Patent Publication Number: US-2010126526-A1

Title: Safety arrangement for a dishwasher

Description:
FIELD OF THE INVENTION 
     The present invention relates to dishwashers and, more particularly, to dishwashers including safety arrangements for determining whether a rack is present in a washing chamber of a dishwasher. 
     BACKGROUND 
     Most dishwashers include a washing chamber into which items may be loaded for washing, usually with detergent and hot water. Often, dishwashers include racks that can be moved out of the washing chamber to facilitate loading of items to be washed and then moved into the chamber for washing. 
     As it is, the dimensions of many washing chambers are such that the chamber is capable of accommodating a small child, and one must be careful to assure that children do not become accidentally trapped within the washing chamber, especially during a wash cycle, which could result in injury to or even death of the child. When a rack is present in the chamber, the rack tends to block access to the chamber. However, there is always a possibility that a small child may remove the lower rack of a dishwasher and enter the resulting empty space within the unit, and therefore be exposed to the hazards associated therewith. 
     SUMMARY 
     In one aspect, a safety arrangement for a dishwasher is provided. The safety arrangement may include a rack sensing component configured to determine whether a rack is in a washing location in a dishwasher and to provide a signal in response thereto. A processing unit may be in communication with the rack sensing component and may be configured to receive the signal. The processing unit may be further configured to prevent a washing procedure of the dishwasher when the signal indicates that the rack is not disposed in the washing location. The dishwasher may include a water inlet valve in communication with the processing unit, and the processing unit may be configured to prevent opening of a water inlet valve when the signal indicates that the rack is not disposed in the washing location. The dishwasher may further include a user interface in communication with the processing unit. The user interface can be configured to provide an indicia of the rack not being disposed in the washing location in response to the signal, and/or may be rendered inoperable by the processing unit when the signal indicates that the rack is not disposed in the washing location. 
     In one embodiment, the rack sensing component may be configured to physically engage the rack when the rack is disposed at the washing location. In such case, the determination as to whether the rack is in the washing location involves the rack sensing component sensing physical engagement with the rack. The rack sensing component may define an incomplete electrical circuit configured to be completed by the rack when the rack is disposed in the washing location, for example, by urging a switch into a closed position to complete the electrical circuit. In another embodiment, the rack sensing component may include a detection device configured to detect the rack and a disposition thereof with respect to the washing location. 
     In another aspect, a dishwasher is provided that includes a washing chamber defining therein a washing location. A rack may be disposed within and selectively removable from the washing chamber. A washing mechanism may be configured to dispense fluid into the washing chamber. The dishwasher may further include a safety arrangement including a rack sensing component and a processing unit in communication with the rack sensing component and the washing mechanism. The rack sensing component may be configured to determine whether the rack is in the washing location and to provide a signal in response thereto. The processing unit may be configured to receive the signal and to prevent a washing procedure of the dishwasher when the signal indicates that the rack is not disposed in the washing location. 
     In yet another aspect, a method of controlling a dishwasher is provided. The method includes determining whether a rack is in a washing location in a dishwasher and providing a signal in response thereto. A washing procedure of the dishwasher may be prevented when the signal indicates that the rack is not disposed in the washing location. 
