Hand-held power tool with control unit and locking units

Abstract

A hand-held power tool, in particular a cordless screwdriver, with a control unit (12) comprising a control element (28) and a control element position sensor (30) and designed to switch between left-hand and right-hand rotation, characterized in that the control element (28) and the control element position sensor (30) each have a detent unit (48, 64) designed to detent at least in a stop position (60) of the control unit (12), wherein one of the detent units (48, 64) is designed to detent in a right-hand rotation position (58) and / or a left-hand rotation position (62) of the control unit (12), and wherein one of the detent units (48, 64) is designed to detent the control element (28) with different holding forces in the stop position (60), the right-hand rotation position (58) and / or the left-hand rotation position (62), wherein at least one of the detent units (48, 64) is intended toto lock the control unit (12) in the positions with different holding forces, wherein the holding force in the stop position (60) is greater than in the clockwise position (58) and in the counterclockwise position (62),

Description

State of the art A hand-held power tool, in particular a cordless screwdriver, with a control unit comprising a control element and a control element position sensor, designed to switch between left-hand and right-hand rotation, has already been proposed, as for example in EP 1 675 708 B1. US 7 987 920 B2 discloses a screwdriver comprising a housing and a motor, the motor being connected to an output shaft via a gearbox. DE 10 2009 027 705 A1 describes a hand-held power tool with a device for specifying a selected direction of rotation of a drive motor associated with the power tool, which is arranged in a tool housing, wherein the device has an actuating element accessible from outside the tool housing for the mechanical actuation of a switching element. From DE 10 2012 220 423 A1, a hand-held machine tool with a drive unit and with an operating unit is known, which is designed to switch between left-hand and right-hand rotation by moving an operating element of the operating unit essentially parallel to a tool rotation axis. DE 10 2008 044 273 A1 represents further state of the art. Disclosure of the invention The invention relates to a hand-held power tool, in particular a cordless screwdriver, with a control unit that has a control element and a control element position sensor and is designed to switch between left-hand and right-hand rotation. It is proposed that the control element and the control element position sensor each have a detent unit designed to engage at least in one stop position of the control element. A "control element" is understood to be, in particular, a device designed to control the movement of a tool holder of the hand-held power tool, dependent on an operator's action. Preferably, the control element switches a drive unit of the hand-held power tool between counterclockwise and clockwise rotation. Preferably, the control element outputs an electrical control parameter, upon which the drive unit switches between counterclockwise and clockwise rotation. Alternatively, the control element could act mechanically on the rotation reversal device of the drive unit.Advantageously, the drive unit includes electronics that control and / or regulate a gearbox and / or, advantageously, a motor of the drive unit depending on the operating parameter. An "operating element" is understood to be, in particular, an element of the operating unit that is intended to be actuated by an operator, especially directly, to switch between clockwise and counterclockwise rotation. Preferably, the operating element is arranged at least partially on an external surface of the hand-held power tool. In particular, an "operating element position sensor" is understood to be a means that is intended to output a parameter, mechanically and / or advantageously electrically, that depends on the position of the operating element. Preferably, the operating element position sensor is designed as an electrical switch, in particular with three different switch positions.Alternatively, or especially additionally, the control element position sensor could be designed as a potentiometer. "Provided for" is understood to mean, in particular, specially equipped, designed, and / or arranged. Specifically, "counterclockwise rotation" is understood to mean an operating state in which the tool holder is driven counterclockwise when viewed in the main working direction. "Right-hand rotation" is understood to mean, in particular, an operating state in which the tool holder is driven clockwise when viewed in the main working direction. "Main working direction" is understood to mean, in particular, a direction directed into a workpiece in front of the tool holder.A "latching unit" is understood to mean, in particular, a unit designed to exert a force on the control element that opposes movement, at least from the stop position. Specifically, the term "latching" means that the force required by the operator to move the control element from a position in at least one direction is greater than the force that opposes movement of the control element in a position other than that position. Preferably, the control element latches in the stop position in two directions, particularly in the direction of a counterclockwise rotation and in the direction of a clockwise rotation. Preferably, the latching unit is designed to latch the control element against a spring force.The phrase "latched against a spring force" is intended to mean, in particular, that the control element can be moved in a position against the force of a spring. Preferably, the spring force acts essentially perpendicular to a direction