HAND TOOL MACHINE

Description

[0001] The present invention relates to a hand-held power tool according to the preamble of claim 1, as known, for example, from EP1466698 A1. State of the art

[0002] Furthermore, reference is made to the documents CN 205 817 487 U, EP 2 712 705 A2, WO 2008 / 153486 A1 and CN 207 509 035 U. Disclosure of the invention

[0003] A hand-held power tool is proposed having the features of claim 1. Advantageous embodiments, variants, and further developments of the invention can be found in the subclaims.

[0004] The invention is based on a hand-held power tool, in particular a grinder, for simultaneously driving a plurality of grinding wheels, preferably for simultaneously driving three, in particular tiltable, rotating and / or oscillating and / or randomly circularly driven or driven grinding wheels, comprising at least one housing part which has grinding wheel receiving areas and / or openings in which or through which grinding wheel receptacles or output shafts for driving the grinding wheels are arranged. It is proposed that the at least one housing part forms at least one air duct between at least two adjacent grinding wheel receiving areas and / or openings. The at least one air duct is arranged on an outer side of the housing part. The outer side is arranged adjacent to the grinding wheels. The outer side differs from an inner side which accommodates drive train components.The air duct is formed as a recess or notch, in particular a concave recess or notch. The number of air ducts corresponds to the number of grinding wheels to be driven. The housing part is in particular formed as a one-piece housing part. It is, for example, a plastic injection-molded part or a metal part. Typically, in conjunction with other housing parts, in particular other housing shell components with which it together forms the housing of the handheld power tool, it delimits internal components from the outside of the handheld power tool. Apart from the openings, the housing part delimits an inner region of the housing part from an outer region of the housing part. In particular, an "air duct" or "recess" is not to be understood as a hole or opening in the housing part, in particular not from the outside to the inside of the housing part.The internal components of the housing are typically a drive motor, gear components, electronic components, or the like. The air duct or recess forms a guide structure. It serves to guide the air, in particular the low-loss air guidance of an exhaust air stream, in particular a dust exhaust air stream. This exhaust air stream can be generated by attaching an extraction source in the area of ​​the housing part, in particular in conjunction with a dust extraction hood. The recess is intended to form an air duct. The cross-section between the housing part and the sanding plate, i.e. the side of the sanding plate that faces away from a processing surface or the abrasive receiving surface of the sanding plate, is enlarged. The concave structure of the recess additionally reduces the friction of the air stream on the housing part. It creates rounded transitions and reduces the resistance to the air stream.The recess increases the cross-section for the airflow or dust extraction between the housing and the sanding disc. This enables low-loss, as even aspiration of sanding dust as possible, or airflow in the area where the sanding dust is generated, particularly in the area around the sanding disc and / or between adjacent sanding discs.

[0005] According to the invention, the dimension of the recess in the housing part increases from a central region of the housing part radially outward toward an edge of the housing part. This allows for more homogeneous extraction along the outer surface of the housing part. In particular, dust extracted from the central region of the housing part can be supplied from all peripheral regions of the housing part.

[0006] It is proposed that a number of air ducts correspond to a number of openings and / or a number of sanding pad receptacles, or a number of sanding pads to be driven, in particular wherein the air ducts are arranged in the space between adjacent openings and / or sanding pad receptacle areas. For example, the handheld power tool has a total of three air ducts in the space between the three openings. This makes it possible to achieve improved air guidance for dust extraction in the entire area between the housing part and the sanding pads. Even if the air is only extracted from one side of the sander, for example, dust extraction can still be improved in the area of ​​all sanding pads to be driven.

[0007] Furthermore, it is proposed that the air duct ensures contact-free tilting of the sanding discs relative to the housing. This allows the distance between the sanding disc(s) and the housing, in particular the openings or sanding disc receptacles and the sanding discs to be as small as possible. Despite the small distance to the openings or sanding disc receptacles, the sanding discs or their outer peripheral surfaces do not hit the housing when the sanding discs are tilted. This gives the sander a compact design. The center of gravity can be shifted closer to the workpiece or sanding surface. This improves the force applied by the operator to the surface to be sanded. The sander becomes more manageable. Even narrow or hard-to-reach areas can be reached with the handheld power tool or sander. The air ducts andRecesses advantageously provide both air channeling and tilting capability, thereby improving user-friendliness.

[0008] The recess(es) enable extraction of sanding dust with low pressure loss or resistance. They form air ducts, particularly dust extraction ducts, and enable homogeneous dust extraction. The pressure loss of the sanding dust extraction flow from the extraction device connection point to the furthest sanding disc or edge of the housing is reduced. Furthermore, the sanding disc remains tilt-free while maintaining a more compact design, particularly since the tiltable sanding discs can tilt into the recesses or air ducts without touching the housing.

[0009] It is proposed that a housing parting edge, in particular a housing parting joint, between the at least one housing part and a further housing part, in particular further housing shells, serves as a form-fitting element, in particular a locking groove, for receiving a corresponding form-fitting element, in particular a locking extension, of a dust extraction hood. As a result, no additional locking elements such as housing notches, locking pins or the like are required on the housing part of the grinder. This simplifies the design. Costs can be saved. Aesthetically and haptically, the grinder is thus free of superstructures and / or other sometimes disruptive elements. The dust extraction hood can be attached directly to the housing of the grinder. The number of parts remains low.

[0010] It is proposed that the air duct(s) serve(s) as a further form-locking element, in particular as a stop element, for a further corresponding form-locking element of the dust extraction hood. This allows the dust extraction hood to be positioned even more securely axially on the grinder. The dust extraction hood is fixed to the grinder by the outer contour of the housing part. Viewed in the radial circumferential direction, essentially parallel to the grinding surface. The locking element and the form-locking element or stop element, which are arranged in particular at an axial distance from one another, also securely fix the dust extraction hood in the axial direction. Corresponding locking or form-locking elements on the dust extraction hood can therefore be arranged at a small distance from one another axially. The dust extraction hood can therefore be designed to be relatively slim axially.

