Cleaning Tool for Floor Surfaces Having an Illumination Element for a Working Area

[0001] The invention relates to a cleaning tool for floor surfaces, upholstery surfaces or the like, in particular, a vacuum cleaning tool for vacuum cleaning devices such as a vacuum cleaner. The cleaning tool is comprised of a housing having a working chamber whose bottom plate comprises a suction slot that extends transversely to the working direction of the cleaning tool and is designed for taking up dirt. The cleaning tool further comprises a forwardly facing housing end wall provided with a receptacle for an illumination element for illuminating the surface to be cleaned, wherein the illumination element is arranged behind a light-permeable cover.

[0002] Such a vacuum cleaning tool is disclosed in U.S. Pat. No. 5,896,618. This patent proposes to arrange a rod-shaped incandescent lamp at the housing end face of the cleaning tool for providing a sufficient illumination of the working area. The rod-shaped incandescent lamp is exposed to high mechanical loads because it is provided on the end face of the housing that is exposed to mechanical loads by impact so that the lamp filament has the tendency to break. Also, a sufficient dissipation of thermal energy must be provided which is effected by a branched-off flow portion of the sucked-in air. In this connection, it cannot be prevented that the illumination body (incandescent lamp) will become soiled.

[0003] It is an object of the present invention to provide a cleaning tool for floor surfaces with a working area illumination that, on the one hand, ensures a bright uniform illumination of the working area and, on the other hand, provides high mechanical load resistance.

[0004] In accordance with the present invention, this is achieved in that the illumination element is a cold light emitting cold light lamp.

[0005] The illumination element is a cold light lamp that emits cold light and therefore has only minimal heat development. In this way, it becomes possible to arrange the cold light lamp in a substantially closed housing so that soiling by means of dirt particles or dust particles entrained in the sucked-in vacuum flow is prevented. The cold light lamp is resistant to strong mechanical impacts because no filament is present. Despite of this, it provides a bright glistening light that ensures a uniform strong illumination of the working area.

[0006] Preferably, the cold light lamp is a cold cathode lamp that has a rod-shaped basic form and ensures, when arranged transversely to the working direction, an excellent illumination of the working area across the working width. It can also be expedient to provide the cold light lamp in the form of several ultra bright LEDs (light emitting diodes) wherein the LEDs have a luminous power of at least 2,000 mcd (millicandela), preferably more than 5,000 mcd, and have a radiation angle of 20 degrees to 30 degrees.

[0007] In a preferred embodiment, the cold light lamp is arranged on a printed circuit board support and the printed circuit board support together with a casing and a cover that is advantageously embodied as a lens form a module. In this way, when mounting the lamp as well as in a maintenance situation, a simply exchange of the defective cold light lamp can be realized. For this purpose, the module is secured expediently by locking (snap) elements in the receptacle and the electrical connection is provided in particular by contact elements that extend expediently through the back wall of the receptacle and contact in the housing an electrical voltage connector. In this connection, the contact elements and the voltage connector are advantageously designed as a plug connection wherein one part of the plug connection is provided at the printed circuit board support and the other part of the plug connection is arranged behind the back wall in the housing. The illumination module is therefore secured mechanically safely within the receptacle of the housing by means of the snap connection as well as by means of the plug connection.

[0008] According to another aspect of the invention, it is proposed for compensation of alignment errors to provide between the motor shaft of an electrical drive motor and the drive shaft of a belt drive a cardan-type connection by means of a coupling wherein the coupling is configured like a claw coupling whose coupling elements engage one another with minimal radial and/or axial play. Without great constructive expenditure, mounting tolerances as well as alignment errors can be compensated by enabling corresponding radial and/or axial play.

[0009] According to a further independent aspect of the invention, it is provided that brush rollers are supported at their ends by means of substantially circular disk shaped support plates in the housing wherein the bearing shaft ends of the brush roller engage the support plates and the support plates, in turn, are received in a substantially rectangular bearing receptacle of the housing. In this connection, the width of the bearing receptacle is matched approximately to the diameter of the support plate.

[0010] In a preferred embodiment, the bearing plate is comprised of an elastic material, preferably of a soft-elastic material, particularly rubber, so that the manufacturing and mounting tolerances can be compensated easily without this having an effect on the support action of the brush roller.