of movement of the control element. Alternatively, the spring force could be oriented essentially parallel to a direction of movement of the control element, with the spring force acting on the control element being essentially zero in the control element's stop position. A "stop position" is understood to mean, in particular, a position of the control element in which the drive unit prevents the operator from activating the drive unit's motor. Preferably, the stop position of the control element is located between the left-hand and right-hand rotation positions of the control element.The inventive design of the hand-held power tool allows for a high holding force to be achieved, at least in the stop position, through simple construction. Furthermore, the motor and electronics of the drive unit are advantageously protected against high currents that can occur when the operator switches between left and right rotation with the drive unit activated. In a further embodiment, it is proposed that at least one of the detent units be designed to lock in a clockwise and / or counterclockwise rotation position of the control unit, thereby preventing accidental adjustment of the control element. Preferably, both detent units are designed to lock in the counterclockwise and / or clockwise rotation positions. A "counterclockwise position" of the control element is understood to mean, in particular, a position of the control element in which counterclockwise rotation is activated when the engine is running. A "clockwise position" of the control element is understood to mean, in particular, a position of the control element in which clockwise rotation is activated when the engine is running. Preferably, at least one of the detent units is designed, and especially preferably, to lock in both the counterclockwise and clockwise rotation positions. Furthermore, it is proposed that at least one of the detent units be designed to lock the control element with different holding forces in the stop position, the clockwise position, and / or the counterclockwise position, thereby enabling convenient operation. A "holding force" is understood to mean, in particular, the maximum force that the operator must apply to the control element to move it from the stop position, the counterclockwise position, and / or the clockwise position to any other position. Preferably, both detent units are designed to lock the control element with different holding forces in the stop position, the counterclockwise position, and / or the clockwise position. It is particularly advantageous if the control element locks with the same holding force in both the counterclockwise and clockwise positions. Furthermore, it is proposed that the locking unit of the control element has multiple locking devices, thereby achieving a high holding force in a simple and space-saving manner. Alternatively, the locking unit of the control element could have only one locking device. In particular, a "locking device" is understood to be a device that directly generates the holding force. Preferably, the locking unit of the control element has two locking devices, advantageously four locking devices, and most advantageously three locking devices. Alternatively, the locking unit of the control element could have more than four locking devices. Furthermore, it is proposed that the control element position sensor have an actuation direction that differs from the actuation direction of the control element, thereby advantageously allowing the control element position sensor to be arranged in a machine housing of the hand-held power tool. An "actuation direction of the control element position sensor" is understood to mean, in particular, a direction in which a movable part of the control element position sensor is movably mounted, especially within a stationary part of the control element position sensor, for changing the characteristic value of the control element position sensor. In particular, an "actuation direction of the control element" is understood to mean a direction in which the control element is movably mounted. Preferably, the control element is mounted differently from the movable part of the control element position sensor.The term "different" shall be understood in particular to mean that the direction of actuation of the control element and the direction of actuation of the control element position sensor differ from each other by more than 45 degrees, advantageously by more than 60 degrees, and particularly advantageously by substantially 90 degrees. Furthermore, it is proposed that the control element be mounted so as to be displaceable essentially parallel to a tool rotation axis, thereby providing a particularly intuitive operating unit for switching between counterclockwise and clockwise rotation. In particular, the term "essentially" with regard to a direction is to be understood as meaning that the directions deviate by less than 30 degrees, advantageously by less than 15 degrees, and most advantageously by less than 5 degrees from the specified directions. A "tool rotation axis" is to be understood in particular as an axis about which the hand-held power tool rotates the tool holder. In an advantageous embodiment of the invention, it is proposed that the hand-held power tool has a pistol-shaped housing with a main handle, thus enabling a comfortable hand position, particularly when a work operation requires significant force from the operator. The term "pistol-shaped" is understood to mean, in particular, that the housing comprises a housing section extending parallel to the tool's axis of rotation and a housing section forming the main handle, extending approximately perpendicular to the tool's axis of rotation, that is, in particular at an angle deviating by less than 45 degrees from