SWITCH FOR MACHINE TOOL AND SWITCHING LOGIC

Abstract

A method for controlling a machine tool-having an operating switch and a lock switch including: activating the operating switch by exerting a force in a direction onto the operating switch for switching over the machine tool from a deactivation mode to an activation mode, so that the drive is adjusted to a first predetermined rotation speed value; deactivating the operating switch, so that no more force is exerted in direction onto the operating switch, wherein the drive is adjusted in the first predetermined rotation speed value for a predetermined time period; activating the lock switch within the first predetermined time period after deactivation of the operating switch, so that the drive is adjusted to a predetermined second rotation speed value; and activating the operating switch by exerting a force in a direction onto the operating switch or activating the lock switch by exerting a force in a direction onto the lock switch for switching over the machine tool from the activation mode to the deactivation mode.

Claims

1-14. (canceled)

15. A method for controlling a machine tool, the machine tool including a control apparatus, a drive, a tool driven by the drive, an operating switch and a lock switch, the method comprising: activating the operating switch by exerting a force in a direction (N) onto the operating switch for switching over the machine tool from a deactivation mode to an activation mode, so that the drive is adjusted to a first predetermined rotation speed value; deactivating the operating switch, so that no more force is exerted in the direction (N) onto the operating switch, wherein the drive is adjusted in the first predetermined rotation speed value for a predetermined time period; activating the lock switch within the first predetermined time period after deactivation of the operating switch, so that the drive is adjusted to a predetermined second rotation speed value; and activating the operating switch by exerting a force in the direction (N) onto the operating switch or activating the lock switch by exerting a force in the direction (N) onto the lock switch for switching over the machine tool from the activation mode to the deactivation mode.

16. The method as recited in claim 15 wherein the first rotation speed value and the second rotation speed value are identical.

17. The method as recited in claim 15 wherein first rotation speed value and the second rotation speed value are different.

18. A machine tool for carrying out the method as recited in claim 15, the machine tool comprising: the control apparatus; the drive; the tool driven by the drive; the operating switch; and the lock switch;

19. The machine tool as recited in claim 18 wherein the operating switch and the lock switch are formed by a common switch apparatus.

20. The machine tool as recited in claim 19 wherein the common switch apparatus is formed by a rocker switch.

21. The machine tool as recited in claim 19 wherein the common switch apparatus has a first pressure surface and a second pressure surface.

22. The machine tool as recited in claim 19 wherein the common switch apparatus has a flat surface.

23. The machine tool as recited in claim 19 wherein the common switch apparatus has recesses for the first pressure surface or the second pressure surface.

24. The machine tool as recited in claim 18 wherein the operating switch (7) and the lock switch interact with microbuttons.

25. The machine tool as recited in claim 21 wherein the first pressure surface and the second pressure surface interact with microbuttons.

26. The machine tool as recited in claim 18 further comprising a handle, the operating switch and the lock switch being constituent parts of the handle.

27. The machine tool as recited in claim 21 further comprising a handle, the operating switch and the lock switch being constituent parts of the handle.

28. The machine tool as recited in claim 18 further comprising at least one light source for indicating a ready-to-operate state of the machine tool.

29. The machine tool as recited in claim 1 wherein the tool is an abrasive means.

30. The method as recited in claim 15 wherein the machine tool is a sander and the tool is an abrasive means.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In the figures, components that are the same and components of the same type are designated by the same reference signs. In said figures:

[0033] FIG. 1 shows a perspective view of a handle of a machine tool according to the invention with an operating switch and a lock switch;

[0034] FIG. 2 shows a view from the rear of the handle of the machine tool according to the invention with the operating switch and the lock switch;

[0035] FIG. 3 shows a sectional view along the section line A-A according to FIG. 2;

[0036] FIG. 4 shows a first graph for illustrating a first aspect of the method according to the invention;

[0037] FIG. 5 shows a second graph for illustrating a second aspect of the method according to the invention;

[0038] FIG. 6 shows a third graph for illustrating a third aspect of the method according to the invention; and

[0039] FIG. 7 shows a fourth graph for illustrating a fourth aspect of the method according to the invention;

[0040] FIG. 8 is an illustration of a preferred embodiment of the machine tool, in particular of the handle of the machine tool; and

[0041] FIG. 9 is an illustration of a preferred embodiment of the machine tool, in particular of the handle of the machine tool.

