Abstract:
An automatic warewashing machine includes a washing chamber, a hinged door configured to close the washing chamber, and a force-locking latching mechanism configured to hold the door in a closed position and release the door in response to a pulling force. The force-locking latching mechanism is disposed on the washing chamber or on a body enclosing the washing chamber. A door opening system is also included and has a push-open unit configured to automatically open the door to at least an ajar position. The push-open unit includes a motor-driven push-type opening bar.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German Patent Application No. DE 10 2010 016 918.8, filed on May 12, 2010 and European Patent Application No. EP 10 401 128.3, filed on Aug. 3, 2010, both of which are hereby incorporated by reference herein in their entireties. 
     FIELD 
     The present invention relates to an automatic warewashing machine with a door that can be held in the closed position by a force-locking or force- and form-locking latching mechanism. 
     BACKGROUND 
     In automatic warewashing machines having a force-locking or force- and form-locking door lock which is disposed on the washing chamber side and may also be referred to as “pull-type release lock”, it is desirable to provide a unit which allows the door to be automatically opened by a few centimeters, either by the automatic warewashing machine in a cycle-dependent manner or by the user. Cycle-dependent opening is generally performed shortly before the end of the cycle to assist in the drying process. An automatic door opening system should always be made available to the user when there is no handle that would allow the user to pull the door open. This is the case, for example, in handle-free, fully integratable appliances. 
     A dishwasher having an automatic door-opening system is described, for example, in DE 10 2005 028 449 A1. In this appliance, the latching mechanism is mounted on the door and adapted to engage with a latch keeper secured on the washing chamber. In order to allow the door to be automatically opened to an ajar position in a program-controlled manner, the latch keeper is mounted to a closing plate which is movable by a motor. Upon receipt of a signal from the appliance controller, the motor extends the closing plate, and thus the latch keeper. In this manner, the door is opened to an ajar position, but kept in a latched state. In order to open the door, a handle is pulled up, thereby rotating a latching member to a position where it is no longer held by the latch keeper. 
     In document WO 2009/146 874 A1, too, the latch keeper mounted on the washing chamber is moved by a driving mechanism to open the door to an ajar position. Here, the driving mechanism is implemented as a spring which is tensioned as the door is opened further. 
     The aforementioned automatic door opening devices can only be used in automatic warewashing machines where the latching mechanism is mounted in the door and the latch keeper is disposed on the washing chamber or housing of the machine. This results in disadvantages. 
     For example, displays or controls cannot be mounted in the middle of the door, and the space actually available for such components is limited. It is necessary to use printed circuit boards which have cutouts for the latching mechanism and, therefore, are expensive to manufacture. In addition, in the case of door-mounted latching mechanisms, the door must have a cutout, which may lead to ingress of moisture and damage to the electronics. 
     U.S. Pat. No. 4,951,693 also describes a dishwasher having an automatic opening system. Here, a spring mechanism becomes loaded as the door is closed, and the door is latched in the closed position. Upon release of the latch by a solenoid, the spring mechanism automatically opens the door. Additional springs hold the door in a partially open position. 
     A spring mechanism for opening the door to an ajar position is also used in a dishwasher as described in EP 2 210 547 A1, where a pull-type release lock is used as the latching mechanism. 
     During operation, the washing chamber of automatic warewashing machines should be closed liquid-tight. To this end, the access opening of the washing chamber is surrounded by a seal against which the door presses. The latching mechanism must be capable of counteracting the force with which the seal presses against the door in the opening direction. If the latching mechanism is suddenly released, such as in U.S. Pat. No. 4,951,693 A, or is overcome by spring force (see EP 2 210 547 A1), then a sudden acceleration occurs. Door springs are provided to counteract this acceleration. However, such door springs may be misadjusted or may even break. In such case, the door drops down from the closed position to the horizontal and may injure persons as it drops. Small children present in the pivoting range of the door might even be struck dead. 
     German Patent Application No. DE 10 2008 058 257 A1 describes an automatic washing machine where the latching mechanism is mounted in the door. This automatic washing machine is also provided with a system for automatically opening the door to an ajar position. In this system, part of the latching mechanism is moved out of the body of the machine by a motor. The door remains latched until a release device is actuated. 
