Handheld electric rotary tool

Abstract

Power tool (1), comprising: a tool housing (2) having a wall portion (5), the wall portion (5) having a switch opening (16) defined by a wall edge (18) extending between an outer surface (19) of the wall and an inner surface (20) of the wall; a motor (22) arranged in the tool housing (2); a power source (44) connected to the motor (22) via an electrical circuit (26), the electrical circuit (26) being arranged in the tool housing (2); and an electrical switch (38) arranged in the electrical circuit (26), the electrical circuit (26) having a switch main part (39) and a contact element (40) protruding from the switch main part (39), the contact element (40) being movable relative to the switch main part (39) between a first switching position in which the electrical circuit (26) is open and current is prevented from flowing from the power source (44) to the motor (22), and a second switching position in which the electrical circuit (26) is closed and current flows from the power source (44) to the motor (22), a switching actuator (50) arranged in the tool housing (2) such that it is accessible to an operator of the tool (1) via the switch opening (16), the switching actuator (50) comprising a guide plate (51) arranged in the tool housing (2) and an elastic arm (66) extending from the guide plate (51) and formed integrally therewith, where the switching actuator (50) is movable relative to the tool housing (2) between a first actuator position and a second actuator position, when the switching actuator (50) is in the first actuator position, the guide plate (51) is arranged inwardly relative to an inner surface of the wall section (5), a first edge section of the guide plate (51) is in a first guide plate position relative to the tool housing (2), the elastic arm (66) has a first distance (d1) relative to the guide plate (51) and thus projects into the switch opening (16), and a section of an edge of the elastic arm (66) engages the wall edge (18), when the switching actuator (50) is in the second actuator position, the guide plate (51) is arranged inwardly with respect to the inner surface of the wall section (5), the first edge section of the guide plate (51) is in a second guide plate position with respect to the tool housing (2), the second guide plate position is at a distance from the first guide plate position in the longitudinal direction, the elastic arm (66) has a second distance (d2) with respect to the guide plate (51), and the second distance (d2) is less than the first distance (d1), whereby the section of an edge of the elastic arm (66) is detached from the wall edge (18) and is arranged inwardly with respect to the inner surface of the wall section (5), and the switching actuator (50) interacts with the contact element (40) in such a way that, when the switching actuator (50) is in the first actuator position, the contact element (40) is in the first switching position, and, when the switching actuator is in the second actuator position, the contact element (40) is in the second switching position.

Description

background

[0001] Handheld electric rotary tools may include a motor with an output shaft to which tools and / or accessories can be attached. For example, a wide variety of accessories can be interchangeably connected to the output shaft, including bits, grinding wheels, polishing wheels, scouring pads, etc. The motor is powered by a power source, and its operation is controlled by an on / off switch located in an electrical circuit connecting the motor to the power source.

[0002] Some small handheld electric rotary tools have an on / off switch designed to operate via a sliding motion. In some cases, on / off slide switches may be inadvertently operated. For example, such inadvertent operation may occur if the tool is accidentally dropped in such a way that it strikes the switch. In this situation, the power tool may be switched on even though no operator is holding it. Furthermore, if a machining accessory such as a bit, grinding wheel, scouring pad, etc. is attached to the power tool output shaft, the power tool may cause damage to the surrounding area if the power tool is switched on even though no operator is holding it. For this reason at least, it is desirable to prevent inadvertent operation of the on / off switch.

[0003] For example, DE 39 02 964 C1 describes an electrically driven switch-on device for food slicers, such as bread and cold cuts slicers, comprising a button element in a housing wall of the food slicer for actuating an on / off switch, and a spring-loaded safety device for preventing the switch from being accidentally closed. WO 2018 / 081 331 A1 describes a soldering tool comprising a housing with a handle portion defining a first longitudinal axis and a head portion coupled to the handle portion and defining a second axis. The soldering tool further comprises a heating element connected to the head portion and movable therewith. The head portion is movable relative to the handle portion between a first orientation in which the second axis is coaxial with the first axis and a second orientation in which the second axis is not coaxial with the first axis.US 2014 / 0 069 676 A1 describes mechanisms for controlling the speed of the output shaft of a rotating power tool. DE 28 50 120 A1 describes a switch actuating device for the motor of a portable power tool. Brief description

[0004] In some aspects, a power tool includes a tool housing. The tool housing includes a wall portion, and the wall portion includes a switch opening defined by a wall edge extending between an outer surface of the wall and an inner surface of the wall. The power tool includes a motor disposed within the tool housing and a power source connected to the motor via an electrical circuit. The electrical circuit is disposed within the tool housing. The power tool includes an electrical switch disposed within the electrical circuit. The electrical switch includes a switch body and a contact element extending from the switch body.The contact element is movable relative to the switch body between a first switching position in which the electrical circuit is open and current is prevented from flowing from the power source to the motor, and a second switching position in which the electrical circuit is closed and current flows from the power source to the motor. The power tool also has a switching actuator arranged in the tool housing and thus accessible to an operator of the tool via the switch opening. The switching actuator has a guide plate arranged in the tool housing and a resilient arm extending from the guide plate and formed integrally therewith. The switching actuator is movable relative to the tool housing between a first actuator position and a second actuator position.When the switch actuator is in the first actuator position, the guide plate is arranged inward with respect to an inner surface of the wall section, a first edge section of the guide plate is in a first guide plate position with respect to the tool housing, the elastic arm has a first distance with respect to the guide plate and thus projects into the switch opening, and a section of an edge of the elastic arm engages the wall edge.When the switching actuator is in the second actuator position, the guide plate is arranged inward with respect to the inner surface of the wall section, the first edge section of the guide plate is in a second guide plate position with respect to the tool housing, the second guide plate position is at a distance from the first guide plate position in the longitudinal direction, the elastic arm has a second distance with respect to the guide plate and the second distance is less than the first distance, whereby the section of an edge of the elastic arm is detached from the wall edge and is arranged inward with respect to the inner surface of the wall section.The switching actuator also interacts with the contact element in such a way that when the switching actuator is in the first actuator position, the contact element is in the first switching position, and when the switching actuator is in the second actuator position, the contact element is in the second switching position.

