Patent Publication Number: US-7895998-B2

Title: Door lock device

Description:
FIELD OF THE INVENTION 
     The present invention relates to a door lock device. More particularly, the present invention relates to a door lock device in which, for the purpose of protecting a user from a heat generated at the time of execution of a self-cleaning function of an oven, a solenoid device is installed in a receptacle to forcibly lock the door, thereby preventing the user from artificially opening the door. 
     BACKGROUND OF THE INVENTION 
     As well known in the art, a cooking oven is a cooking instrument for receiving and cooking food by a radiant heat and a convection heat within a cavity of the oven. 
     As the oven is diversified in its function, even kind of cookable food increases, so its use increases. Therefore, an opportunity of contaminating the internal of the cavity owing to food dregs, etc. increases that much. In order to clean the stained cavity, the oven generally has a self-cleaning function. 
     The self-cleaning function refers to a function of cleanly cleaning the cavity internal by keeping the cavity internal of the cooking oven at about 450° C. for a predetermined time (about 15 minutes to the minimum), thermally analyzing food contaminants accumulated in the internal, and then exhausting out gas and smoke generated from the thermal analysis. The self-cleaning function requires processes of increasing a temperature of the cavity internal to a high temperature of about 400° C., maintaining the high-temperature cavity internal for about 15 minutes, and then again cooling the cavity internal. In general, it takes two hours or more to complete all the processes. 
     During the operation processes, the cavity is kept at a high temperature. Thus, a careless infant or user may get burned because of a heat emitted out when a door is opened. In order to prevent this accident, the oven door is now equipped with a safety device. However, because the safety device is generally installed at the outside of the door, the user may undesirably open the door by force, thus reducing by half a function of a lock device and also having poor appearance. 
     SUMMARY OF THE INVENTION 
     An aspect of exemplary embodiments of the present invention is to address at least the problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide a door lock device for forcibly keeping a door in a lock state at the time of execution of a self-cleaning function of an oven. 
     According to one aspect of exemplary embodiments of the present invention, provided is a door lock device. The device includes a fixing rack, an operation rack, a solenoid device, an engaged fragment, and a locking pin. The fixing rack is installed in a receptacle of an oven and has a hinge shaft. The operation rack is coupled with the hinge shaft of the fixing rack to open/close a door. The solenoid device is installed in the receptacle and has a rod. The engaged fragment is assembled to the rod of the solenoid device and ascends or descends depending on an operation of the solenoid device. The locking pin is installed in the operation rack and performs a locking or unlocking function depending on an operation of the engaged fragment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a side cross-section illustrating an assembly structure of a door lock device according to an exemplary embodiment of the present invention; 
         FIG. 2  is an exploded perspective diagram illustrating concrete constituent elements of a locking means of the door lock device of  FIG. 1 ; 
         FIG. 3  is a block diagram illustrating a construction of a door lock device according to an exemplary embodiment of the present invention; 
         FIG. 4  is a cross section illustrating a state of enabling a locking function of a door lock device according to an exemplary embodiment of the present invention; and 
         FIG. 5  is a cross section illustrating a state of disabling a locking function of a door lock device according to an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, the same drawing reference numerals will be understood to refer to the same elements, features and structures. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Exemplary embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for conciseness. 
       FIGS. 1 to 3  are diagrams illustrating a construction of a door lock device according to an exemplary embodiment of the present invention. The door lock device includes a door hinge  40  and a locking means  50 . The door hinge  40  includes a fixing rack  10 . The fixing rack  10  is installed in a receptacle (R) and supports constituent parts of the door hinge  40 . The door hinge  40  includes an operation rack  12 , a rotary plate  14 , and a connection member  24 . The operation rack  12  is coupled with the fixing rack  10  by a hinge shaft  22  and rotates centering on the hinge shaft  22  at a time a door (D) is opened and closed. 
     The operation rack  12  has a U-shaped cross section. The rotary plate  14  and the connection member  24  are installed within the operation rack  12 . The connection member  24  has a U-shaped cross section (see  FIG. 2 ) and is received within the operation rack  12  and has a fitting hole  24   a  into which a locking pin  26  described later is fitted. The operation rack  12  has guide holes  16  at its both lateral sides such that a guide pin  18  described later can move up/down as the door (D) rotates. The guide pin  18  is fitted into the guide holes  16 . The guide pin  18  is coupled with the rotary plate  14  and moves slidably in the guide holes  16 . The guide pin  18  is coupled with a spring  20  installed in the operation rack  12 . One end of the spring  20  is fixed to the upper portion of the operation rack  12 , and the other end to the guide pin  18 . When the door (D) is opened, the spring  20  moves along the guide pin  18 , enabling smooth opening of the door (D) by a tension force. 