the perpendicular to the tool's axis of rotation. Specifically, the term "machine housing" is understood to mean a component that arranges and protectively encloses the other components of the hand-held power tool relative to one another.The term "main handle" refers in particular to an area of ​​the machine housing that is intended to be gripped by the operator during a work process. Furthermore, it is proposed that the hand-held power tool include a fastening and contacting device that secures the control position sensor within the machine housing, thereby enabling particularly cost-effective production. A "fastening and contacting device" is understood to mean, in particular, a means that positions the control position sensor within the machine housing and transmits electrical signals from the control position sensor. Advantageously, the fastening and contacting device is formed in one piece. Preferably, the fastening and contacting device is designed as a circuit board. Furthermore, it is proposed that the control element be mounted on a side of the machine housing facing away from the main handle, thus advantageously placing the control element within the operator's field of vision in a particularly large number of operating situations during a work process. Specifically, a "side facing away from the main handle" is understood to be a side of the machine housing that is adjacent to the drive unit, runs essentially parallel to the tool's axis of rotation, and lies at least partially on a straight line that intersects the main handle and the tool's axis of rotation. Furthermore, it is proposed that the machine housing have an overall length of less than 180 mm, which would allow the handheld power tool to be used advantageously in hard-to-reach places. The term "overall length" is understood to mean, in particular, the maximum dimension of the machine housing parallel to the tool's axis of rotation. Preferably, the machine housing has an overall length of less than 140 mm, and more preferably less than 120 mm. The hand-held power tool according to the invention is not intended to be limited to the application and embodiment described above. In particular, the hand-held power tool according to the invention may, in order to fulfill a function described herein, have a different number of individual elements, components and units than the number mentioned herein. drawing Further advantages will become apparent from the following description of the drawing. The drawing illustrates an embodiment of the invention. The drawing, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. Figure 1 shows a hand-held power tool according to the invention with a control unit comprising a control element and a control element position sensor, in a side view; Figure 2 shows a front view of the control element and the control element position sensor from Figure 1 in a clockwise position; Figure 3 shows the front view of the control element and the control element position sensor from Figure 1 in a counterclockwise position; Figure 4 shows the control element position sensor from Figure 1 in a perspective view; Figure 5 shows a rear view of the control element in a perspective view; Figure 6 shows the front view of the control element in a perspective view; Figure 7 shows a part of the hand-held power tool from Figure 1 with an open machine housing in a perspective view; Figure 8 shows a part of the hand-held power tool from Figure 1 in a sectional view.Fig. 9 shows a further embodiment of a hand-held power tool according to the invention with a control unit comprising a control element and a control element position sensor, in a partial section, and Fig. 10 shows the control element of the hand-held power tool from Fig. 9 in a perspective view. Description of the exemplary embodiment Fig. 1 shows a hand-held power tool 10 according to the invention, designed as a cordless screwdriver. The hand-held power tool 10 comprises a first control unit 12, a machine housing 14, a tool holder 16, a drive unit 18, electronics 20, a battery 21, and a second control unit 22. The second control unit 22 is provided for speed control of the drive unit 18. The battery 21 supplies the drive unit 18 with electrical energy via the electronics 20. The battery 21 is permanently integrated into the machine housing 14. The electronics 20 are designed to provide a direction of rotation of the drive unit 18, i.e., counterclockwise or clockwise, by varying the current supplied to a motor of the drive unit 18. Alternatively, a first control unit could change the current supplied to a motor of the drive unit.The drive unit 18 rotates the tool holder 16 about a tool axis 24 in operation. The drive unit 18 comprises the motor and a gearbox. The tool holder 16 is designed to secure a tool. In this case, the tool holder 16 is designed to secure a bit. The machine housing 14 has a total length of approximately 125 mm parallel to the tool axis of rotation 24. The machine housing 14 is pistol-shaped and comprises two housing halves. These halves are separated on a plane parallel to the tool axis of rotation 24. The machine housing 14 also forms a main handle 26, which is oriented approximately perpendicular to the tool axis of rotation 24. The electronics 20 and the battery 21 are located in the main handle 26. The second control unit 22 is located on the main handle 26. The second control unit 22 is positioned so that it can be operated by at least one index finger of a hand gripping the main handle 26. The first control unit 12 is mounted on a side of the machine housing 14 facing away from the main handle 26. As shown particularly in Figures 2 and 3, the first control unit 12 comprises a control element 28 and a control element position sensor 30. The drive unit 18 can be switched between