Patent Publication Number: US-2010126235-A1

Title: Household appliance having a collecting apparatus for leakage water

Description:
The invention relates to a home appliance for care of laundry items, especially a washing machine or a washer-dryer, with a collection facility for leakage water on the floor of the home appliance and a float arranged in the collection facility which is embodied for electrical contacting of a switch depending on the water level in the collection facility. 
     A home appliance with a corresponding overflow device and a so-called aquastop switch, with which a stop valve in the cold water feed pipe is able to be put into its closed position if a specific volume of leakage water has collected in the collection vessel and float rises in order to trigger this aquastop switch, is known from DE 199 36 420 B4. 
     A problem which can arise with a known generic home appliance is that with relatively low amounts of leakage water, said water can accumulate below the float and can cause the float to stick or to become calcified. The functionality, especially the aquastop function of the float, can be adversely affected by this. 
     The object of the present invention is thus to create a home appliance for care of laundry items from which such impaired functioning is excluded. 
     The object is achieved by a home appliance which has the features claimed in claim  1 . 
     An inventive home appliance is embodied for the care of laundry items and comprises a collection facility for leakage water which is arranged on the floor of the home appliance. In addition the home appliance comprises at least one float which is arranged in the collection facility for leakage water. This float is embodied so that it is embodied for electrically contacting a switch of the home appliance depending on the water level in the collection facility. In particular this switch is switched via a switch circuit so that a stop valve of a cold water feed pipe is able to be moved into its closed position for the home appliance. The float is arranged in a first subarea or of the collection facility with said first subarea being separated from a second subarea of the collection facility by a water-retaining wall. 
     This embodiment allows the collection facility to be subdivided into at least two subareas and the functionality of the float to be improved since sticking or calcification of the float as a result of a relatively small amount of leakage water collecting beneath the float can be prevented in this way. 
     Preferably the water-retaining wall is integrated into the collection facility. The integral embodiment makes simple manufacturing possible, which also allows costs to be reduced. Above and beyond this the integral embodiment of this water-retaining wall in the collection facility also enables a mechanically-stable arrangement to be created. 
     Preferably the home appliance includes a device for catching water running over the top of the device down onto it and for diverting the water into the collection facility. The precise collection and introduction of the water into the collection facility can be guaranteed by this device. Preferably at least parts of this device are embodied from plastic. This enables a relatively light element to be produced which in addition can also be manufactured at low cost. For example the device can be embodied as an injection-molded part. The plastic embodiment also enables a wear-resistant component to be provided since water cannot attack the plastic material. 
     Preferably the device is embodied or arranged so that the water caught can be introduced into the second subarea, especially exclusively into the second subarea of the collection facility. This embodiment makes it possible to ensure that only a relatively small amount of leakage water occurring does not reach the first subarea and thus sticking or calcification of the float is reliably prevented. Only when a larger volume of leakage water has collected in the second subarea and is retained by the water-retaining wall can an overflow into the first subarea then occur. Preferably the water-retaining wall is embodied so that water collected in the second subarea flows away or over this water-retaining wall and reaches the first subarea of the collection facility. This means that only relatively large amounts of leakage water are directed into the first subarea which no longer cause sticking or calcification of the float. 
     In addition this also enables it to be guaranteed that a premature triggering for small amounts of leakage water no longer occurs. 
     The water-retaining wall is preferably curved or at least embodied in the shape of a curve in some areas. 
     It has proved especially advantageous for water-retaining wall to have a height of between 3 mm and 10 mm, especially around 5 mm. The retaining wall preferably has a height which is embodied smaller than a side delimiting wall of the collection facility. This guarantees that initially a specific volume of leakage water is collected in the second subarea and only when this volume is sufficient for a sticking or a calcification to be prevented does it overflow, preferably over the retaining wall, into the first subarea, yet an overflow of the collection facility is still prevented. An escape of collected leakage water from the collection facility can be avoided in this way. Damage to or adverse effects on the function of the home appliance by the overflow of leakage water can also be prevented by this. 
     Preferably the water-retaining wall is essentially the same height over its entire length. This on the one hand enables an even overflow to be guaranteed. There can however also be provision for the water-retaining wall to be a different height over at least part of its overall length. The water-retaining wall can thus be embodied as required and individually depending on the required construction of the home appliance. 
    
    
     
       An exemplary embodiment of the invention is explained in more detail below with reference to the schematic drawing. The figures show: 
         FIG. 1  a perspective view of housing parts of a home appliance; 
         FIG. 2  a perspective part section of a home appliance; 
         FIG. 3  a further perspective part section of a home appliance; and 
         FIG. 4  and  FIG. 5  a cross-sectional view through the part sections according to  FIG. 3  in each case. 
     
