Portable working tool

Abstract

The invention relates to a portable work device comprising a housing (2), a tool (9) wherein a first intake opening (11) and a second intake opening (12) for cooling air for cooling the drive motor (5) are formed on the housing (2), a first cooling air duct (13) and a second cooling air duct (14), wherein the first cooling air duct (13) extends from the first intake opening (11) to the first end (7) of the motor housing (20) of the drive motor (5), and wherein the second cooling air duct (14) extends from the second intake opening (12) to the second end (8) of the motor housing (20) of the drive motor (5), wherein the first cooling air duct (13) and the second cooling air duct (14) are connected to each other via a bypass (15).

Description

[0001] The invention relates to a portable working device.

[0002] Portable work devices are known from the prior art, comprising a housing, a drive motor arranged in the housing, and a tool driven by the drive motor. One or more intake openings are provided on the housing to cool the drive motor. Cooling air can flow into the housing through the intake openings, cool the drive motor, and exit through an outlet opening. Corresponding portable work devices are known from patent documents US9718180 B2 and US10434635 B2. Document US9718180 B2 discloses the preamble of claim 1.

[0003] It has been shown that cooling performance can be reduced during operation of such devices. This can lead to overheating of the drive motor and electronic components. Consequently, the operator must stop using the device until it has cooled down. Furthermore, it is known that overheating of a device can also lead to damage to the device.

[0004] The invention is therefore based on the object of providing a portable working device that reliably ensures sufficient cooling capacity for cooling the drive motor.

[0005] The problem is solved by a portable working device having the features of claim 1.

[0006] It has been observed that during operation of the implement, the intake openings of the implement's housing can become blocked and impede the supply of cooling air. The invention is based on the finding that the blockage of an intake opening essentially has two effects. Firstly, the supply of overall cooling air is reduced, which also reduces the cooling performance of the implement. Secondly, the cooling performance is only provided partially, for example via essentially one intake opening, which results in uneven cooling of the drive motor and / or the electronic components. In particular, the components that are intended to be surrounded by the cooling air from the blocked intake opening do not receive sufficient cooling.

[0007] The portable work device according to the invention comprises a housing with a rear end and a front end, a tool, the tool being arranged at the front end of the housing, a drive motor arranged in the housing between the rear end and the front end and having a rotational axis for driving the tool, the drive motor having a motor housing with a first end facing the rear end of the housing and a second end facing the front end of the housing, a first intake opening and a second intake opening for cooling air for cooling the drive motor being formed on the housing, the first intake opening being arranged between the rear end of the housing and the first end of the motor housing of the drive motor, the second intake opening being arranged between the front end of the housing and the first end of the motor housing of the drive motor, a first cooling air duct and a second cooling air duct,wherein the first cooling air duct extends from the first intake opening to the first end of the motor housing of the drive motor, and wherein the second cooling air duct extends from the second intake opening to the second end of the motor housing of the drive motor, wherein the first cooling air duct and the second cooling air duct are connected to each other via a bypass.

[0008] The portable work device according to the invention provides a first cooling air duct and a second cooling air duct for cooling the drive motor. Additionally, the cooling air ducts are connected to each other via a bypass.

[0009] If one of the two intake openings becomes blocked, the lack of cooling air at the blocked intake opening can be compensated for by cooling air flowing in via the bypass. The cooling air is distributed evenly via the bypass to the cooling air ducts connected to the intake openings. This compensates for a partial lack of cooling capacity, ensuring consistent and reliable cooling of the drive motor and / or electronic components.

[0010] The drive motor comprises a fan impeller rotating about the rotational axis. During operation of the drive motor, the fan impeller generates a first cooling air stream flowing along the first cooling air duct and a second cooling air stream flowing along the second cooling air duct. Advantageously, at least one outlet opening is provided on the housing for discharging the cooling air streams from the housing. This allows the heated cooling air to be transported out of the housing of the implement.

[0011] The bypass runs, in particular, outside the drive motor. This allows for the cooling air to be distributed outside the drive motor. The cooling air surrounds the drive motor and ensures uniform cooling. According to the invention, a rotational plane spanned by the fan impeller intersects the bypass. Accordingly, the bypass is located at the level of the drive motor. The bypass is preferably arranged directly on the motor housing 20.

