BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective illustration of a vacuum cleaning tool according to the invention.
FIG. 2 is a perspective illustration showing a longitudinal section of a vacuum cleaning tool according to the invention.
FIG. 3 is a first perspective illustration of the vacuum cleaning tool with removed upper housing shell.
FIG. 4 is a second perspective illustration of the vacuum cleaning tool with removed upper housing shell.
FIG. 5 is a third perspective illustration of the vacuum cleaning tool with removed upper housing shell.
FIG. 6 is a fourth perspective illustration of the vacuum cleaning tool with removed upper housing shell.
FIG. 7 shows a control device in a perspective partially sectioned illustration.
FIG. 8 shows the control device according to FIG. 7 in a perspective illustration.
FIG. 9 is another perspective illustration of the control device according to FIG. 7.
FIG. 10 shows the control device of FIG. 7 in a perspective, partially sectioned illustration in a first control position.
FIG. 11 shows the control device of FIG. 7 in a perspective partially sectioned illustration in a second control position.
FIG. 12 is a perspective illustration of the control device in the control position shown in FIG. 11.
FIG. 13 is a schematic section illustration of a control device in a first control position.
FIG. 14 is a schematic section illustration of the control device in a second control position.
FIG. 15 is a schematic illustration of the function of a control device.
FIG. 16 is another schematic illustration of the function of a control device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The vacuum cleaning tool 1 illustrated in FIG. 1 has a housing 2 that is comprised of an upper housing shell 49 and a lower housing shell 50. Two front wheels 18 are rotatably supported on the housing 2. A connecting socket 17 for connecting the vacuum cleaning tool 1 to a vacuum device of a vacuum cleaning device is arranged on the housing 2 of the vacuum cleaning tool 1.
In FIG. 2, the vacuum cleaning tool 1 is shown in a section view. The front wheel 18, as shown in FIG. 2, can also be arranged at the front side of the housing 2. In the lower housing shell 50, a suction opening 4 is provided that extends across the entire width of the vacuum cleaning tool 1 transversely to the working direction. The suction opening 4 is slot-shaped. Above the suction opening 4 a cleaning tool, i.e., a brush roller 8, is supported to be rotatable about axis of rotation 9. A plurality of bristles 28 are secured on the brush roller 8. The housing 2 is divided transversely to the working direction and parallel to the axis of rotation 9 of the brush roller 8 by a partition 11 into a working chamber 3 in which the brush roller 8 is arranged and a turbine chamber 5 in which an air turbine 6 is rotatably supported. The air turbine 6 is rotatably supported about axis of rotation 7 that is parallel to the axis of rotation 9 of the brush roller 8.
The turbine chamber 5 is in fluid communication by means of first flow connection 12 and by means of second flow connection 13 with the turbine chamber 5. The first flow connection 12 is of an open configuration. On the second flow connection 13 a control element, i.e., a control flap 14, is arranged that controls the flow cross-section of the second flow connection 13. An outlet opening 15 is provided on the turbine chamber 5 to which is connected the connecting socket 17. In operation, the vacuum device of the vacuum cleaning device connected to the connecting socket 17 conveys the working air flow through suction opening 4 into the working chamber 3. From the working chamber 3, the working air flow flows via the flow connections 12 and 13 into the turbine chamber 5 and via the outlet opening 15 out of the connecting socket 17. The total air flow that is conveyed by the vacuum device serves as a working air flow for conveying dirt particles from the suction opening 4 to the outlet opening 15.
In FIG. 2 an imaginary plane 43 is shown that contains the axis of rotation 7 of the air turbine 6 as well as the geometric center M of the outlet opening 15. The first flow connection 12 is below the plane 43, i.e. on the side of the plane 43 where the suction opening 4 is located, and the second flow connection 13 is arranged above the plane 43. A first suction air flow that flows in the direction of arrow 20 through the first flow connection 12 drives the air turbine 6 in rotational direction 51. A second suction air flow branched off the working air flow flows in the direction of arrow 21 through the second flow connection 13 into the turbine chamber 5. The suction air flow that enters the turbine chamber 5 through the second flow connection 13 brakes the air turbine 6. At the same time, the second suction air flow provides an air cushion between the housing 2 and the air turbine 6 that results in a reduction of the running noise of the air turbine 6.
