FR2774254A1 - LAWN MOWER WITH COLLECTION DEVICE FOR CUT MATERIALS - Google Patents

Abstract

The mower comprises a housing (1) guided on a lawn (4) by a handle (3), which encloses a cutting chamber (5) towards the lawn (4). A knife (13) driven by a motor (17) rotates around a vertical axis (14) in the chamber (5). A collector (19) is mounted on the housing (1) for the cut materials. A channel (25) is provided with a suction opening (26) for the reception and an outlet (27) for the passage of the cut materials to the collector (19). A fan (28) produces a suction current in the manifold (19) and in the channel (25). The knife (13) comprises at least one blade (16) without wings, the suction opening (26) communicates with a suction section of the housing, in the cutting chamber (5) above the knife (13) ) forward in the cutting direction (12), and the suction side (29) of the fan (28) communicates with the manifold (19).

Description

The present invention relates to a lawn mower which comprises a housing.

  capable of moving over a surface of lawn to be mowed and of being carried out by hand by means of a guide handle, said casing enclosing a cutting chamber open towards the surface of the lawn, comprising a knife arranged in rotation around '' a vertical axis of rotation in the cutting chamber and capable of being driven in rotation by a motor, comprising a collecting device mounted on the housing for the materials cut and separated by the knife, and comprising a guide channel which has a suction opening for the reception of cut materials and an outlet opening for the passage of these cut materials, as well as a fan which produces

  a suction current in the collection device.

  Such a lawn mower is described in document EP 0 457 433 B 1.

  This is an air cushion lawn mower, the fan of which produces an air current which generates an overpressure in the cutting chamber, so that the casing slides on this air cushion on the surface of the lawn. The fan draws air from the collection device suspended from the housing. The collection device is suspended on the housing in the direction of the guide handle. With the exception of a suction opening, the collection device is produced in closed form. The suction opening is located in the collection device in the vicinity of the surface of the lawn, and is arranged behind the knife, which is located forward in the cutting direction. In this arrangement, the materials cut and separated by the knife are first deposited on the surface of the lawn, to then be sucked into the collection device during the passage of the suction opening. The disadvantage of this embodiment is that the cut materials are first deposited on the surface of the lawn after being separated, and then they are breathed in with an expense.

  relatively high energy.

  The principle mentioned above is also described in document EP 0 643 905 A2. From this document we can also see a lawn mower whose casing can be moved on wheels and in which the fan arranged coaxially with the knife drive shaft draws air from the collection device and blows it into the room cutting. The materials cut and separated by the knife are deposited on the ground, then they are taken by the collecting device which follows in the cutting direction, when its suction opening passes over the mowed grass. The disadvantage is that the cut materials are first deposited on the ground, then

  sucked in with a high suction force.

  The object of the invention is to propose a lawn mower which has only a reduced energy requirement for cutting the grass and for the passage of the cut materials into the

collection device.

  In accordance with the present invention, this objective is achieved by a lawn mower comprising a housing capable of being moved over a surface of lawn to be mowed and of being guided by hand by means of a guide handle, said housing enclosing a cutting chamber open towards the surface of the lawn, comprising a knife arranged in rotation about a vertical axis of rotation in the cutting chamber and capable of being driven by a motor, comprising a collecting device mounted on the housing for the materials cut and separated by the knife, said mower comprising a guide channel which has a suction opening for reception and an outlet opening for the passage of the cut materials to the collection device, comprising a fan which produces a current of aspiration in the collecting device and in the guide channel, characterized in that said knife comprises at least one blade devoid of wings, the opening re aspiration of the guide channel being in communication with a suction section of the housing, located in the cutting chamber above the cutting zone of the knife located forward in the normal cutting direction, and in that the suction side of the

  fan is in communication with the collection device.

  The advantage of this embodiment is that thanks to the suction section and the particular arrangement of the suction opening of the guide channel, the energy required for transporting the cut materials is reduced to a minimum. , since the cut materials are then already aspirated while they are still in a "suspended" state in the cutting chamber. In addition, thanks to the realization of the wingless blade, the energy requirement for cutting is significantly reduced. In addition, with the realization of the wingless knife, compared to normal clippers with rejection at the rear, we can achieve a significant reduction in noise. This also applies to clippers in which the wing effect is achieved by bending the knife in the region of the blade. The air flow that can be achieved here is particularly low compared to the energy expenditure. The realization of the mower knife, that is to say the blade, must be chosen as flat as possible, so that one obtains during the

  rotate a swept section as small as possible.