     DE 20 2007 006 818 U1, WO 2009/106 292 A1, EP 1 935 313 A1, which are incorporated by reference herein in their entireties, describe appliance doors openable by knocking on a decorative front panel of the door. 
     SUMMARY 
     In an embodiment, the present invention provides an automatic warewashing machine including a washing chamber, a hinged door configured to close the washing chamber, and a force-locking latching mechanism configured to hold the door in a closed position and release the door in response to a pulling force. The force-locking latching mechanism is disposed on the washing chamber or on a body enclosing the washing chamber. A door opening system is also included and has a push-open unit configured to automatically open the door to at least an ajar position. The push-open unit includes a motor-driven push-type opening bar. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention are described in more detail below and are schematically shown in the drawings, in which: 
         FIG. 1  is a perspective view of a dishwasher, shown with the appliance door in an ajar position; 
         FIG. 2  is an enlarged view showing a detail of  FIG. 1 ; 
         FIG. 3  is a detailed top view of a push-open unit, shown with a housing cover removed; 
         FIG. 4  is an exploded view showing structural details of the push-open unit; 
         FIG. 5  is a perspective view showing the underside of a push-type opening bar; 
         FIG. 6  is a plan view showing the underside of the push-type opening bar; 
         FIG. 7  is a view of the underside of the push-type opening bar, showing various points along the guide track which are indicative of discrete states; 
         FIG. 8  is a view of an alternative embodiment of a freewheel; and 
         FIG. 9  is a detail view of the inner sleeve of the freewheel shown in  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     In an embodiment, the present invention provides an automatic warewashing machine which overcomes the aforedescribed disadvantages and has an opening system that is simple in design and easy and safe to operate. 
     Automatic slow opening is made possible by mounting the latching mechanism on the washing chamber or on the body and providing the push-open unit with a motor-driven push-type opening bar. In this manner, the acceleration of the door during opening is kept low. 
     In order to provide even greater protection against excessively rapid opening of the door, the door may be retainable on the push-type opening bar by a magnetic coupling. 
     Furthermore, in an embodiment, the push-open unit of the present invention allows the appliance door opening to be opened at different speeds. This is advantageous in particular in the variant of a handle-free, fully integrated dishwasher. The appliance door should be opened quickly, for example, when a request for opening the door is made by knocking on the decorative front panel of the appliance door. In contrast, at the end of a cycle, the door may be opened relatively slowly. In this manner, the drying of the items washed is significantly improved (see U.S. Pat. No. 5,901,746 A, which is incorporated by reference herein in its entirety). This variation in the opening speed is made possible by the motor drive of the push-type opening bar, for which different motor variants can be used. Conveniently, a double-coil synchronous motor is used in the case of conventional dishwashers, while in the case of fully integratable dishwashers, an extra low voltage DC motor is used. As for the positioning of the motor, it is advantageous if the axis of rotation of the motor shaft extends parallel to the direction of movement of the push-type opening bar. In automatic warewashing machines of conventional design, sufficient space for accommodating a motor is available only laterally between the washing tub and the housing wall. Therefore, in particular elongated motors are preferably only be mounted in the aforesaid position. 
     Another advantage of embodiments of the present invention resides in the space gained on the door, which allows a deeper handle recess to be formed thereon. Besides, one locks design can be used both for appliances having an exposed control panel and for fully integrated variants. Moreover, there is no need to modify the structure of the latching mechanism for automatic warewashing machines that are not equipped with an automatic opening system. A latching mechanism having a simple design includes a resiliently mounted roller which engages with a lock catch  22  provided on the door. Further structural advantages result from the fact that the latching mechanism and the push-open unit are two independent assemblies which, therefore, can be installed and inspected independently of each other. It is also advantageous if the latching mechanism is arranged in a corner formed by the push-type opening bar and a driving shaft acting upon the push-type opening bar. In this manner, a space-saving design is achieved. The push-type opening bar and the driving shaft may be disposed in an angled housing. 
