Connecting pipe for a hand-held, portable work device

Abstract

Connecting pipe for guiding an airflow from a blower (2) of a hand-held, portable work device (1) to a component (3), in particular a collection bag, of the hand-held, portable work device (1), wherein the connecting pipe (4) is curved in an arc in a plane of curvature (K), wherein the connecting pipe (4) has an inlet opening (10) for the airflow, wherein the connecting pipe (4) has an outlet opening (30) for the airflow, wherein the outlet opening (30) and the inlet opening (10) are oriented relative to each other such that the airflow in the connecting pipe (4) is deflected in the plane of curvature (K) by at least 70°, in particular by at least 80°, wherein the connecting pipe (4) has flow cross-sections (13, 23, 33) oriented perpendicular to a longitudinal centerline (50), wherein each Flow cross-section (13, 23, 33) an internal height (h1, h2) measured perpendicular to the plane of curvature (K).h3) having, wherein the connecting pipe (4) has a central flow cross-section (20) oriented perpendicular to the longitudinal centerline (50) at the midpoint between the inlet opening (10) and the outlet opening (30), wherein each flow cross-section (13, 23, 33) oriented perpendicular to the longitudinal centerline (50) has an inner width (b1, b2, b3) in a direction perpendicular to its inner height (h1, h2, h3), and wherein the inner height (h2) of the central flow cross-section (20) is greater than the inner width (b2) of the central flow cross-section (20), characterized in that the connecting pipe (4) has a tangential plane (T) which runs perpendicular to the plane of curvature (K) and which connects the inlet opening (10) at a first point of contact (P1) and the outlet opening (30) at a second point of contact (P2). affected that the first point of contact (P1) has a point distance (s) from the second point of contact (P2), that each flow cross-section (13, 23,33) of the connecting pipe (4) to the tangential plane (T) has a plane spacing measured perpendicular to the tangential plane (T), and that a maximum plane spacing (d) of all plane spacings of the flow cross-sections (13, 23, 33) to the tangential plane (T) is at least 25%, in particular at least 30%, in particular at least 35%, of the point spacing (s).

Description

[0001] The invention relates to a connecting pipe for guiding an air flow from a blower of a hand-held, portable working device to a component, in particular to a collecting bag of the hand-held, portable working device.

[0002] Typically, the collection bag of such a handheld, portable tool, especially a vacuum cleaner, is connected to the blower of the handheld, portable tool via such a connecting pipe, also known as a bend. The curved curvature of the connecting pipe in a single plane of curvature enables ergonomic positioning of the collection bag and ergonomic carrying of the handheld tool.

[0003] For higher fan power and a larger desired throughput through the connecting pipe, the smallest flow cross-section of the connecting pipe must be selected to be large. Typically, the connecting pipe has an inlet opening and an outlet opening for the air flow, with the outlet opening and the inlet opening oriented relative to each other such that the air flow in the connecting pipe is deflected in the plane of curvature by at least 70°, in particular by at least 80°. The connecting pipe has a longitudinal center line. Along the longitudinal center line, the connecting pipe has flow cross-sections oriented perpendicular to the longitudinal center line. Each flow cross-section has an internal height measured perpendicular to the plane of curvature. To enable a higher flow rate for the air flowing through the connecting pipe, the smallest of these flow cross-sections must be selected to be large.From a certain minimum size for the smallest flow cross-section, the blower is accessible to a user from the outlet opening of the connecting pipe despite the curvature of the connecting pipe.

[0004] US 2013 / 0112298 A1 discloses a turbocharger connected to an air filter via an air supply line. Between its inlet and outlet, the air supply line has a non-circular flow cross-section.

[0005] From AT 522001 A1 a pipe elbow for a fluid is known which has a non-circular flow cross-section between its inlet and its outlet.

[0006] The invention is based on the object of developing a generic connecting pipe for guiding an air flow from a blower of a hand-held, portable working device to a component, in particular to a collecting bag, of the hand-held, portable working device in such a way that even at a high flow rate for the air flow guided through the connecting pipe, a safe and streamlined use of the connecting pipe is possible.

[0007] This object is achieved by a connecting pipe having the features of claim 1.

[0008] The connecting pipe has a central flow cross-section oriented perpendicular to the longitudinal center line along the longitudinal center line in the middle between the inlet opening and the outlet opening. Each flow cross-section oriented perpendicular to the longitudinal center line has an inner width in the direction perpendicular to its inner height. According to the invention, the inner height of the central flow cross-section is greater than the inner width of the central flow cross-section. This allows the central flow cross-section to have a large area and at the same time prevents anyone from reaching through the connecting pipe. The inner width of the central flow cross-section can be selected to be so small that a user cannot reach or reach through the connecting pipe from the outlet opening of the connecting pipe to the outlet opening with their arm or hand.Even if the component, which may be designed as a collection bag, is dismantled, the user is protected from interfering with the blower.

