HAND-FLED WORK TOOL

Description

[0001] The invention relates to a hand-held working device of the type specified in the preamble of claim 1. Such a hand-held working device is disclosed, for example, in document EP 2 460 399 A1.

[0002] Work devices are known that comprise a housing, a drive motor arranged in the housing, and a tool driven by the drive motor. Such work devices have an actuating element for actuating the drive motor. The actuating element is operatively connected to a locking element, which locks the actuating element in a locked position and releases it in an operating position. Furthermore, such work devices can also have switches that must be actuated in addition to the locking element in order to transmit a corresponding release signal to a control system of the work device, thus enabling operation of the work device.

[0003] The invention is therefore based on the object of creating a hand-held working device of the generic type which enables improved commissioning of the working device.

[0004] This object is achieved by a hand-held working device having the features of claim 1.

[0005] The hand-held tool comprises a housing, a tool and a drive motor arranged in the housing for driving the tool, a switching unit for actuating the drive motor for driving the tool, at least one actuating element, wherein the at least one actuating element can be switched at least into a first position and into a second position, an electronic switch for detecting the switching positions of the at least one actuating element, wherein the electronic switch generates a status signal dependent on the switching positions of the actuating element and a controller, wherein the controller switches the operational readiness of the drive motor depending on the status signal of the electronic switch.The electronic switch comprises a switching element with a Hall sensor and an actuating element formed separately from the switching element, wherein the actuating element for actuating the switching element is operatively connected to the Hall sensor and is arranged on the at least one actuating element.

[0006] By using the Hall sensor, the triggering mechanism of the electronic switch is no longer based on a mechanical principle. The Hall sensor is activated without contact.

[0007] It is advantageous that the switching element comprises a circuit, with the Hall sensor being part of the circuit. Particularly preferably, the Hall sensor is arranged on a circuit board. Thus, the effect of the Hall sensor when activated is not limited to closing or opening an electrical circuit. The status signal emitted by the switching element is therefore an information signal that can be evaluated by the controller. In both the first and second positions of the actuating element, a corresponding status signal is sent from the switching element to the controller, allowing the controller to infer the switching status of the actuating element.

[0008] It is preferably provided that the actuating element is designed as a magnet for actuating the switching element. If the magnet is moved relative to the Hall sensor, the magnetic field and the magnetic flux density flowing through the Hall sensor change. Consequently, the position of the actuating element can be determined via the Hall sensor. In an alternative embodiment, the actuating element can also be designed as a shielding element for interrupting the magnetic field between the magnet and the Hall sensor. In such a design, the magnet and Hall sensor are firmly fixed relative to one another. The change in the magnetic field and the magnetic flux density flowing through the Hall sensor occurs by inserting the shielding element into the magnetic field. In the second position of the actuating element, the shielding element is preferably arranged between the magnet and the Hall sensor, such that the magnetic flux density flowing through the Hall sensor is reduced.

[0009] It is preferably provided that the adjusting element is a locking lever, wherein the locking lever releases the switching unit for actuation in the first position and locks it in the second position. In an alternative embodiment, the implement comprises a braking device with a brake lever, wherein the at least one adjusting element corresponds to the brake lever of the braking device. This allows the position of the brake lever to be determined by the control system.

[0010] Particularly preferably, the actuating element is operatively mechanically connected to the switching unit in at least one of its at least two positions. Preferably, the actuating element mechanically locks the switching unit in the first position. Preferably, the actuating element releases the switching unit in the second position. Thus, the drive motor is started up via both a mechanical and an electronic safety mechanism. Preferably, the actuating element is arranged on the actuating element in such a way that the mechanical switching state of the actuating element is coupled to the electrical switching state of the electronic switch.

[0011] According to the invention, a further control element with a further actuating element is provided for actuating the switching element. The further control element is preferably arranged on the switching element of the electronic switch.

[0012] Embodiments of the invention are explained below with reference to the drawings. They show: Fig. 1 shows a side view of a hand-held working device not according to the invention, Fig. 2 shows a partial sectional view of a handle section of the hand-held working device with Hall sensor and actuating element in a first position of the actuating element, Fig. 3 shows a partial sectional view of a handle section of the hand-held working device with Hall sensor and actuating element in a second position of the actuating element and Fig. 4 shows a partial sectional view of a handle section of a hand-held working device according to the invention with Hall sensor and two actuating elements.