[0012] A first filter is preferably provided at the intake openings, wherein the first filter is preferably a metal filter. In particular, a second filter is provided at the intake openings, wherein the second filter is preferably a foam filter. The first filter at the first intake opening and the first filter at the second intake opening are in particular designed separately from one another. Likewise, the second filter at the first intake opening and the second filter at the second intake opening are designed separately. The filters are provided to filter particles so that the drive motor and other components arranged in the housing of the working device do not become dirty. The first filter, designed as a metal filter, serves to filter coarse dirt particles. The second filter, designed as a foam filter, in contrast, serves to filter smaller dirt particles.The second filter preferably has a smaller pore size than the first filter. The first filter and the second filter are arranged one behind the other at each intake opening. The first filter and the second filter are each arranged at an intake opening such that the intake air or cooling air flows first through the first filter and then through the second filter.

[0013] It is advantageously provided that the first intake opening and the second intake opening are arranged offset from one another at an angular distance relative to the rotational axis of the drive motor. The angular distance between the intake openings is at least 15°, preferably at least 25°, in particular approximately 30°. The angular distance between the intake openings is preferably at most 150°, in particular at most 120°, preferably at most 90°. It is advantageously provided that the first intake opening has a first distance from the front end of the housing and the second intake opening has a second distance from the front end of the housing, wherein the first distance is greater than the second distance.

[0014] When the tool is in operation, dirt particles are generated by the tool in use and distributed across the housing. The trajectory of such dirt particles depends, among other things, on the type of tool, its position and also on external factors such as the weather. If, for example, the tool is a pole pruner, at least some of the resulting sawdust from the tool will fly over the housing. The offset arrangement of the intake openings reduces the likelihood of the intake openings becoming blocked at the same time, as at least one of the two intake openings is not in the trajectory path of the dirt particles. This advantage results from both the angular distance between the intake openings and the different distances between the intake openings and the front end of the housing.

[0015] The housing preferably has a total length extending from the rear end to the front end. The first distance preferably corresponds to at least 50%, preferably at least 70%, in particular approximately 80% of the total length of the housing. The second distance corresponds to at least 25%, preferably at least 35%, in particular at least 40% of the total length of the housing. Accordingly, the intake openings are also arranged offset from one another in the direction of the rotational axis of the drive motor or in the longitudinal direction of the implement.

[0016] It is preferably provided that the housing has a top side, a bottom side, a first longitudinal side and a second longitudinal side, wherein the first suction opening is arranged on the top side of the housing. The first suction opening, which is a greater distance from the front end of the housing and thus also from the tool, is therefore arranged on the top side of the housing. The second suction opening, which is arranged closer to the front side of the housing, is preferably arranged on one of the two longitudinal sides of the housing. Due to the orientation of the guide bar and the associated direction of movement of the saw chain, pole pruners and chainsaws generally tend to become dirty on the top and bottom of the housing. The suction opening arranged closer to the tool and thus also closer to the source of the dirt particles is preferably designed and protected from dirt on one of the two long sides.

[0017] Further features of the invention will become apparent from the following description and the exemplary embodiments illustrated in the drawings. They show: Fig. 1 shows a perspective view of an embodiment of a portable working device with a guide tube and a tool at one end and a power source at the other end of the guide tube, Fig. 2 shows a side view of the portable working device according to the invention with a schematically indicated guide tube, Fig. 3 shows a plan view of the portable working device according to Fig. 2 , Fig. 4 in a view from behind the portable working device after Fig. 2 , Fig. 5 in a sectional view in a view from above the portable working device according to Fig. 2 , Fig. 6 in a schematic representation of the working device according to the invention, and Fig. 7 in a side sectional view of the portable working device according to Fig. 2 .

[0018] In the figures, identical components are provided with identical reference symbols.

[0019] In Fig. 1 The portable tool 1 is shown, which is designed as a pole pruner. The portable tool 1 can also be designed as a power chain saw, hedge trimmer, circular saw, or similar tool. The portable tool 1 comprises a housing 2, a drive motor 5 arranged in the housing 2, and a tool 9 drivable by the drive motor 5. As shown in the Figures 5 to 7As shown, the drive motor 5 is designed as an electric motor. The electric motor can be a DC motor in the form of a commutator motor or an EC motor controlled by a DC voltage via a control device (e.g., a universal motor, a brushless DC motor, or an electronically commutated DC motor). In an alternative embodiment of the portable work device, the drive motor can also be designed as an internal combustion engine.