[0009] Despite the narrow internal width of the central flow cross-section, the area of ​​the central flow cross-section can be large due to its large internal height. This allows for a high airflow rate. The connecting pipe according to the invention is simultaneously safe, designed for high fan power, and aerodynamically optimized. The flow path of the airflow through the connecting pipe can be designed without any additional component for intrusion protection inside the connecting pipe. This enables an undisturbed, turbulence-free flow of the airflow in the connecting pipe.

[0010] Advantageously, the inner height of the central flow cross-section is at least 120%, in particular at least 140%, in particular at least 160% of the inner width of the central flow cross-section.

[0011] The central flow cross-section of the connecting pipe is advantageously oval. In particular, the central flow cross-section of the connecting pipe is elliptical. This allows for simple manufacturing of the connecting pipe. The oval, and in particular the elliptical, shape of the central flow cross-section allows the connecting pipe to be designed to be particularly stable. The oval, and in particular the elliptical, shape of the central flow cross-section creates favorable flow conditions inside the connecting pipe. This, in particular, helps prevent flow separation.

[0012] In an advantageous development of the invention, it is provided that the area of ​​the flow cross sections of the connecting pipe increases in the direction from the inlet opening to the outlet opening along the longitudinal center line. In particular, it is provided that the area of ​​the flow cross sections of the connecting pipe increases continuously in the direction from the inlet opening to the outlet opening along the longitudinal center line. Due to the increase in the area of ​​the flow cross sections, the flow velocity of the air flowing through the connecting pipe decreases in the direction towards the outlet opening of the connecting pipe. Particles that are conveyed by the air flow through the connecting pipe from the inlet opening to the outlet opening then reach the component connected to the connecting pipe, in particular to the collection bag connected to the connecting pipe, at a lower velocity.This allows the particles to be collected in the collection bag without being unnecessarily stirred up by the incoming airflow. The lower airflow velocity increases the service life of the collection bag.

[0013] The inner width of the central flow cross-section is expediently from 90% to 110%, in particular at most 105%, in particular at most 100%, of the inner width of the flow cross-section at the inlet opening.

[0014] In particular, the inner width of the central flow cross-section is from 60% to 80%, in particular at most 70%, in particular at most 65%, of the inner width of the flow cross-section of the outlet opening.

[0015] The inner height of the central flow cross-section is expediently at least 110%, in particular at least 130%, in particular at least 150%, of the inner height of the flow cross-section of the inlet opening. This allows the area of ​​the central flow cross-section to be increased even if the inner width of the central flow cross-section is reduced compared to the inner width of the flow cross-section at the outlet opening.

[0016] The inner height of the central flow cross-section is expediently from 90% to 110%, in particular from 95% to 105%, in particular less than 100% of the inner height of the flow cross-section of the outlet opening.

[0017] The flow cross-section of the connecting pipe's inlet opening is advantageously circular. This allows for easy manufacturing of the connecting pipe. The circular shape of the flow cross-section of the inlet opening allows for easy connection of the connecting pipe to the blower of a handheld, portable tool.

[0018] The connecting pipe has a tangential plane. The tangential plane runs perpendicular to the plane of curvature. The tangential plane is tangent to the inlet opening at a first point of contact and simultaneously to the outlet opening at a second point of contact. In particular, the tangential plane does not intersect any of the flow cross-sections of the connecting pipe. Advantageously, the tangential plane only lies adjacent to the total set of flow cross-sections and does not intersect them.

[0019] The first contact point of the inlet opening is at a point distance from the second contact point of the outlet opening. Each flow cross-section of the connecting pipe has a plane distance from the tangential plane, measured perpendicular to the tangential plane. The plane distance of an individual flow cross-section can also be zero. This applies in particular to flow cross-sections that are tangent to the tangential plane.

[0020] According to the invention, the largest plane spacing of all plane spacings of the flow cross-sections is at least 25%, in particular at least 30%, expediently at least 35% of the point spacing. This results in the connecting pipe being more curved than a circular arc. For a 90° circular arc, the ratio of a corresponding plane spacing to a corresponding point spacing is approximately 20%.

[0021] The fact that this ratio for the connecting pipe is at least 25%, in particular at least 30%, in particular at least 35%, provides effective protection against interference.

[0022] The connecting pipe has a radius of curvature in the plane of curvature at the center flow cross-section on the more sharply curved side of the connecting pipe. The radius of curvature is advantageously less than 50%, preferably less than 40%, and especially less than 30%, of the point spacing. This curvature enables reliable protection against intrusion. The curvature prevents a user from reaching from the outlet opening of the connecting pipe to the inlet opening of the connecting pipe with their arm or hand.