[0013] In Fig. 11 shows a working device 1 not according to the invention, which is designed as a motor-driven chainsaw. The working device 1 comprises a housing 2 and a drive motor 3 arranged in the housing 2. The drive motor 3 is shown only schematically by a dashed rectangle. In the preferred embodiment, the drive motor 3 is an electric motor, but can alternatively be designed as an internal combustion engine. The drive motor 3 is supplied with energy via a rechargeable battery or a connecting cable. The working device comprises a tool 4 driven by the drive motor 3, which tool 4 is designed as a saw chain in the embodiment. A rear handle 36 and a handle tube 37 for guiding the working device 1 are fixed to the housing 2. On the side of the housing 2 opposite the rear handle 36, a guide rail 38 projects forward. The saw chain is arranged circumferentially on the guide rail 38.Alternatively, the hand-held tool can be, for example, a power cutter, a blower, a brush cutter, a hedge trimmer or similar.

[0014] The drive motor 3 drives a drive shaft that protrudes from the housing 2. A drive sprocket is arranged on the drive shaft. The drive sprocket serves to drive the saw chain, which is guided over the drive sprocket during operation. The implement 1 further comprises a tensioning device, via which the guide bar 38 can be moved forward in its longitudinal direction away from the drive sprocket, thus tensioning the saw chain.

[0015] As in Fig. 1As shown, the guide rail 38 has a longitudinal axis 40. When the implement 1 is parked on a flat, horizontal floor 41, the longitudinal axis 40 runs centrally through the guide rail 38 approximately parallel to the horizontal floor 41. The term "approximately" is to be understood such that the longitudinal axis 40 forms an angle of no more than 15° with the floor 41. The guide rail 38 has a longitudinal plane 42, which, when the implement 1 is parked on a flat, horizontal floor 41, contains the longitudinal axis 40 and is perpendicular to the floor 41.

[0016] As in Fig. 1As shown, the housing 2 has a handle portion 5, wherein the handle portion 5 is provided on the rear handle 36 in the exemplary embodiment. The working device 1 has a switching unit 8 for actuating the drive motor 3. The switching unit 8 is provided on the handle portion 5 in the exemplary embodiment. The switching unit 8 is designed as a switching lever in the exemplary embodiment.

[0017] As in Fig. 1 As shown, the working device 1 comprises at least one actuating element 9. The actuating element 9 can be switched at least into a first position 51 and a second position 52. In the preferred embodiment, the actuating element 9 is designed as a locking lever. In the preferred embodiment, the actuating element 9 serves to mechanically lock and release the switching unit 8. In the preferred embodiment of the working device 1, the actuating element 9 mechanically locks the switching unit 8 in the first position 51 ( Fig. 2) and releases the switching unit 8 in a second position 52 ( Fig. 3 ) free.

[0018] As in Fig. 1 As shown, the handle section 5 has an upper side 6 and a lower side 7 opposite the upper side 6. In the exemplary embodiment, the handle section 5 is a part of the housing 2, on which the switching unit 8 and the adjusting element 9 are arranged. In the exemplary embodiment, the adjusting element 9 is arranged on the upper side 6. The switching unit 8 is arranged on the lower side 7 of the handle section 5. Preferably, the handle section 5 also comprises a gripping area 43, which is provided for holding the working device 1 during operation of the working device 1.

[0019] As in the Figures 2 and 3As shown, the adjusting element 9 is pivotally mounted on the housing 2 about a first pivot axis 15. The working device 1 comprises a first return spring 19, wherein the first return spring 19 acts on the adjusting element 9 and preloads the adjusting element 9 into the first position 51 of the adjusting element 9. In the exemplary embodiment, the first return spring 19 is designed as a leg spring. The return spring 19 is arranged on the housing 2 and acts with one leg on the adjusting element 9.

[0020] As in the Figures 2 to 4 As shown, the switching unit 8 is pivotally mounted on the housing 2 about a second pivot axis 16. The working device 1 has a second return spring (not shown in detail), which acts on the switching unit 8 and preloads the switching unit 8 into an inoperative position. In the inoperative position, the drive motor 3 is deactivated.

[0021] A locking contour 34 is formed on the actuating element 9, which, in the first position 51 of the actuating element 9, blocks the switching unit 8 when it is pivoted into an operating position. If the switching unit 8 is pressed while the actuating element 9 is in the first position 51, the switching unit 8 abuts with its holding contour 35 against the locking contour 34 of the actuating element 9. The switching unit 8 is blocked by the locking contour 34. Only when the actuating element 9 is pivoted into the second position 52 is the switching unit 8 released, whereby pivoting of the switching unit 8 into the operating position is possible.

