Patent Publication Number: US-6666219-B2

Title: Fast interrupt of dishwasher hand sensor

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a method and apparatus for a dishwasher. More specifically, this invention relates to a dishwasher having a sensor that provides for the interrupt or shut off of the dishwasher prior to opening. 
     Dishwashers have conventionally been designed with electrical mechanical latch and switch mechanisms that disconnect power to the dishwasher when the latch is open, but before the dishwasher door is swung open. This configuration allows power to be interrupted to the dishwasher in order to prevent hot water from being sprayed out onto the user and/or the surrounding areas. 
     It is desirable to use a simpler and alternative means to open a dishwasher. For example, such a dishwasher can include a magnetic or simple pole-latch that allows the dishwasher door to be opened more immediately and more conveniently. One problem with using a magnetic or simple pole-latch to open a dishwasher door is that if the door opens immediately, then the dishwashing machine does not shut off in time to prevent hot water from being sprayed out onto a user potentially causing injury or water damage to the flooring and/or surrounding area. 
     A further problem involves dishwashing machines, such as drawer-type dishwashing machines, that have inflatable seals. If these inflatable seals are engaged while a dishwasher drawer is pulled open, then these inflatable seals can be damaged. Therefore, although it is desirable to create a dishwasher that can be easily and immediately opened, problems remain. 
     Thus, it is a primary object of the present invention to provide a method and apparatus for a dishwasher that improves over the state of the art. 
     It is a further object of the present invention to provide a dishwasher capable of automatically interrupting operation of dishwasher components prior to being opened. 
     Yet another object of the present invention is to provide a method and apparatus for a dishwasher that prevents hot water from being sprayed out of the dishwasher when the dishwasher is opened. 
     A further object of the present invention is to provide a method and apparatus for a dishwasher that allows the dishwasher to be easily and conveniently opened. 
     These and other objects, features, or advantages of the present invention will become apparent from the specification and claims that follow. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a method and apparatus for a dishwasher that includes a sensor for sensing that a user intends to open the dishwasher prior to the user opening the dishwasher. The dishwasher has an openable cabinet and a washing compartment disposed within the openable cabinet. A handle is attached to the openable cabinet for opening the cabinet and providing access to the washing compartment. A sensor is in operative communication with the handle such that when a user grasps the handle, the sensor senses the user prior to opening the cabinet. Once the sensor senses the user, a pump and/or sprayer, an inflatable seal, or other dishwashing component can be interrupted or shut off. Thus, a dishwashing component can be interrupted or shut off prior to the dishwasher cabinet being opened. 
     According to one method, the present invention provides for access to a washing compartment disposed within an openable cabinet of a dishwasher. The method includes sensing that a user intends to access the washing compartment and interrupting one or more functions of the dishwasher after sensing that a user intends to access the washing compartment. The step of sensing can include sensing that the user has broken a light curtain or beam of light or sensing that the user has touched a handle of the dishwasher. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view showing the cabinet in an open position providing access to the washing compartment. 
     FIG. 2 is a pictorial representation of a user opening the dishwasher of the present invention. 
     FIG. 3 is a front view of a handle with a sensor according to the present invention. 
     FIG. 4 is a block diagram showing the electrical control of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a dishwasher  10 . The dishwasher  10  includes an openable cabinet  12 . A washing compartment  14  is disposed within the openable cabinet  12 . The openable cabinet  12  also includes a door  16  for opening the cabinet  12  and providing access to the washing compartment  14 . The present invention contemplates that instead of a door  16 , the openable cabinet  12  can be otherwise opened. For example, the dishwasher  10  may be of a drawer type such that the cabinet  12  is opened by opening a drawer. The door  16  shown includes a bottom edge  18  and side edges  20  and  22 . In addition, the dishwasher  10  includes a handle  24 . The handle  24  can be integral with the door  16 , embedded within the door  16 , or of other construction. The door  16  can be secured with a magnetic or simple pull-latch (not shown) such that the dishwasher door  16  is easily and conveniently opened. 