[0023] The connecting pipe is advantageously free of a grid bar to prevent intrusion. This prevents the formation of turbulence in the airflow. This prevents a negative impact on the airflow. By eliminating a grid bar to prevent intrusion, the noise emissions from the connecting pipe can be reduced.

[0024] The outlet opening has an outlet edge. In an advantageous development of the invention, the outlet edge has at least one projection that projects in the direction of the longitudinal center line. In particular, the projection projects in the direction of the longitudinal center line relative to a base body of the connecting pipe. Due to the projection, the noise emission caused by the air flow exiting the outlet opening of the connecting pipe is reduced. Because a portion of the air flow accelerated by the fan can exit the connecting pipe at a point on the outlet edge that is located closer to the inlet opening along the longitudinal center line than the end of the projection furthest away from the inlet opening along the longitudinal center line, the air mass compressed by the fan does not expand all at once. A portion of the compressed air mass only exits the connecting pipe at the end of the projection.The air mass or air flow exiting the connecting pipe is distributed over a projection height measured along the longitudinal centerline. This reduces noise emissions.

[0025] The projection has a projection height. The projection height is measured in the direction of the longitudinal centerline. The projection height is measured from the base body of the connecting pipe. Advantageously, the projection height is at least 20%, in particular at least 30%, in particular at least 40%, of the inner width of the flow cross-section of the outlet opening of the connecting pipe. This allows the pressure of the air flow to dissipate over a sufficiently long distance upon exiting the outlet opening of the connecting pipe.

[0026] The trailing edge advantageously has several protrusions. In particular, the trailing edge is wave-shaped due to the multiple protrusions. Such patterns are known as chevrons on the trailing edges of aircraft nozzles. Such sawtooth-shaped patterns lead to better mixing of air flows of different speeds. The pattern does not have to be strictly sawtooth-shaped. The tips of the sawtooths can also be rounded.

[0027] An embodiment of the invention is explained below with reference to the drawings. They show: Fig. 1 a perspective view of a hand-held, portable working device designed as a suction device with a connecting pipe for guiding an air flow from a fan of the working device to a component of the hand-held working device designed as a collecting bag, Fig. 2 to 5 perspective views of the connecting pipe from Fig. 1, Fig. 6 a sectional view of a section through the connecting pipe from the Fig. 2 to 5 along the curvature plane of the connecting pipe, Fig. 7 a sectional view of a section along the Fig. 6 drawn section plane VII-VII, Fig. 8 a sectional view of a section along the Fig. 6 drawn section plane VIII-VIII, Fig. 9 a sectional view of a section along the Fig. 6 drawn section plane IX-IX, Fig. 10 a plan view of the connecting pipe from the Fig. 2 to 9 in the direction perpendicular to the plane of curvature of the connecting pipe.

[0028] Fig. 1 shows a working device 1. The working device 1 is a hand-held, portable working device for its intended use. In the illustrated embodiment, the working device 1 is a vacuum cleaner. However, it can also be a vacuum / blower device. The working device can also be another hand-held working device in which a blower delivers an air flow to a component (such as a collection bag).

[0029] In the exemplary embodiment, the working device 1 comprises a blower 2. The working device 1 comprises a component 3. In the exemplary embodiment, the component 3 is designed as a collecting bag. The working device 1 comprises a connecting pipe 4. The connecting pipe 4 connects the blower 2 to the component 3. The connecting pipe 4 serves to guide an air flow from the blower 2 to the component 3. The blower 2 conveys air through the connecting pipe 4 into the component 3 designed as a collecting bag.

[0030] The working device 1 has a suction pipe 5. The blower 2 generates an air flow that is sucked in through the suction pipe 5. The air flow sucks in objects to be sucked in during use of the working device 1, such as leaves or grass clippings, and conveys them via the blower 2 through the connecting pipe 4 into the collection bag. The working device 1 comprises a bow handle 6. The working device 1 comprises an operating handle 7. The operating handle 7 is designed separately from the bow handle 6. The bow handle 6 is used for carrying and guiding the working device 1 during use of the working device 1.

[0031] The operating handle 7 is used to guide and operate the implement 1 during use. A control element 8 is provided on the operating handle 7. The control element 8 can be used to control the power of a motor (not shown). In the illustrated embodiment, the motor is an electric motor. However, it can also be an internal combustion engine. The motor drives the fan 2.

[0032] In the exemplary embodiment, the operating handle 7 defines a handle opening 9. The operator can reach through the handle opening 9 and thus grasp the operating handle 7. The handle opening 9 extends in a gripping plane G. A holding area 41 of the bow handle 6 extends transversely, in the exemplary embodiment perpendicular to the gripping plane G of the handle opening 9.