  Thanks to the use of blades without wings, a considerable energy saving is obtained. The knife can be designed in various ways. It is thus possible to choose a knife with blade sections added to the radially outer zones. Alternatively, it is also possible to use an arrangement in which several knives are mounted in distribution on the periphery of a plate, which have the shape of a flat iron, and blades are provided at their ends. Finally, it is also possible to arrange on the periphery of a tray a plurality of blades in the manner of saw teeth. It is preferably provided that the suction section is formed by a recess, directed away from the knife, in the ceiling of the

  casing which closes the cutting chamber upwards away from the ground.

  In addition, it is proposed for this purpose that the section of the recess increases in the direction of rotation of the knife, that the recess extends in the form of a circular annular sector around the axis of rotation of the knife at a lower angle. at 360, in particular about 180, and that the recess communicates in the region of its largest section with the suction opening of the guide channel. Thanks to this, an advantageous guidance of the mowed grass is obtained. However, it is also possible to be satisfied with one embodiment, in order to achieve an advantageous operating mode, in which it is provided that the suction section is represented directly by the section of the cutting chamber which is located between a ceiling of the housing, which closes the cutting chamber upwards, and the cutting zone of the knife, and that the suction opening for the guide channel is made in this section of cutting chamber in the ceiling. For a first embodiment of the mower, it is possible to use the interval between the housing and the surface of the lawn in order to suck in the air. However, it is preferable to provide a chosen air inlet. For this purpose, the casing is provided with at least one air inlet opening which communicates with the cutting chamber. Here, according to a first embodiment, the air inlet opening can be arranged near the suction opening of the guide channel. Thanks to this, we get

  rapid removal of the cut material from the cutting area.

  Here, the air inlet opening section can be made variably. Thanks to the low power consumption, it is also possible to provide that the motor intended to drive the knife is designed as an electric motor and also to drive the fan by an electric motor. In this case, the fan drive can

  be mechanically derived from the electric motor of the knife.

  However, it is particularly advisable to provide an embodiment in which separate electric motors are provided for driving the knife and the fan. In this case, due to the low energy requirement, the power supply to the drives can take place from a battery. In addition, in the case of a separate drive for the fan it can be provided that the power of the fan can be controlled. The power control can take place by modifying the speed of rotation and / or the blowing section of the fan. It is also possible to associate the fan with the collection device. The collection device can then be detachably connected to the housing, that is to say that it can comprise a container capable of being fixed to the housing, or even form a receiving chamber which receives a separate collection container. , and the reception chamber is at least partially enclosed so as not to let air pass, the fan being associated with the reception chamber. A part of the collection container can form a wall of the receiving chamber, in order to ensure a completely airtight closure. The control of the transport of the cut materials in the guide channel can also take place by the fact that the opening of

  guide channel outlet is designed in a variable way.

  Preferably, the lawn mower is made so that it can move on wheels on the surface of the lawn. For this purpose, the wheels

are associated with the housing.

  Preferred embodiments of the invention are illustrated schematically in the drawings, and will be explained in more detail with reference to them. The figures show: FIG. 1, a simplified representation in longitudinal section of a lawn mower according to the invention, in a first embodiment; Figure 2, a bottom view in the cutting chamber, to illustrate the section of the suction opening; Figures 3 and 4, two alternative embodiments of the knife according to Figure 2; FIG. 5, another embodiment of a lawnmower according to the invention, with air intake in the anterior region of the cutting chamber, seen from the upper side of the casing; FIG. 6, the illustration of the casing only of the lawn mower with an air inlet at the front surface of the casing; Figure 7, a simplified longitudinal section through a lawn mower according to the invention, comprising a fan which can be driven by a separate electric motor; Figure 8, a simplified representation of a lawn mower with a recess in the housing, partially in longitudinal section; and Figure 9, a simplified representation of the lawn mower according to the

Figure 8, in front view.

