BACKWEAR BLOW DEVICE

Description

[0001] The invention relates to a backpack blower according to the preamble of claim 1.

[0002] Such a blowing device comprises a backpack with a support frame, a blowing tube with a carrier-side tube section held at a rear of the support frame and a hand-side tube section extending past a first side area of ​​the support frame, a drive motor, a power source for the drive motor and an axial blower driven by the drive motor, which has an axial blower axis and is arranged in the carrier-side tube section of the blowing tube.

[0003] Such a blower is carried on the back by the user during operation. The back-mounted carrier typically has carrying or shoulder straps attached to the frame, allowing the user to shoulder the carrier and frame like a backpack. The terms "carrying-side tube section" and "hand-side tube section" refer to a tube section located near the frame and a section on the side of the user's hand, respectively. During use, the user can grasp and operate the blower tube at the hand-side section with one or both hands. The frame houses the other essential components of the blower, in particular the carrying-side tube section with the axial blower, the drive motor that powers the axial blower, and the power source for the drive motor.

[0004] Blowers of this and similar types are used as blowing blowers, particularly leaf blowers, and as suction blowers, e.g., backpack vacuums. In blowing blowers, the carrying-side tube section forms the air inlet section, i.e., the section of the blower tube where the material being blown is drawn in, while the hand-side tube section forms the air outlet section, i.e., the section of the blower tube where the material being blown is discharged. Conversely, in suction blowers, the hand-side tube section forms the air inlet section, while the carrying-side tube section forms the air outlet section. For ease of understanding, the terminology used here refers to blowing blowers.These terms are to be understood accordingly modified for the suction type of blowing equipment; that is, the air inlet side is then the air outlet side, an air inlet channel is an air outlet channel, etc. Usually, the blowing medium is air; however, in special cases, it may also be another blowing medium. For the sake of simplicity, the terms referring to the blowing medium air, such as air inlet side, air outlet side, air inlet channel, etc., are to be understood in a general sense for the designation of corresponding blowing equipment components, which also includes these other cases in which the blowing medium is not air.

[0005] For such blowers, alternative versions with an internal combustion engine as the blower drive motor and a gasoline tank as the associated energy source, and versions with an electric motor as the blower drive motor and a battery pack as the associated energy source are commonly used, whereby in this case the term battery pack is to be understood in a general sense to denote any conventional type of electric battery.

[0006] Insofar as orienting terms such as top, bottom, front, back, vertical direction, and horizontal direction, etc., are used for the blower and, more specifically, for the backpack carrier or carrying frame, these refer to the blower in its carrying position on the back of a user. The top is then the vertically oriented upper side, the bottom the vertically oriented lower side, the long sides of the blower or backpack carrier run laterally to the left and right in an essentially vertical direction, the transverse sides of the blower or backpack carrier run essentially horizontally across the top and bottom, the front is the side facing the carrying user, the back is the side of the blower or backpack carrier facing away from the carrying user, and the direction from front to back and from back to front is referred to as the front-to-back direction.

[0007] German patent application EP 3 225 098 A1 discloses an electric blowing device in which an electric motor and the axial blower with a common axial motor / blower axis are integrated into a common blower body, which is arranged in the support-side tube section with an axial blower axis parallel to the longitudinal direction of this tube section. Preferably, two blower tubes are provided, the hand-side tube sections of which extend past a left and right side area of ​​the support frame, respectively, for ambidextrous operation by the user. The respective support-side tube section is arranged on the support frame such that its longitudinal axis, and thus the blower axis of the integrated axial blower, extends parallel to a rear surface of the back support or the support frame. Alternatively, instead of arranging the support-side tube sections substantially vertically on the left and right sides of the support frame, the device may also be arranged in a different configuration.For the backpack carrier, next to a battery pack held at the rear of the support frame, a positioning of the respective carrier-side pipe section at the rear of the support frame below the battery pack is proposed, with a horizontal orientation or an oblique orientation relative to the horizontal and vertical. The respective carrier-side pipe section extends from one side of the support frame, past which it passes, along the rear of the support frame towards the opposite side, and terminates a distance in front of this with an end section that tapers conically to an axial blowpipe end cap as the air inlet.

[0008] The patent application EP 2 684 446 A2 discloses a backpack leaf blower with a radial blower, which together with an associated drive motor is held on a support frame of a backpack in such a way that a common drive axis of motor and radial blower with a vertical principal directional component runs at an acute angle between approximately 5° and approximately 35° to a support frame plane in which the support frame is substantially located, wherein the drive axis intersects the support frame plane at a point which is close to a top of the support frame.