DETAILED DESCRIPTION

[0042] FIGS. 1 and 2 show a portion of a machine tool 1 in the form of a sander. However, it is also possible for the machine tool 1 to be configured as a drill, saw or the like.

[0043] The machine tool 1 substantially contains a housing 2, a drive 100, a transmission 101, a drive shaft 102, a tool holder 104, an energy source 105 and a control apparatus 106. In this case, the drive can be configured, for example, in the form of a brushless electric motor. The drive is positioned in the housing 2 such that a torque which is generated by the drive is transmitted to the tool via the drive shaft and the tool holder. The control apparatus controls or regulates all functions of the machine tool 1 and, in particular, the functions of the drive. The energy source serves to supply electrical energy to the electrical consumers of the machine tool 1. One electrical consumer is, in particular, the drive. Here, the energy source can be configured in the form of a rechargeable battery (also called storage battery). The energy source, which is configured as a rechargeable battery, can be connected to the housing 2 of the machine tool 1. As an alternative, the energy source can also be implemented as a power cable for releasably connecting the machine tool 1 to a mains power connection (i.e. plug socket).

[0044] The control apparatus controls and regulates, in particular, the supply of electrical energy, i.e. electric current, to the drive, as a result of which specifically the rotation speed of the drive which is designed as an electric motor is controlled or regulated.

[0045] The drive 100, the transmission 101, the drive shaft 102, the tool holder 104, the energy source 105, the control apparatus 106 and the tool 108, such as an abrasive means on tool holder 104, are shown schematically in FIG. 1.

[0046] The subregion shown in FIGS. 1 and 2 is a rear portion of the housing 2 of the machine tool 1 and, in particular, one of the handles of the machine tool 1 which is configured as a sander. The handle serves to hold and guide the machine tool 1. A further handle is usually provided on a front section of the machine tool 1 which is configured as a sander.

[0047] As can be seen in FIG. 1, a first, second, third and fourth switch 3, 4, 5, 6 is positioned on the handle of the machine tool 1. The first, second, third and fourth switches 3, 4, 5, 6 are each configured as a pressure switch. Furthermore, a multi-level scale S is also provided on the handle.

[0048] The first switch 3 is an operating switch 7 by way of which the machine tool 1 can be selectively and reversibly moved to an activation or deactivation mode. The operating switch 7 can also be referred to as an “I/O button”. If the machine tool 1 is moved to the activation mode, a corresponding signal is sent from the operating switch 7 to the control apparatus. The control apparatus ensures that the drive 100 is activated by the supply of the electrical energy (i.e. supply of current) from the energy source, as a result of which a torque is generated by the drive. In other words: in the activation mode, the machine tool 1 is switched on, so that work can be carried out using said machine tool. The operating switch 7 can preferably be formed by a first pressure surface 13 if the functions of the operating switch 7 and of the lock switch 8 are taken over by a common switch apparatus 11 which is preferably formed by a rocker switch.

[0049] If, however, the machine tool 1 is moved to the deactivation mode, a corresponding signal is sent from the operating switch 7 to the control apparatus. The control apparatus ensures that—advantageously after a predefined delay time, such as, for example, 1 second for moving the thumb—no more 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 carried out using said machine tool. The control apparatus is still active for a certain time, even if the drive has already been shut down.

[0050] The operating switch 7 is correspondingly connected to the control apparatus for signal transmission by means of lines (not shown). In order to operate the operating switch 7, a certain force or a certain pressure is exerted by a user of the machine tool 1 in arrow direction N onto the surface of the operating switch 7 or of the first pressure surface 13 of the common switch apparatus 11, so that the operating switch 7 is moved in arrow direction N. As soon as no more force is exerted onto the operating switch 7, the operating switch 7 moves counter to the arrow direction N back to the starting position. For this purpose, the operating switch 7 can be configured with a corresponding spring (not shown). As an alternative, the operating switch 7 can also be formed from an elastic material, for example rubber. The machine tool 1 is generally only activated as long as the operating switch 7 or the first pressure surface 13 of the common switch apparatus 11 remains pressed in arrow direction N. The operating switch 7 is therefore not a switch with a latching function which remains in a desired (i.e. pressed) position by being pressed once.