[0005] In some embodiments, the switching actuator is actuated by applying a manual force to the elastic arm in two directions.

[0006] In some embodiments, movement of the switching actuator between the first actuator position and the second actuator position requires a first movement in a first direction followed by a second movement in a second direction, and the second direction is perpendicular to the first direction.

[0007] In some embodiments, the guide plate includes a central opening defined by an inner edge, and the resilient arm extends from the inner edge.

[0008] In some embodiments, the elastic arm includes a lever portion and a slope portion connecting the lever portion to the inner edge, and the slope portion is sloped relative to an outwardly facing surface of the guide plate, thereby offsetting the lever portion from the guide plate.

[0009] In some embodiments, the switching actuator is a spring.

[0010] In some embodiments, the guide plate includes a switching opening. Additionally, when the switch actuator is in the first actuating position, a portion of the contact element extends into the offset opening, thereby positioning the electrical switch in the first switching position. When the switch actuator is in the second actuating position, the portion of the contact element abuts an inwardly facing surface of the guide plate, thereby positioning the electrical switch in the second switching position.

[0011] In some embodiments, when the switching actuator is in the first actuation position, the resilient arm is biased toward the wall edge such that the portion of an edge of the resilient arm engages the wall edge, thereby preventing movement of the switching actuator to the second actuation position. Additionally, when the switching actuator is in the second actuation position, the portion of an edge of the resilient arm is pushed away from the wall edge, thereby enabling movement of the switching actuator to the second actuation position.

[0012] In some embodiments, the tool housing includes a boss extending from the wall portion and at least partially underlying the switch opening, and the switch actuator is positioned on and slidable relative to the boss.

[0013] In some embodiments, the projection has an opening and the contact element extends through the opening.

[0014] In some embodiments, the tool housing includes a pair of positioning ribs extending from the wall portion toward the switching actuator, the positioning ribs extending in a direction perpendicular to a direction of movement of the switching actuator. The guide plate includes a second edge portion and a tab extending from the second edge portion. When the switching actuator is in the first actuating position, the tab abuts a first rib of the pair of positioning ribs, and the first rib of the pair of positioning ribs is disposed between the tab and the second rib of the pair of positioning ribs. When the switching actuator is in the second actuating position, the tab is further disposed between the first rib of the pair of positioning ribs and a second rib of the pair of positioning ribs.

[0015] In some embodiments, the resilient arm includes an outwardly facing surface and a plate extending from the outwardly facing surface. The plate is shaped and sized to be received within the switch opening regardless of the switch actuator position, and the plate includes surface features that facilitate a gripping of the plate by a power tool user.

[0016] A handheld electric rotary tool includes a motor and a power source connected via a switch arranged in an electrical circuit. The switch controls the on / off state of the motor and is actuated by a switch actuator that serves as a spring element. The switch actuator includes a guide plate mounted on the housing and a resilient arm extending from the guide plate into an opening in the tool housing. When the switch actuator is in a first actuating position relative to the housing, the resilient arm is biased toward an edge of the opening and engages the edge, thereby preventing inadvertent movement of the switch actuator to the second actuating position.When the switching actuator is actuated by applying a manual force in two directions to the elastic arm, the elastic arm is pushed away from the edge, allowing the switching actuator to move to the second actuator position.

[0017] The switching actuator is made of molded plastic and is designed to act as a spring. The switching actuator requires two movements that the user must make relative to the tool housing to operate the switch that controls the on / off state of the motor. The first movement is inward and is performed by the user pressing the actuator switch inward with the tip of a finger, thereby exerting a radially directed force on the switching actuator. This movement detaches the actuator switch from the tool housing. The second movement is longitudinal and is performed by the user exerting a longitudinal force on the switching actuator by moving the actuator longitudinally with the tip of a finger. The second movement can only be performed after the first movement.Although an impact load applied to the switching actuator, for example caused by the power tool falling onto the switching actuator, may inadvertently cause the first movement, it is unlikely that the subsequent second movement will occur during the impact, whereby the switching actuator would prevent an inadvertent change in the operating state of the power tool. Short description of the drawings Fig. 1 is a top perspective view of the handheld electric rotary tool having a switching actuator. Fig. 2 is a perspective view of the power tool of Fig. 1, where a section of the tool housing has been removed in the illustration so that the internal components of the power tool can be seen. Fig. Figure 3 is a simplified diagram illustrating the electrical circuit used in the power tool of Fig. 1 is provided for. Fig. 4 is a plan view of a portion of the power tool of Fig. 1. Fig. 5 is a side view of a portion of the tool housing of the power tool of Fig. 1. Fig. 6 is a perspective view of a portion of the power tool of Fig. 1, wherein a section of the tool housing has been removed in the illustration so that the internal components of the power tool can be seen and the switching actuator is shown in the first actuator position. Fig. Figure 7 is another perspective view of a portion of the power tool of Fig. 1, wherein in the illustration a section of the tool housing and some internal components are removed so that the switching actuator can be seen and the switching actuator is shown in the second actuator position. Fig. Figure 8 is a perspective view of the switching actuator shown in a configuration corresponding to the first actuator position. Fig. 9 is a side view of the switching actuator shown in a configuration corresponding to the first actuator position. Fig. 10 is a perspective view of the switching actuator shown in a configuration corresponding to the second actuator position. Fig. 11 is a side view of the switching actuator shown in a configuration corresponding to the second actuator position. Fig. 12 is a cross-sectional view of the power tool of Fig. 1 along line 12-12 from Fig. 6, whereby a section of the tool housing and some internal components are removed in the illustration, so that the switching actuator can be seen in the first actuator position. Fig. 13 is a cross-sectional view of the power tool of Fig. 1 along line 13-13 from Fig. 7, wherein a section of the tool housing and some internal components are removed in the illustration, so that the switching actuator can be seen in the second actuator position. Fig. 14 is another perspective view of the handheld electric rotary tool of Fig. 1. Fig. 15 is a front view of the handheld electric rotary tool of Fig. 1. Fig. 16 is a rear view of the handheld electric rotary tool of Fig. 1. Fig. 17 is a left side view of the handheld electric rotary tool of Fig. 1. Fig. 18 is a right side view of the handheld electric rotary tool of Fig. 1. Fig. 19 is a plan view of the handheld electric rotary tool of Fig. 1. Fig. 20 is a view of the handheld electric rotary tool of Fig. 1 from the bottom. Detailed description