[0009] The patent application US 2016 / 0208449 A1 discloses a backpack electric blower in which a battery pack is held on a carrying frame of a backpack, while an axial blower and an associated electric drive motor are arranged in a hand-held blower tube which is connected to the backpack battery pack via a flexible support connection and an electrical cable.

[0010] The German patent application EP 3 682 730 A1 discloses a blower unit for a portable, hand-held blower with a tubular housing section in which an axial blower and its associated drive motor are housed. An air guide plate is arranged axially in front of an intake opening, the outer dimensions of which are larger than the outer dimensions of the intake opening. Between the air guide plate and an outer edge of the housing section, an annular intake gap is formed, equipped with an air inlet grille or protective grille. An air supply channel extends from this gap, bounded radially outwards by a tubular wall of the housing section and radially inwards by an air guide cone that connects to the air guide plate towards the intake opening.

[0011] Various blowing devices of the type mentioned above are disclosed in the patent applications EP 3 420 807 A1, WO 2019 / 206581 A1 and US 2020 / 0154962 A1.

[0012] The invention is based on the technical problem of providing a backpack blowing device of the type mentioned above, which offers advantages over the prior art mentioned above, in particular with regard to the arrangement of the carrying-side pipe section of the blowing tube on the carrying frame and / or with regard to the blowing medium guidance.

[0013] The invention solves this problem by providing a backpack blower with the features of claim 1. Advantageous further developments of the invention, which contribute to solving this and other problems, are specified in the dependent claims, the content of which is hereby fully incorporated by reference to the content of the description.

[0014] In the present blower, the carrying-side section of the blowpipe runs with a main directional component in a transverse direction of the support frame and has an axial blowpipe end that projects laterally beyond a second side of the support frame facing away from the first side and / or is at least partially surrounded by a protective ring element connected to the support frame. The transverse direction of the carrying mechanism is understood here to be the direction that is perpendicular to the front-to-back direction and runs horizontally or substantially horizontally when the blower is in use on the back of a user.

[0015] In this configuration of the blowing device, the carrier-side pipe section of the blowing tube therefore extends with its longitudinal direction parallel to the carrier transverse direction of the support frame or at least predominantly in this carrier transverse direction of the support frame, i.e. with a larger directional component in this direction than in a direction perpendicular to it, which represents a favorable condition for a compact arrangement of this carrier-side blowing tube section on the support frame of the back carrier.

[0016] In the relevant aspect of the invention, the support-side pipe section, with its axial end termination, projects laterally, i.e., transversely or in a lateral direction, beyond the facing side region of the support frame, i.e., its left or right side region. This allows the support-side pipe section to be arranged very compactly and in a space-saving manner on the support frame, even if it has a conical extension in this axial end region in a radially outward direction, e.g., in the form of an air inlet funnel. In particular, the support-side pipe section does not necessarily have to be positioned with the full cross-section or diameter of its conically extended end termination behind the support frame and / or behind other blower components held on the support frame. Rather, this optionally conically extended end termination can be positioned in the depth direction of the back support, i.e.,in the front-to-back direction, overlapping with the support frame and / or other blower components held to it.

[0017] In the relevant aspect of the invention, the axial end of the blowpipe section on the carrying side of the tube is surrounded by the protective ring element connected to the carrying frame, at least along a portion of the total circumference of the blowpipe end. This allows the end of the blowpipe to be protected from damaging external influences by the protective ring element that at least partially surrounds it. In particular, the protective ring element can provide impact and drop protection for this end of the blowpipe against impacts that may occur from the outside, for example, if the carrying frame or backpack accidentally falls to the ground, is placed on the ground by the user, or if the user accidentally bumps the blower they are carrying on their back against a solid obstacle.

[0018] According to the invention, the blower axis forms a horizontal angle between 2° and 15° with a vertical cross-plane of the support frame. The vertical cross-plane is understood to be the vertical plane perpendicular to the front-to-back direction of the back carrier or support frame, in which the support frame is predominantly located. In this case, the blower axis, and thus normally also the carrier-side section of the blowpipe, runs with its longitudinal direction in the horizontal plane at an angle to the vertical cross-plane of the support frame and thus to its cross-direction lying in the horizontal plane. This can contribute to an optimized placement of the carrier-side blowpipe section and to optimized guidance of the blowing medium within the carrier-side blowpipe section.Furthermore, this inclined position of the blower axis in relation to the support frame allows the protective ring element to protrude with its side facing the support frame on the corresponding side of the support frame and, in a case where the back carrier hits a surface with this side, i.e. its left or right side, provide further impact protection by absorbing the impact forces specifically with this protruding section and transferring them to the support frame.