[0011] Furthermore, the handheld power tool has a dust extraction hood with a connecting piece for connection to a dust extraction device, which protrudes outside the dust extraction hood and has an extraction opening extending from the connecting piece and opening towards the interior of the dust extraction hood, in particular wherein the dust extraction hood has a substantially triangular geometry. The dust extraction hood has an extension in the area of ​​the intake opening to prevent cross-airflow, which extension protrudes into the interior or center of the dust extraction hood. A dust extraction hood is understood to mean a frame that is intended for connection to the grinder. The "interior" is in particular the area of ​​the center of the frame. The contour of the dust extraction hood or frame is at least partially adapted to the contour of the grinder; in particular, the contour is adapted to a radial circumferential contour of the housing part parallel to the grinding plane. The dust extraction hood orThe frame is designed for a substantially close-gap connection to the grinder, in particular for a substantially close-gap connection to the housing part of the grinder. This prevents airflow between the peripheral surface of the housing part and the dust extraction hood. This prevents a "leakage airflow" that would reduce the efficiency of dust extraction. The nozzle is typically designed for connection to a vacuum cleaner hose or its adapter. The nozzle is designed in particular for connection to various mobile or stationary dust extraction devices. The extension serves as an air guide surface. It directs a suction airflow, in particular from the center of the dust extraction hood, toward the opening and at least partially prevents a transverse airflow perpendicular to the opening. The extension enables the formation of a more homogeneous suction airflow within the hood.A transverse air flow, particularly from the flat side of the extension or baffle facing away from the opening, is reduced in the area of ​​the opening. This distributes the extraction flow more evenly over the entire area to be extracted between the housing part and the sanding disc and around the sanding discs. In this way, a more homogeneous negative pressure for extracting the sanding dust can be created in the space between the sanding discs and the housing part. Starting from the opening, the extension has an essentially triangular (with the tip of the triangle protruding into the dust extraction hood) or semicircular (with the round side of the semicircle protruding into the dust extraction hood) shape.

[0012] It is proposed that the extension has a main direction of extension from the dust extraction hood and / or the opening into the interior or center of the dust extraction hood.

[0013] It is proposed that the extension have at least one wall, in particular several walls, which serve to reduce the cross-air flow, in particular to reduce the cross-flow from below the dust extraction hood and / or from air sucked in laterally within the dust extraction hood. The wall(s) have(s) at least one direction of extension parallel to the main direction of extension of the extension. The wall(s) are aligned orthogonally to the extension or baffle. An air guide channel pointing towards the center of the dust extraction hood can thus be created between adjacent walls and the extension, in particular with three delimiting walls over an angle of 270°. A fourth delimiting wall of this channel, so that the channel is at least partially delimited radially on all sides around the main direction of extension, can advantageously form the housing part of the grinder when the dust extraction hood is mounted on the grinder.

[0014] It is proposed that the extension and / or the wall be at least partially open laterally, in particular to enable cross-airflow in at least this area. This allows grinding dust to be extracted from the side of the opening and within the hood, in particular axially limited by the housing part of the grinder, as well as from the sides, in particular the corners of the hood.

[0015] It is proposed that the hood or the frame of the dust extraction hood be flexible, in particular to enable spring-elastic pretensioning and / or pressing of the dust extraction hood and / or form-fitting elements of the dust extraction hood and / or the frame of the hood against the housing of the grinder, in particular for tool-free and / or secure and / or gap-minimized connection thereto. This allows the dust extraction hood and / or form-fitting elements of the dust extraction hood and / or the frame of the dust extraction hood to be pressed against the housing or housing part of the grinder. Furthermore, the dust extraction hood or the frame can be connected to the housing part without tools and / or securely and / or with minimal gaps. The flexibility enables spring-elastic pretensioning of the dust extraction hood or the frame on the housing or housing part of the grinder.

[0016] It is further proposed that the frame or hood tapers from bottom to top, i.e. it tapers in the area of ​​the form-fitting elements for connection to the form-fitting elements of the handheld power tool. This ensures that an upper edge of the frame or dust extraction hood can rest against the housing of the handheld power tool with as little gap as possible, and that the pre-tensioning force of the dust extraction hood is effective in this area. Advantageously, the form-fitting connection to the handheld power tool can also be opened by pressing on the lower edge of the dust extraction hood or frame. This shape also serves to improve distancing or as a stop element. In addition, this design can elastically cushion any impact with the dust extraction hood, for example against a wall.

[0017] The dust extraction hood is essentially triangular in design. The dust extraction hood is removable and can be pushed onto the housing or housing part, particularly the output shaft housing.

[0018] It is proposed that the dust extraction hood be designed as a spacer and / or impact guard for the sander. It thus serves as a spacer and / or impact guard for the sander. This prevents radial impact of the sanding discs, for example, on a surface arranged vertically to the sanding plane, and thus prevents potential damage to this surface. The spacer or impact guard makes working on a floor surface along a wall or similar easier, evener, and / or damage-free. Scratching of the sander at the expense of scratching the hood can be avoided.

[0019] It is further proposed that the dust extraction hood have a handle contour on the outside of the dust extraction hood, wherein the handle contour corresponds to the silhouette contour of at least one region of the handheld power tool. In particular, the handle contour corresponds at least substantially to the lateral silhouette contour of the air duct or the recess of the grinder. This allows for simplified assignment of the dust extraction hood to the handheld power tool. If a user owns and / or uses several different handheld power tools, possibly with different hoods, this makes it easier to recognize or assign the respective dust extraction hood to the handheld power tool.However, it is also conceivable that a group of hand-held power tools - for example a delta sander and a three-disc sander - together have at least partially the same or at least a similar silhouette contour which is the same or similar to a silhouette contour of at least one handle area of ​​the dust extraction hood, so that a simple group assignment is possible for the user.