[0022] As in Fig. 2As shown, the working device 1 comprises an electronic switch 10 for detecting the switching positions of the at least one actuating element 9. The electronic switch 10 comprises a switching element 11 with a Hall sensor 12 and an actuating element 13 formed separately from the switching element 11. The actuating element 13 is operatively connected to the Hall sensor 12. The switching element 11 with the Hall sensor 12 is arranged on the housing 2, in particular on the handle section 5, of the working device 1. The switching element 11 with the Hall sensor 12 is fixedly connected to the housing 2, in particular to the handle section 5. The actuating element 13 is arranged on the actuating element 9. The actuating element 13 is movable relative to the switching element 11 with the Hall sensor 12. In the preferred embodiment, the actuating element 13 is designed as a magnet. The magnet generates a magnetic field.As the magnet approaches the Hall sensor 12, a magnetic field flows through the Hall sensor 12. Depending on the magnetic flux density and the current, the Hall sensor 12 generates an output voltage. The electronic switch 10 generates a status signal. The status signal depends on the output voltage of the Hall sensor 12. The status signal is received by a schematically illustrated controller 17.

[0023] In a preferred embodiment, the status signal of the electronic switch 10 in the first position 51 of the actuating element 9 is a blocking signal. In the first position 51 of the actuating element 9, the actuating element 9 is not actuated. In the second position 51, in the exemplary embodiment, the actuating element 13 is arranged at a distance from the Hall sensor 12 such that the intensity of the magnetic field acting on the Hall sensor 12 is low. Consequently, the output voltage applied to the Hall sensor 12 is also low. In the second position 52 of the actuating element 9, the status signal of the electronic switch 10 is an enable signal. In the second position 52 of the actuating element 9, the actuating element 9 is actuated. In the second position 52, the actuating element 13 is arranged at a distance from the Hall sensor 12 such that the intensity of the magnetic field acting on the Hall sensor 12 is greater than in the first position 51.In the first position 51 of the actuating element 9, the distance between the actuating element 13 and the Hall sensor 12 is smaller than in the second position 52.

[0024] The controller 17 serves to control the drive motor 3. In the preferred embodiment, the controller 17 is designed as a computer-based control unit that serves for computer-aided signal processing. Consequently, the signal sent by the electronic switch 10 can be an information signal that is further processed in the controller 17. In the exemplary embodiment, the controller 17 is connected to the electronic switch 10 via a connecting line 18. The connecting line 18 is in the Figures 2 to 4 shown only schematically in dashed lines. In an alternative embodiment of the working device 1, the connection between the electrical switch 10 and the control unit 17 can also be wireless, in particular via radio.

[0025] The controller 17 is designed such that the drive motor 3 is only enabled by the controller 17 when a group of operating conditions is met. At least one operating condition of the group of operating conditions is the receipt of the status signal sent by the electronic switch 10, a release signal. In an alternative embodiment of the implement 1, it may also be provided to provide further operating conditions, such as the activation of an on / off switch of the implement 1, upon the fulfillment of which the operation of the drive motor 3 is enabled by the controller 17.

[0026] The controller 17 is configured such that upon receiving the blocking signal from the electronic switch 10, the controller blocks the operation of the drive motor 3. Furthermore, the controller 17 also blocks the operation of the drive motor 3 if the controller 17 does not receive a status signal from the electronic switch 10.

[0027] In order to activate the drive motor 3, in the present embodiment of the working device 1, the actuating element 9 must be actuated. This, on the one hand, mechanically releases the switching unit 8, and on the other hand, activates the electronic switch 10, which sends an enable signal to the controller 17. As a result, the drive motor 3 is released by the control circuit 17. In an alternative embodiment of the working device 1, it can also be provided that actuating the actuating element 9 merely electronically releases the drive motor 3 for operation. In such an embodiment, the switching lever 8 cannot be mechanically locked by the actuating element 9.

[0028] As in the Figures 2 and 3As shown, the actuating element 13 has a distance a from the pivot axis 15 of the adjusting element 9. Furthermore, the adjusting element 9 has an extension radius r which corresponds to the maximum distance between an outer contour 33 of the adjusting element 9 and the first pivot axis 15 of the adjusting element 9. The distance a between the actuating element 13 and the pivot axis 15 of the adjusting element 9 preferably corresponds to at least 60%, in particular at least 80%, preferably at least 90%, preferably at least 95% of the extension radius r. Accordingly, the actuating element 13 is to be arranged as far away as possible from the first pivot axis 15 of the adjusting element 9, so that the actuating element 13 is moved over the greatest possible distance even with a small pivot angle of the adjusting element 9.This results in an increased change in the magnetic flux density, so that the switching points from the first position 51 to the second position 52 can be determined very precisely.