[0019] In one embodiment of the invention, the horizontal angle lies specifically in the range between 2° and 3°. A resulting inclined position of the blower axis, and thus also of the support-side blowpipe section, relative to the support transverse direction of the support frame, can be particularly advantageous for certain blower designs, especially with regard to optimized placement and / or optimized impact or drop protection.

[0020] In a further development of the invention, the blower axis forms a vertical angle of at most 45° with a horizontal support plane of the support frame. The horizontal support plane is understood to be the plane defined by the front-to-back direction and the transverse direction of the support frame. In this case, the blower axis, and thus usually also the blowpipe section on the support side, runs horizontally or at an angle of at most 45° upwards or downwards relative to the horizontal. This orientation of the blower axis or the blowpipe section on the support side is optimal for many blower applications. In alternative configurations, the blower axis is arranged with a predominantly vertical orientation, i.e., it then forms a vertical angle of more than 45° with the horizontal support plane of the support frame.

[0021] In one embodiment of the invention, the vertical angle is at most 10°. In this configuration, the blower axis or the carrying-side blowpipe section thus runs horizontally or at least largely horizontally in the operating position of the blower on the back of a user, which proves to be optimal for many applications.

[0022] In a further development of the invention, the support-side pipe section has a curved section made of rigid pipe material with a curvature angle of less than 90°. The selection of a rigid pipe material for the curved section of the support-side blowpipe contributes to good stability of this pipe section in this curvature region, which can, for example, form a transition to the hand-side pipe section. Due to the smaller curvature angle compared to 90°, this curved section results in a pipe bend and thus a deflection of the blowing medium that is less than a right-angle bend, which can be advantageous for pipe guidance and the guidance of the blowing medium within the blowpipe in appropriate applications.Advantageously, this angle of curvature can be adjusted, if necessary, to accommodate a certain inclination of the blower axis relative to the transverse direction of the support frame, such that the curved section ends essentially parallel to the front-to-back direction in the direction of the hand-side blowpipe section. In alternative designs, the curved section is made of a flexible tube material and / or has a curvature angle of 90° or more.

[0023] In one embodiment of the invention, the angle of curvature lies specifically in the range between 60° and 85°. This represents an optimal curvature for the carrying-side section of the blowpipe for certain blower applications.

[0024] In a further development of the invention, the drive motor is an electric motor, and the energy source comprises a battery pack held on the support frame. In this configuration, the blower is therefore an electric blower. In alternative embodiments, the blower can, for example, include an internal combustion engine as the drive motor and a gasoline tank as the energy source.

[0025] In a further development of the invention, the drive motor has a motor axis parallel to the blower axis and / or is arranged in the support-side pipe section. This configuration offers a favorable prerequisite for a compact arrangement of the drive motor and axial blower, e.g., as an integrated motor / blower unit in the support-side blowpipe section. In alternative embodiments, the drive motor has a motor axis not parallel to the blower axis and / or is arranged outside the support-side pipe section of the blowpipe.

[0026] In one embodiment of the invention, the drive motor and the axial fan are arranged in a housing-forming area of ​​the support-side tube section. This achieves an integration of the drive motor and axial fan in a common housing, which is advantageous for many applications. In this case, the housing also functions as part of the support-side blowpipe section, by which the support-side blowpipe section can be held on the support frame. In alternative embodiments, the drive motor and axial fan are arranged in a common housing that is located inside the support-side blowpipe section.

[0027] In a further development of the invention, the support-side pipe section is connected to the support frame by a sleeve-shaped retaining element. For this purpose, the sleeve-shaped retaining element can, for example, fully encircle the support-side pipe section or, alternatively, partially encircle it, preferably more than half its circumference. In an advantageous embodiment, the retaining element encircles the support-side pipe section in its housing-forming area, which accommodates the drive motor and the axial fan. Depending on requirements, the retaining element can, for example, be formed in one piece or in multiple parts, e.g., in the form of two half-shells, as a component fixed to the support frame or, alternatively, as a component integral with the support frame.

[0028] In a further development of the invention, the protective ring element is supported on the sleeve-shaped retaining part and / or directly on the support frame. This can contribute to increased impact resistance, as the protective ring element can transfer impact forces to the appropriately impact-resistant retaining part or directly to the support frame.

[0029] In a further development of the invention, the protective ring element surrounds the axial blowpipe end cap at a radial distance and / or projects axially beyond the axial blowpipe end cap by an axial overhang. In this case, the protective ring element for the blowpipe end cap can function as a radially and axially positioned impact guard, so that the blowpipe end cap can be completely protected from impact forces.