[0020] Furthermore, a dust extraction hood is proposed which is designed for detachable connection to the housing of the hand-held power tool by means of at least one positive-locking and / or non-positive-locking and / or frictional-locking element, wherein the dust extraction hood has an elastic band, in particular a rubber-elastic band, particularly preferably in the region of a connecting piece. The elastic band is provided for connection to a handle of the hand-held power tool. The elastic band enables additional fixing of the dust extraction hood to the hand-held power tool. In particular, the connecting piece of the dust extraction hood can thereby be easily supported on the handle. Since the hand-held power tool orSince the sander is sometimes relatively light compared to the vacuum cleaner hose and / or the dust extraction hood connector is relatively delicate, the additional connection of the elastic band to the power tool prevents the dust extraction hood from being accidentally pulled off the power tool. Furthermore, the stress on the transition between the connector and the frame can be reduced, preventing breakage of the frame and / or connector.

[0021] The dust extraction hood forms an enveloping contour around all sanding pads relative to the sanding plane. It also forms an enveloping contour around all tool holders. It advantageously forms an enveloping contour around the housing in the area of ​​the sanding pads or the housing part. This allows a vacuum zone to be created when a dust extraction system is connected to the nozzle in the area of ​​the sanding pads. The dust extraction hood overlaps the housing axially, starting from the sanding plane. The dust extraction hood is spaced from the sanding pads in such a way that there is no contact between them during operation. This enables simple, user-friendly operation of the hand tool.

[0022] It is proposed that an air duct, in particular a recess, in the housing part and the extension of the hood, form a suction channel defined by the two when the hand tool and hood are connected. This creates a low-resistance airflow and / or reduces transverse airflow. This serves to improve suction and ensure more homogeneous pressure distribution across all sanding discs of the sander. Drawings

[0023] The invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawings. They show: Fig. 1: The handheld power tool in a front view; Fig. 2: The handheld power tool in a sectional view AA; Fig. 3: The handheld power tool in a sectional view BB; Fig. 4: The handheld power tool in a side view in a rest position; Fig. 5: The handheld power tool in a side view; Fig. 6: The handheld power tool in a rear view; Fig. 7: The dust extraction hood in a perspective view; Fig. 8: The handheld power tool and dust extraction hood in a side view; Figs. 9a-d: The handheld power tool in a hatched representation in four views; Fig. 10: The sectional area or the sectional area ratio of a constricted and an expanded area of ​​the handheld power tool; Fig. 11: The handheld power tool in a perspective view.

[0024] Fig. 1shows the hand tool in the form of a grinder 10 in a front view. The grinder 10 is designed to simultaneously drive three grinding wheels 12, 14, 16. One front grinding wheel 12 and two rear grinding wheels 14, 16. By means of a cardanic or cardanic suspension (cf. Fig. 2 ) The sanding discs 12, 14, 16 are mounted so that they can pivot or tilt. They are driven in rotation and are well suited for sanding even curved surfaces. The sander 10 can be activated via an actuating switch 18. A marking element 20 conveniently assigns this device to a device series or manufacturer.

[0025] Fig. 2 shows the hand tool in the form of the grinder 10 in a sectional view AA through the plane A (cf. Fig. 1). The front-side sanding disc 12 is arranged in front of a central wheel axle 22. It is arranged opposite a handle 24 with respect to a central wheel axle 22. The two rear sanding discs 14, 16, of which only the sanding disc 16 can be seen in this illustration, are arranged on a side of the central wheel axle 22 facing the handle 24. The three sanding discs 12, 14, 16 are identical in construction and are interchangeable. A motor 26 has a drive shaft 28. The motor 26 or its drive shaft 28 defines a motor shaft axis 30. Via a pinion 32, the motor 26 drives a central wheel 34, which defines the central wheel axle 22. The central wheel 34 is driven by the pinion 32 via a spur gear 36. The central gear 34 has a toothing 38 with which it drives three output shafts 40, of which only the front one is visible in section AA. These output shafts 40, in turn, define output shaft axes 42.Each output shaft 40 is in turn provided for at least indirectly driving one grinding disc 12, 14, 16. The central gear 34 drives three spur gears 44 via the gearing 38 (of which the spur gear 44 driving the grinding disc 12 is shown in section and the spur gear 44 driving the grinding disc 16 is shown in side view). The front spur gear 44 drives the output shaft 40; the drive mechanism is transmitted analogously to all spur gears 44 driving the grinding discs 12, 14, 16. The output shaft 40 is mounted here, for example, via at least one deep groove ball bearing 46 in a housing part 60. A plain bearing 48 additionally supports the output shaft 40 in another housing part 62. The two housing parts 60, 62 form an output shaft housing 202.The output shaft housing 202, together with a motor housing 200, which essentially encloses the motor 26, forms a main housing 64, which accommodates at least the motor 26, the central gear 34, and the input and output shafts 28, 40. The output shaft 40 engages via a driver 50 in coupling means 52 of the sanding plate 12. The sanding plate 12 can be clipped into a sanding plate receptacle 56 by means of locking hooks 54. The sanding plate receptacle 56 is arranged in the region of an opening 100 in the housing part 60. The coupling means 52 of the sanding plate 12 or the locking hooks 54 can be inserted into the sanding plate receptacle 56 or onto the driver 50 through the opening 100. The sanding disc holder 56 enables not only the low-friction rotation bearing of the sanding disc 12 (here with deep groove ball bearing 58) but also pivoting (here by means of a spherical plain bearing in a spherical holder of the housing part 60).The articulated shaft-like drive allows the sanding disc 12 to tilt relative to the housing part 60 or relative to the grinder 10. The central gear 34 drives the sanding discs 12, 14, 16 in a forced rotation. In principle, however, an oscillating drive or a random circular drive of the sanding discs 12 is also possible, for example, by means of output shafts 40 eccentrically mounted in the spur gear 44, which drive the sanding discs 12, 14, 16 in a forced or random rotation, or an eccentric that generates an oscillating movement by restricting the degrees of freedom of the sanding disc and / or the output shaft - or the like (not shown in detail here).