       FIG. 1  shows, in a perspective view, a dishwasher  1  with an appliance door  2  in an ajar position, while  FIG. 2  shows an enlarged portion of  FIG. 1 . In these figures, the cover of dishwasher  1  is removed to show the components of the present invention located therebelow. Door  2  closes front opening  12  of a washing chamber  10 . A latching mechanism centrally disposed on the washing chamber side and hereinafter referred to as door lock  3  holds door  2  in the closed position. Dishwasher  1  further has an automatic opening system, hereinafter referred to as push-open unit  5 . Door lock  3  is equipped with a resiliently supported roller  30  which engages behind a lock catch which is located opposite on the door and takes the form of a projection  22 . Push-open unit  5  is disposed adjacent and to the left of door lock  3  on the washing chamber side in an angular space defined by housing parts  500  and  502 , which are described elsewhere herein. The push-open unit may also be mounted on the right-hand side. Mounting push-open unit  5  on the right-hand side is advantageous in the case of narrow dishwashers  1 . 
     Advantageously, door lock  3  is disposed centrally in a U-shaped strengthening channel  14  of washing chamber  10  of dishwasher  1 . Push-open unit  5  and door lock  3  are not connected to each other and, therefore, constitute two independent assemblies, which also simplifies the development of design variants. For example, push-open unit  5  can also be used in dishwashers  1  having a force-locking door lock  3  provided on the door. Further, door lock  3  may also be used without a push-open unit  5  if required, for example, in inexpensive dishwashers  1 . If the aforementioned advantages provided by the separate design of door lock  3  and push-open unit  5  are not considered essential, these two assemblies may also be combined into one unit. 
       FIG. 2  illustrates further structural details of embodiments of the present invention. For example, push-open unit  5  includes a push-type opening bar  504  which is mainly moved by motor  506 , which is mounted laterally between dishwasher side wall  16  and the radial transition from the cover to the side wall of the washing chamber. Preferably, the axis of rotation of the shaft (indicated in  FIG. 3  by a dot-dash line  508 ) of motor  506  extends parallel to the direction of movement of push-type opening bar  504 . This advantageously allows different types of driving mechanisms (synchronous motor, DC motor) to be used in push-open unit  5 . DC motors, in particular, are relatively long compared to their diameter. Here, it is only the above-described parallel mounting position within dishwasher  1  that provides a sufficient degree of freedom for installation. Moreover, this mounting position makes it possible to develop design variants. It is primarily the above-described design variant of a handle-free, fully integrated dishwasher  1  that takes advantage of a DC motor to achieve a rapid opening movement. Normally; i.e., when the purpose is to automatically open appliance door  2  in order to assist in the drying process, motor  506  is designed as a double-coil synchronous motor. Since such a motor operates at a low speed of about 250 or 500 rpm, appliance door  2  is opened relatively slowly in about 15 to 20 seconds, provided the transmission is suitably designed for this purpose. The advantages of such synchronous motors are that they feature very low operating noise levels, are inexpensive, and allow AC mains powered operation, which permits relatively easy control by the electronic cycle control. If there is a requirement for a higher door opening speed, such as, for example, to open the door of a handle-free, fully integrated dishwasher  1  toward a user, it is preferred to use an extra low voltage DC motor in place of the double-coil synchronous motor. At typical speeds of 2500 to 5000 rpm, the dishwasher door is then opened in 1.5 to 2 seconds. Preferably, the driving mechanism is designed such that push-open unit  5  can be operated with both a double-coil synchronous motor and an extra low voltage DC motor using the same transmission stages  510  (shown in  FIG. 3 ) and without requiring any modifications. 
     Further details of push-open unit  5  are shown in the top view of  FIG. 3 , in which housing cover  502  is removed. 
     The torque of motor  506  is transmitted to push-type opening bar  504  by transmission stages  510  and a shaft  512  disposed at a right angle relative to motor shaft  508  and to the direction of movement of push-type opening bar  504 . Transmission stages  510 , on the one hand, perform a gear reduction function; i.e., a speed-reducing function, and, on the other hand, they deflect the axis of rotation at an angle of 90° by means of a bevel gear or worm gear stage. At its left end; i.e., at its motor end, shaft  512  is supported directly in lower housing part  500 . At its right end; i.e., at the opening bar end, shaft  512  is supported in lower housing part  500  via end shield  514 . In  FIG. 4 , reference numeral  516  denotes the end of shaft  512  that is rotatably received in end shield  514 . Push-type opening bar  504  and shaft  512  form two right angles  518  and  520 , which are also present in housing parts  500  and  502 . This is where door lock  3  is located. 
