Patent Abstract:
Disclosed is a washing machine, a control panel assembly of which has an improved structure to minimize problems caused by a shaking of a rotary knob and the interference of the rotary knob with other surrounding parts. The control panel assembly of the washing machine includes a control panel, a knob guide installed on the control panel, and a rotary knob rotatably mounted on the knob guide and including a boss passing through the knob guide. The knob guide includes a boss insertion part restricting the boss to prevent the rotary knob from shaking. The boss insertion part includes an extension extended from the bottom surface of the knob guide and forming a boss insertion hole, into which the boss is inserted, therein.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of U.S. Ser. No. 12/071,797 filed in the United States on Feb. 26, 2008, and claims the priority benefit of Korean Patent Application No. 2007-0050632, filed May 25, 2007, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    The present invention relates to a washing machine, and more particularly, to a washing machine, a control panel assembly which has an improved structure to minimize problems caused by a shaking of a rotary knob and an interference of the rotary knob with other surrounding parts. 
         [0004]    2. Description of the Related Art 
         [0005]    Washing machines are apparatuses that wash clothes using electric power. In general, a washing machine includes a tub storing washing water, and a drum rotatably installed in the tub. When the drum is rotated or a pulsator installed in the drum is rotated under the condition that laundry and washing water containing a detergent are put into the drum, the laundry rubs against the drum and the washing water, thus being washed. 
         [0006]    The washing machine further includes a control panel assembly installed on an upper end of a front surface of a main body forming the external appearance of the washing machine to control the operation of the washing machine.  FIG. 1  is an exploded perspective view of a control panel assembly of a conventional washing machine. 
         [0007]    The control panel assembly of the washing machine shown in  FIG. 1  includes a substrate  3 , on which various electric components, such as a rotary switch  1  and LEDs  2 , are installed, and a control panel  4  covering the substrate  3  to protect the substrate  3  and provided with an opening  4   a  formed through one side thereof. A decoration window  5  is installed at the opening  4   a  of the control panel  4 . The decoration window  5  transmits light irradiated from the LEDs  2 , and is provided with a through hole  5   a  to pass a rotary knob  6  therethrough. An encoder bracket  7  covering the LEDs  2  to protect the LEDs  2  is installed on the substrate  3 , and the rotary knob  6  is connected to a rotary shaft  1   a  of the rotary switch  1  installed on the substrate  3 . When the control panel  4  and the substrate  3  are assembled, the rotary knob  6  is protruded forward from the control panel  4  through the through hole  5   a  of the decoration window  5 . 
         [0008]    In such a control panel assembly, when a user manipulates the rotary knob  6 , the rotary knob  6  shakes and thus provides an unpleasant feeling to the user. That is, since the rotary switch  1  is fixed to the substrate  3  having a small thickness, the rotary knob  6 , which is assembled with the rotary switch  1 , is easily shaken together with the rotary switch  1 . This problem can be solved by reducing the size of the through hole  5   a  to allow the decoration window  5  to prevent the shaking of the rotary knob  6 . However, in this case, when the rotary knob  6  is manipulated, the rotary knob  6  interferes with the decoration window  5  and thus cannot be smoothly rotated, or the rotary knob  6  provides an unpleasant feeling to the user. Further, noise due to friction occurs. 
       SUMMARY 
       [0009]    Therefore, one aspect of the embodiment is to provide a washing machine, which minimizes a shaking of a rotary knob, and a control panel assembly thereof. 
         [0010]    Another aspect of the embodiment is to provide a washing machine, which minimizes problems caused by an interference of a rotary knob with other surrounding parts, and a control panel assembly thereof. 
         [0011]    Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. 
         [0012]    The foregoing and/or other aspects are achieved by providing a washing machine having a control panel assembly to control an operation of the washing machine, the control panel assembly including a control panel; a knob guide installed on the control panel and including a boss insertion part; and a rotary knob rotatably mounted on the knob guide and including a boss passing through the knob guide, wherein the boss insertion part restricts the boss to prevent the rotary knob from shaking. 
         [0013]    The boss insertion part may include an extension extended from a bottom surface of the knob guide and forming a boss insertion hole, into which the boss is inserted, therein. 
         [0014]    An inner surface of the extension forming the boss insertion hole may be inclined such that a distance between the inner surface of the extension and the boss gradually increases from a point at which the extension abuts the boss. 
         [0015]    A diameter of the boss insertion hole may be varied in an extended direction of the extension. 
         [0016]    The rotary knob may include a connection part connected to the knob guide when the rotary knob is mounted on the knob guide; and the knob guide may include a restriction part restricting the connection part of the rotary knob. 