[0033] The connecting pipe 4 is also arranged on one side of the handle plane G of the handle opening 9. The connecting pipe 4 is arranged at the end of the suction pipe 5 facing away from an inlet opening 10 of the suction pipe 5. The connecting pipe 4 is arranged in the area of ​​the blower 2. The connecting pipe 4 is arranged between the operating handle 7 and the suction pipe 5. The connecting pipe 4 is fastened to a housing of the working device 1. The housing has a housing opening (not shown). The housing opening completely penetrates a wall 45 of the housing that delimits the housing to the outside. The housing opening serves to conduct the air flow generated by the blower from the interior of the housing to the outside of the housing, or to the component 3 designed as a collecting bag. The connecting pipe 4 is arranged on the housing opening. The connecting pipe 4 covers the housing opening. The connecting pipe 4 is connected to the housing in an airtight manner.

[0034] The connecting pipe 4 is tubular. An outer wall 43 of the connecting pipe 4 encloses an interior of the connecting pipe 4. The outer wall 43 of the connecting pipe 4 has the inlet opening 10 and the outlet opening 30 as openings to the interior.

[0035] As in Fig. 2, the connecting pipe 4 is curved in an arcuate manner. The connecting pipe 4 is in a curvature plane K, which is also shown in Fig. 6, is curved in an arc shape. The plane of curvature K is in Fig. 1. The curvature plane K runs transverse to the grip plane G. In the example, the curvature plane K runs perpendicular to the grip plane G. As in Fig. 1, due to the curved shape of the connecting pipe 4, the component 3 designed as a collecting bag can be arranged next to the blower 2. The collecting bag can be arranged at a distance from the suction pipe 5 next to the suction pipe 5. Due to the curvature of the connecting pipe 4, the collecting bag can be arranged in a plane that runs parallel to the handle plane G. Due to the curved shape of the connecting pipe 4, the working device 1 is ergonomically designed. During use, the operator can hold the working device 1 by the handle 6, operate it with the operating handle 7 and at the same time place the component 3 designed as a collecting bag next to him and Fig. 1. Due to the curved curvature of the connecting pipe 4, the objects to be sucked in can be deflected downwards by the blower 2 while the working device 1 is in use. In this way, the sucked-in objects can be easily collected in the component 3 designed as a collecting bag using gravity. The curved curvature of the connecting pipe 4 slows down the air flow on its way to the component 3 designed as a collecting bag. This reduces turbulence in the collecting bag and increases the service life of the collecting bag.

[0036] The connecting pipe 4 is also called the manifold. As in Fig. 2, the connecting pipe 4 has an inlet opening 10. The inlet opening 10 serves for the air flow to enter the connecting pipe 4. The connecting pipe 4 has an outlet opening 30. The air flow can exit the connecting pipe 4 through the outlet opening 30. In the exemplary embodiment, the connecting pipe is arranged in the working device 1 with the inlet opening 10 near the blower 2. The end of the connecting pipe 4 with the outlet opening 30 points away from the blower 2. The outlet opening 30 of the connecting pipe 4 is connected to the component 3 designed as a collection bag. The air flow enters the component 3 designed as a collection bag through the outlet opening 30.

[0037] The outlet opening 30 and the inlet opening 10 are oriented to each other in such a way that the air flow in the connecting pipe 4 in the curvature plane K is deflected by an angle Fig. 10, of at least 70°, in the exemplary embodiment of at least 80°. In the exemplary embodiment, the deflection angle α is approximately 90°. In particular, the deflection angle α is exactly 90°. In the exemplary embodiment, the deflection angle α is at most 120°, in particular at most 110°. Between the inlet opening 10 and the outlet opening 30, the air flow changes direction along a single arc. Starting from the inlet opening 10, the air flow always changes direction only toward the outlet opening 10 due to the guidance through the connecting pipe 4.

[0038] As in Fig. 10, the connecting pipe 4 has a longitudinal center line 50. The air flow is conveyed along the longitudinal center line 50 from the inlet opening 10 through the connecting pipe 4 to the outlet opening 30. The longitudinal center line 50 is curved in an arc. The longitudinal center line 50 runs through the centroids of the flow cross-sections of the connecting pipe 4. The plane of curvature K contains the longitudinal center line 50. The longitudinal center line 50 is also referred to as the longitudinal center axis, center of gravity line or center of gravity axis. The longitudinal center line 50 has a length of a maximum of 850 mm, measured along the curved longitudinal center line 50 from the inlet opening 10 to the outlet opening 30. The length of the longitudinal center line 50 is expediently determined by a path integral along the longitudinal center line 50 from the inlet opening 10 to the outlet opening 30.