       FIG. 4  illustrates further structural details of embodiments of the present invention in an exploded view. 
     Shaft  512  has mounted thereon a freewheel  522  ( FIG. 3 ), which is formed by an inner sleeve  524 , an outer sleeve  526 , and a movable slide member  528  ( FIG. 4 ). Inner sleeve  524  is non-rotatably connected to shaft  512  and has a helical groove  530  on its surface, which moves slide member  528  during relative motion (rotation) between shaft  512  and outer sleeve  526 . Helical groove  530  is bounded by a left stop  532  and a right stop  534  (as seen from a position in front of the appliance). Outer sleeve  526  concentrically surrounds shaft  512  and, consequently, is rotatably supported thereon. The outer sleeve has two guide grooves  536  arranged parallel to the shaft and adapted to receive guide ribs  538  of slide member  528 . Due to the aforedescribed arrangement, slide member  528  reciprocates between the two stops  532  and  534  depending on the direction of rotation of shaft  512  and outer sleeve  526 . In this manner, a freewheel  522  is created between shaft  512  and outer sleeve  526 , since the rotation of shaft  512 , respectively of inner sleeve  524 , is not transmitted to outer sleeve  526  while the slide member moves. The number of freewheeling revolutions can be varied by the length of helical groove  530 . Transmission of rotational movement from shaft  512  to outer sleeve  526  does not take place until slide member  528  reaches left stop  532  or right stop  534  (depending on the direction of rotation). 
     A double pinion  542  is mounted on an extension  540  of outer sleeve  526  ( FIG. 4 ) and meshes with lateral toothed tracks  544  formed on the underside of push-type opening bar  504  (see  FIGS. 5 through 7 ). Double pinion  542  is driven by outer sleeve  526  of freewheel  522  via meshing facial toothings  546 . Facial toothings  546  are pressed together by a compression spring  548  via a drive dog  550  and double pinion  542 . In this manner, a mechanical safety coupling; i.e., a slip coupling, is created. The torque transmittable by the slip coupling can be adjusted via the helix angle of facial toothings  546  and the force of compression spring  548 . A torsion spring  552  is mounted on a spring sleeve  554  concentrically around compression spring  548  between end shield  514  and drive dog  550 . The function of this torsion spring will be explained later herein. 
     Double pinion  542  drives push-type opening bar  504  which, in order to open appliance door  2 , presses into the rabbet of inner door panel  20 , releasing roller  30  of door lock  3  from lock catch  22 . The underside of push-type opening bar  504  has a guide track  556  formed between lateral toothed tracks  544 . Guide track  556  is engaged by a locking pin  558  formed on an anchor member  560  (see  FIG. 4  in conjunction with  FIG. 5 ). Anchor member  560  is pivotally mounted in a receiving formation  562  in lower housing part  500  and has two functions. First, it retains push-type opening bar  504  in particular positions via locking pin  558  (in this regard, see the description of  FIG. 7  in section “Sequence of Operation”). Second, it actuates a microswitch  570  via an arm  564  when push-type opening bar  504  has moved to its end position in housing ( 500 ,  502 ). Microswitch  570  is polled by a controller of dishwasher  1 . Preferably, if motor  506  is a synchronous motor or a double-coil synchronous motor, all further positions of push-type opening bar  504  that are different from its rear end position are approached in a time-controlled manner. Alternatively, in particular if motor  506  is an extra low voltage DC motor, all further positions of push-type opening bar  504  that are different from its rear end position can be sensed by one or more additional microswitches. 
     All other functions provided by the interaction of locking pin  558  with guide track  556  on the underside of push-type opening bar  504  are also described below. 
     Appliance door  2  is opened by about 100 mm as push-type opening bar  504  is moved out. Door  2  is magnetically held in this state. To this end, a ferromagnetic metal insert  566  is attached to push-type opening bar  504 , and a magnet  24  is disposed at a corresponding position behind the inner door panel so as to cooperate with one another. During automatic opening of appliance door  2 , the magnetic holding means ensure that the door is retained in the event it has a tendency to open by itself. This may be necessary, for example, if the door springs are set too weak or are broken. Once the ajar position is reached during automatic opening, the user can fully open the door for unloading and loading of dishware. After the magnetic holding means are separated, push-type opening bar  504  should in any case be returned to the retracted position, even if the user has already turned off dishwasher  1 , disconnecting it from the mains power supply. Otherwise there would be a risk of getting injured by the extended push-type opening bar  504  or of damaging the same. In addition, the extended push-type opening bar would hinder the unloading and unloading of dishware. 