[0029] In an alternative embodiment of the work device 1, it can be provided that the electronic switch 10 generates a continuously variable status signal. The continuously variable status signal depends on a sensor distance b, wherein the sensor distance b corresponds to the distance between the actuating element 13 and the Hall sensor 12. As the sensor distance b decreases, the magnetic flux density at the Hall sensor 12 increases, whereby the output voltage of the Hall sensor 12 also increases. The controller 17 is designed such that it can continuously determine the position of the actuating element 9, in particular the angular position of the actuating element 9, using the continuously variable status signal of the Hall sensor 12. Thus, the continuously variable status signal can be used analogously to the signal from a rotary encoder to determine the angular position of the actuating element 9.

[0030] In an alternative, not shown embodiment of the working device 1, it can also be provided that a magnet and the switching element 11 with the Hall sensor 12 are firmly fixed relative to one another. Accordingly, the magnet and the Hall sensor 12 are not movable relative to one another. The magnet is arranged opposite the Hall sensor 12 such that the magnet is in operative connection with the Hall sensor 12, i.e. the magnetic field of the magnet 12 acts on the Hall sensor 12. In such an embodiment of the working device 1, the actuating element 13 arranged on the adjusting element 9 is designed as a shielding element. The actuating element 13 is arranged so as to be movable relative to the switching element 11 with the Hall sensor 12 and to the magnet. An active zone is formed between the Hall sensor 12 and the magnet. In the first position 51 of the adjusting element 9, the actuating element 13 designed as a shielding element is arranged outside the active zone.The magnet acts on the Hall sensor 12, causing the switching element 11 to output the status signal as an enable signal to the controller 17. In the second position 52 of the actuating element 9, the actuating element 9 is located between the magnet and the Hall sensor 12 in the effective zone. This shields the Hall sensor 12 from the magnetic field emanating from the magnet. The switching element 11 sends the status signal as an enable signal to the controller 17.

[0031] In the preferred embodiments according to the Figures 2 to 4The switching element 11 is designed as a printed circuit board. The Hall sensor 12 is attached to the printed circuit board. Accordingly, the Hall sensor 12 is preferably a Hall sensor 12 integrated into the printed circuit board. Thus, the Hall sensor 12 is part of the circuit of the switching element 11. The switching element 11 preferably comprises signal amplification, analog-to-digital conversion, digital signal processing, and / or offset and temperature compensation. The Hall sensor 12 is preferably designed as a lateral Hall sensor or as a vertical Hall sensor. In an alternative embodiment, it may also be expedient to design the Hall sensor 12 as a 3D Hall sensor. It may also be expedient to design the Hall sensor 12 as a gradient Hall sensor.

[0032] In Fig. 41 shows an embodiment of a hand-held working device 1 according to the invention, wherein the working device 1 comprises a further actuating element 14. The further actuating element 14 is preferably designed as a magnet. In the preferred embodiment, the further actuating element 14 interacts with the Hall sensor 12. The further actuating element 14 is provided on a further adjusting element 30. In the exemplary embodiment, the further adjusting element 30 is the switching unit 8. The further actuating element 14 is preferably arranged on an outer contour 32 of the switching unit 8. Accordingly, when the switching unit 8 is pivoted about the second pivot axis 16, the further actuating unit 14 is also pivoted. Accordingly, the further actuating unit 14 is arranged so as to be movable relative to the Hall sensor 12.The further actuating element 14 is arranged on the switching unit 8 such that the further actuating element 14 has a maximum distance from the Hall sensor 12 when the switching unit 8 is inoperative. In the operating position of the switching unit 8, the actuating element 14 is at a distance from the Hall sensor 12 that is smaller than the maximum distance. This increases the magnetic flux density flowing through the Hall sensor 12, which also increases the output voltage of the Hall sensor 12. When the switching unit 8 is inoperative, the electronic switch 10 sends a first signal to the control unit 17. When the switching unit 8 is inoperative, the electronic switch 10 sends a second signal to the control unit 17. The control unit 17 is designed such that it does not actuate the drive motor 3 upon receiving the first signal from the electronic switch 10.The control unit 17 is configured to actuate the drive motor 3 upon receipt of the second signal from the electronic switch 10. In a preferred embodiment of the implement 1, the electronic switch 10 generates a continuously variable status signal depending on the distance of the further actuating element 14 from the Hall sensor 12. The dependency of the continuously variable status signal has already been described above.