[0018] With reference to Fig. 1 to 3, a handheld electric rotary tool 1 includes an electric motor 22 disposed within a tool housing 2. The tool housing 2 has a generally cylindrical shape with an ergonomic profile to enable it to be held in a user's hand, whereby the tool housing 2 serves as a handle of the power tool 1. An output shaft 23 of the electric motor 22 extends parallel to a longitudinal axis 21 of the tool housing 2 and is gearlessly connected to a tool spindle 24. The tool spindle 24 projects outwardly from a first end 3 of the tool housing 2 and is adapted to provide mechanical connection to various accessories (not shown) to enable machining of a workpiece.The accessories may include, but are not limited to, an engraving cutter, a milling tool, a grinding wheel, a grindstone, a polishing tip, a polishing wheel, a polishing brush, a cutting wheel, a saw blade, and a drill bit. The electric motor 22 is powered by a power source 44 that is detachably connected to a second end 4 of the tool housing 2. The power source 44 is connected to the electric motor 22 via an electrical circuit 26 disposed within the tool housing 2. The power tool 1 has an electrical switch 38 disposed within the electrical circuit and controlling the on / off state of the electric motor 22. The electrical switch 38 is disposed entirely within the tool housing 2 and is actuated by an operator of the power tool 1 via a switch actuator 50.The switching actuator 50 is arranged in the tool housing 2 such that it is accessible to an operator of the power tool 1 via a switch opening 16 provided in the tool housing 2. The switching actuator 50 interacts with the electrical switch 38 such that a movement of the switching actuator 50 relative to the tool housing 2 causes a change in the on / off state of the electrical switch 38. The switching actuator 50 is thus used by the operator of the power tool 1 to control the on / off state of the power tool 1. The switching actuator 50 has a guide plate 51 arranged in the tool housing 2 and an elastic arm 66 extending from the guide plate 51 and formed integrally therewith. The elastic arm 66 projects into the switch opening 16 and is thus accessible to the operator of the power tool 1.The switching actuator 50 is designed to prevent inadvertent actuation of the electrical switch 38, as described in detail below.

[0019] In the illustrated embodiment, the power source 44 includes a battery pack 45 detachably connected to the second end 4 of the tool housing. In further embodiments, the power source 44 may consist of primary batteries housed within the tool housing 2. In further embodiments, the power source 44 may be located remotely from the tool housing 2 and connected to the tool housing 2 via a cable (not shown) surrounding an electrically conductive wire.

[0020] The electrical switch 38 has a switch body 39 and a contact element 40 that protrudes from the switch body 39. In the illustrated embodiment, the contact element 40 is an elongated lever arm that is used to switch the electrical switch 38 between a first and second position by changing the angle of the contact element 40 relative to the switch body 39. The contact element 40 is particularly movable via the switch body 39 between a first switching position, which is Fig. 3 with the broken line 38(1), in which the electrical circuit is open and current is prevented from flowing from the power source 44 to the motor 22, and a second switching position. In the second switching position, which is shown in Fig. 3 with the broken line 38(2), the electrical circuit is closed and current flows from the power source 44 to the motor 22. In the illustrated embodiment, the electrical switch 38 is held in the tool housing 2 in an orientation in which the contact element 40 is movable in a plane which is parallel to the longitudinal axis 21 of the tool housing.

[0021] When the electrical switch 38 is in the second switch position, the electric motor 22 drives the tool spindle 24 at a speed in excess of 10,000 rpm. In some embodiments, the speed of the electric motor 22 can be adjusted by an operator via a speed adjustment knob 42 between 10,000 rpm and 40,000 rpm.

[0022] The power tool 1 includes an output shaft locking mechanism 28 with a depressible control knob 29 mounted on a locking rod 30. When actuated via the control knob 29, the locking rod 30 is configured to engage an opening 31 in the output shaft 23, thus preventing rotation of the output shaft 23 while an accessory is being attached thereto. The output shaft locking mechanism 28 also includes a spring 33 that biases the locking rod 30 and the control knob 29 toward a released configuration.