     In order to achieve this, torsion spring  552  located on spring sleeve  554  is tensioned as push-type opening bar  504  is moved out; i.e., during the automatic opening of the door. To this end, spring  552  is secured at its two ends in receptacles on drive dog  550  and end shield  514 . As appliance door  2  is fully opened by the user, the aforedescribed magnetic holding means cause push-type opening bar  504  to be pulled out up to a front limit stop. Then, push-type opening bar  504  detaches from door  2  and is retracted by torsion spring  552 . This also works when dishwasher  1  is off, which makes it possible to avoid standby consumption, which would be required in alternative, electric motor based approaches for the then required control electronics. Spring sleeve  554  allows compression spring  548  and torsion spring  552  to be arranged on shaft  512  in a space-saving manner and concentrically within one another; i.e., concentrically one over the other. End shield  514 , which is rotatably disposed in lower housing part  500 , serves to support shaft  512  and to adjust the bias of torsion spring  552 . 
     Push-type opening bar  504  is provided with a resilient stop to allow easy opening of the door by the user during periods when no washing operation takes place, such as in a situation where the washed dishes have been unloaded and new items to be washed need to be loaded. This is achieved by means of a stop spring  572 . The two legs  574  and  576  of stop spring  572  are biasingly clamped between two bearing blocks  578  and  580 . Front leg  574  can be pressed by about 15 mm rearward by stop  582  of push-type opening bar  504 . When the user closes the door, stop  582  of push-type opening bar  504  first contacts front leg  574 , and the lock is at the changeover point. In the further sequence of movements, the user pushes the door by about another 5 mm rearward, and roller  30  of door lock  3  drops behind lock catch  22 . When appliance door  2  is closed, the so-biased push-type opening bar  504  presses with a force of, for example, 25 N from behind against the door, so that the spring force of push-type opening bar  504  counteracts the closure force of door lock  3 , which is 40 N, for example. In this example, the resulting reduced closure force of door lock  3  would be 15 N. Thus, the user can open appliance door  2  particularly easily. When the wash cycle is initiated, the driving mechanism presses push-type opening bar  504  by another 10 mm to the rear end position against the force of stop spring  572 , so that it no longer contacts the door. Now, the full closure force of 40 N is exerted by door lock  3  on door  2 , which is the force required to ensure tightness of the door seal, so that now the washing operation can be started. 
     A description of the automatic opening sequence and the subsequent closing operation will be given with reference to  FIG. 7 . Table 1 below gives a brief overview of this sequence of operation.  FIG. 7  is a view of the underside of push-type opening bar  504 , showing the positions of locking pin  558  within guide track  556 . The points denoted by position characters indicate states, while the arrows denoted by position characters indicate transitions between two states. Locking pin  558  is guided in upper guide slot  584 , middle guide slot  586  or in lower guide slot  590 . 
     During the washing operation, door  2  is closed; push-type opening bar  504  has been retracted to its end position by the driving mechanism formed by motor  506  and transmission stage  510 . There is no contact between door  2  and bar  504 . The driving mechanism is at rest; freewheel  522  is located at left stop  532 . Locking pin  558  is in position A, and arm  564  of anchor member  560  actuates microswitch  570 . To initiate the automatic opening, the driving mechanism is activated, causing push-type opening bar  504  to be released. In this process, stop spring  572  pushes push-type opening bar  504  out of housing  500  and  502 . Arm  564  clears microswitch  570 , and locking pin  558  moves via B to C. In position C, push-type opening bar  504  has moved out 15 mm, which corresponds to the travel of spring  572 . Opening bar  504  initially remains in this position, while freewheel  522  is traversed from left stop  532  to right stop  534 . Once right stop  534  is reached, double pinion  542  moves opening bar  504  further in the forward direction; locking pin  558  moves via position D to position E, changing from upper guide slot  584  to middle guide slot  586  in the process. When arrived there, the driving mechanism is reversed and freewheel  522  is traversed from right stop  534  back to left stop  532 . Once the entire path through freewheel  522  is traversed, the driving mechanism is stopped. Depending on the adjustment of the door springs, door  2  remains in its position, is slightly pulled back by tensioned torsion spring  552  via opening bar  504 , or opens a little further by itself. Accordingly, locking pin  558  either remains in position E, moves to position E. 1  (if door  2  is pulled back), or moves to position E. 2  (if door  