left-hand and right-hand rotation by means of the first control unit 12. The control element 28 is arranged on the side of the machine housing 14 facing away from the main handle 26, so that it can be actuated by the operator. For actuation by the operator, the control element 28 is mounted to be displaceable in an actuation direction 32, which is oriented essentially parallel to the tool rotation axis 24. More precisely, the control element 28 is mounted to be movable within a small angular range about a pivot axis located at a distance from the control element 28. The pivot axis is located more than 5 cm away from the control element 28, which means that the control element 28 is mounted to be movable essentially in a translational manner. Alternatively, a control element could be mounted to be movable purely in a translational manner. As shown in Fig. 4, the control position sensor 30 has a part 34 movable in an actuation direction 40 of the control position sensor 30 relative to the machine housing 14 and a part 36 that is stationary relative to the machine housing 14. The movable part 34 of the control position sensor 30 is mounted in the stationary part 36 of the control position sensor 30. Electrical components of the control position sensor 30 (not shown) output a characteristic value that depends on the position of the movable part 34. The control position sensor 30 has several contacts 38 for outputting the characteristic value. The movable part 34 of the control position sensor 30 is movable parallel to a main dimension of the control position sensor 30. The direction of actuation 32 of the control element 28 differs from the direction of actuation 40 of the movable part 34 of the control element position sensor 30. The direction of actuation 32 of the control element 28 is essentially perpendicular to the direction of actuation 40 of the control element position sensor 30. As shown particularly in Fig. 5, the control element 28 has a conversion means 42, which is designed to transmit a movement of the control element 28 upon actuation into a movement of the movable part 34 of the control element position sensor 30 relative to the machine housing 14. The conversion means 42 is designed as a cam guide. The conversion means 42 comprises two parallel-aligned projections between which the movable part 34 of the control element position sensor 30 runs.The conversion surfaces 44, 46 of the conversion means 42, which exert a force on the movable part 34 of the control means position sensor 30 when the control element 28 is actuated, have an angle of essentially 45 degrees to the actuation direction 32 of the control element 28. The control position sensor 30 has a detent unit 48. The detent unit 48 of the control position sensor 30 is arranged essentially within the stationary part 36 of the control position sensor 30. The detent unit 48 of the control position sensor 30 comprises a spring-loaded detent element 50 and three detent recesses 52, 54, 56. The detent element 50 is movably mounted in the movable part 34 of the control position sensor 30. The detent recesses 52, 54, 56 are arranged on the stationary part 36 of the control position sensor 30. Here, the detent recesses 52, 54, 56 are formed as slots in a housing of the stationary part 36 of the control position sensor 30. Alternatively or additionally, at least one detent recess could be arranged on a movable part of a control device position sensor and at least one detent element on a stationary part of the control device position sensor. A spring (not shown) presses the detent element 50 into one of the detent recesses 52, 54, 56 in a clockwise position 58, a stop position 60, and a counterclockwise position 62. When the control element 28 is moved from the clockwise position 58, the stop position 60, and the counterclockwise position 62, the operator must apply a force to the control element 28 to move the detent element 50 out of one of the detent recesses 52, 54, 56. The detent element 50 can penetrate deeper into one of the detent recesses 54 than into at least one of the other two detent recesses 52, 56. The detent element 50 can penetrate deeper into a middle detent recess 54. This detent recess 54 is associated with the stop position 60. The movable part 34 of the control position sensor 30 thus detentes in the stop position 60 with a greater holding force than in the clockwise position 58 and the counterclockwise position 62. As shown in Figures 6, 7, and 8, the operating element 28 has a detent unit 64 comprising several detent elements 66, 68, and 70. The detent elements 66, 68, and 70 are integrally formed with a portion of the operating element 28. Each detent element 66, 68, and 70 is designed as a spring-loaded lug. A first detent element 66 is arranged on a side of the operating element 28 facing the tool holder 16. A second and a third detent element 68 and 70 are arranged on a side of the operating element 28 facing away from the tool holder 16. Between an actuating surface 78 of the control element 28, which the operator presses during actuation, and the detent elements 66, 68, 70, the control element 28 has spring sections 80, 82, 84 that connect the detent elements 66, 68, 70 to the actuating surface 78 in a spring-loaded manner. The machine housing 14 forms detent recesses 72, 74, 76 of the detent unit 64 of the control element 28.Alternatively or additionally, at least one locking element of a locking unit of a control element could be arranged on a machine housing, and locking recesses of the locking unit of the control element could be arranged on the control element. Furthermore, alternatively or additionally, at least one of the locking recesses could be spring-loaded. In addition, locking recesses of a locking unit of a control element could be designed