[0039] The connecting pipe 4 has flow cross sections oriented along the longitudinal center line 50 perpendicular to the longitudinal center line 50. In the Fig. 7 to 9, the flow cross sections 13, 23 and 33 are shown as examples. The outer wall 43 of the connecting pipe defines the flow cross sections 13, 23, 33. Each flow cross section 13, 23, 33 has an inner height h1, h2, h3 measured perpendicular to the curvature plane K. The Fig. The flow cross section 13 of the inlet opening 10 shown in Figure 7 has the inner height h1. Fig. The flow cross section 23 shown in Figure 8 has the inner height h2. Fig. The flow cross section 33 of the outlet opening 30 shown in Figure 9 has the inner height h3. Fig. The flow cross-section 23 shown in Figure 8 is also referred to as the center flow cross-section 20. The center flow cross-section 20 is oriented perpendicular to the longitudinal center line 50. The center flow cross-section 20 is arranged along the longitudinal center line 50 midway between the inlet opening 10 and the outlet opening 30. The center flow cross-section 20 has the inner height h2. The inner heights h1, h2, h3 are each the greatest extent of the associated flow cross-section 13, 23, 33 measured in the direction perpendicular to the curvature plane K.

[0040] The longitudinal center line 50 has an integrated length in the area between the inlet opening 10 and the outlet opening 30. The center flow cross-section 20 divides the section associated with this length into two equal sections.

[0041] Each flow cross-section oriented perpendicular to the longitudinal centerline 50 has an inner width. The inner width is measured parallel to the curvature plane K. In the exemplary embodiment, the inner width is measured in the curvature plane K. The inner width is measured in the direction perpendicular to the inner height. In the direction parallel to the curvature plane K, the inner width is the largest dimension of the associated flow cross-section. Fig. 7, Fig. 8 and Fig. 9 shows the inner widths b1, b2 and b3 as examples. The inner width b1 is assigned to the flow cross-section 13 of the inlet opening 10 ( Fig. 7). As in Fig. 8, the inner width b2 is assigned to the flow cross-section 23, in the exemplary embodiment to the central flow cross-section 20. As shown in Fig. As shown in Figure 9, the inner width b3 is the width of the flow cross-section 33 of the outlet opening 30. The inner height h1 is perpendicular to the inner width b1. The inner height h2 is perpendicular to the inner width b2. The inner height h3 is perpendicular to the inner width b3.

[0042] The inner height h2 of the center flow cross-section 20 is greater than the inner width b2 of the center flow cross-section 20 ( Fig. 8). The inner height h2 of the central flow cross-section 20 is at least 120%, in particular at least 140%, in the exemplary embodiment at least 160% of the inner width b2 of the central flow cross-section 20.

[0043] The inner height h2 of the central flow cross-section 20 is in particular at most 200%, in particular at most 190%, in the exemplary embodiment at most 180% of the inner width b2 of the central flow cross-section.

[0044] The central flow cross-section 20 of the connecting pipe 4 has an oval shape. In the exemplary embodiment, the central flow cross-section 20 of the connecting pipe 4 has an elliptical shape. In particular, the shape of the central flow cross-section 20 deviates from a circular shape.

[0045] The inner height of each individual flow cross-section from the set of flow cross-sections of the connecting pipe 4 along the longitudinal center line 50 starting from the outlet opening 30 in the direction of the inlet opening 10 over at least 60%, in particular over at least 70%, in the exemplary embodiment over at least 80%, of the distance of the longitudinal center line 50 between the inlet opening 10 and the outlet opening 30 is advantageously greater than the inner width belonging to the individual flow cross-section.

[0046] The individual flow cross sections from the set of flow cross sections of the connecting pipe 4 along the longitudinal center line 50 starting from the outlet opening 30 in the direction of the inlet opening 10 over at least 60%, in particular over at least 70%, in the exemplary embodiment over at least 80%, of the distance of the longitudinal center line 50 between the inlet opening 10 and the outlet opening 30 each have an oval shape, in the exemplary embodiment an elliptical shape.

[0047] As can be seen from the summary of the Fig. 2 to 6, the area of ​​the flow cross sections of the connecting pipe 4 increases in the direction from the inlet opening 10 to the outlet opening 30 along the longitudinal center line 50. This is exemplified in the Fig. 7 to 9 for the flow cross-sections 13, 23, and 33 at the inlet opening 10, in the center of the connecting pipe 4 along the longitudinal center line 50, and at the outlet opening 30. In the exemplary embodiment, the area of ​​the flow cross-sections 13, 23, 33 of the connecting pipe 4 increases continuously in the direction from the inlet opening 10 to the outlet opening 30 along the longitudinal center line 50.

[0048] The inner width b2 of the central flow cross-section 20 is from 90% to 110%, in particular at most 100% of the inner width b1 of the flow cross-section 13 of the inlet opening 10.

[0049] The inner width b2 of the central flow cross-section 20 is from 60% to 80% of the inner width b3 of the flow cross-section 33 of the outlet opening 30. As also Fig. 6, the inner width b2 of the central flow cross-section 20 is the smallest inner width of the connecting pipe 4, in particular of all flow cross-sections of the connecting pipe 4.