  In one embodiment of the lawn mower according to Figures 1 and 2, there is provided a housing 1, which can be moved on the surface 4 of the lawn to treat it, by means of four wheels 2 in total at the corners, that is to say at the front part 10 and at the rear part 11. The casing 1 comprises in the middle region a cutting chamber 5 which is delimited upwards by the ceiling 7 Downwards, that is to say towards the surface 4 of the lawn, the cutting chamber 5 is open. The opening is designated by the reference 6. The casing 1 can be moved over the surface 4 of the lawn by means of a guide handle 3 which an operator can grasp by hand, and the normal cutting direction 12 is that of the arrow. Correspondingly, the front face which is at the front in the cutting direction 12 is designated by the reference 8 and the rear part which is at the rear in the cutting direction 12 is designated by the reference 9. A the exterior, on the ceiling 7 of the cutting chamber 5, is fixed the electric motor 17 supplied from a battery 18. This motor comprises a drive shaft 15 which rotates around the axis of rotation 14. To this shaft a knife 13 is fixed in the form of a knife bar. The latter has, at these external sections, blade sections 16 which extend over the length L. In cross section, the knife 13 is produced equally over its entire width, with the exception of grinding in the region of the blade 16, so that the surface projected in the direction of rotation occupies a minimum. The casing 1 has a suction opening 26 in the ceiling 7, which has an approximately oval shape and covers an at least essential part of the cutting zone of the knife 13 when moving in the cutting direction 12. It can be recognized that the blade 16 of the knife 13 is located in the region of the radial extension of the suction opening 26, with reference to the axis of rotation 14. The knife 13 rotates in the direction of the arrow illustrated in FIG. 2 around the axis of rotation 14. The suction opening 26 opens into a guide channel 25 which ends with the outlet opening 27 in a collecting device 19. The collecting device 19 comprises walls 22 and a cover 23 which closes these walls in an essentially airtight manner and which forms a reception chamber 20. In the reception chamber 20 is placed a separate collection container 21. In the wall of the reception chamber 20 East formed an opening, provided with a mesh 24 in order to prevent the passage of cut materials. To this opening is connected a suction channel 31, led in the direction of the rear part 1 1 of the casing 1, and at the lower end of this channel, in the region of the ceiling 7, is an opening to which is connected a fan 28, the suction side 29 of which faces the suction channel 31. The side of

  blowing 30 is turned towards the rear part 11 open downwards.

  The fan rotor can be driven by a drive belt 32, which is driven from the drive shaft of the motor 17. The drive energy for the fan 28 is

  therefore derived from the drive motor 17 for the knife 13.

  Thanks to this, a suction current, illustrated by large arrows, is produced in the suction channel 31, which continues in the receiving chamber 20 and in the guide channel 25 because the

  suction channel 31 communicates with the reception chamber 20.

  Thanks to this, immediately above the cutting region in which the grass is separated by the blade 16 of the knife 13, the cut materials which are still "floating" are sucked up. This is illustrated by the small arrows. The cut materials penetrate, via the suction opening 26, into the guide channel 25, then they are transported with the air stream and pass from the outlet opening

  27 into the collection container 21.

  During this time, the air is sucked out of the cutting chamber 5 in the cutting zone from the bottom, i.e. from the surface 4

turf.

  Figure 3 shows an embodiment of a knife 113 which differs from the design of the knife 13 of Figure 2 in the manner of a knife bar. A tray 33 is provided on which three bars-shaped blades 116 are arranged, distributed on the periphery. Blades 116

  are made flat. The plate 33 can take different forms.

  We can choose a form favorable to flows. FIG. 4 shows another embodiment of a knife 213, in which individual blades 216 are arranged in distribution at the periphery

  of a plate 33, so that this results in a "sawtooth" shape.

  Figures 5 to 9 show embodiments, deviating from the embodiment of Figure 1, of lawn mowers according to the invention. The parts which correspond to those of FIG. 1 being provided with reference numbers which are increased, compared to those of FIGS. 1 and 2, by the value 500 in the embodiment of FIG. 5, by the value 600 in the embodiment of FIG. 6, of the value 700 in the embodiment of FIG. 7, and of the

  value 800 in the embodiment according to FIGS. 8 and 9.