     The fixing rack  10  is installed in the receptacle (R). A solenoid device  32  is installed at an upper side of the fixing rack  10 . The solenoid device  32  forcibly locks the door (D) during the execution of a self-cleaning function of an oven and unlocks the locked door (D) after completion of the self-cleaning function. These are performed through an engaging member  28  and the locking pin  26 . The self-cleaning function is controlled by a controller  100  in response to switching of a self-cleaning switch  104  shown in  FIG. 3 . In addition, an operation switch  102  is a switch for operating the oven. In response to switching of the operation switch  102 , the controller  100  enables a driving mode  108  for executing an oven function. A temperature sensor  106  senses an internal temperature of the oven and transmits the sensed temperature to the controller  100 . 
     A link  30  is fitted to a rod  32   a  of the solenoid device  32  at its one end and is fitted to the engaging member  28  at the other end. The engaging member  28  is formed in a rectangular shape. The engaging member  28  is bent at its lower end part and has a fitting part  28   a  having a long-hole or groove shape by cutaway along the a center. Having the open-end groove shape, the fitting part  28   a  can effectively catch the locking pin  26  which has a cylindrical shape. 
     The locking pin  26  is fitted into the fitting part  28   a . The locking pin  26  is fitted into or released from the fitting part  28   a  in response to an operation of the solenoid device  32 . That is, the locking pin  26  has a cylindrical shape with a cylindrical fitting protrusion  26   a  protruded and formed at its distal end. The fitting protrusion  26   a  is caught against a rear surface of the U-shaped groove portion of the fitting part  28   a  and prevents user&#39;s inadvertent opening of the door when a user undesirably intends to open the locked door (D). 
     A cylindrical protrusion  26   b  is protruded and formed in the other end of the locking pin  26  and is fitted into the fitting hole  24   a  of the connection member  24 . The locking pin  26  is assembled such that the locking pin  26  is fitted into the fitting hole  24   a  of the connection member  24  and is not released from the fitting hole  24   a  by the cylindrical protrusion  26   b . In an alternate method, the connection member  24  can perform the same function by providing a separate hole in the operation rack  12  and fitting the locking pin  26  into the hole of the operation rack  12 . 
     Operation of the above-constructed door lock device according to an exemplary embodiment of the present invention is described below with reference to accompanying  FIGS. 3 to 5 . A rotation operation of the door hinge  40  included in the door lock device according to an exemplary embodiment of the present invention is a well-known technology and thus, its detailed description is omitted below. 
     In response to switching of an operation switch  102 , a controller  100  enables a driving mode  108  and performs an oven function. The controller  100  switches on a self-cleaning switch  104  to perform a self-cleaning function after food is cooked. Depending on switching of the self-cleaning switch  104 , the controller  100  operates a solenoid device  32 , so a rod  32   a  installed in the solenoid device  32  descends and a link  30  coupled to the rod  32   a  descends together. 
     Then, as the link  30  descends, engaging member  28  coupled to the link  30  descends and a fitting part  28   a  of the engaged fragment  28  is fitted to a locking pin  26 . By this, when a user undesirably intends to open a door (D) by force, a rear surface of the fitting part  28   a  is caught by a front surface of the fitting protrusion  26   a  of the locking pin  26 , thus avoiding inadvertently opening the door (D). 
     Then, when the self-cleaning function of the oven is completed and a temperature decreases below a predetermined temperature (desirably, a room temperature of  30  ° C. to  50  ° C. with no danger of burn), a temperature sensor  106  senses and transmits the temperature signal to the controller  100  and the controller  100  sends an electrical signal to the solenoid device  32  to disable a locking function. At this time, a locking means  50  initiates an unlocking operation inverse to a locking operation. As the rod  32   a  ascends, the link  30  coupled to the rod  32   a  also ascends. As a consequence, the engaging member  28  coupled to the link  30  ascends, so the coupling between the locking pin  26  and the engaging member  28  is released. After that, a user can open the door (D) with a handle (not shown) of the door (D). 
     According to an alternative embodiment , in order for the user to manually open the door upon occurrence of power failure or emergency after completion of the self-cleaning function, a separate hole or open/closable small door can be provided at a place where the locking means  50  is installed, desirably, in the receptacle (R) such that the user can move up the engaging member  28  manually. 
     As described above, exemplary embodiments of the present invention provide an effect of preventing a careless infant or user from getting burned because of an internal heat when artificially opening a door, by installing a solenoid device in a receptacle of an oven to forcibly lock the door at the time of execution of a self-cleaning function of the oven. 
     Further, there is an effect of providing a good appearance by installing a locking device within the receptacle. 
     While the invention has been shown and described with reference to a certain preferred embodiment 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 as defined by the appended claims.