[0051] The second switch 4 is a lock switch 8 which serves to lock the machine tool 1 or the control apparatus and the drive in the activation mode. In a preferred embodiment of the invention, the lock switch 8 can be designed as a second pressure surface 14 of a rocker switch 11. After activation of the lock switch 8, the machine tool 1 and also the control apparatus and the drive remain in the activation mode, even if the operating switch 7 is no longer pressed or no more force is exerted onto the operating switch 7 in arrow direction N. This constitutes a substantial advantage of the invention by way of which the object of providing a machine tool 1 which can be used by a user without permanent operation of a pressure surface (13 or 14) being necessary is achieved.

[0052] Furthermore, the lock switch 8 as well as the operating switch 7 can be used in order 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 operating, for example, the lock switch 8, the machine tool 1 is moved from the activation mode to the deactivation mode. In order to operate the lock switch 8, a certain force or a certain pressure is exerted by a user of the machine tool in arrow direction N onto the surface of the lock switch 8, so that the lock switch 8 is moved in arrow direction N.

[0053] Various modes and functions of the machine tool 1 are illustrated in FIGS. 4 to 7.

[0054] FIG. 4 illustrates, with the aid of the graph, the situation that the operating switch 7 or the first pressure surface 13 of the common switch apparatus 11 remains pressed by the user for six seconds. The machine tool 1 and the control apparatus and the drive are therefore in the activation mode for six seconds. Within the first second, the rotation speed of the drive which is configured as an electric motor increases linearly from zero to 5250 revolutions per minute (RPM). The rotation speed of the drive remains constant at 5250 RPM for five seconds. Starting from the sixth second, no more force or pressure is exerted by the user onto the operating switch 7. After the operating switch 7 is no longer pressed, the rotation speed for the drive remains at the value of 5250 RPM. The value of the rotation speed for the drive decreases in a linear manner from 5250 RPM to zero only after one second, i.e. from the sixth to the seventh second. The value zero is reached for the rotation speed starting from the ninth second. When the rotation speed for the drive has reached zero, the drive and therefore the machine tool 1 are in a deactivation mode.

[0055] The profile illustrated with the aid of the graph in FIG. 4 constitutes the situation in which the operating switch 7 has been pressed by the user only for a time period of six seconds and the machine tool 1 is accordingly in an activation mode for a total of nine seconds.

[0056] FIG. 5 illustrates, with the aid of the graph, a situation in which the user presses or operates the operating switch 7 or the first pressure surface 13 of the common switch apparatus 11 only for 0.8 seconds. The rotation speed for the drive which is configured as an electric motor increases from zero to a value of 2625 RPM in the period from zero to 0.75 seconds. The rotation speed remains constant at 2625 RPM for a total of one second, i.e. for the period from 0.75 to 1.75 seconds. Starting from 1.5 seconds, the rotation speed value drops from 2625 RPM to zero. The drive finally stops at 2.5 seconds and the machine tool 1 and also the drive change from the activation mode to the deactivation mode.

[0057] FIG. 6 illustrates, with the aid of the graph, a situation in which the user presses or operates the operating switch 7 or the first pressure surface 13 of the common switch apparatus 11 only for 6 seconds. The rotation speed value for the drive increases linearly from zero to 5250 RPM within one second. The operating switch 7 remains pressed for a total of 6 seconds. The machine tool 1 and also the control apparatus and the drive therefore change from the deactivation state to the activation mode.

[0058] After 6 seconds, no more pressure or no more force is exerted by the user onto the operating switch 7. Within one second, i.e. starting from the seventh second, after the operating switch 7 is no longer pressed, the lock switch 8 is pressed once by the user. By way of operating or pressing the locking switch 8 or the second pressure surface 14 of the common switch apparatus 11, the machine tool 1 and the drive remain in the activation mode or can be moved to a working mode by the user. Furthermore, the rotation speed value for the drive remains at 5250 RPM as before. After 15 seconds or starting from the fifteenth second, the operating switch 7 is pressed again. By way of operating the operating switch 7 again, the machine tool 1 and the drive change from the activation mode to the deactivation mode. As an alternative, instead of operating the operating switch 7, the lock switch 8 can also be operated in order to allow the machine tool 1 and the drive to change from the activation mode to the deactivation mode. The rotation speed value for the drive drops linearly and from 5250 RPM to zero within one second. The drive stops starting from the seventeenth second.