[0030] In one embodiment of the invention, an air guide cone is coaxially positioned upstream of an axial pipe wall end region of the support-side pipe section, forming an annular radial air inlet opening. The air guide cone forms a funnel-shaped axial outer boundary of an associated air inlet channel that opens radially therefrom, and its axially outer end forms the end termination of the blowpipe. The support-side pipe section of the blowpipe can optionally be correspondingly funnel- or cone-shaped in its axial pipe wall end region, or alternatively, it can terminate axially without a conical widening.

[0031] An air inlet grille made of an elastically deformable material is arranged at this air inlet opening, wherein the air inlet grille surrounds the axial pipe wall end region of the support-side pipe section at least partially around its circumference without contact and at a radial distance, and is connected on the one hand at an axially outer end axially in front of the axial pipe wall end region of the support-side pipe section to the protective ring element and on the other hand at an axially inner end axially behind the axial pipe wall end region of the support-side pipe section to the sleeve-shaped retaining part and / or the support frame.

[0032] This design allows the air inlet grille to be used as a shock-absorbing element. It can elastically deform in response to an impact on the stiffer protective ring element, thereby absorbing and dissipating impact energy. The axial end wall region of the load-bearing pipe section remains unaffected by any elastic deformation of the air inlet grille, which thus acts as a shock-absorbing element, as it has no mechanical contact with it. For this purpose, the radial distance of the air inlet grille from the axial end wall region of the load-bearing pipe section is advantageously chosen to be at least as large as the expected changes in distance due to such elastic deformation of the air inlet grille under impact. Overall, this embodiment of the invention represents a highly advantageous design with regard to air supply functionality and impact protection.

[0033] In a further development of the invention, the protective ring element surrounds the axial end of the blowpipe, at least on its underside. This allows the protective ring element to act specifically as impact protection against impacts on the end of the blowpipe from below, such as those that can occur, for example, when the blower is placed on the ground or accidentally falls to the ground.

[0034] In one embodiment of the invention, the protective ring element completely surrounds the axial end of the blowpipe, i.e., essentially completely along its entire circumference, whereby comparatively small circumferential areas of a few degrees can remain uncovered if necessary. This provides correspondingly comprehensive protection of this end of the blowpipe, e.g., against impacts from any radial direction.

[0035] In a further development of the invention, the protective ring element comprises a ring retaining section connected to the support frame and a protective section extending at an angle from the ring retaining section, which surrounds the axial blowpipe end closure over a circumferential angle of at least 180°. This represents an advantageous design of the protective ring element with regard to its structural connection to the support frame and with regard to impact protection for the axial blowpipe end closure and impact force dissipation.

[0036] Advantageous embodiments of the invention are illustrated in the drawings. These and further advantageous embodiments of the invention are described in more detail below. The drawings show: Fig. 1 a perspective view from the rear left of a backpack-mounted electric blower, Fig. 2 a perspective view of the blower from the rear right, Fig. 3 a top view from the rear of the blower, Fig. 4 a top view from above of the blower, Fig. 5 a right side view of the blower, Fig. 6 a left side view of the blower, Fig. 7 a sectional view along a line VII-VII in Fig. 3 , Fig. 8 a sectional view along a line VIII-VIII in Fig. 4 and Fig. 9 a sectional view along a line IX-IX in Fig. 4 .

[0037] As in the embodiment shown according to the Fig. 1 bis 9 As can be seen, the backpack blower according to the invention comprises a backpack carrier 1, a blower tube 4, a drive motor 2, a power source 3 for the drive motor 2, and an axial blower 6 driven by the drive motor 2. The backpack carrier 1 has a support frame 1a, on the rear of which a carrier-side tube section 4a of the blower tube 4 is held. The carrier-side tube section 4a terminates axially with an axial blower tube end cap 9, as can be seen in particular from the sectional view of Fig. 7 visible.

[0038] Furthermore, the blowpipe 4 includes a hand-side pipe section 4b, which extends past a first side area S 1 of the support frame 1a, as shown, for example, in the Fig. 2 and 3The axial blower 6 has an axial blower axis 6a and is arranged in the support-side pipe section 4a of the blowpipe 4. By means of the axial blower 6, a blowing medium, preferably air, can be drawn in at one end of the blowpipe 4, guided through the blowpipe 4 and blown out at the other end of the blowpipe.

[0039] In corresponding embodiments, the support-side pipe section 4a of the blowpipe 4, as in the example shown, runs with a main directional component in a support transverse direction RQ of the support frame 1a, i.e. a longitudinal axis LR a of the support-side pipe section 4a extends parallel to the support transverse direction RQ or, as in the example shown, obliquely to it with a larger directional component parallel to the support transverse direction RQ than in the direction perpendicular to it.