         [0017]    The connection part may include at least one hook protruded towards the knob guide and connected to the knob guide when the rotary knob is mounted on the knob guide, and the restriction part may include at least one hook protruded towards the rotary knob and restricting the rotary knob when the rotary knob is mounted on the knob guide. 
         [0018]    The connection part may include first hooks protruded towards the knob guide, and the restriction part may include second hooks protruded towards the rotary knob and engaged with the first hooks of the connection part. 
         [0019]    The foregoing and/or other aspects are achieved by providing a control panel assembly of a washing machine including a rotary knob including a boss protruded therefrom; and a knob guide including a base panel to pass the boss through a central portion thereof, and an extension extending from the base panel to restrict the boss. 
         [0020]    The extension may be inclined such that a distance between the extension and the boss gradually decreases in an extended direction of the extension to a point at which the extension abuts the boss. 
         [0021]    The rotary knob may include first hooks protruded towards the knob guide, and the knob guide may include second hooks protruded towards the rotary knob and engaged with the first hooks when the boss of the rotary know is passed through the central portion of the base panel of the knob guide. 
         [0022]    Drain holes to drain water flowing from an outside to the base panel may be formed through the base panel. 
         [0023]    The foregoing and/or other aspects are achieved by providing a washing machine, including: a drum to receive laundry to be washed; and a control panel assembly, including: a rotary knob including a boss extending therefrom; and a knob guide receiving the boss and including an angled extension contacting the received boss to restrict the boss. 
         [0024]    The angled extension may abut the boss at an abutting point and angle away from the boss from the abutting point to increase a diameter of a boss insertion hole formed between the angled extension and the boss. 
         [0025]    The knob guide may include a restriction part and the rotary knob may include a connection part, the restriction part and the connection part being engaged to fix the rotary knob to the knob guide when the boss is received by the knob guide. 
         [0026]    At least one of the knob guide and the rotary knob may include a connection part and an other of the knob guide and the rotary knob may include connection holes formed through the other of the knob guide and the rotary knob, the connection part being received into the connection holes to affix the rotary knob and the knob guide to one another. 
         [0027]    The foregoing and/or other aspects are achieved by providing a washing machine, including: a drum to receive laundry to be washed; and a control panel assembly, including: a rotary knob including a connection part extending therefrom; and a knob guide including a restriction part extending therefrom, wherein the connection part and the restriction part are engaged to fix the rotary knob to the knob guide. 
         [0028]    The rotary knob may include a boss extending therefrom and the knob guide receives the boss and includes an angled extension contacting the received boss to restrict the boss. 
         [0029]    The angled extension may abut the boss at an abutting point and angle away from the boss from the abutting point to increase a diameter of a boss insertion hole formed between the angled extension and the boss. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the embodiment, taken in conjunction with the accompanying drawings in which: 
           [0031]      FIG. 1  is an exploded perspective view of a control panel assembly of a conventional washing machine; 
           [0032]      FIG. 2  is a perspective view of a washing machine in accordance with a present embodiment; 
           [0033]      FIG. 3  is an exploded perspective view of a control panel assembly of the washing machine in accordance with the present embodiment; 
           [0034]      FIG. 4  is a sectional view of the control panel assembly of the washing machine in accordance with the present embodiment; and 
           [0035]      FIGS. 5A to 5C  are views illustrating a process of assembling the control panel assembly of the washing machine in accordance with the present embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0036]    Reference will now be made in detail to the embodiment, an example of which is illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiment is described below to explain the present invention by referring to the annexed drawings. 
         [0037]      FIG. 2  is a perspective view of a washing machine in accordance with the present embodiment. 
         [0038]    As shown in  FIG. 2 , the washing machine in accordance with the present embodiment includes a main body  10  forming an external appearance of the washing machine, a tub (not shown) installed in the main body  10  to store washing water, and a drum  12  rotatably installed in the tub to wash laundry. An opening  13  is formed through a front surface of the main body  10  so that a user can put laundry into an inside of the tub through the opening  13 , and a door  14  to open and close the opening  13  is installed. A control panel assembly  100  to control an operation of the washing machine is provided on an upper portion of the front surface of the main body  10 . 
         [0039]      FIG. 3  is an exploded perspective view of the control panel assembly of the washing machine in accordance with the present embodiment, and  FIG. 4  is a sectional view of the control panel assembly of the washing machine in accordance with the present embodiment. As shown in  FIGS. 3 and 4 , the control panel assembly  100  includes a control panel  110  provided with an opening  111  formed through one side thereof, and a circuit board  120  installed in the control panel  110 . 