     Within the washing compartment  14 , a rack  26  is shown for holding items to be washed. A central spray tower  28  is shown. The central spray tower  28  or other sprayer is used for spraying water. In addition, within the washing compartment  14  are upper washing arms  30  and lower washing arms  34 . The rack  26  is mounted on rollers  32  so that the rack  26  can be extended for loading and unloading. The particular configuration of the dishwasher  10  shown is merely one configuration, the present invention contemplates that other configurations may be used. 
     FIG. 2 shows a pictorial representation of a hand of a user opening a door  16  or drawer of the dishwasher  10 . As shown in FIG. 2, the door  16  has a handle recess  36 . A sensor such as the touch sensitive sensor  40  shown is operatively attached to the handle  24  so that when a user makes contact with the touch sensitive sensor  40 , operation of the dishwasher  10  is interrupted. Because the user must touch the handle  24  and thus the touch sensitive sensor  40  in order to open the door  16 , the touch sensitive sensor  40  senses the presence and intention of the user to open the door  16  prior to the door  16  being opened. 
     Another embodiment of the present invention is shown in FIG.  3 . In FIG. 3, the recess  36  includes an unexposed portion  38  behind the handle  24 . The user reaches into the recess  36  in order to grasp the handle  24 . A light beam or curtain  46  is created through use of a light emitter  42 . A light receiver  44  is placed opposite the light emitter  42  so that light  46  emitted by the emitter  42  is received by the receiver  44  when the light beam or curtain  46  is unobstructed. A user accesses the washing compartment  14  of the dishwasher  10  by using the handle  24  to open the door  16 , thus interrupts the reception of the light  46  in the process of opening the door  16 . 
     The present invention contemplates variations in the type of sensor used. The sensor can be a touch sensitive sensor  40 , can include a light emitter  42  and light receiver  44 , can include an infrared light emitter and an infrared light receiver or other variations such that the user&#39;s intention to open the door  16  or drawer is determined prior to the user&#39;s opening of the door  16  or drawer. 
     FIG. 4 shows a block diagram of the electronic control of the present invention. As shown in FIG. 4, the sensor  48  is electrically connected to a control circuit  50 . The control circuit  50  is operatively connected to a pump/sprayer  52  and an inflatable seal  54 . The pump is fluidly connected to the sprayer and the sprayer is disposed within the washing compartment (see FIG.  1 ). Thus, as shown, the pump and/or sprayer  52  is operatively connected to the sensor  48  so that when a user grasps the handle  24  (see FIGS.  1 - 3 ), the sensor  48  engages to interrupt operation of the pump and/or sprayer  52 . The pump/sprayer  52  and inflatable seal  54  are merely examples of dishwasher components that can be controlled by the control circuit  50 . The present invention contemplates that other dishwashing components can be similarly controlled. According to the present invention, once the sensor  48  senses the user&#39;s intention to open the door  16 , the operation of the pump/sprayer  52 , the inflatable seal  54  or other dishwasher components is interrupted. For example, a pump/sprayer  52  can be simply turned off. This prevents water from being sprayed out onto the user and surrounding areas when the dishwasher door  16  or drawer is opened. An inflatable seal  54  is deflated such as through release of a valve or other means. The control circuit  50  can be an analog circuit such as a circuit including a relay, opto-isolator or other control circuit for disconnecting power or otherwise interrupting operation of dishwasher components. The control circuit  50  can also include a controller, microcontroller, processor, or other intelligent control. Similarly the control circuit  50  can include an integrated circuit or a portion of an integrated circuit. The specific implementation of the control circuit varies according to the environment or specific application. 
     Thus, a method and apparatus for a dishwasher has been disclosed. The invention provides for variations in the type of sensor used, the configuration of the dishwasher, the manner in which the dishwasher is opened, the dishwasher components that are interrupted, the manner in which dishwasher components are interrupted, and other variations within the spirit and scope of the invention.