2  opens a little further by itself). Middle guide slot  586  has a bevel  588  at point E. 1 . When the user presses door  2  closed when in the automatically opened position with push-type opening bar  504  in the extended position, locking pin  558  moves up this bevel as push-type opening bar  504  is pushed in, and then moves through path F. 1  to position G. Because anchor member  560  is freely supported in the region of locking pin  558 , it allows for the lifting of locking pin  558  on the higher, middle guide slot. As path F. 1  is traversed, the torsion spring relaxes, and freewheel  522  is traversed from left stop  532  to right stop  534 . Normally, the user will pull the door further open after the automatic opening operation is completed. In this process, push-type opening bar  504  is initially pulled further out by the magnetic coupling until the locking pin reaches point E. 2 . Then, the magnetic coupling is disconnected. Tensioned torsion spring  552  then pulls opening bar  504  back into housing  5 , in which process the locking pin moves, via F, from middle guide slot  586  to lower guide slot  590  and to G, where it is held. As opening bar  504  retracts, freewheel  522  is traversed from left stop  532  to right stop  534 . Position G in the middle guide slot is configured as a receptacle in which locking pin  558  is held. Because of this, upon manual opening of the closed door, push-type opening bar  504  is held in this position and prevented from also moving out. Once a new wash cycle is initiated, opening bar  504  is fully retracted again, and locking pin  558  moves via H onto upper guide slot  584  and back to position A. In this process, the freewheel is traversed from right stop  534  to left stop  532 . 
       FIGS. 8 and 9  show an alternative embodiment of a freewheel  622 . In contrast to the aforedescribed variant, this variant provides protection against the following failure: 
     Door  2  is pulled down to the horizontal position by its own weight already when in a slightly open state. The weight of door  2  is counteracted by conventional door springs. However, when one or even both door springs are broken, the weight is not or not sufficiently balanced anymore. In this case, door  2  is initially held by torsion spring  552  as push-type opening bar  504  moves out. When at a certain opening angle, the weight of door  2  exceeds the retaining force of spring  552 , the door accelerates its dropping motion. In the first variant of freewheel  522 , the freewheel is traversed from right stop  534  to left stop  532  in this process, and push-type opening bar  504  is fully pulled out up to the stop. The acceleration occurring in this process, and the subsequent sudden deceleration occurring when push-type opening bar  504  reaches the end of its path, may disconnect the coupling between metal insert  566  and magnet  24 . In that case, door  2  continues to drop unbraked to the horizontal position and may injure persons or destroy objects on its way. 
     To avoid this, the variant of freewheel  622  shown in  FIGS. 8 and 9  is latched in its position at right stop  634 . To this end, unlike the first variant, an outer sleeve  626  is non-rotatably fixed to shaft  512  at the drive end. An inner sleeve  624  is partially received within outer sleeve  626  and is rotatably supported on shaft  512 . Inner sleeve  624  merges into an extension  640  having double pinion  542 , compression spring  548 , torsion spring  552  and spring sleeve  554  slidably supported thereon. The drive dog for attachment of torsion spring  552  is here in the form of a hook  650  integrally formed on double pinion  542 . End shield  514  and slide member  528  are not shown here, but function in the same way as in the first variant. Besides the laterally reversed arrangement of inner sleeve  624  and outer sleeve  626 , a main difference of the second freewheel variant is the separation of right stop  634  from the remainder (left stop  632  and helical groove  630 ) of inner sleeve  624 , and the provision of left stop  632  with a latch bevel  692 , which is engageable with slide member  528 . Right stop  634  has a pin  694 , which engages in a hole  696 . In this manner, stop  634  and the remainder of inner sleeve  624  are indeed non-rotatably connected to each other, but remain axially movable relative to each other. If slide member  528  now moves through freewheel  622  up to right stop  634  in response to activation of the driving mechanism, it moves up the latch bevel  692 . In this process, the slide member presses right stop  634  toward the right against the compression spring and moves beyond the falling portion of latch bevel  692 . In this manner, slide member  528  is fixed in position and locks freewheel  622 . Then, door  2  can only be moved by the driving mechanism, and automatic opening and the acceleration involved are prevented. When outer sleeve  626  is rotated in the opposite direction by the driving mechanism, and freewheel  622  is traversed from the right to the left, freewheel  622  is released from the locked state. 
     While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Positions of locking pin (558) and sequence of operation 
               