[0020] As in Fig. 1As shown, the portable working device 1 comprises a guide tube 51 with a first end 52 and a second end 53. The housing 2 of the working device 1 is held at the first end 52 of the guide tube. A second housing 54 is held at the second end 53 of the guide tube 51. The second housing 54 has a receiving shaft 55 for accommodating a battery or similar energy source. It may be expedient to use a stationary power grid as the energy source, which is connected via an electrical line to the second housing 54 or to control electronics arranged in the second housing 54. In the exemplary embodiment shown, an operating handle 56 with operating elements is provided at the second end 53 of the guide tube 51. In the exemplary embodiment shown, the operating elements are an operating element referred to as an operating lever 57 or throttle lever, and a locking lever 58. The operating lever 57 serves to control the drive motor 5.The locking lever 58 is intended to secure the operating lever 57.

[0021] As in Fig. 1 As shown, in the exemplary embodiment, the guide tube 51 is designed to be telescopic. The guide tube 51 comprises a first tube section 62 with the first end 52 of the guide tube 51 and a second tube section 63 with the second end 53 of the guide tube 51. The guide tube 51 comprises a clamping device 59. The clamping device 59 is preferably fastened to the second tube section 63. The clamping device 59 serves to fix the first tube section 62 to the second tube section 63.

[0022] As in Fig. 2As shown, the housing 2 of the portable power tool 1 extends in a longitudinal direction 19 from a rear end 3 to a front end 4. The tool 9 is arranged at the front end 4 of the housing. The tool 9 is designed in the exemplary embodiment as a saw chain 33. The saw chain 33 is connected to the chain drive wheel 38 ( Fig. 5) is driven in a rotating direction 37 around a guide rail 32. The rotating direction 37 of the saw chain 33 is the direction of movement of the saw chain 33 intended for the intended operation of the work device 1 for chip removal. The chain drive wheel 38 is driven in rotation via the drive motor 5. The guide rail 32 is arranged at the front end 4 of the housing 2 and extends in a longitudinal direction 34 which corresponds to a direction from the rear end 3 to the front end 4 of the housing 2. The saw chain 33 spans a tool plane 30, with both the saw chain 33 and the guide rail 32 lying in the tool plane 30.

[0023] As in Fig. 2As shown, the guide rail 32 comprises an upper side 35 and a lower side 36. During normal operation of the portable tool 1, the saw chain 33 runs along the upper side 35 of the guide rail 32 in the direction away from the front end 4 of the housing 2. During normal operation of the portable tool 1, the saw chain 33 runs along the lower side 35 of the guide rail 32 in the direction toward the front end 4 of the housing 2. Both the upper side 35 of the guide rail 32 and the lower side 36 of the guide rail 32 lie in the tool plane 30.

[0024] As in the Figures 2 and 3As shown, the housing 2 extends along its longitudinal direction 19 from its rear end 3 to its front end 4. The rear end 3 forms the first end face 39 of the housing 2. The front end 4 of the housing 2 forms the second end face 40 of the housing 2. The housing 2 comprises an upper side 26 and a lower side 27. In addition, the housing 2 comprises a first longitudinal side 28 and a second longitudinal side 29. The first end face 39 and the second end face 40 of the housing 2 are connected to one another via the upper side 26, the lower side 27, the first longitudinal side 28 and the second longitudinal side 29 of the housing 2. During normal operation of the working device 1, the upper side 26 of the housing 2 lies above the underside 27 of the housing 2. A vertical direction 45 running from the underside 27 to the upper side 26, together with the longitudinal direction 19 or with the axis of rotation 6 of the drive motor 5, spans a longitudinal plane 46 of the housing 2.The housing 2 comprises a transverse plane 47, which is oriented orthogonally to the longitudinal plane 46 and the vertical direction 45. The longitudinal sides 28, 29 are arranged opposite one another with respect to the longitudinal plane 46. The top side 26 and the bottom side 27 are arranged opposite one another with respect to the transverse planes 47. In the exemplary embodiment, the longitudinal plane 46 of the housing 2 is oriented parallel to the tool plane 30.