[0011] In order to ensure a safe securing action of the support plate in the bearing receptacle, it can be advantageous to match the bottom of the bearing receptacle to the circumferential geometry of the support plate. A simple electrical cable routing is achieved in that the vacuum connector is provided with a housing section through which an electrical connecting cable can be supplied. The connecting cable is in particular guided in the pivot axis of the vacuum connector for which purpose bearing pins of the vacuum connector are hollow, in particular, they are configured as tubular pins. The cable can thus be guided through the bearing pins directly into the housing or the motor chamber of the housing in order to be connected to a connector module.

[0012] FIG. 1 is a perspective view onto the cleaning tool according to the invention in a configuration as a vacuum cleaning tool for a vacuum cleaner or the like.

[0013] FIG. 2 is a view according to FIG. 1 with the illumination module being removed.

[0014] FIG. 3 is a perspective rear view of the illumination module.

[0015] FIG. 4 is a perspective view of the illumination module according to FIG. 3 in a view from the front.

[0016] FIG. 5 is a perspective view of a printed circuit board support with illumination element.

[0017] FIG. 6 is a detail view of the cleaning tool according to FIG. 1 with removed top cover and demounted drive unit.

[0018] FIG. 7 is a perspective view of the cleaning tool according to FIG. 1 with removed top cover.

[0019] FIG. 8 is a detail view of a belt drive for driving a brush roller arranged in the cleaning tool.

[0020] FIG. 9 shows in a schematic illustration the belt drive according to FIG. 8.

[0021] FIG. 10 is a detail view of the bottom part with a bearing receptacle provided in the sidewall.

[0022] FIG. 11 is a view of an end of the brush roller with slipped-on support plate.

[0023] FIG. 12 is a view according to FIG. 10 with a support plate arranged in the bearing receptacle.

[0024] FIG. 13 is a perspective rear view of the bottom part of the housing.

[0025] FIG. 14 is a perspective view of a vacuum connector socket.

[0026] The cleaning tool for floor surfaces, upholstery surfaces or the like, as illustrated in the drawings, is configured as a vacuum cleaning tool for a vacuum cleaning device such as a vacuum cleaner. It is comprised of, as shown in FIGS. 1 and 2, of a two-part housing 1 with a top cover 2 and a bottom part 3. FIGS. 6 through 8 show that a working chamber 4 is provided in the housing 1 and a brush roller 5 is arranged in the working chamber 4 and driven so as to rotate about an axis of rotation 6. The drive action is realized by a belt drive 7 that, in the illustrated embodiment, is driven by a drive motor 8. The drive motor 8 is part of a drive unit 9 that can be inserted as a module into the motor chamber 10 of the housing 1. The motor chamber 10 is separated from the working chamber 4 wherein the working chamber 4 in the illustrated embodiment is connected by a vacuum connector 11 to a vacuum cleaning device. The connection between the working chamber 4 and the vacuum connector 11 is realized by a vacuum opening 12 that is provided in the partition between the motor chamber 10 and the working chamber 4. A channel extending underneath the drive unit 9 to the vacuum connector 11 adjoins the opening 12.

[0027] As illustrated in FIGS. 10 and 12, in the bottom plate 13 of the working chamber 4 a suction slot 14 is formed which extends transversely to the working direction 15 essentially across the entire width of the working chamber 4. As illustrated in particular in FIG. 7, the width of the working chamber 4 corresponds approximately to the width of the vacuum cleaning tool or the width of its housing 1.

[0028] The housing 1 of the vacuum cleaning tool glides with front rollers 16 and rear rollers 17 on the surface to be cleaned wherein the housing 1 has an end face or front wall 18 facing in the working direction 15 on which an illumination module 22 for illuminating the surface to be cleaned is arranged.

[0029] In the illustrated embodiment, the illumination module 22 is arranged in a receptacle 19 (FIG. 2) of the housing 1 wherein the receptacle 19 is arranged above the working chamber 4 and is integrated into the housing 1 or its top cover 2. The top cover 2 has a part-circular central section 21 that delimits the motor chamber 10 for the drive unit 9 and covers the working chamber 4 in a central area at least partially. The central section 21, transversely to the working direction 15, is narrower than the bottom part 3 so that the vacuum cleaning tool in a plan view is of a substantially T-shaped configuration.

[0030] The receptacle 19 for the illumination module 22 is essentially provided in the central section 21 and has a width that matches the width of the central section 21 transversely to the working direction 15. The receptacle 19, as illustrated in FIG. 2, has a substantially triangular cross-section whose base is open for insertion of the illumination module 22.