    
    
     In the figures the same elements or those with the same function have been labeled with the same reference symbols. 
       FIG. 1  shows parts of a housing of a home appliance for care of laundry items embodied as a washing machine  1 . The washing machine  1  comprises side panels  2  and  3  as well as a floor element  4 . 
     A collection facility  5  for leakage water is embodied in the floor element  4 . As can be seen from  FIG. 1 , the collection facility  5  is embodied by a recess in the floor element  4  and thus forms a type of collecting bowl. The collection facility  5  is delimited by side walls  51 . 
     In addition the collection facility  5  features a water-retaining wall  52  which is integrated into the floor element  4  and thereby also into the collection facility  5 . The water-retaining wall  52  is embodied in the shape of a curve in the exemplary embodiment and adjoins the side wall  51  of the collection facility  5 . The water-retaining wall  52  is embodied as a raised structure and therefore extends upwards. 
     The collection facility  5  is divided by this water-retaining wall  52  into a first subarea  5   a  and a second subarea  5   b.  In the first subarea  5   a  there is furthermore a spherical positioning structure  53  which is embodied to accommodate a float  81 , cf:  FIG. 5 . This float  81  is be placed approximately on this positioning structure  53 , so that the float  81 , depending on the water level in the collection facility  5 , especially in the first subarea  5   a,  can only move vertically upwards and downwards, but is essentially not able to be moved in the horizontal plane. 
       FIG. 2  shows a perspective diagram of a subarea or of the housing of the washing machine  1  shown in  FIG. 1 . A first channel  6  is arranged in the area of the side wall  2  and of the floor element  4  which an exemplary embodiment is embodied from plastic. This first channel  6  is embodied for catching water running from above the channel  6  down into it and for directing the water into the collection facility  5  for leakage water. Leakage water can occur in the washing machine  1  if a fault in the controller and/or a mechanical fault occurs in which parts of the washing machine  1  start to leak. For example leaks can occur in this case in the water feed system or from connections of flexible water hoses to any sort of hard support services on water-conducting containers or from connections of sensors or actuators in the tub or other water conducting contains within the washing machine. 
     In addition bad seals on the housing of the washing machine  1  which above all appear on the front outer side of the relevant washing machine  1  can lead to the escape of leakage water. These types of bad seals can for example occur at rubber hoses which connect the loading opening in the housing of a front-loading washing machine  1  with an opening lying behind it of the swung-suspension tub. Furthermore escape of water from a front wall opening for a detergent dispensing drawer of the washing machine  1  can lead to leakage water. 
     This leakage water dripping or running respectively on to the channel  6  is directed via spout-shaped projections  61  and  62  into a water guidance system which comprises recesses in the floor element  4  to the collection facility  5 . This routing system in floor element  4  is embodied so that the collected water is directed exclusively into the second subarea  5   b  of the collection facility  5 . 
       FIG. 3  shows a perspective diagram of a further part section of the washing machine  1 . This section shows the embodiment at the transition between the side wall  3  and the floor element  4  and thus on the opposite side to the diagram shown in  FIG. 2 . 
     Here too a second channel  7  is arranged, which is also embodied from plastic. The second channel  7  is essentially embodied in the same way as the first channel  6  and includes a spout-type projection  71 . The caught water is likewise directed into the second subarea  5   b  of the collection facility  5  via this projection  71 . 
     In addition a switch  8  is arranged on a pedestal  72  which is also embodied from plastic and which is connected to the channel  7 . This switch  8  enables, after electrical contacting with the float  81  not shown, cf.  FIG. 5 , which is arranged below the pedestal  72 , via a circuit not shown, for a stop valve to be put into its closed position to interrupt the further feed of water from the domestic water supply to the washing machine  1 . This allows the aquastop functionality to be guaranteed. 
     The float  81  arranged below the pedestal  72  is thus located in a first subarea  5   a  of the collection facility  5 . The water-retaining wall  52  prevents leakage water collected in the second subarea  5   b  being able to reach the first subarea even in initially small volumes and reaching the float  81  there, which can cause the latter to stick or calcify with the small volumes of leakage water. The height of this water-retaining wall  52  is around 5 mm and is lower than the height of the side wall  51  of the collection facility  5 . The water-retaining wall  52  is embodied to be essentially the same height over its entire curved length. The leakage water located and collected in the second subarea  5   b  is retained up to the height of this water-retaining wall  52  and can only then overflow over the water-retaining wall  52  and get into the first subarea  5   a.  Through this water-retaining wall  52  which, depending on the mechanical design of the collection facility  5 , can also be embodied as completely circular and represents the delimitation of the first subarea  5   a,  with small volumes of leakage water prevents a constant filling and drying off of the collection facility leading to a calcification or sticking between the float  81  and the floor area of the collection facility  5  and can thus lead to the aquastop functionality not functioning. 
       FIG. 4  and  FIG. 5  show a sectional diagram along the line AA in accordance with  FIG. 3 .  FIG. 4  shows only the pedestal  72 ,  FIG. 5  additionally shows the float  81  positioned below the pedestal  72 . This float is a flat cylinder made of light, especially foam plastic floating on water which sits loosely with a corresponding recess on the positioning structure  53 . 
     A situation is shown in each of these sectional diagrams in which a leakage water W has accumulated in the second subarea  5   b  and has been retained by the water-retaining wall of  52  and is prevented from penetrating into the first subarea  5   a.  The float  81  sitting on the positioning structure  53  is thus protected against small amounts of leakage water getting underneath it, and sticking and calcification can be prevented in this way. If the water rises further it runs over the water-retaining wall  52  into the subarea  5   a  as well, which lifts the float  81  and contacts the switch  8  (cf.  FIG. 3 ) at some point.