FIG. 3 shows that the air turbine 6 has turbine vanes 16 on both faces of a baseplate 52. It can also be provided to arrange turbine vanes 16 only on one face of the baseplate 52. As shown in FIGS. 2 and 3, the air turbine 6 is designed as a cross-flow turbine. Sucked-in air can flow through the turbine vanes 16 into the area of the axis of the air turbine 6 and from there through additional turbine vanes 16 radially outwardly.
As shown in FIG. 3, a section of the partition 11 is formed on an insert 19. The flow connections 12 and 13 are arranged on the insert 19. For controlling the control flap 14 a control device 22 is provided. The control device 22 is in communication with a pressure measuring opening 23 in the insert 19; the opening 23 opens into the working chamber 3. The air turbine 6 drives the brush roller 8 by means of drive shaft 24 and drive belt 10.
In FIG. 4, the vacuum cleaning tool 1 with its control device 22 is shown. The control device 22 has a housing 32 that is arranged in the turbine chamber 5. The housing 32 has a connecting socket 33 connected to the insert 19. In FIG. 6, the vacuum cleaning tool 1 is shown without control device 22. As shown in FIG. 6, in the area of the pressure measuring opening 23 and of the connecting socket 33 on the insert 19, a guide 35 is arranged onto which the connecting socket 33 can be pushed into place. As shown in FIG. 5 and FIG. 6, the wall of the turbine chamber 5 has a connecting opening 30 through which a connecting hose 26 illustrated in FIG. 4 extends. The connecting hose 26 connects the interior of the housing 32 of the control device 22 with ambient air. The connecting hose 26 opens into the interior of a wheel cover 25. In FIG. 4, schematically a rear wheel 27 is illustrated that is arranged underneath the wheel cover 25. The interior of the wheel cover 25 is protected from becoming soiled so that clogging of the connecting hose 26 with dirt particles is prevented. The control device 22 can be retrofitted in existing vacuum cleaning tools by exchanging an existing insert for an insert 19 with the control device 22.
In FIG. 5, the arrangement of a control lever 31 of the control device 22 is illustrated. The control lever 31 has a short end that is positioned in the area of the guide 35 on the insert 19; the long end of the control lever 31 projects into the housing 32 (not shown in FIG. 5) of the control device 22. As shown in FIGS. 4 and 5, the control flap 14 is arranged on a bearing shaft 41 that is supported on the side opposite the control device 22 in a bearing 29 provided on the insert 19. The housing of the control device 22 is connected by means of a fastening screw 36 to the insert 19.
In FIGS. 7 through 12, the function of the control device 22 is illustrated. As shown in FIG. 7, in the interior of the housing 32 a diaphragm 37 is arranged that is attached sealingly on the inner circumference of the housing 32. On one face of the diaphragm 37 there is a control ball 38 on which the long end of the control lever 31 rests. In the completely closed position of the control flap 14 shown in FIG. 7, the control ball 38 rests against a stop 39 in the housing 32. The control lever 31 and the control ball 38 are arranged in a first chamber 70 in the housing 32. The pressure measuring opening 23 opens into this first chamber 70 of the housing 32. The control lever 31 is positioned in the area of the pressure measuring opening 23 so as to neighbor the insert 19 but it does not closed off the opening 23. A first pressure pA1 of the working chamber 3 is present in the first chamber 70 because of the pressure measuring opening 23. The diaphragm 37 separates the first chamber 70 from a second chamber 71 that is connected by means of connecting socket 40 to ambient air. The connecting hose 26 is secured on the connecting socket 40 as shown in FIG. 4. In the second chamber 71 ambient pressure pu is present.