[0023] The tool housing 2 encloses the motor 22, the electrical switch 38, the switch actuator 50, the output shaft locking mechanism 28, the speed adjustment knob 42, the output shaft bearings 26, a printed circuit board 34 supporting a controller 35, and other additional components and structures. The controller 35 can, for example, regulate a voltage supplied to the electric motor 22.

[0024] In the illustrated embodiment, the longitudinal axis 21 of the tool housing extends between the opposite ends, the first and second ends 3, 4, of the tool housing and runs parallel to the motor output shaft 23. In addition, the tool housing 2 is elongated along the longitudinal axis 21. The tool housing 2 is a thin-walled construction comprising two wall sections or "half-shells" 5, 6 which fit together to enclose the other components of the power tool 1. The wall sections 5, 6 form the left and right sides of the tool housing 2, which are connected along a joint 7 which runs longitudinally along the top and bottom of the power tool 1, the terms "top" and "bottom" being used with reference to the Fig. 2 and are not intended to be limiting. The wall sections 5, 6 are generally mirror images of each other. In Fig. 2 and 5 to 7 and 12 to 13, only the wall section 5 is shown, whereas the further wall section 6 has been omitted so that the components located in the housing and / or the structure inside the housing can be seen.

[0025] With reference to Fig. 4 and Fig. 5, the tool housing 2 has a switch opening 16 that receives the switch actuator 50 and is arranged on top of the tool housing 2 at a location that coincides with the joint 7. The switch opening 16 is located between the first end 3 of the tool housing and a midpoint between the first and second ends 3, 4 of the tool housing. The switch opening 16 is defined by a wall edge 18 that extends between an outer surface 19 of the tool housing 2 and an inner surface 20 of the tool housing 2. The profile of the switch opening 16 is rectangular when the tool housing 2 is viewed upwards and is elongated in a direction parallel to the longitudinal axis 21. The wall edge 18 has a first end portion 18(1) that extends perpendicular to the longitudinal axis 21 and a second end portion 18(2) that is opposite the first end portion 18(1).The first end portion 18(1) is disposed between the second end portion 18(2) and the first end 3 of the tool housing. The wall edge 18 further includes a first side portion 18(3) extending between the first and second end portions 18(1), 18(2) and secured in the first wall portion 5, and a second side portion 18(4) extending parallel to the first side portion 18(3) and secured in the second wall portion 6. The first end portion 18(1) of the wall edge 18 includes a recess 18(5) at the junction of the wall edge 18 and the inner surface 20 of the tool housing. The recess 18(5) provides an abutment surface that engages a portion of the switch actuator 50 when the switch actuator 50 is in a first actuation position, as discussed in more detail below.

[0026] The tool housing 2 has a knob opening 43 that accommodates the speed adjustment knob 42. The knob opening 43 is located at the top of the tool housing 2 at a location that coincides with the groove 7. The knob opening 43 is located between the second end 4 of the tool housing and the switch opening 16.

[0027] The tool housing 2 has an operating button opening 32 which accommodates the depressible operating button 29 for the shaft locking mechanism 28.

[0028] The control button opening 32 is arranged at the top of the tool housing 2 at a location that coincides with the joint 7. The control button opening 32 is located between the first end 3 of the tool housing and the switch opening 16.

[0029] The tool housing 2 has a projection 8 projecting from opposite portions of the wall portions 5, 6 such that the projection 8 extends parallel to and lies beneath the switch opening 16. The projection 8 is generally planar and has a longitudinal dimension greater than the longitudinal dimension of the switch opening 16, whereby the first end 8(1) of the projection is aligned with the control button opening 32 and the second end 8(2) of the projection, which is opposite the first end 8(1), is arranged between the switch opening 16 and the button opening 43. A surface 13 of the projection 8 facing the switch opening has low, flattened elevations 11. The elevations 11 extend in a direction perpendicular to the longitudinal axis 21 and are spaced apart along the longitudinal axis 21.During use, the switching actuator 50 rests on the protrusions, and when the switching actuator 50 is actuated, the switching actuator 50 is displaced longitudinally along the projection 8, whereby the protrusions 11 serve to provide a sliding surface with reduced friction and to wipe away particles from the facing surface 55 of the switching actuator 50 that collect in the space between adjacent protrusions 11.

[0030] The projection 8 has an opening 12 shaped and sized to allow the contact element 40 to pass therethrough. The opening 12 is positioned longitudinally closer to the second end 8(2) of the projection than to the first end 8(1) of the projection, thereby aligning it with the second end portion 18(2) of the wall edge 18 defining the switch opening 16.

[0031] The tool housing 2 has a stop wall 9 and an alignment wall 10 that project inward and extend in a direction perpendicular to the extension 8. The stop wall 2 is connected to the second end 8(2) of the extension and limits the movement of the switching actuator 50 toward the second end 4 of the tool housing. The alignment wall 10 is arranged between the stop wall 9 and the switch opening 16. The alignment wall 10 projects toward the extension 8, but is spaced from the extension 8. The gap between the alignment wall 10 and the extension 8 is dimensioned to accommodate a portion of the switching actuator 50 with clearance. With this design, the alignment wall 10 holds the switching actuator 50 in a desired alignment with the tool housing 2, for example, by preventing a tilting movement of the switching actuator 50 relative to the extension 8.