[0040] In corresponding embodiments, the support-side pipe section 4a with its axial blowpipe end closure 9, as in the example shown, projects laterally beyond a second side area S 2 of the support frame 1a facing away from the first side area S 1, as shown from Fig. 7 As can be seen, in the example shown, the first side section S 1 of the support frame 1a is a right side section of the same and the second side section S 2 is a left side section; in alternative versions it is the other way around.

[0041] In corresponding embodiments, the axial blowpipe end closure 9, as in the example shown, is at least partially surrounded on its circumference by a protective ring element 10, which is connected to the support frame 1a.

[0042] In the illustrated embodiment, the backpack blower is specifically an electric blower, i.e., the drive motor 2 is an electric motor, which could, for example, be an electric leaf blower. In the latter case, the air inlet duct 18 functions as an intake duct. As in the examples shown, the energy source 3 in this case is a battery pack 11 held on the support frame 1a. Preferably, as in the example shown, the blower tube 4 with its support-side tube section 4a is positioned vertically below the battery pack 11.

[0043] In alternative designs, the blower can be of the suction type instead of the blowing type shown in the example, and / or be equipped with an internal combustion engine as the blower drive motor and a petrol tank or the like as the associated energy source.

[0044] A user can carry the blower on their back, for which purpose the back carrier 1 in the illustrated embodiment has suitable carrying or shoulder straps attached to the support frame 1a, e.g., as shown, two shoulder straps 12 and / or a waist belt unit 13. When the blower is carried on a user's back, the support frame 1a has a front side TV facing the user's back and a rear side TR facing away from it. The transverse direction RQ of the support frame 1a runs in a horizontal plane perpendicular to a front-to-back direction VH defined by the distance between the support frame's front side TV and rear side TR.

[0045] When the user has shouldered the blower, i.e., the backpack carrier 1, and is carrying it on their back, they can grasp and guide the hand-side blower tube section 4b with their corresponding hand on the same side; in the case of the blower shown, this is their right hand. As a gripping aid and for operating the blower, the hand-side tube section 4b of the blower tube 4 has an associated operating handle 17, preferably projecting upwards.

[0046] In corresponding implementations of the blowing device, the support frame 1a, as in the illustrated embodiment, has a foot area 16 with which the support frame 1a or the back carrier 1 can be placed on the ground.

[0047] In corresponding versions, the blower shaft 6a, as in the example shown, closes a gap in Fig. 4 The explicitly specified horizontal angle Wh is between 2° and 15° with a vertical cross-plane EV of the support frame 1a. In specific implementations, this horizontal angle Wh lies in the range between 2° and 3°.

[0048] In corresponding versions, the blower shaft 6a, as in the example shown, closes a gap in Fig. 3 The explicitly specified vertical angle Wv of at most 45° with a horizontal support plane EH of the support frame 1a. In special implementations, this vertical angle Wv is at most 10°, where it is, for example, 0° if in a corresponding implementation the blower axis 6a runs horizontally and therefore parallel to the horizontal support plane EH or to the transverse support direction RQ of the support frame 1a.

[0049] In advantageous embodiments, the support-side pipe section 4a, as in the illustrated embodiment, has a curved section 7 made of rigid pipe material with a curvature angle Kw of less than 90°. In specific implementations, this curvature angle Kw lies in the range between 60° and 85°. In the illustrated embodiment, the curvature angle Kw is close to 90°.

[0050] In corresponding versions, the drive motor 2, as in the example shown, has a motor axis 2a parallel to the blower axis 6a, as shown in the sectional view of Fig. 7 to recognize. Specifically, in the example shown, the blower axis 6a and the motor axis 2a coincide with the longitudinal axis LRa of the support-side pipe section 4a.

[0051] In corresponding embodiments, the drive motor 2 is arranged in the support-side pipe section 4a, as in the example shown. Alternatively, it can be arranged outside of this section, e.g., on the support frame 1a. The positioning of the drive motor 2 and the axial fan 6 in the support-side pipe section 4a in the example shown is particularly evident in the sectional view of Fig. 7 to recognize.

[0052] In advantageous embodiments, the drive motor 2 and the axial fan 6, as in the illustrated embodiment, are arranged in a housing-forming area 14 of the support-side pipe section 4a, which simultaneously mechanically holds the support-side pipe section 4a to the support frame 1a. For this purpose, a sleeve-shaped retaining element 15 is provided, which surrounds the housing-forming area 14 of the support-side pipe section 4a and is fixed to the support frame 1a. The term "housing-forming area" here refers to that part of the support-side pipe section 4a which encloses the drive motor 2 and the axial fan 6 in a housing-like manner.