         [0040]    A rotary switch  121  is installed on the circuit board  120 , and a plurality of LEDs  122  is installed on the circuit board  120  around the rotary switch  121 . The rotary switch  121  includes a push shaft  121   a  protruded forwardly, and a rotary shaft  121   b  surrounding a lower portion of the push shaft  121   a.  A knob assembly  150  including a rotary knob  160  and a push button  151  is assembled with the rotary switch  121 . A user rotates the rotary shaft  121   b  of the rotary switch  121  or presses the push shaft  121   a  of the rotary switch  121  through the rotary knob  160  and the push button  151 , and thus is capable of selecting a function, such as a washing course or a washing time. 
         [0041]    An encoder bracket  130 , provided with cylindrical cell parts  131  respectively covering the LEDs  122  to protect the LEDs  122  and guiding light irradiated from the LEDs  122  forwardly is installed on the circuit board  120 . A through hole  132  to pass the rotary shaft  121   b  and the push shaft  121   a  of the rotary switch  121  is formed through a central portion of the encoder bracket  130 . 
         [0042]    A knob guide  140  is installed at the opening  111  of the control panel  110 , and the knob assembly  150  is mounted on a front surface of the knob guide  140 . The knob guide  140  serves to support the knob assembly  150  to prevent the knob assembly  150  from shaking, and to display a function, selected by rotating or pressing the knob assembly  150 , to the user. 
         [0043]    The knob guide  140  includes a base panel  141 , on which the knob assembly  150  is mounted, a ring-shaped display panel  142  formed along a circumference of the base panel  141 , and protrusions  143  formed along a circumference of the display panel  142 . Letters or marks are printed on the display panel  142  so that the user can recognize the function selected by the knob assembly  150 . The display panel  142  has light transmission parts  142   a  to transmit the light irradiated from the LEDs  122  of the circuit board  120  in a forward direction. The protrusions  143  are fastened to an edge of the opening  111  when the knob guide  140  is installed on the control panel  110 . Drain holes  141   a  to drain water flowing from the outside into the base panel  141  are formed through the base panel  141 . 
         [0044]    The knob assembly  150  includes the rotary knob  160  rotatably mounted on the base panel  141  of the knob guide  140 , the push button  151  disposed on the rotary knob  160 , and a button cover  152  covering an edge of the push button  151 . 
         [0045]    The rotary knob  160  includes a knob body  161  having a button reception part  161   a  to receive the push button  151  formed on an upper portion thereof and a circumferential surface  161   b  to be held by a user when the operation of the washing machine is controlled, and a boss  162  protruded downwardly from a central portion of the knob body  161 . A shaft insertion hole  163  is formed in the boss  162 , and a connection protrusion  163   a  connected with the rotary shaft  121   b  of the rotary switch  121  is provided in the shaft insertion hole  163 . The connection protrusion  163   a  is connected to a connection groove  121   c  of the rotary shaft  121   b  when the rotary shaft  121   b  of the rotary switch  121  is inserted into the shaft insertion hole  163 . A button shaft  151   a  of the push button  151  is also inserted into the shaft insertion hole  163 . The button shaft  151   a  inserted into the shaft insertion hole  163  is connected to the push shaft  121   a  of the rotary switch  121  in the shaft insertion hole  163 . Thus, the user can operate the rotary switch  121  by rotating the rotary knob  160  or pushing the push button  151 , thereby selecting a desired function. 
         [0046]    The knob body  161  of the rotary knob  160  is seated on the base panel  141  of the knob guide  140 , and the boss  162  of the rotary knob  160  passes through the base panel  141  and is extended downwardly. The knob guide  140  further includes a boss insertion part  170 , which restricts the boss  162  to prevent the rotary knob  160  from shaking. Since the boss insertion part  170  prevents the rotary knob  160  from shaking, as described above, when the rotary knob  160  and the knob guide  140  contact each other, an area of friction therebetween is reduced. That is, when a conventional rotary knob rubs against surrounding parts, the circumferential surface of the body of the rotary knob rubs against the surrounding parts. However, in the present embodiment, the boss  162 , which has a relatively small diameter, rubs against the boss insertion part  170 , and thus noise and malfunction caused by the friction are reduced. 
         [0047]    The boss insertion part  170  is provided with an extension  170   a  extended upwardly from the base panel  141  of the knob guide  140 . A boss insertion hole  171 , into which the boss  162  of the rotary knob  160  is inserted, is formed within the extension  170   a.  Although this embodiment illustrates the extension  170   a  extended upwardly, the extension  170   a  is not limited thereto and thus may be extended downwardly from the base panel  141 , for example. 