[0026] The drive shaft 28 or the motor shaft axis 30 is arranged eccentrically to the central gear 34 or the central gear axis 22. It is arranged between the front output shaft axis 42 and the central gear axis 22. Both axes 22, 30 are intersected by or lie in plane A. The motor 26 is displaced in the direction of the front sanding disc 12 or its sanding disc holder 56. The motor 26 or its motor shaft axis 30 is arranged opposite the handle 24 with respect to the central gear axis 22. The handle 24 is also intersected centrally by plane A, ideally divided in a mirror-symmetrical manner. The motor shaft axis 30, the central gear axis 22, and the output shaft axes 42 are aligned parallel to one another. The handle axis 66 or the central axis 86 or longitudinal axis 84 of the particularly rod-shaped handle 24 is arranged transversely to the central wheel axis 22.The angle α is approximately 45-135°, in the present embodiment approximately 100°. The handle 24 protrudes from the main housing 64. The plane A or the section plane AA is also spanned, so to speak, by the handle axis 66 and the central wheel axis 22. The handle 24 is rod-shaped, essentially round or oval or the like. It is formed by the handle housing 68, which can be at least partially formed integrally with the main housing 64. The handle 24 is provided for receiving a rechargeable battery 70. This can be permanently integrated or designed as a replaceable rechargeable battery 70. In the present embodiment, it is designed as a replaceable plug-in rechargeable battery 72. It is inserted into the free end 74 of the handle 24 and is detachably connected to the handle housing 68 via locking elements (not shown here). Optionally, the speed of the motor 26 can be adjusted using an adjusting wheel 76.Furthermore, the handle 24 and the main housing 64 are ergonomically shaped. The concave notch 78 in the transition from the handle 24 to the main housing 64 serves as an intuitive grip with the index finger. This area can also be covered with a soft grip 80. Of course, other areas of the hand tool can also be covered with special haptic and / or tactile materials. However, the upper side 82 of the main housing 64 is also intended for resting a hand, in particular the palm of the hand, whether to operate the hand tool with two hands or with one hand, solely by grasping the main housing 64.

[0027] Fig. 3 shows the grinder Fig. 1in a sectional view BB in plane (B). The drive shaft 28 drives the central gear 34 via the pinion 32. The motor shaft axis 30 and thus the motor 26 are arranged eccentrically to the central gear 34, namely in the direction of a front side 90 of the grinder 10. The central gear axis 22, the motor shaft axis 30 and the output shaft axis 42 of the front output shaft lie in plane A. Plane B is spanned orthogonally to this plane A. The output shafts 40, which are arranged mirror-symmetrically to plane A, lie in plane B. The central gear axis 22 is arranged in the center of a regular triangle 92, in the corners of which the three drive shaft axes 42 are arranged. The three spur gears 44 are driven in rotation via the central gear 34. The spur gears 44 in turn drive the output shafts 40, which at least indirectly drive the grinding wheels 12, 14, 16 or grinding wheel holders 56 (cf. Fig. 2). Furthermore, parts of the main housing 64 or the housing part 60 and the further housing part 62 are shown, which hold the drive and driven elements of the grinder 10 in position.

[0028] Fig. 4shows the grinder 10 in a resting position on a support surface 94, for example, a workpiece to be machined. The grinder 10 rests on three points, namely on a free end 96 of the insertable accumulator 70 (alternatively, it could also rest on the free end 74 of the handle 24, particularly in the case of an accumulator 70 permanently installed in the handle 24) and on the edge 98 of the rear grinding discs 14, 16, particularly the two edges 98 of the grinding discs 14, 16 facing the free end 74, 96 of the handle 24 or insertable accumulator 72 (whereby only the grinding disc 14 is visible, since it conceals the grinding disc 16). In principle, the same reference numerals are assigned to identical components from the different figures, but they are not necessarily explained again for each figure.

[0029] Fig. 5shows the hand tool or a grinder 10 in a side view. The housing part 60 has three grinding disc receiving areas 102, of which Fig. 5only two can be seen. The sanding disc receiving area 102 is defined as the area of ​​the housing part 60 that supports the sanding disc receptacle 56 and its components, such as bearings. By way of example, this is the area with the enveloping circle diameter 104 around the sanding disc receiving area 102. In the present exemplary embodiment, this area is offset from a particularly immediately surrounding housing area 106 of the housing part 60, in the direction of the sanding plane 112 (to accommodate the bearings, to provide better accessibility and / or to improve the freedom of movement of the sanding discs 12, 14, 16, e.g. when tilting / pivoting). In other words, the surrounding housing area(s) 106 are set back from the sanding disc receiving area(s) 102. However, this setback is not to be understood as a recess 108 within the meaning of the invention.The sanding disc receiving areas 102 each have openings 100 through which the removable sanding discs 12, 14, 16 can be connected to the sander 10. Thus, the coupling means 52 and / or locking hooks 54 can be connected to the output shafts 40 and / or sanding disc receptacles 56 (see sectional view). Fig. 2 ). Alternatively, the sanding disc receptacles 56 or the output shafts 40 can also protrude through the sanding disc receptacle areas 102. If only output shafts 40 protrude through the housing part, either because the sanding discs 12, 14, 16 are accommodated outside the housing part 60 of the handheld power tool, or because the sanding discs 12, 14, 16 are permanently connected to the output shafts 40, the sanding disc receptacle area 102 can also be understood to mean only the area that represents the opening 100; or the area that supports the output shafts 40 in the housing part 60 of the handheld power tool.