[0059] FIG. 7 illustrates, with the aid of the graph, a situation in which the user presses or operates the operating switch 7 or the first pressure surface 13 of the common switch apparatus 11 only for 0.75 seconds. The machine tool 1 and the drive change from the deactivation mode to the activation mode. The rotation speed value increases only from zero to 2625 RPM. The rotation speed for the drive remains at 2625 RPM for one second. Within one second, i.e. starting from 0.75 seconds after the operating switch 7 is no longer pressed, the locking switch 8 or the second pressure surface 14 of the common switch apparatus 11 is pressed once by the user. By way of operating or pressing the lock switch 8, the machine tool 1 and also the drive remain in the activation mode. Furthermore, the rotation 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 starting from the fifteenth second. By way of operating the operating switch 7 again, the machine tool 1 and the drive change from the activation mode to the deactivation mode. As an alternative, instead of operating the operating switch 7, the lock switch 8 can also be operated in order to allow the machine tool 1 and the drive to change from the activation mode to the deactivation mode. The rotation speed value for the drive drops linearly and within two seconds from 5250 RPM to zero. The drive stops starting from the seventeenth second.

[0060] As illustrated in FIG. 3, the housing 2 of the machine tool 1 is configured such that the operating switch 7 is located in a recess 10. If the operating switch 7 and the lock switch 8 are formed by a common switch apparatus 11, it is likewise preferred for the rocker switch to be present in a recess 12. The surface of the operating switch 7 can be positioned lower in direction N than the surface of the housing 2 of the machine tool 1. The distance D between the surface of the operating switch 7 and the surface of the housing 2 of the machine tool 1 here is, for example, between 5 and 20 mm. However, a recess of the operating switch with a depth or height in a range from 1 to 15 mm is very particularly preferred. In a particularly advantageous refinement, the distance D has a value of 10 mm. The edge surfaces 9 of the recess 10 on the surface of the machine tool 1 are beveled and inclined in relation to the operating switch 7. As shown in FIG. 3, the inclination of the beveled edge surfaces is configured here such that a circle with the radius R bears against individual points of the edge surfaces and also at a single point on the surface of the operating switch 7. This special configuration of the recess 10 of the surface of the operating switch 7 serves to make it difficult to operate the operating switch 7 and therefore to not be inadvertently operated. A user has to engage by way of a finger into the recess of the housing 2 in a targeted manner in order to operate the operating switch 7 in a targeted and deliberate manner. Furthermore, the recess serves to ensure that the operating switch 7 is not inadvertently operated when the machine tool 1 is set down on a substrate upside-down, i.e. on the surface of the housing 2 on which the operating switch 7 is located. Unevennesses, such as stones which are located on the ground, cannot trip the operating switch 7 owing to the special recess of the operating switch.

[0061] In order to additionally prevent the machine tool 1 from being inadvertently switched on, all or individual switches—apart from the recessed operating switch 7 or the first pressure surface 13 of the switch apparatus 11—can be of raised design. The switches are preferably interconnected in such a way that the operating switch 7 or the first pressure surface 13 of the switch apparatus 11 is active only when no other switch is pressed at the same time.

[0062] It may be preferred within the meaning of the invention for the operating switch 7 and the lock switch 8 to be formed by a common switch apparatus 11. The surface of this common switch apparatus 11 can be flat or planar. However, it may also be preferred for the rocker switch 11 to have recesses in the surface in the region of the first pressure surface 13 and the second pressure surface 14, which recesses are advantageously designed to guide the finger of a user. As a result, the user can preferably orientate himself better on the surface of the common switch apparatus and operate the rocker switch 11 particularly accurately.

[0063] The third and fourth switches 5, 6 are gear selector switches by way of which the individual gears of the transmission of the machine tool can be selected. Selection and also engagement of the gears preferably takes place electronically. By way of exerting a force or a pressure in arrow direction N onto the fourth switch 6, a higher gear is selected and engaged. By way of exerting a force or a pressure in arrow direction N on the third switch 5, a lower gear is selected and engaged. The multi-stage scale S consists of a plurality of light sources (e.g. LEDs) and accordingly indicates, by lighting up the individual light sources, which gear is selected in the transmission or in the engine electronics system.