[0050] The Fig. 8, the inner height h2 of the central flow cross-section 20 is at least 110%, in particular at least 130%, in the exemplary embodiment at least 150%, of the Fig. 7 shown inner height h1 of the flow cross-section 13 of the inlet opening 10.

[0051] The inner height h2 of the central flow cross-section 20 is from 90% to 110%, in particular from 95% to 105%, in the exemplary embodiment less than 100% of the inner height h3 of the flow cross-section 33 of the outlet opening 30. In the exemplary embodiment, the inner height of the connecting pipe 4, in particular of all flow cross-sections of the connecting pipe 4, increases starting from the inlet opening 10 along the longitudinal center line 50 to the outlet opening 30, in particular continuously.

[0052] As in Fig. 7, the flow cross-section 13 of the inlet opening 10 of the connecting pipe 4 is circular.

[0053] In the exemplary embodiment, the inner height h1 of the flow cross-section 13 of the inlet opening 10 is from 25 mm to 135 mm, in particular from 45 mm to 115 mm, in particular from 55 mm to 105 mm.

[0054] In the exemplary embodiment, the inner width b1 of the flow cross-section 13 of the inlet opening 10 is from 25 mm to 135 mm, in particular from 45 mm to 115 mm, in particular from 55 mm to 105 mm.

[0055] In the exemplary embodiment, the inner height h2 of the central flow cross-section 20 is from 90 mm to 190 mm, in particular from 110 mm to 170 mm, in particular from 120 mm to 160 mm.

[0056] In the exemplary embodiment, the inner width b2 of the central flow cross-section 20 is from 25 mm to 135 mm, in particular from 45 mm to 115 mm, in particular from 55 mm to 105 mm.

[0057] In the exemplary embodiment, the inner height h3 of the flow cross-section 33 of the outlet opening 30 is from 100 mm to 200 mm, in particular from 120 mm to 180 mm, in particular from 130 mm to 170 mm.

[0058] In the exemplary embodiment, the inner width b3 of the flow cross-section 33 of the outlet opening 30 is from 70 mm to 170 mm, in particular from 90 mm to 150 mm, in particular from 100 mm to 140 mm.

[0059] As in Fig. 10, the connecting pipe 4 has a tangential plane T. The tangential plane T runs perpendicular to the plane of curvature K. The tangential plane T is tangent to the inlet opening 10 at a first point of contact P1 and simultaneously to the outlet opening 30 at a second point of contact P2. The tangential plane T intersects neither the outlet opening 30 nor the inlet opening 10. The tangential plane T only intersects the flow cross-sections of the connecting pipe 4. None of the flow cross-sections of the connecting pipe 4 is intersected by the tangential plane T. In particular, the tangential plane T lies adjacent to the flow cross-section 13 of the inlet opening 10 and simultaneously to the flow cross-section 33 of the outlet opening 30. Neither the flow cross-section 13 of the inlet opening 10 nor the flow cross-section 33 of the outlet opening 30 is intersected by the tangential plane T. The tangential plane T lies on the more curved side of the connecting pipe 4.

[0060] The first contact point P1 lies on the edge of the inlet opening 10. The first contact point P1 lies on the edge of the flow cross-section 13 of the inlet opening 10. The second contact point P2 lies on the edge of the outlet opening 30. The second contact point P2 lies on the edge of the flow cross-section 33 of the outlet opening 30.

[0061] The first contact point P1 has a point distance s from the second contact point P2. In the exemplary embodiment, both the contact point P1 and the contact point P2 lie in the curvature plane K. The point distance s is measured in the curvature plane K.

[0062] Each flow cross-section of the connecting pipe 4 has a plane distance measured perpendicular to the tangential plane T. Examples are shown in Fig. 10 shows the flow cross-sections 13, 23, and 33 of the connecting pipe 4, each of which has a plane distance from the tangential plane T. For the flow cross-section 13 of the inlet opening 10, the plane distance is zero. Likewise, the plane distance for the flow cross-section 33 of the outlet opening 30 is zero.

[0063] The set of all plane distances includes a largest plane distance d. In the exemplary embodiment, the largest plane distance d is located at the location of the central flow cross-section 20. The plane distance of the central flow cross-section 20 is the largest plane distance d of all plane distances. Of all flow cross-sections of the connecting pipe 4, the central flow cross-section 20 has the largest plane distance, namely the largest plane distance d. The largest plane distance d is at least 25%, in particular at least 30%, in the exemplary embodiment at least 35% of the point distance s. This prevents a user from reaching the inlet opening 10 of the connecting pipe with a hand or arm, starting from the outlet opening 30 through the connecting pipe 4.Due to the large maximum interplane distance d, the (direct) path from the outlet opening 30 through the connecting tube 4 to the inlet opening 10 is so narrow or curved that a user cannot reach through with their hand or arm. Bending the hand or arm to such an extent is not possible.