[0030] Between two adjacent sanding pad receiving areas 102 or the openings 100 (in the intermediate space 122, so to speak), the housing part 60 has an air duct 120. This is formed by a recess 108. In the area of ​​the air duct 120 or the recess 108, the distance 110 between the housing part 60 and a sanding plane 112 is increased, in particular increased compared to the distance 111 of the housing area 106 to the sanding plane 112. The recess 108 is therefore set back from the housing area 106. The recess 108 has a concave shape 118. It tapers towards the center of the housing part 60, or becomes narrower in the circumferential direction. In addition, the extent of the recess decreases in this direction. The housing part 60 is therefore drawn in or notched in the direction away from the sanding plane 112.Starting from a central region 114 of the housing part 60, in particular a central region 114 in the center between the sanding discs 12, 14, 16 or in the region of the central wheel axis 22 intersecting the housing part 60, the distance 110 between the housing part 60 and the sanding plane 112 increases radially outward along the air duct or the recess 108, i.e., toward the edge 116 of the housing part 60. The recess 108 is therefore larger in the outer region of the housing part 60 than in a central region. The recess 108 serves to improve air flow. The recess 108 forms at least part of an air duct 120, in particular for dust extraction.

[0031] Analogous to the recess 108 between the sanding discs 12, 16 (front and rear sanding disc) or the associated sanding disc receiving areas 102, a recess 108 is also provided between the rear sanding discs 14, 16 or the associated sanding disc receiving areas 102 (cf. Fig. 6 ). The Fig. 6 , which shows this recess in the rear view, it can also be seen that the recess or the distance 110 increases from the central area 114 of the housing part 60 to the edge 116 of the housing part 60 or from the center radially outwards. The rear recess 108 is constructed mirror-symmetrically to plane A (compare also section AA according to Fig. 2). The recess 108 also enables contact-free tilting 124 of the sanding discs 12, 14, 16 relative to the housing part 60. Thus, for example, during operation of the grinder 10, an edge of the sanding disc 12, 14, 16 does not rub against the housing part 60. The three recesses 108 between the sanding discs 12, 14, 16 and the sanding disc receptacles 56 are each offset from one another by 120°, starting from the center. They are each mirror-symmetrical to the angle bisectors of the regular triangle.

[0032] Fig. 5 and 6also show a housing separating edge 126. The housing separating edge 126 is arranged between the housing part 60 and the further housing part 62. Both housing parts 60, 62 are part of the output shaft housing 202 and the main housing 64, respectively. The housing separating edge 126 represents, in particular, a housing separating joint 130. The housing separating edge 126 or the housing separating joint 130 is formed by assembled housing shells of the hand-held power tool or the grinder 10. It forms a recess in the housing surface. It runs circumferentially around the output shaft housing 202. It represents a positive-locking element 132, in particular a locking groove 134, for receiving a corresponding positive-locking element 136 of a dust extraction hood 138 (cf. Fig. 7), preferably a locking projection 140 of a dust extraction hood 138. The form-locking element 132 can, in principle, also represent a protuberance or male form-locking element instead of a groove or recess. Likewise, a female form-locking element can be provided on the dust extraction hood 138 instead of a male one. Furthermore, the recess 108 in the housing part 60 serves as a further form-locking element 142, in particular as a stop element 144 for a further corresponding form-locking element 146 on the dust extraction hood 138. When the dust extraction hood 138 is pushed from the sanding plate level 112 onto the output shaft housing 202 or slipped over the housing part 60, the form-locking element(s) 146 serve as a stop or stopper. Thus, the dust extraction hood 138 is not pushed too far onto the output shaft housing 202.As soon as the form-locking elements 146 strike, the form-locking elements 136 also snap into their intended position or into the corresponding form-locking elements 132.

[0033] Fig. 7 shows the dust extraction hood 138 of the hand tool in a perspective view.

[0034] The dust extraction hood 138 has a connecting piece 148 for connection to a dust extraction device (not shown here) - typically a mobile or stationary vacuum cleaner or dust extraction device. The connecting piece 148 projects outward 149 of the dust extraction hood 138. The dust extraction hood 138 has an extraction opening 150 extending from the connecting piece 148, which is open to the interior 152 of the dust extraction hood 138. The dust extraction hood 138 has a substantially triangular geometry, in particular a substantially regular triangular geometry. By substantially, it is to be understood here that the corners 154 of the "triangle" as in Fig. 7 shown may be rounded. In addition, the legs 156 may also deviate from a straight shape, for example, be slightly curved or the like.

[0035] In the area of ​​the extraction opening 150, the dust extraction hood 138 has an extension 158. This serves to prevent cross-air flow, in particular from below 184 (cf. Fig. 8) of the extension 158, i.e., below the side of the extension 158 facing away from the suction opening 150. The extension 158 projects into the interior 152 of the dust extraction hood 138. Starting from the suction opening 150, the extension 158 has a main extension direction 160 into the interior 152 of the dust extraction hood 138. Furthermore, the extension 158 has at least one, in particular two, walls 162. These serve / serve to reduce the cross air flow, in particular to reduce the cross loss flow from below 184 of the dust extraction hood 138 and / or from the side 164 within the dust extraction hood 138. The extension 158 and / or the wall 162 can, however, also be at least partially open laterally 166, 168, in particular to enable cross air flow in at least this area 170, 172. The extension 158 forms part of an air duct 159. In particular, the part of the air duct 120 and the other part of the air duct 159 together form an air duct 120, 159.