differently to provide different holding forces. The hand-held power tool 10 has a fastening and contacting element 86 that secures the control position sensor 30 in the machine housing 14. The fastening and contacting element 86 is designed as a circuit board. The control position sensor 30 is soldered to the fastening and contacting element 86. The fastening and contacting element 86 is positively locked between the two housing halves of the machine housing 14. Figures 9 and 10 show a further embodiment of the invention. The following descriptions and drawings are essentially limited to the differences between the embodiments, whereby with regard to identically designated components, in particular components with the same reference numerals, reference may also be made to the drawings and / or the description of the other embodiments, in particular Figures 1, 2, 3, 4, 5, 6, 7 to 8. Fig. 9 shows a part of a hand-held power tool 10, designed as a cordless screwdriver. The hand-held power tool 10 comprises a control unit 12 and a drive unit (not shown in detail). The control unit 12 is designed to switch between left and right rotation of the drive unit. The control unit 12 has a control element 28 and a control element position sensor 30. The control element position sensor 30 has a detent unit 48, which is designed as described in the preceding embodiment. The control element 28 has a detent unit 64 with a single detent element 88. The detent element 88 is arranged on a side of the control element 28 facing a tool holder. The detent element 88 is integrally formed with a portion of the control element 28. The detent element 88 is designed as a spring-loaded lug. Between an actuating surface 78 of the control element 28, which the operator presses during actuation, and the detent element 88, the control element 28 has a spring section 80 that connects the detent element 88 to the actuating surface 78 in a spring-loaded manner. The detent element 88 engages a first detent surface 90 in a counterclockwise rotation position, a second detent surface 92 in a stop position, and a third detent surface 94 in a clockwise rotation position. The detent surfaces are internal surfaces of a machine housing 14 of the hand-held power tool 10.

Claims

A hand-held power tool, in particular a cordless screwdriver, with a control unit (12) comprising a control element (28) and a control element position sensor (30) and designed to switch between left-hand and right-hand rotation, characterized in that the control element (28) and the control element position sensor (30) each have a detent unit (48, 64) designed to detent at least in a stop position (60) of the control unit (12), wherein one of the detent units (48, 64) is designed to detent in a right-hand rotation position (58) and / or a left-hand rotation position (62) of the control unit (12), and wherein one of the detent units (48, 64) is designed to detent the control element (28) with different holding forces in the stop position (60), the right-hand rotation position (58) and / or the left-hand rotation position (62), wherein at least one of the detent units (48, 64) is intended toto lock the control unit (12) in the positions with different holding forces, wherein the holding force in the stop position (60) is greater than in the clockwise position (58) and in the counterclockwise position (62), Hand-held power tool according to claim 1, characterized in that the locking unit (64) of the control element (28) has several locking means (66, 68, 70). Hand-held power tool according to claim 1 or 2, characterized in that the control element position sensor (30) has an actuation direction (40) which differs from an actuation direction (32) of the control element (28). Hand-held power tool according to one of the preceding claims, characterized in that the operating element (28) is slidably mounted essentially parallel to a tool rotation axis (24). Hand-held power tool according to one of the preceding claims, characterized by a pistol-shaped machine housing (14) which has a main handle (26). Hand-held power tool according to claim 5, characterized by a fastening and contacting means (86) which fastens the control means position sensor (30) in the machine housing (14). hand-held power tool at least according to claim 5, characterized in that the operating element (28) is mounted on a side of the machine housing (14) facing away from the main handle (26). Hand-held power tool at least according to claim 6, characterized in that the machine housing (14) has a total length of less than 180 mm. hand-held power tool according to one of the preceding claims, characterized in that the control element position sensor (30) is provided to output a characteristic parameter that depends on a position of the control element (28) mechanically and / or advantageously electrically. Hand-held power tool according to claim 3, characterized in that the actuation direction (40) of the control element position sensor and the actuation direction (32) of the control element differ substantially by 90 degrees from each other and the control element (28) has a conversion means (42) in the form of a cam guide. Hand-held power tool according to claim 2, characterized in that the multiple locking means (66, 68, 70) are designed as spring-loaded noses formed integrally with the operating element (28). Hand-held power tool according to claim 5, characterized in that the operating element (28) is arranged so that it can be operated by the thumb of a hand holding the main handle (24). Hand-held power tool according to one of the preceding claims, characterized in that the operating unit (14a-g) has at least one display means (30a-g) which indicates to the operator a set direction of travel.

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