     In still another aspect, a safety arrangement for a dishwasher is provided. The dishwasher may include a tub portion sealable by a door pivotably engaged therewith, and may include a rack disposed about a lower end of the tub portion and a control device configured to actuate a wash cycle in the dishwasher. The safety arrangement may include an actuation device operably engaged with the dishwasher and configured to interact with the rack. The actuation device may be further configured to be in communication with the control device so as to direct the control device to prevent actuation of the wash cycle in the dishwasher upon the actuation device determining that the rack is not present in the tub portion. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Reference will be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  is a perspective view of a dishwasher configured in accordance with an example embodiment; 
         FIG. 2  is a perspective view of the dishwasher of  FIG. 1  with the door open and the rack removed; 
         FIGS. 3A and 3B  are block diagrams of dishwashers configured in accordance with respective example embodiments, each dishwasher including a safety arrangement and a control device; 
         FIG. 4  is a block diagram of a dishwasher configured in accordance with another example embodiment; 
         FIG. 5  is a perspective schematic view of a washing mechanism for a dishwasher configured in accordance with an example embodiment; 
         FIG. 6A  is a block diagram of a circuit including a safety arrangement configured in accordance with an example embodiment, the safety arrangement including a switch in an open position; 
         FIG. 6B  is a magnified perspective view of the switch of  FIG. 6A ; 
         FIG. 7A  is a block diagram of the circuit of  FIG. 6A  with the switch in a closed position; 
         FIG. 7B  is a magnified perspective view of the switch of  FIG. 7A ; 
         FIG. 8A  is a block diagram of a circuit including a safety arrangement configured in accordance with an example embodiment, the safety arrangement including a pair of contacts; 
         FIG. 8B  is a magnified perspective view of the contacts of  FIG. 8A ; 
         FIG. 9A  is a block diagram of the circuit of  FIG. 8A  with the contacts bridged by a wire of a rack engaged by the safety arrangement; 
         FIG. 9B  is a magnified perspective view of the contacts being bridged by the wire of a rack engaged by the safety arrangement; 
         FIG. 10A  is a side view of a safety arrangement for a dishwasher, the safety arrangement including a switch that is protected by a guard member; 
         FIG. 10B  is a magnified perspective view of the switch and guard member of  FIG. 10A ; 
         FIG. 11A  is a block diagram of a circuit including a safety arrangement configured in accordance with an example embodiment, the safety arrangement including a complete optical link; 
         FIG. 11B  is a perspective view of a dishwasher incorporating the optical link of  FIG. 11A ; 
         FIG. 12A  is a block diagram of the circuit of  FIG. 11A  with the optical link disrupted; and 
         FIG. 12B  is a perspective view of the optical link of  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION 
     The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. 
     Referring to  FIGS. 1 and 2 , therein are shown views of a dishwasher  100  configured in accordance with an example embodiment. The dishwasher  100  includes a washing chamber  102  defining therein a washing location  104 . The washing chamber  102  may include a tub portion  106  sealable by a door  108  pivotably engaged therewith. A rack  110  may be disposed within and selectively removable from the washing chamber  102 . For example, the rack  110  may sit on wheels  112  that roll along the floor  114  of the tub portion  106  and the washing location  104  may be disposed at a lower end portion of the tub portion. The rack  110  may be formed of an array of wire  116  that is configured to allow the rack to hold items while allowing liquids to flow therethrough. The dishwasher  100  may also include a washing mechanism  118  configured to dispense fluid into the washing chamber  102 . For example, the washing mechanism  118  may be coupled to a water supply line  120  and configured to dispense water throughout the washing chamber  102 . 
     The dishwasher  100  may also include a control device  122 , for example, integrated into or otherwise coupled to the door  108 . As discussed further below, a user may utilize the control device  122  to actuate a wash cycle or otherwise initiate and/or control a washing procedure of the dishwasher  100 . When a washing procedure is initiated, the washing mechanism  118  may direct water from the water supply line  120  into the washing chamber  102 . 
     Referring to  FIGS. 1 ,  2 ,  3 A, and  3 B, the control device  122  can include a user interface  124  and a processing unit  126  that communicate therebetween and allow a user to enter commands, such as, for example, initiating a washing procedure to be carried out by the washing mechanism  118 . The dishwasher  100  may also include a safety arrangement  128 , for example, coupled to or integrated with the washing chamber  102 . The safety arrangement  128  may include a rack sensing component  130  configured to determine whether the rack  110  is in the washing location  104  and to provide a signal in response thereto. Non-limiting examples of possible configurations for the rack sensing component  130  are provided below. The rack sensing component  130  may be in communication with a processing unit  132 , which may be configured to receive the signal from the rack sensing component and to prevent the washing procedure of the dishwasher  100  when the signal indicates that the rack  110  is not disposed in the washing location  104 . The safety arrangement  128  may be in communication with the control device  122  (as shown in  FIG. 3A ) or may be in direct communication with the washing mechanism  118  (as shown in  FIG. 3B ). In addition, in some embodiments, the processing unit  126  and the processing unit  132  may be integrated (see  FIG. 4 ). Additionally, in response to the signal from the rack sensing component  130 , indicia of the rack  110  not being disposed in the washing location  104  may be provided via the user interface  124 . 