  Unlike the embodiment according to Figure 1, there is provided in Figure 5 an air intake for which there is provided on the front part 510, therefore towards the front part 508, an air inlet opening 535 in the ceiling 507, which is directed upwards, and the air supply channel 534 which is led from this opening towards the cutting zone of the knife. The air necessary for the transport of the cut materials is therefore led partially via the opening 506 is partially via the air inlet opening 535 and the air intake channel 534 near the opening of suction 526. The

  knife can have one of the shapes seen in Figures 2 to 4.

  In FIG. 6, only the lower part is shown, therefore the casing 601. The air intake takes place in the region of the front surface of the front part 610, facing the front side 608, and through openings 635 in the wall towards the cutting chamber 605

  and towards the knife cutting area.

  In the embodiment according to FIG. 7, a fan 728 has been arranged on one of the walls which surround the reception chamber 720, this fan being able to be driven by means of a separate electric motor 736, so that the it is possible to regulate the rotation speed of this motor separately. Such an embodiment is particularly advantageous because the power of the two electric motors 717 and 736 can be regulated independently of one another. However, we prefer to plan a

  only power regulation of the 736 motor which drives the fan.

  The embodiment according to FIGS. 8 and 9 will be described in common in the following. FIG. 8 shows the casing 801 in longitudinal section, and the other components are on the contrary illustrated there without being cut. The casing 801 has a recess 837 in the ceiling 807, directed away from the knife 813. The recess 837 has a circular annular shape, arranged around the axis of rotation 814 of the knife 813. The section of the recess 837 increases continuously in the direction of rotation of the knife 813. In an area of the largest section, the recess 837 is connected to the suction opening 826 of the guide channel 825. The guide channel 825 is connected to the collection device 819 by its outlet opening. The collecting device 819 is fixed to the rear part 811 and protrudes beyond it towards the rear. The fan 828 is arranged on the wall, directed towards the front part 811 of the casing, of the collecting device 819. The recess 837, directed away from the knife 813, in the ceiling of the casing 801, the ceiling which closes the cutting chamber 805 upwards from the ground, thus forms the suction section. The cut materials are therefore carried out during aspiration into the recess 837 and arrive therefrom as far as the guide channel 825. Advantageously, the recess 837 extends under

  an angle of 180 in the cutting area of the knife 813.

  List of references 1,501,601,701,801 casing 2,502,602,702, 802 wheels 3, 503, 703 guide sleeve 4, 504, 604, 704, 804 lawn surface, 505,605, 705,805 cutting chamber 6, 506, 606, 806 opening 7, 507, 707, 807 ceiling 8.508. 608,708,808 front side 9, 509, 609, 709, 809 rear part, 510, 610, 710, 810 front part 11, 711, 811 rear part 12 cutting direction 13, 113,213,813 knife 14, 514, 614, 714, 814 axis of rotation, 815 drive shaft 16, 116,216 blade 17,517,617,717 motor 18,518,718 battery 19, 519, 719, 819 collecting device, 520, 720 receiving chamber 21, 521, 721 collecting container 22, 522, 722 walls 23, 523, 723 cover 24, 524 mesh, 525,725, 825 guide channel 26, 526, 626, 726, 826 suction opening 27, 527, 727, 827 outlet opening 28, 528.628, 728, 828 fan 29.529, 829 suction side, 530, 830 supply side 31, 531 suction channel 32 drive belt 33 plate 534 air intake channel 535.635 air inlet opening 736 fan motor 837 recess L blade length

Claims (16)