[0064] In particular, the largest plane distance d is at most 70%, in particular at most 60%, in the exemplary embodiment at most 50% of the point distance s.

[0065] As in Fig. As shown in Figure 10, the connecting pipe 4 has a radius of curvature r1 on its more strongly curved side in the curvature plane K at the center flow cross-section 20. The more strongly curved side of the connecting pipe 4 is also referred to as the side of the inner curvature. The radius of curvature r1 is less than 50%, in particular less than 40%, in the exemplary embodiment less than 30% of the point spacing s. The radius of curvature r1 at the center flow cross-section 20 is a measure of the curvature of the more strongly curved side of the connecting pipe 4 in the curvature plane K. The smaller the radius of curvature, the greater the curvature.

[0066] Due to the small ratio of the radius of curvature r1 to the point spacing s, the curvature at the center flow cross-section 20 is large. The sharp curvature of the connecting pipe 4 provides protection against intrusion. This sharp curvature prevents a user from reaching or reaching from the outlet opening 30 through the connecting pipe 4 to the inlet opening 10 with their hand or arm.

[0067] This protection against intrusion is also provided although the connecting pipe 4 is free of a grid bar for protection against intrusion.

[0068] In the exemplary embodiment, the radius of curvature r1 is greater than 10%, in particular greater than 20% of the point spacing s.

[0069] As in Fig. As shown in Figure 10, an edge of the inlet opening 10 in the curvature plane K has a first secant point S1 located outside the curvature of the connecting pipe 4. The first secant point S1 lies in the curvature plane K. The first secant point S1 lies at the edge of the flow cross-section 13 of the inlet opening 10.

[0070] The edge of the outlet opening 30 has a second secant point S2 on the outside side with respect to the curvature of the connecting pipe 4 in the curvature plane K. The second secant point S2 lies in the curvature plane K. The second secant point S2 lies at the edge of the flow cross-section 33 of the outlet opening 30.

[0071] A straight line g runs through the first secant point S1 and the second secant point S2. The straight line g runs along a direct connecting line between the exit opening 30 and the inlet opening 10.

[0072] The connecting pipe 4 has the outer wall 43. The straight line g intersects the outer wall 43. In particular, the straight line g intersects the outer wall 43 in the region of the outer wall 43 which lies on the more strongly curved side of the connecting pipe 4. The center flow cross-section 20 is arranged at a straight line distance a from the straight line g, measured perpendicular to the straight line g. The straight line distance a is at least 1%, in particular at least 3%, expediently at least 5%, in the exemplary embodiment at least 7% of the point distance s. The second secant point S2 is arranged at a secant point distance w from the first secant point S1. In the exemplary embodiment, the secant point distance w is measured in the plane of curvature K. The straight line distance a is at least 1%, in particular at least 3%, in the exemplary embodiment at least 5% of the secant point distance w.In the exemplary embodiment, the straight line distance a is at most 50%, in particular at most 30%, expediently at most 15% of the secant point distance w.

[0073] Because the straight line g intersects the outer wall 43 of the connecting pipe 4, it is not possible to reach through the connecting pipe 4 in a straight, direct path from the outlet opening 30 to the inlet opening 10. In such an attempt, an operator would encounter the inner side of the outer wall 43. The inner side of the outer wall 43 limits all flow cross-sections of the connecting pipe 4.

[0074] As in Fig. 6, the outlet opening 30 has an outlet edge 31. The outlet edge 31 has at least one projection 32 in the direction of the longitudinal center line 50. The projection 32 projects beyond a base body 44 of the connecting pipe 4. In Fig. In Figure 6, the imaginary separation between the base body 44 and the projection 32 is indicated by a dashed line. The corresponding separation plane runs perpendicular to the longitudinal center line 50.

[0075] The projection 32 has a projection height v. The projection height v is at least 20%, in particular at least 30%, in the exemplary embodiment at least 40% of the inner width b3 of the flow cross-section 33 of the outlet opening 30 of the connecting pipe 4. The projection height v is measured in the direction of the longitudinal center line 50 at the outlet opening 30. The projection height v is measured starting from the parting plane between the base body 44 and the projection 32 in the direction of the projection 32. The projection height v is measured perpendicular to the parting plane between the base body 44 and the projection 32.

[0076] The trailing edge 31 has a plurality of projections 32. The trailing edge 31 is wave-shaped due to the multiple projections 32. Such a wave-shaped pattern is also called a chevron. Such patterns are familiar from aircraft jet engines.

[0077] The trailing edge 31 runs closed around the longitudinal center line 50. As shown in the Fig. 2 and Fig. As shown in Figure 3, a total of six projections 32 are provided in the exemplary embodiment. The projections 32 give the circumferential exit edge 31 a wave-shaped configuration.

