Abstract:
A cleaning device has a tank for liquid and a conveying device as well as an outlet opening. A conduit is connected to the tank and to the outlet opening. The conveying device is connected to the conduit and introduces a compressed gas into the conduit so that the cleaning medium exiting from outlet opening is a mixture of the liquid contained in the tank and the compressed gas.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a cleaning device, especially for vehicle parts, such as lights, mirrors, window panes, etc., the device comprising a conveying device with which, via at least one line, a cleaning medium contained in at least one container is supplied to an outlet opening.  
           [0002]    It is known to provide for cleaning soiled headlights a cleaning device which sprays water onto the headlight glass. The water is conveyed via a line by a pump to the outlet spray nozzle which is positioned in front of the headlight. The liquid spray pre-soaks the soiled portion and the soil deposit is then removed by the wiper which is arranged in front of the headlight. The windshield as well as the back window of the vehicle can also be cleaned by such cleaning devices in conjunction with wipers.  
           [0003]    Furthermore, devices are known which apply a cleaning liquid at high pressure onto the surface to be cleaned without carrying out a subsequent wiping step.  
           [0004]    A disadvantage of such cleaning devices is that the vehicle must be provided with a relatively large liquid container which increases the weight of the vehicle. Also this has the disadvantage that for heavy soiling it is not ensured in every situation that the dirt particles are removed in a satisfactory manner.  
           [0005]    It is therefore an object of the present invention to provide a cleaning device of the aforementioned kind that allows removal of dirt present on vehicle parts in a simple, inexpensive, and reliable manner.  
         SUMMARY OF THE INVENTION  
         [0006]    This object is inventively solved for a cleaning device of the aforementioned kind by providing a cleaning medium which is a mixture of a liquid and a compressed gas.  
           [0007]    With the inventive embodiment, the cleaning medium is sprayed at high pressure onto the surface to be cleaned so that the dirt particles under the effect of the compressed gas/liquid mixture are initially pre-soaked and then subsequently removed in a simple manner by the impinging spray. By employing a compressed gas/liquid mixture, the water consumption of the inventive cleaning device is considerably reduced so that less cleaning liquid must be stored in the vehicle. This has the advantage that the weight of the vehicle is reduced and the energy consumption of the vehicle is also lowered. Since the dirt can be relatively easily removed by the mixture applied at high pressure and since the dirt can be completely removed, the proper function of the vehicle parts to be cleaned can be simply and completely restored in a very short period of time. This ensures high safety of the vehicle in traffic because the surface to be cleaned regains quickly its full functionality. For example, optical systems, lights, such as headlights or taillights, can be easily cleaned so that the vehicle in traffic can be easily detected at any point in time. The inventive cleaning device is also suitable for cleaning mirrors, window panes, and other vehicle parts. Since the inventive cleaning device requires less liquid for the cleaning action then conventional cleaning devices, it is also possible to use relatively thin supply lines which is also beneficial with regards to cost savings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0008]    The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying only drawing showing the inventive cleaning device in a schematic representation.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0009]    The present invention will now be described in detail with the aid of a specific embodiment utilizing the only FIGURE.  
         [0010]    The drawing shows a liquid tank  1  into which a line  2  projects. The line  2  accommodates a shut-off valve  3 , preferably, a check valve, that closes toward the liquid tank  1 . The line  2  is connected to an arm  4  of a housing  5  in an area outside the tank  1 . For conveying the liquid from the tank  1  to the spray nozzle  10 , a conveying device  6  is provided which is a compressor. It contains also an intermediate pressure container  7  and is connected to a further arm  8  of the housing  5 . A line  9  provides a connection from the housing  5  to the spray nozzle  10  (outlet opening) via which the cleaning medium  11  is dispensed. Thus, the line  2 , the housing  5 , and the line  9  form a conduit for the liquid.  
         [0011]    The compressor  6  produces compressed air which is stored in the intermediate pressure or storage container  7 . By actuating the valve  12 , the intermediate pressure or storage container  7  and the shut-off valve  3  are opened so that compressed air can flow in the direction of arrow  13  through the arms  8  and  9  to the spray nozzle  10 . The high flow velocity of the compressed air produces vacuum in the housing  5  by which the liquid is sucked in from the tank  1  according to the venturi principle and is mixed with the compressed air. The resulting compressed gas/liquid mixture  11  exits from the nozzle  10  and impinges at high pressure onto the surface to be cleaned. The surface may be the glass of a headlight, a mirror, a window pane, or an optical system etc. of the vehicle. In addition, wipers can be arranged in front of the respective vehicle part to enhance the cleaning action. The gas/water mixture impinges on the dirt particles of the surface to be cleaned so that they are pre-soaked and then removed. Subsequently, by closing the shut-off valve  3 , the liquid supply can be interrupted so that only compressed air will impinge on the surface to be cleaned. This results in drying of the cleaned surface.  
         [0012]    It is also possible to supply the gas/water mixture in a pulsating manner onto the surface to be cleaned. This improves removal of dirt particles that adhere strongly to the surface.  
         [0013]    The cleaning device can also be embodied such that the compressor  6  is connected to the liquid tank  1 , respectively, the line or hose  2  so that water is forced under high pressure into the housing  5 . In this case, the venturi effect results in a vacuum sucking in air which is then mixed with the pressurized water to the gas/water mixture  11 .  
         [0014]    The cleaning process can be started automatically or manually. For example, behind the glass of the vehicle headlight sensors may be arranged which determine the degree of soiling of the glass and produce a signal upon surpassing a pre-set soiling limit that results in activation of the cleaning device. Instead of this automatic actuating device, it is also possible to provide a switch at the dash board of the vehicle with which the cleaning device can be manually operated.  
         [0015]    After the vehicle part has been cleaned in the afore described manner, it can now fulfill its designated function, for example, a taillight can now again produce the required light output. This increases the safety of the vehicle in traffic because the vehicle, even under most unfavorable weather conditions, can be detected within the shortest amount of time, after actuation of the cleaning device, by other traffic participants, and the driver will have unimpaired vision in a very short period of time by having the windshield or lights cleaned.  
         [0016]    Since the disclosed cleaning device operates with a relatively minimal amount of liquid, respectively, water, the weight of the vehicle and thus the required energy for operating the vehicle is considerably reduced. The cleaning effect of the disclosed cleaning device can be further improved when the surface to be cleaned has a coating that improves beading of the cleaning liquid.  
         [0017]    The specification incorporates by reference the disclosure of priority document DE 198 35 733.8 of Aug. 7, 1998.  
         [0018]    The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.