[0032] The tool housing 8 includes a pair of positioning ribs 14, 15 projecting from each opposite portion of the wall sections 5, 6 toward the peripheral edge 56 of the switch actuator 50. For this purpose, the positioning ribs 14, 15 are disposed adjacent to the surface 13 of the boss 8 facing the switch opening. The positioning ribs 14, 15 are spaced longitudinally apart and provide a wave structure adapted to engage a corresponding positioning tab 64 projecting from the peripheral edge 56 of the switch actuator 50, as discussed in more detail below.

[0033] With reference to Fig. 6 and Fig. 7, the switching actuator 50 is arranged in the tool housing 2 such that it rests on the projection 8 and partially projects into the switch opening 16. The switching actuator 50 has a flat guide plate 51, which rests on the projection 8, and an elastic arm 66, which is formed integrally with the guide plate 51. A portion of the elastic arm 66 extends into the switch opening 16. The switching actuator 50 will now be described in detail.

[0034] With reference to Fig. 8 to 11, the guide plate 51 has an outwardly facing surface 54 (e.g., a surface facing the switch opening), an inwardly facing surface 55 (e.g., a surface facing the motor) opposite the outwardly facing surface 54, and a peripheral edge 56 extending between the outwardly facing surface 54 and the inwardly facing surface 55. The peripheral edge 56 has a front end portion 56(1) facing the first end 3 of the tool housing and a rear end portion 56(2) opposite the front end portion 56(1) and facing the second end 4 of the tool housing.The peripheral edge 56 has a first side portion 56(3) extending between the front and rear end portions 56(1), 56(2) on one side of the guide plate 51, and a second side portion 56(4) extending between the front and rear end portions 56(1), 56(2) on the opposite side of the guide plate 51.

[0035] The guide plate 51 has a pair of guide rails 63 that extend longitudinally from the front end portion 56(1) of the peripheral edge 56. The guide rails 63, 63 are spaced apart in a direction perpendicular to the longitudinal axis 21. In the second actuator position, which is discussed below, the guide rails 63 extend into the shaft locking mechanism 28 such that a guide rail 63 is arranged on each opposite side of the control knob 29 ( Fig. 7).

[0036] With reference to Fig. 12 and Fig. 13, the guide plate 51 has a positioning lug 64 that projects outwardly from both the first and second side portions 56(3), 56(4) of the peripheral edge 56. The positioning lugs 64 are arranged at a location along the first and second side portions 56(3), 56(4) of the peripheral edge that is closer to the rear end portion 56(2) than to the front end portion 56(1). The positioning lugs 64 have a rounded profile when viewed from above, and each positioning lug 64 is designed to engage a corresponding pair of positioning ribs 14, 15. For this purpose, a longitudinal dimension of each positioning lug 64 is less than the distance between the positioning ribs 14, 15.In particular, when the switching actuator 50 is in the first actuator position, the positioning lug 64 is arranged between the first rib 14 and the second rib 15 of the corresponding pair of positioning ribs 14, 15, and when the switching actuator 50 is in the second actuator position, the positioning lug 64 rests against a rearward-facing surface of the first rib 14 of the corresponding pair of positioning ribs 14, 15.

[0037] The interaction between a positioning lug 64 and the corresponding pair of positioning ribs 14, 15 creates a locking or restraining effect so that the user can easily feel the movement performed by the switching actuator 50 during operation. The interaction between a positioning lug 64 and the corresponding pair of positioning ribs 14, 15 also holds the switching actuator 50 in its desired position. The locking effect provides sufficient resistance to the initial movement so that the likelihood of the switching actuator 50 moving without deliberate force being applied is low. If the switching actuator 50 is used in a handheld power rotary tool such as a Drenel™ tool, normal vibrations that occur during operation of the power tool 1 should not affect the position of the switching actuator 50.

[0038] With reference again to Fig. 8 to 11, the guide plate 51 has a guide tab 65 projecting outwardly from both the first and second side portions 56(3), 56(4) of the peripheral edge. The guide tabs 64 are disposed at a location along the first and second side portions 56(3), 56(4) of the peripheral edge that is intermediate the rear end portion 56(2) and a corresponding positioning tab 64. The guide tabs 65 have a larger longitudinal dimension than the positioning tabs 64, and each guide tab 65 has a generally rectangular profile when viewed from above.

[0039] The guide plate 51 also has a central opening 60 that is spaced from and enclosed by the peripheral edge 56. The central opening 60 is defined by an inner edge 61 that extends between the outwardly facing surface 54 and the inwardly facing surface 55. The central opening 60 has a width dimension (e.g., a dimension perpendicular to the longitudinal axis 21) that is greater than a width dimension of the switch opening 16 and has a length dimension (e.g., a dimension parallel to the longitudinal axis 21) that is greater than a length dimension of the switch opening 16.

[0040] The elastic arm 66 projects from a connecting portion 62 of the inner edge 61. The connecting portion 62 is the portion of the inner edge 61 that is parallel to and closest to the rear end portion 56(2) of the circumferential edge 56 of the guide plate.

[0041] The elastic arm 66 has a generally rectangular peripheral shape when the switching actuator 50 is viewed from above and has dimensions that are slightly smaller than the corresponding dimensions of the central opening 60. The lever portion 68 of the elastic arm 66 can thus be moved into the central opening 60 of the guide plate upon application of an external force thereto ( Fig. 10 and Fig. 11). When no external force is applied, the lever section 68 elastically returns to the configuration in which it is located outside the central opening 60 and towards the guide plate 51 ( Fig. 8 and Fig. 9) is offset.