[0036] The dust extraction hood 138, or the frame 174 of the dust extraction hood 138, is flexible, in particular transversely to the bottom or top of the dust extraction hood 138 or toward the interior 152 or the exterior 149 of the dust extraction hood 138. This enables a spring-elastic preload and / or pressing of the dust extraction hood 138 against the handheld power tool, in particular the grinder 10, or its housing. This allows for a tool-free and / or secure and / or gap-free connection to the grinder 10.

[0037] The frame 174 or the dust extraction hood 138 tapers from bottom to top. In the area of ​​the form-locking elements 136, for connecting to the form-locking elements 142 of the handheld power tool, the frame 174 or the dust extraction hood 138 is tapered. This ensures that an upper edge 186 of the frame 174 or the dust extraction hood 138 can rest against the housing of the handheld power tool with as little gap as possible. The preload force of the dust extraction hood 138 in this area can thus be particularly effective.

[0038] Furthermore, the dust extraction hood 138 can be designed as a spacer and / or stop protection for the hand tool or the grinder (see also Fig. 8). Instead of the housing of the grinder 10, the frame 174 or the rounded corners 154 and / or legs 156 serve as impact protection. The dust extraction hood 138 also has a handle contour 176. The handle contour 176 represents a slight elevation on the leg 156 or the frame 174. The friction between the finger and the dust extraction hood 138 when pressing or pulling the dust extraction hood 138 onto or off the grinder 10 is thereby improved. In addition, the handle contour 176 resembles the silhouette contour 178 of at least one area of ​​the handheld power tool or the grinder (cf. Fig. 5 and 6 ). The silhouette contour is formed by the contour of the edge 116 of the housing part 60, in particular in the region of the recess 108, in particular when viewing the edge 116 or the wiper 10 from the side.

[0039] Fig. 8depicts the handheld power tool or grinder 10 with a connected or attached dust extraction hood 138. In addition to the components already described, the dust extraction hood 138 or the handheld power tool or grinder 10 has a particularly elastic connecting element 179, in particular an elastic band 180, preferably a rubber-elastic band 180 for connecting the nozzle 148 or a nozzle adapter 182 and the grinder 10. The elastic band 180 is stretched, in particular, between a free end 74, 96 of the handle 24 or accumulator 70, 72 of the grinder 10 and the nozzle 148 or nozzle adapter 182. The elastic band is preferably captively attached to the nozzle 148, nozzle adapter 182 or the handle 24. Here, for example, by gluing or injection molding onto the nozzle adapter. Alternatively, the strap can also be detachable on one side, so that when opened it can be attached to or around the other component.can be folded over and fixed again - e.g. with a snap fastener, a locking mechanism or the like.

[0040] Fig. 9 Figure ad shows the hand tool or grinder 10 of the previous figures in a shaded representation to make curvatures visible. Figure 9a shows the grinder 10 in a side view, Figure 9b in a rear view, Figure 9c perspective view and Figure 9d in a plan view. The grinder 10 is for the simultaneous drive of three, in particular tiltable, rotating and / or oscillating and / or randomly circularly driven grinding wheels 12, 14, 16, comprising at least one output shaft housing 202, which essentially has three output shafts 40 (not shown here, see in particular Fig. 2) orthogonal to the output shaft axes 42, 202, 204, 206, and a motor housing 200 that essentially encloses the motor 26 orthogonal to the motor shaft axis 30. The grinder 10 has a handle 24. The front output shaft axis 42, 204 can be better distinguished from the rear output shaft axes 42, 206, 208 by the additional reference numerals. The output shaft housing 202 encloses the three output shafts 40 at least essentially orthogonal to the output shaft axes 42. The motor housing 200 encloses the motor 26 at least essentially orthogonal to the motor shaft axis 30.

[0041] A sectional area 210 of the motor housing 200 orthogonal to the motor shaft axis 30 in a constricted region 212 of the motor housing 200 is less than 70%, in particular less than 65%, preferably less than 55%, relative to a sectional area 214 of the output shaft housing 202 orthogonal to the output shaft axes 42 in an extended region of the output shaft housing 202, in particular the most extended region 216 of the output shaft housing 202. In the illustrated Fig. 10 It is approximately 52%. The extended area 216 is understood to be the area with the largest cross-sectional area 214 of the output shaft housing 202. Thus, in this area 216, an extension, e.g., the length 218 or the circumferential distance or length 215 around the output shaft housing 202, is maximum. Furthermore, in the side, rear and top views of the Figure 9a-cAlso, a length and a width of the motor housing 200 in the constricted region 212 and of the output shaft housing 202 in the extended region 216 are provided with the following reference numerals: Output shaft housing 202: length 218, width 220; Motor housing: length 222, width 224. Relatively, the extended region 216 of the output shaft housing 202 is approximately 30% longer and approximately 65% ​​wider than the constricted region 212 of the motor housing 200. The sectional area ratio of the extended region 216 of the output shaft housing 202 to the constricted region 212 of the motor housing 200 is approximately 190% (cf. Fig. 10 ).