[0025] As in the Figures 5 to 7, the drive motor 5, designed as an electric motor, is arranged in the housing 2 between the rear end 3 of the housing 2 and the front end 4 of the housing 2. The drive motor 5 comprises an axis of rotation 6, which in the exemplary embodiment corresponds to the longitudinal direction 19 of the housing 2. The drive motor 5 comprises a housing 20, which extends along the axis of rotation 6 of the drive motor 5 from a front-side first end 7 to a front-side second end 8 of the motor housing 20. The first end 7 of the motor housing 20 faces the rear end 3 of the housing 2. The second end 8 of the drive motor 5 faces the front end 4 of the housing 2. The drive motor 5 comprises a drive shaft 23, which protrudes from the housing 2 at the second end 8 of the housing 2 in the direction of the front end 4 of the housing 2. At this end of the drive shaft 23, a drive pinion 25 is arranged, which drives the drive sprocket 38 via a bevel gear 24.

[0026] As in the Figures 2 to 4 as well as in Fig. 6 As shown, the housing 2 comprises a first intake opening 11 and a second intake opening 12. The intake openings 11, 12 serve to draw in cooling air to cool the drive motor 5. The housing 2 comprises at least one outlet opening 18, which serves to discharge the cooling air heated by the drive motor 5. In the exemplary embodiment, several outlet openings 18, in particular three outlet openings 18, are provided. A different number of outlet openings 18 may also be expedient. As shown in particular in the Figures 5 and 7As shown, a fan wheel 10 is arranged on the drive shaft 5 of the drive motor 5. The fan wheel 10 is driven to rotate about the rotational axis 6 of the drive motor 5 via the drive shaft 23. The fan wheel 10 is designed as a radial impeller. The fan wheel 10 is designed such that, during operation of the working device 1, cooling air is sucked in through the intake openings 11, 12 via the fan wheel 10 and expelled through the outlet openings 18.

[0027] As in Fig. 6As shown, the first intake opening 11 is arranged between the rear end 3 of the housing 2 and the first end 7 of the motor housing 20 of the drive motor 5. The second intake opening 12 is arranged between the front end 4 of the housing 2 and the first end 7 of the motor housing 20 of the drive motor 5. The working device 1 comprises a first cooling air duct 13 and a second cooling air duct 14. The first cooling air duct 13 extends from the first intake opening 11 to the first end 7 of the motor housing 20. The second cooling air duct extends from the second intake opening 12 to the second end 8 of the motor housing 20. The first cooling air duct 13 and the second cooling air duct 14 are connected to one another via a bypass 15. The bypass 15 ensures pressure equalization between the first cooling air duct 13 and the second cooling air duct 14.If one of the two intake openings 11, 12 is at least partially blocked, the cooling air duct 13, 14 corresponding to the blocked intake opening 11, 12 can be supplied with cooling air from the other cooling air duct 13, 14 via the bypass 15.

[0028] As in Fig. 6 As shown, the motor housing 20 comprises at least one first inlet opening 41 at its first end 7. The motor housing 20 comprises at least one second inlet opening 42 at its second end 8. The motor housing 20 comprises at least one outlet opening 43 on its outer surface. The outlet opening 43 of the motor housing 20 is arranged radially to the fan wheel 10. Accordingly, the outlet opening 43 is at the same height as the fan wheel 43 in the direction of the axis of rotation 6 of the drive motor 5.

[0029] As in Fig. 6As shown, during operation of the working device 1, a first cooling air flow 16 and a second cooling air flow 17 are generated via the fan wheel 10 rotating about the rotation axis 6. The first cooling air flow 16 runs from the first intake opening 11 via the first cooling air duct 13 to the first end 7 of the motor housing 20. Furthermore, the first cooling air flow 16 flows through the at least one first inlet opening 41 into the motor housing 20 and flows to the fan wheel 10. In doing so, the first cooling air flow 16 absorbs heat radiated by the drive motor 5. The second cooling air flow 17 runs from the second intake opening 12 via the second cooling air duct 14 to the second end 8 of the motor housing 20. The second cooling air flow 16 flows through the at least one second inlet opening 42 into the motor housing 20 and flows to the fan wheel 10. The second cooling air flow 17 crosses the coils of the drive motor 5. The second cooling air flow 17 absorbs the heat radiated by the drive motor 5.