[0042] The elastic arm 66 has a lever portion 68 and a beveled portion 69 connecting the lever portion 68 to the connecting portion 62 of the inner edge 61. The lever portion 68 has a fixed end 82 adjoining the beveled portion 69 and a free end 83 opposite the fixed end 82 and facing the first end 3 of the tool housing.

[0043] The beveled section 69 extends obliquely to the outwardly facing surface 54 of the guide plate 51 and to the lever section 68, whereby the lever section 68 is offset from the guide plate 51 and runs parallel thereto when no external load acts on the switching actuator 50 ( Fig. 8 and Fig. 9). In particular, the lever portion 68 is located closer to the switch opening 16 than the guide plate 51 when no external load acts on the switching actuator 50.

[0044] The lever portion 68 of the elastic arm 66 has a plate 81 that projects outwardly (e.g., toward the switch opening 16) from an outwardly facing surface 80 of the lever portion 68. The plate 81 has a rectangular profile when the switching actuator 50 is viewed from above. The plate 81 has a width dimension (e.g., a dimension perpendicular to the longitudinal axis 21) that is slightly smaller than a width dimension of the switch opening 16. The plate 81 can, for example, have a width dimension that has play relative to the portions 18(3), 18(4) of the wall edge 18 facing it. The plate 81 has a length dimension that is smaller than a length dimension of the switch opening 16.The length of the plate 81 is designed, for example, such that a gap g is present between one end of the plate 81 and the switch opening 16, and a length of the gap g corresponds at least to a distance in the longitudinal direction that the switching actuator 50 travels when moving between the first actuator position and the second actuator position. When the switching actuator 50 is in the first actuator position, the gap g is arranged between a first end 81(1) of the plate and the first end portion 18(1) of the wall edge 18 (. Fig. 6). When the switching actuator 50 is in the second switching actuator position, the gap g is also arranged between a second end 81(2) of the plate and the second end portion 18(2) of the wall edge 18 ( Fig. 7).

[0045] In this design, the plate 81 is located in the switch opening 16 regardless of the switch actuator position.

[0046] The outwardly facing surface 84 of the plate 81 includes surface features that facilitate the operation of the plate 81 with a fingertip of a user of the power tool 1. In the illustrated embodiment, the surface features include a finger ridge 85 extending in a width direction of the plate 81. The finger ridge 85 is shaped and sized to receive a fingertip to allow a user to more easily apply a longitudinal force to the switch actuator 50. To this end, the finger ridge 85 includes concavely rounded surfaces 85(1), 85(2) extending between an end edge 86 of the ridge and the outwardly facing surface 84 of the plate 81. In particular, the finger elevation 85 has a first rounded surface 85(1) facing the first end portion 18(1) of the wall edge and a second rounded surface 85(2) facing the second end portion 18(2) of the wall edge.The finger protrusion 85 has a sufficient height dimension that an upper edge of the finger protrusion is flush with the outer surface 19 of the tool housing when the switch actuator is in the first actuator position. In addition to the finger protrusion 85, the outwardly facing surface 84 of the platform 81 may also include surface features that increase the surface friction of the outwardly facing surface 84 of the plate, such as a series of closely spaced flat protrusions or knurling (not shown).

[0047] The guide plate 51 has a switching opening 88 arranged along the connecting portion 62 of the inner edge 61, whereby the switching opening 88 extends into both the guide plate 51 and the beveled portion 69. The switching opening 88 is shaped and sized to receive a terminal end 41 of the contact element 40 in certain positions of the switching actuator 50. In the illustrated embodiment, the switching opening 88 has a rectangular profile when viewed from above, but is not limited to this shape.

[0048] In the illustrated embodiment, the switching actuator 50 is a monolithic structure manufactured from plastic in an injection molding process.

[0049] The switching actuator 50 is used by the operator of the power tool 1 to control the on / off state of the power tool 1 by moving the switching actuator 50 relative to the tool housing 2 between the first actuator position ( Fig. 6, 8 to 9 and 12) and the second actuator position ( Fig. 7, 10 to 11, and 13). During this movement, the switching actuator 50 moves both longitudinally and radially. The terms "longitudinal" and "radial" refer here to directions of movement relative to the longitudinal axis 21. The term "longitudinal" refers in particular to a movement parallel to the longitudinal axis 21, and the term "radial" refers to a movement perpendicular to the longitudinal axis 21.

[0050] With reference to Fig. 6, 8 to 9 and 12, the switching actuator 50 is arranged in the tool housing in the first actuator position as follows: The guide plate 51 lies on the projection 8 such that the guide plate 51 is arranged radially inward with respect to the inner surface 20 of the tool housing 2, and the rear end portion 56(2) of the guide plate 51 is placed adjacent to the stop wall 9. The front end portion 56(1) of the guide plate 51 is also arranged between the first end portion 18(1) of the wall edge and the control button opening 32, and guide rails 63 are spaced longitudinally from the control button 29 for the shaft locking mechanism. The elastic arm 66 is radially offset from the guide plate 51 by a first distance d1 ( Fig. 9), so that the plate 81 projects into the switch opening 16. The free end 83 of the lever portion 68 of the elastic arm 66 engages the wall edge recess 18(5) in such a way that the switching actuator 50 is prevented from moving longitudinally toward the first end 3 of the tool housing. In other words, the switching actuator 50 is held in the first actuator position by the engagement between the free end 83 of the lever portion and the wall edge recess 18(5). The positioning lugs 64 also bear against a rearward-facing surface of the first rib 14 of the corresponding pair of positioning ribs 14, 15.