Claims   1. Lawn mower comprising a housing (1, 501, 601, 701) capable of being moved over a surface of lawn to be mowed (4, 504, 604, 704) and of being guided by hand by means of a guide sleeve (3, 503, 703), said casing enclosing a cutting chamber (5, 505, 605, 705) open towards the surface of the lawn (4, 504, 604, 704), comprising a knife (13, 113, 213) arranged in rotation about a vertical axis of rotation (14, 514, 614, 714) in the cutting chamber (5, 505, 605, 705) and capable of being driven by a motor (17, 517, 617, 717), comprising a collecting device (19, 519, 719) mounted on the casing (1, 501, 601, 701) for the materials cut and separated by the knife (13, 113, 213), said mower comprising a guide channel (25, 525, 725) which has a suction opening (26, 526, 626, 726) for the reception and an outlet opening (27, 527, 727) for the passage of the cut materials to the collection device (19, 79, 719), comprising a fan (28, 528, 628, 728) which produces a suction current in the collecting device (19, 519, 719) and in the guide channel (25, 525, 725), characterized in that said knife (13, 113, 213) comprises at least one blade (16, 116, 216) devoid of wings, the suction opening (26, 526, 626, 726) of the guide channel (25, 525, 725) being in communication with a suction section of the casing, located in the cutting chamber (5, 505, 605, 705) above the cutting zone of the knife (13, 113, 213) located in the forward direction normal cutting (12), and in that the suction side (29, 529) of the fan (28, 528, 628, 728) is in communication with   the collection device (19, 519, 719).   2. Lawn mower according to claim 1, characterized in that: the suction section is formed by a recess (837) directed away from the knife (813), in the ceiling (807) of the casing (801) which closes the cutting chamber (805) upwards away from the lawn surface (804).   3. Lawn mower according to claim 2, characterized in that: the section of the recess (837) increases in the direction of rotation of the knife (813), the recess (837) extending in the form of an annular sector circular around the axis of rotation (814) of the knife (813) at an angle less than 360, in particular about 180, and in that the recess (837) communicates in the region of its maximum section with the suction opening (826) of the guide channel (825).   4. Lawn mower according to claim 1, characterized in that: the suction section is represented directly by the section of cutting chamber which is located between a ceiling (7, 507, 707) of the housing (1, 501, 601, 701) which closes the cutting chamber (5, 505, 605, 705) upwards, and the cutting zone of the knife (13, 113, 213), and in that the suction opening (26 , 526, 626, 726) for the guide channel (25, 525, 725) is produced in this section of the cutting chamber in the ceiling (7, 507, 707).   5. Lawn mower according to claim 1, characterized in that: the casing (501, 601) comprises at least one air inlet opening   (535, 635) connected to the cutting chamber (505, 605).   6. Lawn mower according to claim 5, characterized in that: the air inlet opening (535, 635) is arranged close to   the suction opening (526, 626) of the guide channel (525).   7. Lawn mower according to either of claims 5 and 6, characterized in that:   the section of the air inlet opening is variable.   8. Lawn mower according to claim 1, characterized in that: the motor (17, 517, 617, 717) for driving the knife (13, 113, 213) is produced in the form of an electric motor, and in that the fan (28, 528, 628) is capable of being rotated by the engine (17, 517, 617).   9. Lawn mower according to claim 1, characterized in that: a separate electric motor (736) is associated with the fan (728) for driving.   10. Lawn mower according to either of claims 8 and 9,   characterized in that: for the electrical supply of the drives (17, 517, 617, 717, 736) of the knife (13, 113, 213) and / or of the fan (28, 528, 628, 728)   a battery is provided (18, 518, 718).   11. Lawn mower according to either of claims 9 and 10,   characterized in that: the power of the fan (28, 528, 628, 728) is likely to be ordered.   12. Lawn mower according to claim 11, characterized in that: for the power control, a modification of the speed of rotation and / or of the blowing section of the fan (28, 528, 628, 728).   13. Lawn mower according to one of claims 1 to 12, characterized in that:   the fan (728) is associated with the collection device (719).   14. Lawn mower according to claim 1, characterized in that: the collecting device (19, 519, 719) comprises a receiving chamber (20, 520, 720) associated with the casing (1, 501, 701), and a collection container (21, 521, 721) separate from this chamber, which is at least partially surrounded by the receiving chamber (20, 520, 720), and in that the fan (28, 528, 628, 728) is associated with the room of reception (20, 520, 720).   15. Lawn mower according to claim 1, characterized in that: the section of the outlet opening (27, 527, 727) of the guide channel (25, 525, 725) is variable.   16. Lawn mower according to claim 1, characterized in that: wheels (2, 502, 602, 702) are associated with the casing (1, 501, 601, 701), on which the latter is movable on the surface grass (4, 504, 604, 704).