     Referring to  FIG. 5 , the washing mechanism  118  may include an automatically actuable water inlet valve  134  configured to communicate with one or both of the processing units  126 ,  132 . The processing unit  132  can be configured to prevent opening of the water inlet valve  134  when the rack sensing component  130  provides a signal indicating that the rack  110  is not disposed in the washing location  104 . Alternatively, the processing unit  132  may be configured to inform the control device  122  when the rack sensing component  130  provides a signal indicating that the rack  110  is not disposed in the washing location  104 , such that the control device might prevent opening of the water inlet valve  134 , render the user interface  124  inoperable, and/or prevent power from being transmitted to one or more electrical components of the dishwasher  100 , thereby preventing operation. In either case, a washing procedure may be prevented when the rack  110  is not present to block a child&#39;s access to the washing chamber  102 . 
     Referring to  FIGS. 1 and 3B , the rack sensing component  130  can be configured in any number of ways that facilitates detection of the presence and/or absence of the rack  110  with respect to the washing location  104 . For example, referring to  FIGS. 1 ,  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A, and  9 B, the rack sensing component  130  may be configured to physically engage the rack  110  when the rack is disposed at the washing location  104 , for instance, where the rack sensing component defines an incomplete electrical circuit  138  that is caused to be physically completed by the rack when the rack is disposed in the washing location. 
     Referring to  FIGS. 1 ,  2 ,  6 A,  6 B,  7 A, and  7 B, in one embodiment, the rack sensing component  130  may include an actuation device, such as a switch  140 , capable of being urged into a closed position in order to complete the electrical circuit  138   a . The rack  110  may then act to urge the switch  140  into the closed position (thereby completing the circuit) when the rack is disposed in the washing location  104  (see  FIGS. 7A and 7B ), the switch otherwise being in the open position when the rack is not in the washing location (see  FIGS. 6A and 6B ). As such, when the rack  110  is removed from the washing location  104 , the switch  140  may be in an “open” state, thereby resulting in an open circuit preventing operation of the dishwasher  100 . When the rack  110  is fully inserted into the washing chamber  102  of the dishwasher  100 , the rack (or, a portion of the wire  116  forming the rack) engages the switch  140 , and causes the switch to change to a “closed” state so as to complete a circuit and allow operation of the unit. In some instances, the switch  140  may have a guard member  142  extending at least partially thereabout (see  FIGS. 10A and 10B ). The guard member  142  may be configured to define a minimal opening  144  that allows the wire  116  of the rack  110  to pass therethrough to interact with the switch  140  while preventing access to the switch by a child, such that the child within the dishwasher cannot accidentally interact with the switch to cause a “closed” state. 
     Referring to  FIGS. 1 ,  8 A,  8 B,  9 A, and  9 B, in another embodiment, the rack sensing component  130  may include an electrical circuit  138   b  having two contacts  146  separated by an open area  148 . When the rack  110  is disposed in the washing location  104 , the wire  116  of the rack  110  may act to bridge the open area  148  and complete the circuit  138   b . Completion of the circuit  138   b  would thus enable operation of the dishwasher  100 , the operation otherwise being disabled when the rack  110  is not disposed in the washing location  104 . 
     Referring to  FIGS. 11A ,  11 B,  12 A, and  12 B, as another example, the rack sensing component  130  may include a detection device, such as an optical link  150 , configured to detect the disposition of the rack  110  with respect to the washing location  104 . The optical link  150  may include opposing optical emitter  152  and receiver  154  (e.g., a photoelectric sensor). When the rack  110  is disposed in the washing location  104  (e.g., as in  FIG. 12B ), the rack obstructs the optical path between the emitter  152  and the receiver  154  and the electrical circuit  138   c  is rendered incomplete (as shown in  FIG. 12A ). Otherwise, when the rack  110  is not disposed in the washing location (e.g., as in  FIG. 11B ), the optical link  150  remains completed, such that optical signals emitted by the emitter  152  can be received by the receiver  154 . The control device  122  may thus be appropriately configured with respect to the optical link  150  in communication therewith so as to allow operation of the dishwasher  100  when the rack  110  is disposed in the washing location  104 . Other types of detection devices for detecting the presence of the rack  110  in the washing location  104  may include, for example, capacitive sensors, inductive sensors, ultrasonic sensors, or any other appropriate types of sensors. 
     Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, while the above described embodiments have focused on situations in which a detection device was engaged with the tub portion of the dishwasher and configured to interact with a component of the lower rack, in the alternative, the detection device may be engaged with the lower rack and configured to interact with a component of the tub portion. Further, the rack sensing concept disclosed herein may be extended, in some instances, to any suitable detection device operably engaged with the dishwasher, in or about the lower portion of the washing chamber of a dishwasher, for sensing the presence/absence of the rack and/or proximity of the rack with respect to the dishwasher. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.