[0051] The switching actuator 50 interacts with the contact element 40 such that when the switching actuator 50 is in the first actuator position, the contact element 40 is in the first switching position. In particular, when the switching actuator 50 is in the first actuator position, the terminal end 41 of the contact element 40 extends into the switching opening 88 ( Fig. 6 and Fig. 12), whereby the contact element 40 has a first angle relative to the switch main part 39 and the electrical switch 38 is in the first switching position, e.g. an open position in which no electrical current flows between the power source 44 and the electric motor 22.

[0052] With reference to Fig. 7, Fig. 10 and Fig. 11 and Fig. 13, the switching actuator is displaced in the second actuator position relative to the first actuator position in the longitudinal direction towards the first end 3 of the tool housing. The user pushes the switching actuator 50 from the first actuator position to the second actuator position by placing a fingertip on the second rounded portion 85(2) of the lever portion 68 of the elastic arm 66 and exerting a radially inward force, which results in a first radial movement (shown by arrow A1), followed by a longitudinally forward force, which results in a second longitudinal movement (shown by arrow A2) ( Fig. 11). In the illustrated embodiment, the radial movement and the longitudinal movement are perpendicular to each other. As a result of the applied forces A1, A2, the lever portion 68 moves toward the guide plate 51 and is partially received in the central opening 60. The guide plate 51 is also moved toward the first end 3 of the tool housing.

[0053] More specifically, in the second actuator position, the switching actuator 50 is arranged in the tool housing as follows: The guide plate 51 rests on the projection 8 such that the guide plate 51 is arranged radially inward with respect to the inner surface 20 of the tool housing 2, and the rear end portion 56(2) of the guide plate 51 is spaced longitudinally from the stop wall 9. The front end portion 56(1) of the guide plate 51 is arranged between the first end portion 18(1) of the wall edge and the control knob opening 32 and is closer to the control knob opening than in the first actuator position. The guide plate guide rails 63 therefore protrude into the shaft locking mechanism 28 such that a guide rail 63 is arranged on each of widthwise opposite sides of the control knob 29, and a portion of the control knob 29 is arranged between the guide rails 63.The elastic arm 66 is offset radially from the guide plate 51 by a second distance d2 (. Fig. 11). The second distance d2 is shorter than the first distance d1, thereby separating the free end 83 of the lever portion 68 from the wall edge recess 18(5). The free end 83 of the lever portion is located particularly inwardly relative to the inner surface 20 of the tool housing 2 and is also located between the first end portion 18(1) of the wall edge and the control button opening 32. The positioning lugs 64 are also arranged between the first rib 14 and the second rib 15 of the corresponding pair of positioning ribs 14, 15.

[0054] The switching actuator 50 interacts with the contact element 40 such that when the switching actuator 50 is in the second actuator position, the contact element 40 is in the second switching position. In particular, when the switching actuator 50 is in the second actuator position, the terminal end 41 of the contact element 40 rests on the inwardly facing surface 55 of the guide plate 51 at a location located between the switching opening 88 and the rear end portion 56(2) of the guide plate, whereby the contact element 40 has a second angle with respect to the switch body 39, and the electrical switch 38 is placed in the second switching position, e.g., a closed switching position in which no electrical current flows between the power source 44 and the electric motor 22.

[0055] The switching actuator 50 thus serves as a spring element, so that when the switching actuator 50 is in the first actuating position, the beveled portion 69 of the elastic arm 66 biases the lever portion 68 toward the wall edge 18, so that the lever portion 68 engages the wall edge 18, thereby preventing inadvertent movement of the switching actuator 50 into the second actuating position. Additionally, when the switching actuator 50 is actuated by exerting a force in two directions on the plate 81, the lever portion 68 is pushed away from the wall edge 18, thereby enabling movement of the switching actuator 50 into the second actuating position.

[0056] The user pushes the switch actuator 50 from the second actuator position to the first actuator position by placing a fingertip on the first rounded portion 85(1) of the lever portion 68 of the elastic arm 66 and exerting a longitudinally rearward force (shown by arrow A3). As a result of the longitudinally rearward force A3 applied, the guide plate 51 is pushed longitudinally toward the second end 4 of the tool housing. The longitudinal movement of the switch actuator 50 is limited by an interaction between the rear end portion 56(2) of the guide plate and the stop wall 9, as well as by the interaction between the plate 81 and the second end portion 18(2) of the wall edge 18, which defines the switch opening 16. Furthermore, as the plate 81 is moved toward the second end 4 of the tool housing, the free end 83 of the lever portion is aligned with the switch opening 16.In this position, the lever section 68 is brought back into its original position, radially offset from the guide plate 51, by the elastic properties of the switching actuator 50, in which position the plate 81 projects into the switch opening 16 and the free end 83 of the lever section engages in the wall edge recess 18(5).

[0057] Selected illustrative embodiments of the power tool having the switching actuator have been described in some detail above. It should be understood that only structures deemed necessary to explain the power tool having the switching actuator have been described herein. Other conventional structures, as well as those of additional components and auxiliary components of the power tool and the switching actuator, are assumed to be known and understood by those skilled in the art. Furthermore, while a working example of the power tool having the switching actuator has been described above, the power tool and the switching actuator are not limited to the working example described above, but various design changes may be made without departing from the power tool recited in the claims.