             
          
           
               
                   
                   
                   
                   
                   
                 Force exerted 
                   
                 Total 
                   
                   
               
               
                 Posi- 
                 Appliance 
                 Driving 
                   
                   
                 by Opening 
                 Force exerted 
                 Locking 
                 Retaining 
                 Micro- 
               
               
                 tion 
                 Status 
                 Mechanism 
                 Freewheel 
                 Opening Bar 
                 Bar on Lock 
                 by Lock 
                 Force 
                 Pin 
                 switch 
               
               
                   
               
             
          
           
               
                 A 
                 washing 
                 at rest 
                 
                           
                 
                 at left stop 
                 in rear 
                 
                           
                 
                  0 N 
                 −40 N 
                 −40 N 
                 special 
                 1 
               
               
                   
                   
                   
                   
                   
                 position 
                   
                   
                   
                   
                 position 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 for 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 micro- 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 switch 
                   
               
               
                 B 
                 start of 
                 rotates 
                 
                           
                 
                 ″ 
                 moves out 
                 → 
                 0 N to 20 N 
                 −40 N 
                 −40 N to −20 N 
                 no 
                 0 
               
               
                   
                 door 
                 counter- 
                   
                   
                   
                   
                   
                   
                   
                 function 
                   
               
               
                   
                 opening 
                 clockwise 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 operation 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 C) 
                 continued 
                 rotates 
                 
                           
                 
                 is traversed 
                 extends 15 mm 
                 
                           
                 
                 20 N 
                 ″ 
                 −20 N 
                 no 
                 0 
               
               
                   
                 opening 
                 counter- 
                   
                 from left 
                 out 
                   
                   
                   
                   
                 function 
                   
               
               
                   
                   
                 clockwise 
                   
                 to right 
                   
                   
                   
                   
                   
                   
                   
               
               
                 D 
                 continued 
                 rotates 
                 
                           
                 
                 at right stop 
                 moves out 
                 → 
                 20 N to 0 N  
                 −40 N to 15 N  
                 −20 N to 15 N  
                 no 
                 0 
               
               
                   
                 opening 
                 counter- 
                   
                   
                   
                   
                   
                   
                   
                 function 
                   
               
               
                   
                   
                 clockwise 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 E, 
                 end of 
                 rotates 
                 
                           
                 
                 is traversed  
                 extends 90 mm 
                 
                           
                 
                  0 N 
                  0 N 
                  0 N 
                 holds  
                 0 
               
               
                 E.1 
                 door 
                 clockwise 
                   
                 from 
                 out 
                   
                   
                   
                   
                 opening, 
                   
               
               
                 or 
                 opening 
                   
                   
                 right to left 
                   
                   
                   
                   
                   
                 bar in 
                   
               
               
                 E.2 
                 operation 
                   
                   
                   
                   
                   
                   
                   
                   
                 locked 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 position 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 “Hold/ 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 Door 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 Open” 
                   
               
               