[0042] Out of Fig. 10The sectional area ratio of certain areas is also apparent. The sectional area 214 of the output shaft housing 202 in a rear region 226 of the handheld power tool or grinder 10 is covered by less than 75%, in particular less than 50%, preferably less than 25%, of the sectional area 210 of the motor housing 200 projected along the motor shaft axis 30, in particular in the constricted region 212. Similarly, the grinding surface 232 of grinding discs 14, 16 applied to the rear of the grinder 10 is covered by less than 75%, in particular less than 50%, preferably less than 25%, of the sectional area 210 of the motor housing 200 projected along the motor shaft axis 30, in particular in the constricted region 212.In a front region 228 of the handheld power tool, the cutting surface 210 of the motor housing 200 projected along the motor shaft axis 30, in particular also in the constricted region 212, covers the cutting surface 214 of the output shaft housing 202 by more than 70%, in particular more than 90%, preferably completely. Similarly, the grinding surface 234 of a grinding disc 12 applied to the front of the grinder 10 is covered by more than 70%, in particular more than 90%, preferably completely, by the cutting surface 210 of the motor housing 200 projected along the motor shaft axis 30, in particular also in the constricted region 212.

[0043] Furthermore, Fig. 10Also, a circumferential length 211 of the motor housing 200 orthogonal to the motor shaft axis 30 or the output shaft axes 42 in a particularly constricted region 212 of the motor housing 200 relative to a circumferential length 215 of the output shaft housing 202 orthogonal to the output shaft axes 42, 204, 206, 208 in a particularly extended region 216 of the output shaft housing 202 is evident. It amounts to less than 80%, here approximately 70%. In other words, the circumferential length 215 of the output shaft housing 202 is approximately 145% of the circumferential length 211 of the motor housing 200 in the constricted region 212.

[0044] Furthermore, one, in particular two of the three output shaft axes 42, in particular the rear two output shaft axes 206, 208 of the hand-held power tool, lie outside the motor housing 200, in particular outside the constricted region 212 of the motor housing 200. These output shaft axes 206, 208 thus do not intersect the motor housing 200, at least not in the constricted region 212, in particular nowhere. Furthermore, in particular one, preferably two of the three output shaft axes 204, 206, 208, in particular the rear two output shaft axes 206, 208 of the handheld power tool or of the grinder 10, lie outside the handle 24, in particular the rod-shaped handle 24. They also lie outside a dented area 230 or a concave indentation of the handle 24 and / or motor housing 200 or a dented transition area 276 between the handle 24 and the motor housing 200. The front output shaft axis 204 of the handheld power tool orof the grinder 10, lies within the motor housing 200 and / or within a motor housing handle 236 - thus cutting this / this.

[0045] From the side view according to Fig. 9aIt is further apparent that the ratio of the height 238, 240 of the hand-held power tool in the direction of the output shaft axes 42, 204, 206, 208, in particular a height 238 of a motor and output shaft housing 200, 202, to the length 242 of a substantially rod-shaped handle 24, in particular a length 242 of a rod-shaped handle 24 projecting substantially orthogonally to the motor housing 200 or the input and output shaft axes 30, 204, deviates by less than 50%, in particular deviates by less than 75%, preferably deviates by less than 85%, in particular is approximately identical. A rod-shaped handle projecting substantially orthogonally to the input and output shaft axis(es) 30, 204 is understood here to mean an angle range of 60°-120°, in particular 75°-105°, preferably 90°, relative to the input and output shaft axis(es) 30, 204, 206, 208. This advantageously provides a very compact handheld power tool.The center of gravity S thus moves as close as possible to the grinding wheels 12, 14, 16. Furthermore, a ratio of a total length 244 of the hand-held power tool orthogonal to at least one input or output shaft axis 30, 42, 204, 206, 208, in particular from one end of the motor housing 200 to one end of the rod-shaped protruding handle 24, relative to a height 238, 240 of the hand-held power tool along at least one direction of the input or output shaft axis 30, 42, 204, 206, 208, in particular from a grinding wheel plane 112 to the end of the handle 24 or motor housing 200, is greater than 10%, in particular greater than 25%, preferably around 40% greater.

[0046] Furthermore, the weight of the accumulator 72 relative to the components of the drive train, in particular comprising the motor 26, the pinion 32, the central gear 34, the output shafts 40, and spur gears 44, is approximately 10-50% more, in particular 30-40% more. This can positively influence the position of the center of gravity S. The volume of the motor and output shaft housings 200, 202 compared to the rod-shaped handle housing 68 is approximately 20-70% more, in particular approximately 50% more.

[0047] From the side view and the perspective view according to Fig. 9a , d , as well as the Fig. 11, furthermore, a grinding machine housing 250 is shown with at least one housing shell element 252 and with at least one further housing shell element 254 connected to the housing shell element 252, which at least partially form a handle 24, 258. The grinding machine housing 250 is characterized by at least one ventilation opening 262, in particular a ventilation slot, formed at least partially in the region of a separating edge 260 of the housing shell element 252 and the further housing shell element 254. The ventilation opening 262 advantageously extends over two regions 264, 266, which are arranged at an angle 268, in particular an angle 268 (cf. Fig. 10, side view) are arranged between 90° and 120°, preferably between 100° and 105°, relative to one another. The angle advantageously follows the orientation of the rod-shaped handle to the motor housing. The ventilation opening areas are advantageously aligned parallel to their main extent. The ventilation opening 262, in particular that of section 266 in the area of ​​the handle 258, is advantageously intended to flow around the hand of a user, in particular to cool, warm, and / or dry it.

[0048] The housing shell element 252 and the further housing shell element 254 are connected to one another, in particular fixed to one another, at least substantially free of visible fastening elements, in particular along an at least substantially entire contact line and / or surface of the housing shell element 252 and the further housing shell element 254. Furthermore, the handle 24, 258 is designed to be at least substantially free of separating edges, at least on one side of the handle 24, 258 facing and / or facing away from a grinding disc 12, 14, 16 or tool side.