[0033] The controller 17 is designed such that it can continuously determine the position of the switching unit 8, in particular the angular position of the switching unit 8, using the continuously variable status signal of the Hall sensor 12. Based on this status signal, the controller 17 controls the drive motor 3, preferably continuously.

[0034] In the version of the working device 1 according to Fig. 4The electronic switch 10 is arranged such that it can detect the magnetic fields caused by the movements of the actuating element 13 and the further actuating element 14. In the present embodiment, the actuating element 13 arranged on the actuating element 9 is arranged on a switching tongue 31 of the actuating element 9, which extends toward the electronic switch 10.

[0035] As in Fig. 4As shown, the actuating element 13 and the additional actuating element 14 act on only one Hall sensor 12. The controller 17 is designed such that it detects the positions of the actuating element 9 and the switching unit 8 solely based on the signals received from the one electronic switch 10. For this purpose, the Hall sensor 12 is preferably arranged as a 3D Hall sensor. This allows the Hall sensor 12 to also detect the magnetic fields of the actuating elements 13, 14 that are not aligned perpendicular to the Hall sensor 12.

[0036] In a further, not shown, alternative embodiment of the working device 1, it can also be provided that the working device 1 comprises two Hall sensors, both of which are arranged on the one switching element 11 designed as a circuit board. Each Hall sensor is assigned to an actuating element 13, 14.

[0037] In a further embodiment of the hand-held tool 1 (not shown in detail), the tool 1 comprises a braking device with a brake lever. The braking device serves to brake the tool. For this purpose, the braking device preferably acts on a drive element, wherein the drive element is driven by the drive motor 3 and acts on the tool 4. It may be expedient for the actuating element 9 of the tool 1 to be designed as a brake lever. Accordingly, the actuating element 13 is arranged on the brake lever. When the brake lever is moved, the actuating element 13 is moved relative to the Hall sensor 12, whereby the controller 17 can detect the position of the brake lever and thus also the state of the braking device via the status signals emitted by the switching element 11. Based on this information, the controller 17 can enable or disable the operational readiness of the drive motor 3.

Claims

1. Handheld work apparatus, - having a housing (2), a tool (4) and a drive motor (3) arranged in the housing (2) for driving the tool (4), - having a switching unit (8) for actuating the drive motor (3), - having at least one setting element (9), wherein the at least one setting element (9) can be switched at least to a first position (51) and to a second position (52), - having an electronic switch (10) for detecting the switching positions of the at least one setting element (9), wherein the electronic switch (10) generates a state signal dependent on the switching positions of the setting element (9), - and having a controller (17), wherein the controller (17) switches the operational readiness of the drive motor (3) depending on the state signal of the electronic switch (10), wherein the electronic switch (10) comprises a switching element (11) with a Hall sensor (12) and an actuating element (13) formed separately from the switching element (11), wherein the actuating element (13) for actuating the switching element (11) is operatively connected to the Hall sensor (12) and is arranged on the at least one setting element (9), characterized in that a further setting element (30) with a further actuating element (14) for actuating the switching element (11) is provided.

2. Work apparatus according to Claim 1, characterized in that the switching element (11) comprises a circuit, wherein the Hall sensor (12) is part of the circuit.

3. Work apparatus according to Claim 1 or 2, characterized in that the Hall sensor (12) is arranged on a printed circuit board.

4. Work apparatus according to one of Claims 1 to 3, characterized in that the actuating element (13) is designed as a magnet for actuating the switching element (11).

5. Work apparatus according to one of Claims 1 to 3, characterized in that the actuating element (11) is designed as a shielding element for interrupting the magnetic field between the magnet and Hall sensor (12).

6. Work apparatus according to one of Claims 1 to 5, characterized in that the setting element (9) is a locking lever, wherein the locking lever, in the first position (51), releases the switching unit (8) for actuation and, in the second position (52), locks said switching unit.

7. Work apparatus according to one of Claims 1 to 5, characterized in that the work apparatus (1) comprises a brake device with a brake lever, wherein the at least one setting element (9) corresponds to the brake lever of the brake device.

8. Work apparatus according to one of Claims 1 to 7, characterized in that, in at least one of its at least two positions (51, 52), the setting element (9) is mechanically operatively connected to the switching unit (8).

9. Work apparatus according to Claim 8, characterized in that the actuating element (13) is arranged on the setting element (9) in such a manner that the mechanical switching state of the setting element (9) is coupled with the electrical switching state of the electronic switch (10).