[0053] In the example shown, the retaining part 15 includes, as can be seen in particular from the Fig. 8 und 9 As can be seen, a front half-shell 15a is attached to the support frame 1a, e.g., as shown, via retaining bosses 25 and associated screw connections, and a rear half-shell 15b is fixed to the front half-shell 15a, e.g., also by means of screw connections as shown, and thereby holds the housing-forming area 14 of the support-side tube section 4a clamped between the two half-shells 15a, 15b. Fixing ribs 21, as shown in the sectional view of Fig. 9 The visible features ensure axial and tangential fixation of the housing-forming area 14 of the support-side pipe section 4a to the sleeve-shaped retaining part 15. In the example shown, the front half-shell 15a has a bulge 26 pointing towards the support frame 1a, in which, for example, an electrical control unit 24 for the blower drive motor 2 can be housed in a protected manner. In alternative embodiments, the retaining part 15 can be formed in one piece or form an integral part of the support frame 1a.

[0054] In alternative implementations, the drive motor 2 and the axial fan 6 are arranged without a common housing inside the support-side pipe section 4a, which can then be held, for example, by its pipe wall directly on the support frame 1a.

[0055] Preferably, the protective ring element 10 is supported directly on the support frame 1a and / or on the sleeve-shaped retaining part 15. For this purpose, the protective ring element 10 can be mechanically connected to the support frame 1a directly and / or via the retaining part 15. Alternatively, the protective ring element 10 is additionally or exclusively supported on the support frame 1a via the support-side pipe section 4a, provided that the support-side pipe section 4a is sufficiently rigid for this purpose.

[0056] In advantageous embodiments, the protective ring element 10 surrounds the axial blowpipe end closure 9 radially on the outside with a radial distance Ra and / or projects outwards from the axial blowpipe end closure 9 by an axial projection Üa, wherein both are realized in the example shown, as specifically in Fig. 7 to recognize. This allows the protective ring element 10 to protect the blowpipe end cap 9 against impacts in the radial or axial direction without being mechanically connected to it, since impacts in the radial or axial direction generally act first on the protective ring element 10, which can absorb the impact forces and transmit them directly or indirectly to the support frame 1a, whereby sufficient lateral displacement of the protective ring element 10 relative to the blowpipe end cap 9 is possible. For example, the radial distance Ra is dimensioned such that it is at least as large as the maximum expected temporary radial change in distance of the protective ring element 10 relative to the blowpipe end cap 9 due to such an impact.

[0057] In advantageous embodiments, the blowing device, as in the illustrated embodiment, has an air guide cone 22 which is coaxially arranged upstream of an axial pipe wall end region 23 of the support-side blowpipe section 4a, forming an annular radial air inlet opening 18a, and an air inlet grille 5 made of an elastically deformable material arranged at the air inlet opening 18a. The air guide cone 22 terminates axially to the outside with a end plate, which in this case forms the axial blowpipe end closure 9 and maintains an axial distance Ag to the axial pipe wall end region 23 of the support-side blowpipe section 4a, thus defining an effective air inlet cross-section for the radial air inlet opening 18a.The air inlet grille 5 surrounds the axial pipe wall end region 23 of the support-side blowpipe section 4a without contact with a radial distance Rg at least partially circumferentially and is connected on one side at an axially outer end to the protective ring element 10 and on the other side at an axially inner end to the sleeve-shaped retaining part 15, preferably axially behind the axial pipe wall end region 23 of the support-side blowpipe section 4a.

[0058] The air guide cone 22 forms an airtight, funnel-shaped axial outer boundary of an associated air inlet channel 18, which opens radially through it, and is held on the motor / blower assembly in the support-side pipe section 4a. The axial pipe wall end region 23 of the support-side pipe section 4a of the blower tube can, as in the example shown, optionally be shaped axially outwards in a corresponding funnel or cone shape, thus forming an air inlet funnel 8. In this case, the air inlet channel 18 leading to the blower 6 is axially bounded on both sides by a cone- or funnel-shaped guide surface following the annular radial air inlet opening 18a. In alternative implementations, the support-side pipe section 4a terminates at the axial pipe wall end region 23 without a conical widening.

[0059] Optionally, as in the example shown, the protective ring element 10 has an axial end cap 19, which serves as the axial end of the protective ring element 10 or forms a component thereof. In this case, the protective ring element 10, with its end cap 19, is axially spaced outwards by a gap distance Sa from the end plate 9, which in this case forms the end cap of the blowpipe, as shown in the figure. Fig. 7 The gap distance Sa in this design allows an axial displacement movement of the end cover 19 of the protective ring element 10 relative to the blowpipe end closure 9 under impact, for which purpose it is dimensioned analogously to the radial distance Ra of the protective ring element 10 mentioned above.