[0049] Furthermore, the grinding machine housing 250 has a motor housing section 270 and a rod-shaped handle housing section 272, wherein the grinding machine housing 250 has a concave indentation 278 or a dent in a transition region 276 between the rod-shaped handle housing section 272 and the motor housing section 270 (cf. Fig. 10). This serves as an ergonomic contact surface for a finger, especially a thumb of the user. The dent is particularly visible in the side view of the Fig. 9a clearly visible. The shading indicates the curved areas. Preferably, the ventilation opening(s) 262 can be formed by offsetting a housing edge of the housing shell element 252 and the further housing shell element 254.

Claims

1. Hand-held power tool, in particular sander (10), for simultaneously driving multiple, preferably for driving three, in particular tiltable sanding discs (12, 14, 16) which are driven in a rotating and / or oscillating and / or randomly circular manner, having at least one housing part (60) which has sanding-disc-receptacle regions (102) and / or openings (100) in which or projecting through which are arranged sanding-disc receptacles (56) and / or output shafts (40) for driving the sanding discs (12, 14, 16), wherein the at least one housing part (60) has between at least two adjacent sanding-disc-receptacle regions (102) and / or openings (100) a depression (108), in particular a concave depression (108), characterized in that the depression (108) forms at least a part of an air-guiding channel (120), in particular a part of an air-guiding channel (120) for extraction of dust by suction, and there is an increase in the dimension of the depression (108) in the housing part (60) from a centre region (114) of the housing part (60) radially outwards in the direction of a periphery (116) of the housing part (60).

2. Hand-held power tool according to Claim 1, characterized in that a number of depressions (108) corresponds to a number of openings (100) and / or to a number of sanding-disc receptacles (56), in particular wherein the depressions (108) are arranged in the interspace (122) between in each case adjacent openings (100) and / or sanding-disc-receptacle regions (102).

3. Hand-held power tool according to either of the preceding claims, characterized in that the depression (108) ensures contact-free tilting (124) of the sanding discs (12, 14, 16) relative to the housing part (60).

4. Hand-held power tool according to one of the preceding claims, characterized in that a housing separating edge (126), in particular a housing parting joint (130), between the at least one housing part (60) and a further housing part (62), a form-fit element (132), in particular a latching groove (134), serves for receiving a corresponding form-fit element (136), in particular a latching extension (140), of a dust-suction-extraction hood (138).

5. Hand-held power tool according to Claim 4, characterized in that a depression (108) in the housing part (60) serves as a further form-fit element (142), in particular as a stop element (144), for a further corresponding form-fit element (146) of the dust-suction-extraction hood (138).

6. Hand-held power tool according to one of the preceding claims, characterized in that the hand-held power tool has an in particular removable dust-suction-extraction hood (138) which comprises a connecting piece (148) for connection to a dust-suction-extraction device, said connecting piece projecting to the outside (149) of the dust-suction-extraction hood (138) and having a suction-extraction opening (150) which proceeds from the connecting piece (148) and is open towards the interior (152) of the dust-suction-extraction hood (138), in particular wherein the dust-suction-extraction hood (138) has a substantially triangular geometry.

7. Hand-held power tool according to Claim 6, characterized in that the dust-suction-extraction hood (138) has an extension (158) in the region of the suction-extraction opening (150) for avoidance of transverse air flow, said extension projecting into the interior (152) or centre of the dust-suction-extraction hood (138).

8. Hand-held power tool according to Claim 7, characterized in that the extension (158), proceeding from the dust-suction-extraction hood (138) and / or the suction-extraction opening (150), has a main extent direction (160) into the interior (152) or the centre of the dust-suction-extraction hood (138), and / or in that the extension (158) has at least one wall (162), in particular multiple walls (162), which serve for reducing transverse air flow, in particular for reducing transverse air flow from below (184) the dust-suction-extraction hood (138) and / or from the side (164) within the dust-suction-extraction hood (138).

9. Hand-held power tool according to either of Claims 7 and 8, characterized in that the extension (158) and / or the wall (162) are / is open at least partially at the side (166), in particular for making possible transverse air flow in at least this open region (170, 172).

10. Hand-held power tool according to one of Claims 7-9, characterized in that the dust-suction-extraction hood (138) or the frame (174) of the dust-suction-extraction hood (138) is flexible, in particular in the direction of the interior (152) or centre of the dust-suction-extraction hood (138), in particular for generating a preload and / or pressing of the dust-suction-extraction hood (138) and / or form-fit elements (136, 146) of the dust-suction-extraction hood (138) and / or of the frame (174) of the dust-suction-extraction hood (138) against the housing of the hand-held power tool, in particular for tool-free and / or secure and / or small-gap connection thereto.

11. Hand-held power tool according to one of Claims 6-10, characterized in that the dust-suction-extraction hood (138) is in the form of a spacer and / or impact protector for the hand-held power tool.

12. Hand-held power tool according to one of Claims 6-11, having a gripping contour (176) on the outer side (149) of the dust-suction-extraction hood (138), wherein the gripping contour (176) corresponds substantially to the silhouette contour (178) at least of a region of the hand-held power tool, in particular wherein the gripping contour (176) corresponds at least substantially to the silhouette contour (178) of a depression (108) of the hand-held power tool.

13. Hand-held power tool according to one of Claims 6-12, wherein the dust-suction-extraction hood (138) is configured for releasable connection to a housing of the hand-held power tool by means of at least one form-fit element and / or force-fit element and / or frictionally engaging element, and the dust-suction-extraction hood (138) is connected via an in particular elastic connecting element (179), in particular an elastic band (180), in the region of a connecting piece (148) or connecting-piece adaptor (182) and in a free end (70) of a handle (24) of the hand-held power tool, to the hand-held power tool, in particular wherein the in particular elastic connecting element (179) is connected captively to the hand-held power tool or to the dust-suction-extraction hood (138).