[0031] The illumination module 22, compare also FIGS. 3 through 6, is comprised of a casing 23 that has a triangular cross-sectional shape (FIG. 3) matching that of the receptacle 19. On the back wall 24 of the housing 23, a printed circuit board support 25 (FIG. 5) with an illumination element 20 is arranged. The casing 23 is closed in the forward direction by a light permeable cover 26 that is preferably designed as an optical lens. The cover 26 forms approximately the hypothenuse of the casing 23 that is approximately triangular in cross-section and has a slightly convexly curved outer side wherein the cover 26 is positioned at an angle of approximately 30 degrees up to 60 degrees, preferably approximately 45 degrees, relative to the bottom plate 13 of the bottom part 3 or relative to the surface to be cleaned. The illumination element 20, the printed circuit board support 25, the casing 23, and the cover 26 together form a common illumination module 22 that can be inserted into the receptacle 19.

[0032] As illustrated in FIG. 1, the cover 26 in the mounted state of the module 22 is positioned approximately in the plane of the central section 21 so that no edges, recesses or projections are formed. Preferably, the casing 23 is secured by locking or snap elements 27 in the receptacle 19 wherein the snap elements 27 in the illustrated embodiment are formed by locking recesses in the sidewalls of the casing 23. Counter locking elements 28 on the walls of the receptacle 19 ensure a save securing action for the illumination module 22 in the housing 1 of the cleaning tool.

[0033] As illustrated in FIG. 5, the illumination element 20 is a cold light lamp, in particular, a cold cathode lamp 30. The tubular illumination body 29 of the cold cathode lamp 30 extends transversely to the working direction 15 preferably essentially across the entire width of the casing 23 so that an excellent light distribution is provided. Cold cathode lamps are connectable in a simple way to the supply voltage of the electrical drive motor 8 and do not require any complex ballast. When switching on the supply voltage, a illumination is immediately provided by the cold cathode lamp. A flickering, flash-like initial illumination as it is known from neon lights does not occur. For realizing a connection to the supply voltage, appropriately selected resistors 31 can be used which, as illustrated in FIG. 3, can be positioned in the openings of the back wall 24 of the casing 23.

[0034] It can also be expedient to provide the cold light lamp 20 in the form of several ultra-bright LEDs 32 that have a luminous power of at least 2,000 mcd, preferably more than 5,000 mcd, and have a radiation angle of advantageously approximately 20 degrees to 30 degrees. In order to ensure excellent light distribution, it is moreover provided that the cover 26 is an optical lens like a Fresnel lens. For example, the side of the lens from which the light is emitted can be provided with a plurality of curved ribs 33 that extend approximately in the working direction 15. The curvature of the ribs 33 is selected such that their focal point distance is identical. In this way, excellent diffusion of the light source arranged behind the cover 26 is provided with uniform illumination of the working area.

[0035] The electrical connection of the illumination element 20 is realized preferably by contact elements 34 that project from the back wall 24 of the casing 23 and pass through appropriate slots 35 in the back wall 36 of the receptacle 19. Behind the back wall 36 of the receptacle 19, within the motor chamber 10 in the housing 1 an electrical voltage connector 37 (FIG. 7) is provided with which the contact elements 34 interact. Preferably, the contact elements and the voltage connector 37 provide a plug connection comprised of plug 38 and socket 39 wherein one part of the plug connection, in the embodiment the plug 38, is fastened on the printed circuit board support 25 and the other part of the plug connection, in the embodiment the socket 39, is provided behind the back wall 36 of the receptacle 19 in the motor chamber 10 of the housing 1.

[0036] In the illustrated embodiment, the plug connection, i.e., the sockets 39 of the plug connection, are provided on the drive unit 9 that comprises the motor 10 for driving the brush roller 5 arranged rotatably in the working chamber 4 as well as starter module 82 (FIG. 13).

[0037] In an independent configuration of the invention (FIGS. 6 through 9), the motor shaft 40 of the drive motor 8 is connected by a coupling 41 to the drive shaft 42 of the belt drive 7 in a torque-transmitting way. The coupling 41 is configured as a claw-type plug coupling and realizes a cardan-type connection because the coupling elements 43 and 44 engage one another with minimal radial and/or axial play. As a result of the configuration of the coupling 41, by means of the cardan-like connection realized by the claw coupling axial tolerances as well as possibly occurring axial displacements between the motor shaft 40 and the drive shaft 42 can be compensated without constructive expenditure.