As shown in FIG. 8, the bearing shaft 41 is supported on the connecting socket 33. The control lever 31 is fixedly connected to the bearing shaft 41. As shown in FIG. 9, the control flap 14 extends across the entire height of the second flow connection 13. As shown in FIGS. 7 and 8, the side of the second flow connection 13 that is facing the first flow connection 12 and is positioned below the axis of rotation 42 of the bearing shaft 41 is closed off on the side facing the turbine chamber 5 by wall section 34.
In the completely closed position of the control flap 14 illustrated in FIG. 7 through 9, the pressure pA1 present in the working chamber 3 is significantly lower than the ambient pressure pu. In the working chamber 3 a high underpressure is present as it exists, for example, in operation of the vacuum cleaning tool 1 on carpeting. The ambient pressure pu forces by means of control ball 38 the control lever 31 upwardly so that the control flap 14 is forced into the completely closed position. In this position the entire working air flow flows through the first flow connection 12 from the working chamber 3 into the turbine chamber 5.
In FIG. 10, the position of the control flap 14 at reduced underpressure, i.e., increased absolute pressure pA2 in the working chamber 3, is illustrated. At increased pressure pA2 in the working chamber 3, the control flap 14 as a result of the suction action of the vacuum device is rotated into an open position. This opening action of the control flap 14 is possible because the wall section 34 covers the wall section of the control flap 14 acting in the opposite direction. The pressure pA2 in the working chamber 3 no longer is sufficient in order to deflect the diaphragm 37 completely upwardly. The control lever 31 is pivoted relative to the position illustrated in FIG. 7 by an angle ω2 about axis of rotation 42. In this way, a second suction air flow flows via the second flow connection 13 out of the working chamber 3 into the turbine chamber 5. The second suction air flow is no longer available as a driving air flow for the air turbine 6. The second suction air flow brakes the air turbine 6. In this way, the speed of the air turbine 6 and thus the drive power at which the brush roller 8 is driven in rotation are reduced. At increased pressure pA2 in the working chamber 3 as it exists, for example, when driving across carpet fringes, the speed of the brush roller 8 is reduced as a result of the reduced drive power.
FIGS. 11 and 12 show the control device 22 at farther increased pressure pA3 in the working chamber 3. The vacuum device has deflected the control flap 14 farther. The vacuum power acting on the control flap 14 remains constant but the underpressure acting on the diaphragm 37 in the direction toward the control lever 31 decreases as a result of the increased pressure in the working chamber 3 so that the force counteracting the deflection of the control flap 14 is reduced. The control lever 31 in the position illustrated in FIGS. 11 and 12 has been deflected by an angle ω3 relative to the position illustrated in FIGS. 7 through 9. It can also be provided that the lever 31 acts directly on the diaphragm 37.
Adjusting devices 72 and 73 can be arranged at the flow connections 12 and 13 as indicated in dashed lines in FIG. 9. On the first flow connection 12 an adjusting device 72 is arranged that is configured as a manually actuatable control slide. The control slide can be moved by the user in the direction of the arrow shown in FIG. 9. In this way, the cross-section of the first flow connection 12 is changed independent of the pressures existing within the vacuum cleaning tool 1. At the second flow connection 13, an adjusting device 73 is arranged that is also configured as a manually adjustable control slide. The control slide can also be moved by the user in the direction of the arrow shown in FIG. 9. It can also be provided to arrange an adjusting device 72, 73 either at the first flow connection 12 or at the second flow connection 13. Depending on the desired effect on the flow cross-section of the flow connections 12 and 13, the size of the adjusting devices 72 and 73 can be selected to be different. By means of the adjusting devices 72 and 73, the maximum flow cross-section of the flow connections 12 or 13 are determined. In this way, the division of the air flow onto the two flow connections 12 and 13 can be adjusted also. The control of the control flap 14 at the second flow connection 13 is independent of the position of the adjusting devices 72 and 73. Instead of providing a slide, the adjusting devices 72 and 73 can be configured also in other ways, for example, as an adjusting flap or the like.