Claims

[1] Power tool (1), comprising: a tool housing (2) having a wall portion (5), the wall portion (5) having a switch opening (16) defined by a wall edge (18) extending between an outer surface (19) of the wall and an inner surface (20) of the wall; a motor (22) arranged in the tool housing (2); a power source (44) connected to the motor (22) via an electrical circuit (26), the electrical circuit (26) being arranged in the tool housing (2); and an electrical switch (38) arranged in the electrical circuit (26), the electrical circuit (26) having a switch main part (39) and a contact element (40) protruding from the switch main part (39), the contact element (40) being movable relative to the switch main part (39) between a first switching position in which the electrical circuit (26) is open and current is prevented from flowing from the power source (44) to the motor (22), and a second switching position in which the electrical circuit (26) is closed and current flows from the power source (44) to the motor (22), a switching actuator (50) arranged in the tool housing (2) such that it is accessible to an operator of the tool (1) via the switch opening (16), the switching actuator (50) comprising a guide plate (51) arranged in the tool housing (2) and an elastic arm (66) extending from the guide plate (51) and formed integrally therewith, where the switching actuator (50) is movable relative to the tool housing (2) between a first actuator position and a second actuator position, when the switching actuator (50) is in the first actuator position, the guide plate (51) is arranged inwardly relative to an inner surface of the wall section (5), a first edge section of the guide plate (51) is in a first guide plate position relative to the tool housing (2), the elastic arm (66) has a first distance (d1) relative to the guide plate (51) and thus projects into the switch opening (16), and a section of an edge of the elastic arm (66) engages the wall edge (18), when the switching actuator (50) is in the second actuator position, the guide plate (51) is arranged inwardly with respect to the inner surface of the wall section (5), the first edge section of the guide plate (51) is in a second guide plate position with respect to the tool housing (2), the second guide plate position is at a distance from the first guide plate position in the longitudinal direction, the elastic arm (66) has a second distance (d2) with respect to the guide plate (51), and the second distance (d2) is less than the first distance (d1), whereby the section of an edge of the elastic arm (66) is detached from the wall edge (18) and is arranged inwardly with respect to the inner surface of the wall section (5), and the switching actuator (50) interacts with the contact element (40) in such a way that, when the switching actuator (50) is in the first actuator position, the contact element (40) is in the first switching position, and, when the switching actuator is in the second actuator position, the contact element (40) is in the second switching position. [2] Power tool (1) according to claim 1, wherein the switching actuator (50) is actuated in two directions by exerting a manual force on the elastic arm (66). [3] Power tool (1) according to claim 1, wherein the movement of the switching actuator (50) between the first actuator position and the second actuator position requires a first movement in a first direction followed by a second movement in a second direction, and the second direction is perpendicular to the first direction. [4] Power tool (1) according to claim 1, wherein the guide plate (51) comprises a central opening (60) defined by an inner edge (61) and the elastic arm (66) protrudes from the inner edge (61). [5] The power tool (1) according to claim 4, wherein the elastic arm (66) has a lever portion (68) and a slope portion (69) connecting the lever portion (68) to the inner edge (61), and the slope portion (69) is inclined with respect to an outwardly facing surface of the guide plate (51), whereby the lever portion (68) is offset from the guide plate (51). [6] Power tool (1) according to claim 1, wherein the switching actuator (50) is a spring. [7] Power tool (1) according to claim 1, wherein the guide plate (51) has a switching opening (88), when the switching actuator (50) is in the first actuator position, a portion of the contact element (40) extends into the offset opening (88), whereby the electrical switch is in the first switching position, and when the switching actuator (50) is in the second actuator position, the portion of the contact element (40) abuts an inwardly facing surface of the guide plate (51), whereby the electrical switch (38) is in the second switching position. [8] Power tool (1) according to claim 1, wherein, when the switching actuator (50) is in the first actuating position, the elastic arm (66) is biased towards the wall edge (18) so that the portion of an edge of the elastic arm (66) engages the wall edge (18), thereby preventing movement of the switching actuator (50) into the second actuating position, and, when the switching actuator (50) is in the second actuating position, the portion of an edge of the elastic arm (66) is pushed away from the wall edge (18), thereby enabling movement of the switching actuator (50) into the second actuating position. [9] Power tool (1) according to claim 1, wherein the tool housing (2) has a projection (8) which projects from the wall section (5) and lies at least partially below the switch opening (16), and the switching actuator (50) lies on the projection (8) and is displaceable thereto. [10] Power tool (1) according to claim 9, wherein the projection (8) has an opening (12) and the contact element (40) projects through the opening (12). [11] Power tool (1) according to claim 1, wherein the tool housing (2) has a pair of positioning ribs (14, 15) projecting from the wall portion (5) in the direction of the switching actuator (50), wherein the positioning ribs (14, 15) extend in a direction perpendicular to a direction of movement of the switching actuator (50), and the guide plate (51) has a second edge portion (6) and a nose (64) protruding from the second edge portion (6), when the switching actuator (50) is in the first actuator position, the nose (64) abuts a first rib (14) of the pair of positioning ribs and the first rib (14) of the pair of positioning ribs is arranged between the nose (64) and the second rib (15) of the pair of positioning ribs, when the switching actuator (50) is in the second actuator position, the nose (64) is arranged between the first rib (14) of the pair of positioning ribs and a second rib (15) of the pair of positioning ribs. [12] Power tool (1) according to claim 1, wherein the elastic arm (66) comprises an outwardly facing surface and a plate (81) projecting from the outwardly facing surface, the plate (81) is shaped and dimensioned so that it is received in the switch opening regardless of the switch actuator position, and the plate (81) has a finger elevation (85) extending in a width direction of the plate (81), the finger elevation (85) being shaped and dimensioned to receive a fingertip to enable a user to more easily exert a longitudinal force on the switching actuator (50).

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