[0030] As in Fig. 6 As shown, the heated cooling air streams 16, 17 are conveyed via the fan wheel 10 radially to the rotational axis 6 of the drive motor 5 through the outlet opening 43 of the motor housing 20 out of the drive motor 5. Subsequently, the heated cooling air streams 16, 17 flow from the at least one outlet opening 43 of the motor housing 20 through the outlet openings 18 out of the housing 2. As a result, the heat generated by the drive motor 5 is conducted out of the housing 2.

[0031] As in Fig. 6shown, the bypass 15 runs outside the drive motor 5. The bypass 15 extends over the entire length of the motor housing 20 measured in the direction of the axis of rotation 6. The bypass 15 crosses the cooling air flows 16, 17 as they exit the outlet opening 43 of the motor housing 20. The bypass 15 is designed such that a plane of rotation 31 defined by the fan wheel 10 is intersected by the bypass 15. The plane of rotation 31 is aligned perpendicular to the axis of rotation 6 of the drive motor 5 and intersects the fan wheel 10. In the exemplary embodiment, the plane of rotation 31 is aligned perpendicular to the longitudinal plane 46 and perpendicular to the transverse plane 47.

[0032] As in Fig. 4As shown, the first intake opening 11 and the second intake opening 12 are arranged offset from one another at an angular distance α relative to the rotational axis 6 of the drive motor 5. The angular distance α between the intake openings 11, 12 in the exemplary embodiment is at least 15°, preferably at least 25°, in particular approximately 30°. The angular distance α between the intake openings 11, 12 in the exemplary embodiment is at most 150°, in particular at most 120°, preferably at most 90°.

[0033] As in the Figures 2 to 3As shown, the first suction opening 11 in the exemplary embodiment is arranged on the top side 26 of the housing 2. The second suction opening 12 is preferably arranged on one of the two longitudinal sides 28, 29. In the preferred exemplary embodiment, the second suction opening 12 is arranged on the first longitudinal side 28, wherein the first longitudinal side 28 has a greater distance from the tool plane 30 than the second longitudinal side 29. The distance of the longitudinal sides 28, 29 from the tool plane 30 is to be measured at the front end 4 of the housing 2 perpendicular to the tool plane 30. This is intended to reduce or prevent contamination emanating from the tool 9 at the second suction opening 12.

[0034] As in Fig. 3As shown, the first suction opening 11 is arranged as close as possible to the rear end 3 of the housing 2 in order to maximize the distance from the tool 9. This also reduces or avoids the contamination emanating from the tool 9. The distance of the second suction opening 12 from the tool 9 is less than the distance of the first suction opening 11 from the tool 9. In other words, the housing 2 has a total length l extending from the rear end 3 to the front end 4. The first suction opening 11 has a first distance a from the front end 4 of the housing 2 and the second suction opening 12 has a distance b from the front end 4 of the housing 2. The first distance a is greater than the second distance b. The first distance a corresponds to at least 50%, preferably at least 70%, in particular approximately 80% of the total length l of the housing 2.The second distance b corresponds to at least 25%, preferably at least 35%, in particular approximately 40% of the total length l of the housing 2.

[0035] As in Fig. 4 As shown, the first intake opening 11 has a maximum width c measured in the direction running from the first longitudinal side 28 to the second longitudinal side 29. The maximum width c corresponds to at least 20%, preferably at least 30%, in particular approximately 40% of the maximum width d of the housing 2, i.e. the maximum distance between the first longitudinal side 28 and the second longitudinal side 29. Furthermore, the first intake opening 11 extends over a maximum height e, wherein the height e is measured in the vertical direction 45. The maximum height e of the first intake opening 11 corresponds to at least 5% of the maximum height f of the housing 2, wherein the maximum height f of the housing 2 is also measured in the vertical direction 45.

[0036] As in Fig. 4As shown, the second intake opening 11 also has a maximum height g measured in the vertical direction 45, wherein the maximum height g of the second intake opening 11 corresponds to at least 10%, preferably at least 20%, in particular at least 30% of the maximum height f of the housing 2. As shown in Fig. 2 As shown, the second intake opening 12 has a maximum width h measured in the longitudinal direction 19, wherein the width h of the second opening 12 corresponds to at least 5% of the total length l of the housing 2.