FIGS. 13 and 14 show an embodiment of a control device 44. The control device 44 comprises a bellows 45 whose first end 46 is secured to the insert 19. The first end 46 of the bellows 45 is connected by means of pressure measuring opening 23 to the working chamber 3. The second end 47 of the bellows 45 is connected to ambient pressure pu. At the second end 47 of the bellows 45, a lever 48 is arranged; by means of the lever 48 the second end 47 of the bellows 45 is connected to the control flap 14. At high underpressure in the working chamber 3, i.e., a small absolute pressure value pA1, the underpressure pulls the second end 47 toward the insert 19. The openings in the bellows 45 toward the working chamber 3 and the surroundings are very small so that no significant flow occurs. The control flap 14 is closed. When the absolute pressure is increased to the pressure pA2 indicated in FIG. 14, the force that acts on the second end 47 is no longer sufficient to counteract the force acting on the control flap 14 as a result of the underpressure in the turbine chamber 5. The second end 47 of the bellows 45 moves by the travel stroke ΔS away from the insert 19. The control flap 14 is opened by an angle ω2.
Instead of the diaphragm 37 or of the bellows 45, the control device can also comprise a valve for controlling the control flap 14. Instead of a control flap, other control elements such as slides or the like can be provided.
In FIG. 15 a further embodiment of a control device 54 is shown. The control device 54 comprises a servo motor 55 that acts on the shaft 41 of the control flap 14 and in this way adjusts the position of the control flap 14. The servo motor 55 is connected to a control 57. The control device 54 comprises a pressure senor 56 that measures the pressure in the turbine chamber 5. It is also possible to provide a pressure sensor 56′ for detecting the pressure in the working chamber 3. As a function of the pressure measured by the pressure sensor 56 or 56′ the control 57 controls the servo motor and thus the position of the control flap 14. The control is realized based on the schematically indicated diagram of FIG. 15 that shows the angle ω as a function of the measured pressure p. Below a lower pressure value p0 the control flap 14 is closed. Below the lower pressure value p0 the underpressure in the vacuum cleaning tool 1 is very large. As the pressure increases, i.e., underpressure relative to the surroundings decreases, the control flap 14 is adjusted by increasing the angle ω. At an upper pressure value p1 the control flap 14 is opened by maximum angle ω0. The pressure value p1 can be present, for example, as the vacuum cleaning tool 1 is lifted off the ground. As the pressure increases even more, the control flap 14 remains unchanged until the ambient pressure pu is reached.
In the embodiment illustrated in FIG. 16, the brush roller 8 is driven directly by drive motor 65 and drive belt 68. An air turbine is not provided. The vacuum cleaning tool 61 illustrated in FIG. 16 has a working chamber 3 in which the brush roller 8 is arranged as well as a chamber 62 that connects the working chamber 3 to the connecting socket 17. The vacuum cleaning tool 61 has a control device 64 that comprises a drive motor 65 as well as a pressure sensor 66 and a control 67. The pressure sensor 66 measures the pressure in the chamber 62. The pressure sensor 66 however can also measure the pressure in the working chamber 3. The control 67 controls the current input I of the drive motor 65 and thus the drive power of the brush roller 8. The control is realized based on the schematically shown diagram of FIG. 16. At low pressure p0, i.e., at high underpressure in the chamber 62, the drive motor 65 is operated at high current I1. With increasing pressure, i.e. decreasing underpressure in the chamber 62, the current input I also decreases to a current input I0 at an upper pressure value p1. Until the ambient pressure pu is reached, the current input I is maintained constant. However, it is also possible to further lower the current input I after surpassing the upper pressure value p1. In particular, it can be provided that when an upper pressure value is reached, the drive motor 65 is switched off for safety reasons, for example, when the vacuum cleaning tool 61 is lifted off the ground. Instead of the current input I, the speed or the drive power of the drive motor 65 can be controlled.
The specification incorporates by reference the entire disclosure of German priority document 10 2006 040 557.9 having a filing date of 30 Aug. 2006.
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
Patent Application
20080053479