[0060] In alternative embodiments, the air guide cone 22 is omitted, so that the axial blowpipe end closure 9 is then formed by an axial end face 9' of the axial pipe wall end region 23 of the support-side pipe section 4a, as shown in Fig. 7 indicated. In this case, the protective ring element 10 maintains the aforementioned radial distance Ra and, with its optional end cap 19, the aforementioned axial gap distance Sa to the axial end face 9' of the axial pipe wall end region 23 of the support-side pipe section 4a.

[0061] The air inlet grille 5 forms a grid structure that allows the blowing medium, in particular air, to pass through, providing a radial intake and exhaust characteristic for the blowpipe 4 at this end, which is axially closed to the outside by the air guide cone 22. In this configuration, air can thus enter the air inlet channel 18 radially from the outside. The air inlet grille 5 can act as a shock-absorbing element and elastically absorb impact forces acting on the protective ring element 10, e.g., in the event of an impact, thus preventing damage to the blowpipe end closure 9 or the air inlet funnel 8. The air inlet grille 5 can move within its radial distance Rg relative to the axial pipe wall end region 23 of the support-side pipe section 4a without contacting it. The flexible air inlet grille 5 can therefore move without affecting the axial pipe wall end region 23 or the support-side pipe section 4a.of the air inlet funnel 8, in particular axial and / or radial from the outside, absorb impact forces acting on the stiffer protective ring element 10 by deformation and transfer them from the rigid protective ring element 10 to the rigid retaining part 15, which in turn can transfer them to the support frame 1a.

[0062] The air inlet grille 5 is preferably, as in the example shown, via a e.g. made of Fig. 7 The visible positive-locking connection 20 is axially supported on the sleeve-shaped retaining part 15. Additionally, the air inlet grille 5 can be radially fixed to the sleeve-shaped retaining part 15, e.g., by associated screw connections.

[0063] How exactly from the Fig. 8 und 9As can be seen, the air inlet grille 5 in the example shown is not a closed ring, but rather has a ring shape open in a lower section to provide space for the base 16 of the support frame 1a. This base frame limits the intake chamber or air inlet opening 18a and can also protect the axial blowpipe end cap 9 from impacts. The air inlet grille 5 can be prefabricated as a single piece or assembled from several individual grille sections, depending on requirements.

[0064] In advantageous embodiments, the protective ring element 10, as in the example shown, surrounds the axial blowpipe end cap 9 at least on its underside. This enables the protective ring element 10 to protect the axial blowpipe end cap 9 from impacts and the like. Alternatively, it surrounds the axial blowpipe end cap 9, for example, only in a rear section.

[0065] In advantageous embodiments, the protective ring element 10, as in the example shown, completely surrounds the axial blowpipe end cap 9, i.e., along its entire circumference. This protects the blowpipe end cap 9 from impacts and the like on all sides.

[0066] In advantageous embodiments, the protective ring element 10, as in the illustrated embodiment, comprises a ring retaining section 10a connected to the support frame 1a and an annular protective section 10b extending at an angle from the ring retaining section 10a, which surrounds the axial blast pipe end cap 9 over a circumferential angle of at least 180°. In the illustrated embodiment, the protective section 10b surrounds the blast pipe end cap 9 over its entire circumferential angle of 360°. The air inlet grille 5 is supported on the protective section 10b and, optionally, as in the illustrated example, also on the ring retaining section 10a. Furthermore, in this case, the protective section 10b can also serve as a holder for the end cap 19.

[0067] As the illustrated and further embodiments described above clearly demonstrate, the invention advantageously provides a backpack blower that can be configured as an exhaust blower or, alternatively, as a suction blower. It is optimized with regard to its airflow and allows for a compact arrangement of the blower tube on the backpack's support frame, optionally in conjunction with a battery pack as the power source for the blower drive motor. The predominantly horizontal arrangement of the support-side tube section of the blower tube, which projects laterally beyond the support frame, promotes a compact design with optimal airflow. Additionally or alternatively, the end of the blower tube can be fully or partially protected from external mechanical impacts by the protective ring element.The possibility of positioning the blower tube with its carrying-side tube section below the battery pack also contributes to the compact design of the blower.