Claims

[1] Connecting pipe for guiding an air flow from a blower (2) of a hand-held, portable working device (1) to a component (3), in particular to a collecting bag, of the hand-held, portable working device (1), wherein the connecting pipe (4) is curved in an arcuate manner in a plane of curvature (K), wherein the connecting pipe (4) has an inlet opening (10) for the air flow, wherein the connecting pipe (4) has an outlet opening (30) for the air flow, wherein the outlet opening (30) and the inlet opening (10) are oriented relative to one another such that the air flow in the connecting pipe (4) is deflected in the plane of curvature (K) by at least 70°, in particular by at least 80°, wherein the connecting pipe (4) has flow cross sections (13, 23, 33) oriented along a longitudinal center line (50) perpendicular to the longitudinal center line (50). wherein each flow cross-section (13, 23, 33) has an inner height (h1,h2, h3), wherein the connecting pipe (4) has a central flow cross-section (20) oriented perpendicular to the longitudinal center line (50) in the middle between the inlet opening (10) and the outlet opening (30) along the longitudinal center line (50), wherein each flow cross-section (13, 23, 33) oriented perpendicular to the longitudinal center line (50) has an inner width (b1, b2, b3) in the direction perpendicular to its inner height (h1, h2, h3), and wherein the inner height (h2) of the central flow cross-section (20) is greater than the inner width (b2) of the central flow cross-section (20), , characterized bythat the connecting pipe (4) has a tangential plane (T) which runs perpendicular to the plane of curvature (K) and which is tangent to the inlet opening (10) at a first point of contact (P1) and to the outlet opening (30) at a second point of contact (P2), that the first point of contact (P1) has a point distance (s) from the second point of contact (P2), that each flow cross-section (13, 23, 33) of the connecting pipe (4) has a plane distance measured perpendicular to the tangential plane (T) from the tangential plane (T), and that a greatest plane distance (d) of all plane distances of the flow cross-sections (13, 23, 33) from the tangential plane (T) is at least 25%, in particular at least 30%, in particular at least 35%, of the point distance (s). [2] Connecting pipe according to claim 1, characterized bythat the inner height (h2) of the central flow cross-section (20) is at least 120%, in particular at least 140%, in particular at least 160%, of the inner width (b2) of the central flow cross-section (20). [3] Connecting pipe according to claim 1 or 2, characterized by that the central flow cross-section (20) of the connecting pipe (4) has an oval shape, in particular an elliptical shape. [4] Connecting pipe according to one of claims 1 to 3, characterized by that the areas of the flow cross-sections (13, 23, 33) of the connecting pipe (4) increase, in particular increase continuously, in the direction from the inlet opening (10) to the outlet opening (30) along the longitudinal center line (50). [5] Connecting pipe according to one of claims 1 to 4, characterized by that the inner width (b2) of the central flow cross-section (20) is 90% to 110% of the inner width (b1) of the flow cross-section (13) at the inlet opening (10). [6] Connecting pipe according to one of claims 1 to 5, characterized by that the inner width (b2) of the central flow cross-section (20) is 60% to 80% of the inner width (b3) of the flow cross-section (33) of the outlet opening (30). [7] Connecting pipe according to one of claims 1 to 6, characterized by that the inner height (h2) of the central flow cross-section (20) is at least 110%, in particular at least 130%, in particular at least 150%, of the inner height (h1) of the flow cross-section (13) of the inlet opening (10). [8] Connecting pipe according to one of claims 1 to 7, characterized by that the inner height (h2) of the central flow cross-section (20) is 90% to 110%, in particular 95% to 105%, in particular less than 100%, of the inner height (h3) of the flow cross-section (33) of the outlet opening (30). [9] Connecting pipe according to one of claims 1 to 8, characterized bythat the flow cross-section (13) of the inlet opening (10) of the connecting pipe (4) is circular. [10] Connecting pipe according to one of claims 1 to 9, characterized by that the connecting pipe (4) has a radius of curvature (r1) in the plane of curvature (K) at the central flow cross-section (20) on the more strongly curved side of the connecting pipe (4), that the radius of curvature (r1) is less than 50%, in particular less than 40%, in particular less than 30%, of the point distance (s). [11] Connecting pipe according to one of claims 1 to 10, characterized by that the connecting pipe (4) is free of a grid bar to protect against intrusion. [12] Connecting pipe according to one of claims 1 to 11, characterized by that the outlet opening (30) has an outlet edge (31), and that the outlet edge (31) has at least one projection (32) in the direction of the longitudinal center line (50). [13] Connecting pipe according to claim 12, characterized bythat the projection (32) has a projection height (v), and that the projection height (v) is at least 20%, in particular at least 30%, in particular at least 40%, of the inner width (b3) of the flow cross-section (33) of the outlet opening (30) of the connecting pipe (4). [14] Connecting pipe claim 12 or 13, characterized by that the exit edge (31) has a plurality of projections (32), and that the exit edge (31) is wave-shaped due to the plurality of projections (32).

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