                 F 
                 regular 
                 at rest 
                 
                           
                 
                 is traversed 
                 moves in 
                 ← 
                 0 N to 20 N 
                 15 N to −40 N 
                  15 N to −20 N 
                 moves 
                 0 
               
               
                   
                 opening/ 
                   
                   
                 from 
                 assisted by 
                   
                   
                   
                   
                 to stop 
                   
               
               
                   
                 closing of 
                   
                   
                 left to right 
                 spring force 
                   
                   
                   
                   
                 position 
                   
               
               
                   
                 door 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 F0.1 
                 user 
                 at rest 
                 
                           
                 
                 is traversed  
                 moves in 
                 ← 
                 0 N to 20 N 
                 15 N to −40 N 
                  15 N to −20 N 
                 is pushed 
                 0 
               
               
                   
                 presses 
                   
                   
                 from 
                 assisted by 
                   
                   
                   
                   
                 over 
                   
               
               
                   
                 door 
                   
                   
                 left to right 
                 spring force 
                   
                   
                   
                   
                 the ramp 
                   
               
               
                   
                 closed 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 G 
                 assisted 
                 ″ 
                 
                           
                 
                 is traversed 
                 extends 15 mm 
                 
                           
                 
                 20 N 
                 −40 N 
                 −20 N 
                 holds 
                 0 
               
               
                   
                 door- 
                   
                   
                 bi- 
                 out 
                   
                   
                   
                   
                 opening 
                   
               
               
                   
                 opening 
                   
                   
                 directionally 
                   
                   
                   
                   
                   
                 bar in 
                   
               
               
                   
                 force 
                   
                   
                   
                   
                   
                   
                   
                   
                 locked 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 position 
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 “Hold” 
                   
               
               
                 H 
                 goes to 
                 rotates 
                 
                           
                 
                 is traversed 
                 moves 
                 ← 
                 20 N to 0 N  
                 −40 N 
                 −20 N to −40 N 
                 no 
                 0 
               
               
                   
                 washing 
                 clockwise 
                   
                 from 
                 completely in 
                   
                   
                   
                   
                 function 
                   
               
               
                   
                 position 
                   
                   
                 right to left 
               
               
                   
               
               
                 Definition of forces: 
               
               
                 Force vectors having a positive sign in front point out of the washing chamber; 
               
               
                 force vectors having a negative sign in front point into the washing chamber. 
               
             
          
         
       
     
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  dishwasher 
               10  washing chamber 
               12  access opening of the washing chamber 
               14  strengthening channel 
               16  dishwasher side wall 
               2  door 
               20  inner door panel 
               22  lock catch 
               24  door magnet 
               3  door lock (latching mechanism) 
               30  roller 
               5  push-open unit 
               500  lower housing part 
               502  housing cover 
               504  push-type opening bar 
               506  motor 
               508  motor shaft 
               510  transmission stages 
               512  shaft 
               514  end shield 
               516  shaft end 
               518  right angle between the shaft and to the push-type opening bar 
               520  right angle between the shaft and to the push-type opening bar 
               522  freewheel 
               524  inner sleeve 
               526  outer sleeve 
               528  slide member 
               530  helical groove 
               532  left stop 
               534  right stop 
               536  guide grooves for the slide member 
               538  guide ribs of the slide member 
               540  extension of the outer sleeve 
               542  double pinion 
               544  lateral toothed tracks of the push-type opening bar 
               546  facial toothing 
               548  compression spring 
               550  drive dog 
               552  torsion spring 
               554  spring sleeve 
               556  guide track 
               558  locking pin 
               560  anchor member 
               562  receiving formation for the anchor member 
               564  arm of the anchor member 
               566  ferromagnetic metal insert 
               570  microswitch 
               572  stop spring 
               574  front leg 
               576  rear leg 
               578  front bearing block 
               580  rear bearing block 
               582  stop of the push-type opening bar 
               584  upper guide slot 
               586  middle guide slot 
               588  bevel 
               590  lower guide slot 
               622  second freewheel variant 
               624  inner sleeve 
               626  outer sleeve 
               630  helical groove 
               632  left stop 
               634  right stop 
               640  extension 
               650  hook 
               692  latch bevel 
               694  pin of the anti-rotation feature 
               696  hole of the anti-rotation feature