         [0048]    An inner surface of the extension  170   a,  which forms the boss insertion hole  171 , is provided with an inclined surface  171   a  such that a distance between the inner surface of the extension  170   a  and the boss  162  gradually increases. That is, the extension  170   a  is provided with the inclined surface  171   a  such that a diameter of at least a part of the boss insertion hole  171  in an extended direction of the extension  170   a  is varied. The inclined surface  171   a  causes contact of the boss  162  of the rotary knob  160  with the extension  170   a  of the knob guide  140 , which is similar to line contact, and thus an area of friction between the boss  162  and the extension  170   a  when the boss  162  and the extension  170   a  rub with each other is minimized. 
         [0049]    The rotary knob  160  includes a connection part  164 , which is connected to the knob guide  140 , and the knob guide  140  includes a restriction part  144 , which restricts the connection part  164 . The connection part  164  and the restriction part  144  serve to allow the rotary knob  160  to be rotatably mounted on the knob guide  140  and to prevent the rotary knob  160  from being separated from the knob guide  140  when the user pulls the rotary knob  160 . 
         [0050]    The connection part  164 , as shown in  FIG. 4 , may include at least one hook  164   a  (hereinafter, referred to as a ‘first hook’) protruded from a rear surface of the button reception part  161   a  toward the knob guide  140 . Further, the restriction part  144  may include at least one hook  144   a  (hereinafter, referred to as a ‘second hook’) protruded from the base panel  141  toward the rotary knob  160  to be engaged with the first hook  164   a.    
         [0051]    Although  FIG. 3  illustrates three first hooks  164   a  and three second hooks  144   a  respectively provided in the circumferential directions of the rotary knob  160  and the knob guide  140 , the number of the first hooks  164   a  and the second hooks  144   a  may be properly modified as the occasion demands in terms of design. 
         [0052]    Further, although  FIG. 4  illustrates the rotary knob  160  connected to the knob guide  140  by the engagement between the first hooks  164   a  and the second hooks  144   a,  the rotary knob  160  may be connected to the knob guide  140  by hooks, which are formed on one of the rotary knob  160  and the knob guide  140 , and connection holes, which are formed through the other one of the rotary knob  160  and the knob guide  140  such that the hooks are inserted into the connection holes. Here, the connection holes must have a ring shape in consideration of the rotation of the rotary knob  160 . 
         [0053]    Hereinafter, a process of assembling the control panel assembly of the washing machine in accordance with the present invention will be described with reference to  FIG. 3  and  FIGS. 5A to 5C . 
         [0054]    First, as shown in  FIG. 5A , when the knob guide  140  is inserted into the opening  111  of the control panel  110  from the rear of the control panel  110 , the display panel  142  and the base panel  141  are exposed from the front surface of the control panel  110  to the outside through the opening  111 . The encoder bracket  130  is assembled with the circuit board  120  to protect the rotary switch  121  and the LEDs  122  installed on the circuit board  120 . Here, the push shaft  121   a  and the rotary shaft  121   b  of the rotary switch  121  are protruded forward from the encoder bracket  130  through the through hole  132  of the encoder bracket  130 . 
         [0055]    Thereafter, as shown in  FIG. 5B , the circuit board  120  is fixed to the control panel  110  on which the knob guide  140  is installed by fastening members, such as screws. Then, the push shaft  121   a  and the rotary shaft  121   b  of the rotary switch  121  are exposed from the front surface of the control panel  110  to the outside through the boss insertion part  170  of the knob guide  140 . 
         [0056]    Thereafter, as shown in  FIG. 5C , the rotary knob  160  is assembled with the knob guide  140  from the front of the control panel  110 . Here, the boss  162  of the rotary knob  160  is inserted into the boss insertion part  170 , and the first hooks  164   a  of the rotary knob  160  are engaged with the second hooks  144   a  of the knob guide  140 . When the boss  162  of the rotary knob  160  is inserted into the boss insertion part  170 , the rotary shaft  121   b  of the rotary switch  121  is inserted into the shaft insertion hole  163  formed in the boss  162 , and thus is connected to the boss  162 . Finally, the push button  151  is assembled with the button reception part  161   a  of the rotary knob  160 . Here, the button shaft  151   a  of the push button  151  is connected to the push shaft  121   a  of the rotary switch  121  in the shaft insertion hole  163 . When the assembling of the push button  151  with the button reception part  161   a  is completed, the button cover  152  is put on the push button  151 , thus finishing the appearance of the knob assembly  150 . 
         [0057]    As apparent from the above description, the present embodiment provides a washing machine that prevents a rotary knob from shaking, and a control panel assembly thereof, thereby providing a comfortable feeling to a user manipulating the rotary knob and thus improving the reliability of a product. 
         [0058]    Further, even when the rotary knob interferes with a surrounding knob guide, the area of friction between the rotary knob and the knob guide is minimized. Thus, noise and malfunction caused by the friction are minimized. 
         [0059]    Although an embodiment has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Technology Classification (CPC): 3