[0037] As in the Figures 2 to 4As shown, the first suction opening 11 and the second suction opening 12 are closed in the direction of the front end 4 of the housing 2, i.e. towards the tool 9. This prevents dirt particles from the tool 9 from getting into the suction openings 11, 12. Both suction openings 11, 12 are located in an undercut of the housing 2 with respect to the front end 4 of the housing 2. Accordingly, the suction openings 11, 12 are arranged hidden by the housing 2 towards the front end 4 of the housing 2. In addition, a first filter and a second filter (not shown in detail) are provided at the suction openings 11, 12. The first filter facing the surroundings of the working device is designed as a metal filter. The second filter covered by the first filter is preferably a foam filter. The first filter is used to filter coarse dirt particles, the second filter is used to filter finer dirt particles.

Claims

1. Portable implement, comprising - a housing (2), which has a rear end (3) and a front end (4), - a tool (9), wherein the tool (9) is arranged on the front end (4) of the housing (2), - a drive motor (5) with an axis of rotation (6) for driving the tool (9), which drive motor is arranged in the housing (2) between the rear end (3) and the front end (4), wherein the drive motor (5) has a motor housing (20) with a first end (7), which is directed towards the rear end (3) of the housing (2), and a second end (8), which is directed towards the front end (4) of the housing (2), - wherein a first intake opening (11) and a second intake opening (12) for cooling air are formed at the housing (2) for cooling the drive motor (5), - wherein the first intake opening (11) is arranged between the rear end (3) of the housing (2) and the first end (7) of the motor housing (20) of the drive motor (5) and has a first spacing (a) to the front end (4) of the housing (2), - wherein the second intake opening (12) is arranged between the front end (4) of the housing (2) and the first end (7) of the motor housing (20) of the drive motor (5) and has a second spacing (b) to the front end (4) of the housing (2), - a first cooling-air channel (13) and a second cooling-air channel (14), wherein the first cooling-air channel (13) extends from the first intake opening (11) as far as the first end (7) of the motor housing (20) of the drive motor (5), and wherein the second cooling-air channel (14) extends from the second intake opening (12) as far as the second end (8) of the motor housing (20) of the drive motor (5), wherein the first cooling-air channel (13) and the second cooling-air channel (14) are connected to one another via a bypass (15), wherein the drive motor (5) comprises a fan impeller (10) which rotates about the axis of rotation (6), wherein, during operation of the drive motor (5), a first cooling-air stream (16) flowing along the first cooling-air channel (13) and a second cooling-air stream (17) flowing along the second cooling-air channel (14) are generated by the fan impeller (10), characterized in that a plane of rotation (31) defined by the fan impeller (10) intersects the bypass (15).

2. Implement according to Claim 1, characterized in that, at the housing (2), provision is made of at least one outlet opening (18) for letting the cooling-air streams (16, 17) out of the housing (2).

3. Implement according to Claim 1 or 2, characterized in that the bypass (15) runs outside the motor housing (20) of the drive motor (5).

4. Implement according to one of Claims 1 to 3, characterized in that provision is made of a first filter at the intake openings (11, 12), wherein the first filter is preferably a metal filter.

5. Implement according to Claim 4, characterized in that provision is made of a second filter at the intake openings (11, 12), wherein the second filter is preferably a foam filter.

6. Implement according to one of Claims 1 to 5, characterized in that the first intake opening (11) and the second intake opening (12) are arranged offset from one another by an angular spacing (α) in relation to the axis of rotation (6) of the drive motor (5).

7. Implement according to Claim 6, characterized in that the angular spacing (α) between the intake openings (11, 12) is at least 15°, preferably at least 25°, in particular approximately 30°.

8. Implement according to one of Claims 1 to 7, characterized in that the housing (2) has an overall length (l) extending from the rear end (3) as far as the front end (4), and in that the first spacing (a) corresponds to at least 50%, preferably at least 70%, in particular approximately 80%, of the overall length (l) of the housing (2).

9. Implement according to Claim 8, characterized in that the second spacing (b) corresponds to at least 25%, preferably at least 35%, in particular approximately 40%, of the overall length (l) of the housing (2).

10. Implement according to one of Claims 1 to 9, characterized in that the housing (2) has a top side (26), a bottom side (27), a first longitudinal side (28) and a second longitudinal side (29), wherein the first intake opening (11) is arranged on the top side (26) of the housing (2).

11. Implement according to Claim 10, characterized in that the second intake opening (12) is arranged on one of the two longitudinal sides (28, 29) of the housing (2).

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