[0038] The drive shaft 42 is secured by means of a support disk 45 in an intermediate wall or partition 46 of the housing 1 wherein the free end of the drive shaft 42 supports a pulley 47. An endless belt, in particular, in the form of a toothed belt 48, is arranged on the pulley 47 and drives the pulley 49 (FIG. 9) secured on the base member of the brush roller 5.

[0039] In another independent aspect of the present invention, the brush roller 5 is rotatably secured at its ends 50 and 51 by means of a support plate 52, respectively, in the bottom part 3 of the housing 1. As illustrated in FIG. 9, a bearing shaft end 53 of the brush roller 5 engages the bearing opening 54 of the support plate 52. The support plate 52 is inserted into a bearing receptacle 60. The bearing receptacle 60 is configured in cross-section as a box that is opened toward the partition plane 70 (plane where the top cover 2 and the bottom part 3 meet) of the housing 1 and has a substantially rectangular configuration. As illustrated in FIG. 10, the bearing box (receptacle) is open toward the working chamber 4, preferably completely open, so that the receptacle 60 is embodied similar to a rail into which the support plate 52 is to be inserted.

[0040] Advantageously, the bearing plate 52 is a circular disk-shaped plate, in particular, circular plate or circular disk, which is inserted into the receptacle 60 that is open toward the partition plane 70. As illustrated in FIGS. 10 and 12, the wall of the bearing receptacle 60 is delimited by ribs 61 wherein the support plate 52 rests exclusively on the rib surfaces 62. In the gap 63 that is located between two neighboring ribs 62, respectively, the bearing plate 52 is exposed.

[0041] The bearing receptacle 60 is delimited in the working direction 15 by outer wall ribs 64 and 65 that are positioned approximately perpendicularly to the partition plane 70 and extend from the housing sidewall in the direction toward the working chamber 4. The bearing receptacle 60 is open toward the working chamber 4 so that the bearing plate, compare FIG. 12, is secured between the outer ribs 64 and 65 and is supported in the axial direction toward the housing sidewall by the ribs 61. In the direction toward the working chamber 4, the support plate 52 is secured by the brush member of the brush roller 5.

[0042] Preferably, the bottom 67 of the bearing receptacle 60 is defined by means of the bottom ribs 68 having different height and is matched to the circumferential geometry of the support plate 52 so that, as illustrated in FIG. 12, the support plate 52 is supported about its circumference 55 on the end faces 69 of the bottom ribs 68.

[0043] Preferably, the support plate 52 is formed of an elastic material so that dimensional tolerances can be easily compensated by the elasticity of the support plate 52. In this connection, the spacing 66 of the outer ribs 64 and 65 of the bearing receptacle 60 is sized such that it corresponds approximately to the outer diameter 56 of the circular support plate 52. Preferably, the spacing 66 is somewhat smaller than the spacing 56 so that a clamping securing action of the support plate 52 in the bearing receptacle 60 can be obtained.

[0044] FIGS. 13 and 14 show the supply of electrical energy into the housing 1 of the cleaning tool. By means of an electric plug coupling 80, an external supply cable is connected. The plug coupling 80 itself is electrically connected by means of an inner cable 81 to a starter module 82 of the drive unit 9. The cable 81 extends outside of the tubular vacuum connector 11 in a housing section 83 that is positioned above the vacuum channel 84. As illustrated in FIG. 14, the housing section 83 is provided with lateral bearing pins 85 with which the vacuum connector 11 is secured in the bearing forks 86 of the bottom part 3 of the housing 1. The cable 81 is guided from the plug coupling 80 through the housing section 83 and the tubular bearing pins 85 within the pivot axis 87 of the vacuum connector 11 into the motor chamber 10 of the housing 1 and is connected therein to the connector/starter module 82.

[0045] In the illustrated embodiment, the connector module 82 is supplemented by an electronic unit 9 which, for example, by means of an infrared light barrier 91, determines the dirt load of the vacuum flow entering via the vacuum opening 12 and displays the dirt load value by means of corresponding diodes 92 (green, yellow, red) provided in the top cover 2 of the housing 1.

[0046] 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.