[0064] It can further be seen in FIG. 1 that a first light source 17 in the form of an LED is positioned above the operating switch 7 and a second light source 18 in the form of an LED is positioned above the lock switch 8. The first light source 17 lights up when the operating switch 7 is pressed and the machine tool 1 has been moved from the deactivation mode to the activation mode. The second light source 18 lights up when the lock switch is pressed and the machine tool has been locked in the activation mode.

[0065] The first light source 17 and the second light source 18 can optionally be used to indicate faults. By way of example, a temporary fault in the machine tool 1 can be indicated by a flash code. A temporary fault may be, for example, overheating. A permanent fault may preferably be indicated by permanent lighting of one of the two light sources 17, 18. A permanent fault may be, for example, a service request. It may be preferred within the meaning of the invention for the light sources 17, 18 to be of two-color design. Within the meaning of the invention, this preferably means that the light sources 17, 18 are designed to emit light in at least two different colors, for example red and green. For example, the color “green” can be used for normally indicating the operating state and the color “red” for indicating faults. The two-color characteristic can be achieved either by multicolored lighting means or by different-colored, individual lighting means under a common light guide body. In the preferred embodiment of the invention with a common switch apparatus 11, the provision of the light source 17 can be dispensed with. The statements made above then apply, mutatis mutandis, to the sole light source 18. It is very particularly preferred within the meaning of the invention for the light sources 17, 18 to be formed by or comprise light emitting diodes (LED).

[0066] As an aid to the user, the switches (3-8, 13, 14) and/or light sources 17, 18 themselves or adjacent regions can be provided with symbols or labels.

[0067] FIG. 8 shows a preferred embodiment of the machine tool 1, in particular the handle (illustrated by reference sign 15 in FIG. 9) of the machine tool 1. The common switch apparatus 11, which comprises a first pressure surface 13 and a second pressure surface 14, and also a central web, which connects the two pressure surfaces (13, 14) to one another, are illustrated in particular. The common switch apparatus 11 preferably constitutes a rocker switch. In the embodiment of the invention with a common switch apparatus 11, the handle 15 of the machine tool 1 comprises only one light source which may be, for example, the second light source 18. This one light source 18 can be arranged, for example, between the second pressure surface 14, which preferably corresponds to the lock switch 8, and the third switch 5 and the fourth switch 6.

[0068] FIG. 9 shows a side view of a preferred embodiment of the handle 15 of the machine tool 1. Said figure shows, in particular, the light source 18 which can preferably be connected to an integrated light sources 19. The integrated light sources 19 can be formed, for example, by a light emitting diode (LED). Furthermore, 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 can be connected to a second microbutton 22, whereas the first pressure surface 13 of the common switch apparatus 11 can be connected to a first microbutton 20. The pivot point 21 of the rocker 11 or the rocker switch 11 can be present between the two microbuttons (20, 22). The switches (7, 8) or the pressure surfaces (13, 14) can preferably interact with the microbuttons (20, 22). It is preferred within the meaning of the invention that, by configuring the common switch apparatus 11 as a rocker switch, either the first pressure surface or the second pressure surface 14 is identified by the machine tool 1 as being pressed, but not both pressure surfaces (13, 14) at the same time. For this purpose, the common switch apparatus 11 preferably has a pivot point 21 for the rocker switch. The rocker switch 11 can preferably be present in a recess 12. It is furthermore preferred for the switches (7, 8) or the pressure surfaces (13, 14) to be constituent parts of the handle 15 of the machine tool 1.

LIST OF REFERENCE SIGNS

[0069] 1 Machine tool [0070] 2 Housing [0071] 3 First switch [0072] 4 Second switch [0073] 5 Third switch [0074] 6 Fourth switch [0075] 7 Operating switch [0076] 8 Lock switch [0077] 9 Edge surface [0078] 10 Recess [0079] 11 Common switch apparatus/rocker switch [0080] 12 Recess for the common switch apparatus [0081] 13 First pressure surface [0082] 14 Second pressure surface [0083] 15 Handle of the machine tool [0084] 17 First light source [0085] 18 Second light source [0086] 19 Integrated light source [0087] 20 First microbutton [0088] 21 Pivot point of the rocker switch [0089] 22 Second microbutton [0090] 23 [0091] 100 drive [0092] 101 transmission [0093] 102 drive shaft [0094] 104 tool holder [0095] 105 energy source [0096] 106 control apparatus [0097] 108 tool