferably, the switches (7, 8) and the pressure surfaces (13, 14) with the micro-buttons (20, 22) cooperate. It is preferred for the purposes of the invention that either the first printing surface of the machine tool 1 is detected as pressed by the design of the common switch device 1 1 as a rocker switch or the second pressure surface 14, but not both pressure surfaces (13, 14) simultaneously. For this purpose, the common switch device 1 1 preferably has a pivot point 21 for the rocker switch. Preferably, the rocker switch 1 1 may be present in a recess 12. It is furthermore preferred that the switches (7, 8) or the pressure surfaces (13, 14) are constituents of the handle 15 of the machine tool 1.

LIST OF REFERENCE NUMBERS

1 machine tool

2 housings

3 First switch

4 second switch

5 Third switch

6 Fourth switch

7 operating switch

8 interlock switch

9 edge surface

10 deepening

1 1 Common switch device / rocker switch

12 recess for the common switch device

13 First printing surface

14 second print area

15 handle of the machine tool

17 First light source

18 Second light source

19 Integrated light source

20 First microtaster

21 pivot point of the rocker switch

22 Second microtaster

Claims

claims

1. A method for controlling a machine tool (1), in particular a grinding machine, wherein the machine tool (1), a control device, a drive, a driven by the drive tool, such as an abrasive, an actuation switch (7) and a Includes interlock switch,

characterized by the method steps:

Activating the operation switch (7) by applying a force in a direction (N) to the operation switch (7) to switch the machine tool (1) from a deactivation mode to an activation mode, so that the drive is set to a first predetermined speed value;

Deactivating the operating switch (7) so that no more force is exerted in the direction (N) on the actuating switch (7), wherein the drive is set for a predetermined period of time in the first predetermined speed value;

Activating the interlock switch (8) within the first predetermined time period after deactivating the operation switch (7) so that the drive is set to a predetermined second speed value; and

- Activation of the actuating switch (7) by applying a force in one direction (N) on the actuating switch (7) or activating the locking switch (8) by applying a force in one direction (N) on the locking switch (8) for switching the machine tool (1) from the activation mode to the deactivation mode.

2. The method according to claim 1,

characterized in that the first speed value and the second speed value are identical.

3. The method according to claim 1,

characterized in that the first speed value and the second speed value are different.

4. Machine tool (1) for carrying out the method according to at least one of claims 1 to 3, wherein the machine tool (1), a control device, a drive, a driven by the drive tool, such as a Schleifmit- tel, an actuating switch (7) and a locking switch, characterized in that the machine tool (1) ent ent a control device, a drive, a driven by the drive tool, such as an abrasive, an actuating switch (7) and a locking switch (8) - stops.

5. Machine tool (1) according to claim 4

characterized in that the actuating switch (7) and the locking switch (8) by a common switch device (1 1) are formed.

6. Machine tool (1) according to claim 4 or 5

characterized in that the common switch device (11) is formed by a rocker switch.

7. Machine tool (1) according to one of claims 4 to 6

characterized in that the common switch device (1 1) has a first pressure surface (13) and a second pressure surface (14).

8. Machine tool (1) according to one of claims 4 to 7

characterized in that the common switch device (11) has a planar surface.

9. Machine tool (1) according to one of claims 4 to 7

characterized in that the common switch device 1 1 recesses for the first pressure surface (13) and / or the second pressure surface (14).

10. Machine tool (1) according to one of claims 4 to 9

characterized in that the actuating switch (7) and the locking switch (8) with micro-buttons (21, 22) cooperate.

1 1. Machine tool (1) according to one of claims 7 to 10

characterized in that the first pressure surface (13) and the second pressure surface (14) with micro-buttons (21, 22) interaction.

12. Machine tool (1) according to one of claims 4 to 11

characterized in that the actuating switch (7) and the locking switch (8) are components of a handle (15) of the machine tool (1).

13. Machine tool (1) according to one of claims 7 to 11

characterized in that the first pressure surface (13) and the second pressure surface

(14) are components of a handle (15) of the machine tool (1).

14. Machine tool (1) according to one of claims 4 to 13

characterized in that the machine tool (1) comprises at least one light source (18) for indicating a standby state of the machine tool (1).