Claims

1. Backpack blower, preferably electric leaf blower, comprising - a backpack (1) having a load-bearing frame (1a), - a blower tube (4) having a backpack-side tube section (4a) which is held on a rear side of the load-bearing frame (1a), and having a hand-side tube section (4b) which extends past a first side region (S1) of the load-bearing frame (1a), - a drive motor (2), - an energy source (3) for the drive motor (2), and - an axial fan (6) which is driven by the drive motor (2), has an axial fan axis (6a), and is arranged in the backpack-side tube section (4a) of the blower tube (4), - wherein the backpack-side tube section (4a) of the blower tube (4) runs with a main direction component in a backpack transverse direction (RQ) of the load-bearing frame (1a) and has an axial blower tube end termination (9) which projects laterally beyond a second side region (S2) of the load-bearing frame (1a), which second side region (S2) faces away from the first side region (S1), and / or is surrounded at least on a part of its circumference by a protective ring element (10) which is connected to the load-bearing frame (1a), characterized in that - the fan axis (6a) encloses a horizontal angle (Wh) between 2° and 15°, preferably between 2° and 3°, with a vertical backpack transverse plane (EV) of the load-bearing frame (1a).

2. Backpack blower according to Claim 1, further characterized in that the fan axis (6a) encloses a vertical angle (Wv) of at most 45°, preferably of at most 10°, with a horizontal load-bearing plane (EH) of the load-bearing frame (1a).

3. Backpack blower according to Claim 1 or 2, further characterized in that the backpack-side tube section (4a) has a curvature section (7) made from a rigid tube material with a curvature angle (Kw) of less than 90°, preferably between 60° and 85°.

4. Backpack blower according to one of Claims 1 to 3, further characterized in that the drive motor (2) is an electric motor, and the energy source comprises a rechargeable battery pack (11) which is held on the load-bearing frame (1a).

5. Backpack blower according to one of Claims 1 to 4, further characterized in that the drive motor (2) has a motor axis (2a) which is parallel to the fan axis (6a), and / or is arranged in the backpack-side tube section (4a).

6. Backpack blower according to Claim 5, further characterized in that the drive motor (2) and the axial fan (6) are arranged in a housing-forming region (14) of the backpack-side tube section (4a).

7. Backpack blower according to one of Claims 1 to 6, further characterized in that the backpack-side tube section (4a) is connected by way of a sleeve-shaped holding part (15) to the load-bearing frame (1a).

8. Backpack blower according to one of Claims 1 to 7, further characterized in that the axial blower tube end termination (9) is surrounded at least on a part of its circumference by the protective ring element (10) and the protective ring element (10) is supported on the sleeve-shaped holding part (15) and / or directly on the load-bearing frame (1a).

9. Backpack blower according to one of Claims 1 to 8, further characterized in that the axial blower tube end termination (9) is surrounded at least on a part of its circumference by the protective ring element (10) and the protective ring element (10) surrounds the axial blower tube end termination (9) at a radial spacing (Ra) and / or projects with respect to the axial blower tube end termination (9) by an axial overhang (Üa).

10. Backpack blower according to one of Claims 1 to 9, further characterized by - an air guiding cone (22) which is arranged coaxially in front of an axial tube wall end region (23) of the backpack-side tube section (4a) with the formation of an annular radial air inlet opening (18a), and forms the blower tube end termination (9) with an axially outer end, and - an air intake grille (5) which is made from an elastically deformable material, is arranged on the air inlet opening (18a), surrounds the axial tube wall end region (23) of the backpack-side tube section (4a) at least on a part of its circumference without contact at a radial spacing (Rg), and is connected on the one hand at an axially outer end axially in front of the blower tube end termination (9) to the protective ring element (10) and on the other hand at an axially inner end axially behind the blower tube end termination (9) to the sleeve-shaped holding part (15) and / or the load-bearing frame (1).

11. Backpack blower according to one of Claims 1 to 10, further characterized in that the axial blower tube end termination (9) is surrounded at least on a part of its circumference by the protective ring element (10) and the protective ring element (10) surrounds the axial blower tube end termination (9) at least on its underside.

12. Backpack blower according to Claim 11, further characterized in that the axial blower tube end termination (9) is surrounded at least on a part of its circumference by the protective ring element (10) and the protective ring element (10) surrounds the axial blower tube end termination (9) over its full circumference.

13. Backpack blower according to one of Claims 1 to 12, further characterized in that the axial blower tube end termination (9) is surrounded at least on a part of its circumference by the protective ring element (10) and the protective ring element (10) comprises a ring holding section (10a) which is connected to the load-bearing frame (1a), and a protective section (10b) which leads away in an angular manner from the ring holding section (10a) and surrounds the axial blower tube end termination (9) over a circumferential angle of at least 180°.