Patent Publication Number: US-2010117378-A1

Title: Doorlock device for an electric home appliance

Description:
TECHNICAL FIELD 
     The present invention relates to a doorlock device for closing and opening a door of an electric home appliance, and more specifically to a doorlock device wherein a push cam is moved by a solenoid which is operated by an input of electrical control signal to rotate a rotation cam in predefined direction, thereby moving a slider in left and right direction which restricts a latch slider and a locker by its horizontal movement and separates a movable plate from a fixed plate upon abnormal withdrawal of the latch, which immediately stops the operation of the electric home appliance. 
     BACKGROUND ART 
     Electric home appliance such as laundry machine, dish washing machine, drying machine, kitchen stove, microwave oven and etc is provided with a doorlock device for opening a door of such product only under specified situation. That is, safety regarding home appliance is pursued by having the door of home appliance opened only under specified situation, which needs that the door of home appliance should be kept closed when the home appliance is in use. 
     A number of doorlock devices are already known, one of which is disclosed in the title of ‘device for closing and releasing a door of electric home appliance’ in the U.S. Pat. No. 6,334,637 B1 wherein an inserted latch is inhibited from sliding by rotating two continuous toothed wheels in accordance with the actuation of solenoid, thereby achieving latch restriction. That is, the latch restriction mechanism in the above device is achieved by transmitting reciprocating motion of the solenoid to the toothed wheels, such that the locker is moved which is engaged to the teeth of the toothed wheels. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     However, since in the above doorlock device the teeth of a toothed wheel is engaged with the teeth of the other two toothed wheels such that the doorlock device is operated by the solenoid, entire volume of the doorlock device is increased due to the toothed wheels, and further, said locker often malfunctions in connection with the rotation of the toothed wheels, which leads to low operation credibility of the entire device. Technical Solution 
     The purpose of the present invention is to provide a doorlock device which can address the above problems, wherein a push cam operated by a solenoid causes an eccentric part of a rotation part to move a locker vertically, thus resulting in a latch slider being held by the locker, so that the structure of the doorlock device can be simplified, which makes it possible to manufacture the doorlock device more easily and cheaply as well as to improve the operation credibility. 
     Another purpose of the present invention is to provide a doorlock device which stops the operation of the electric home appliance as soon as the latch is withdrawn abnormally. 
     The doorlock device according to the present invention comprises a latch which is attached to a door for closing it, a cover including a latch opening and a latch slider which is elastically supported due to the insert of the latch, a locker which restricts the latch slider, a slider which moves the locker up and down, a solenoid which pushes a push cam in accordance with control signal to rotate a rotation cam so that the slider is moved left and right, a housing including the locker, the solenoid and a contact point part in which electric signal is inputted, a locker withdrawal part which forcibly withdraws the protruded locker by operation of a torsion spring which is elastically supported, thereby separating a movable plate from a fixed plate upon abnormal withdrawal of the latch. 
     Advantageous Effects 
     According to the doorlock device of the present invention, the push cam operated by the solenoid causes the eccentric part of the rotation part to move the locker vertically, thus resulting in the latch slider being held or released by the locker. This bring about an effect that the structure of the doorlock device can be simplified, so that it becomes easier and cheaper to manufacture the doorlock device. Further, it is possible to provide a doorlock device whose operation credibility is improved. Still further, it is possible to provide a doorlock device which stops the operation of the electric home appliance as soon as the latch is withdrawn abnormally. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows perspective view of a doorlock device according to the present invention. 
         FIG. 2  shows perspective view of a disassembled doorlock device according to the present invention. 
         FIG. 3  shows perspective view of a disassembled doorlock device according to the present invention. 
         FIG. 4  shows perspective view of a push cam and a rotation cam according to the present invention. 
         FIG. 5  shows cross-sectional view of a solenoid and a cam housing according to the present invention. 
         FIG. 6  shows plan view of the doorlock device according to the present invention. 
         FIG. 7  shows cross-sectional view of A-A′ plane of  FIG. 6  before a latch is inserted. 
         FIG. 8  shows cross-sectional view of A-A′ plane of  FIG. 6  after the latch is inserted. 
         FIG. 9  shows cross-sectional view of A-A′ plane of  FIG. 6  when locking is activated. 
         FIG. 10  shows perspective view of  FIG. 8 . 
         FIG. 11  shows perspective view of  FIG. 9 . 
         FIG. 12  shows perspective view of a locker withdrawal part of another embodiment according to the present invention. 
         FIG. 13  shows perspective operational view of the locker withdrawal part when the latch of  FIG. 12  is inserted. 
         FIG. 14  shows perspective operational view of the locker withdrawal part when the latch of  FIG. 12  is forcibly withdrawn. 
     
    
    
     REFERENCE NUMERALS FOR THE PRIMARY CONSTITUTIONAL ELEMENTS IN THE DRAWINGS  
       100  . . . latch 
       200  . . . housing 
       300  . . . cover 
       310  . . . latch opening 
       301  . . . locker opening 
       400  . . . latch slider 
       410  . . . latch slider spring 
       420  . . . latch insert opening 
       421  . . . latch support 
       430  . . . latch holder 
       440  . . . fixing recess 
       500  . . . contact point part 
       510  . . . movable plate 
       520  . . . fixed plate 
       511  . . . locker withdrawal part 
       551 , 560  . . . PTC 
       600  . . . solenoid 
       610  . . . solenoid plunger 
       620  . . . bobbin 
       630  . . . solenoid case 
       700  . . . cam housing 
       710  . . . push cam 
       720  . . . rotation cam 
       730  . . . rotation cam spring 
       750  . . . slider 
       751  . . . slider spring 
       800  . . . locker 
       810  . . . movable plate insert 
       900 , 901  . . . locker withdrawal part 
       910 , 911  . . . protrusion 
       920  . . . locker engagement part 
       921  . . . rib engagement part 
       930 , 931  . . . hinge hole 
       940  . . . fixer 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     One embodiment of the present invention is to be described in detail with reference to the attached drawings. 
       FIG. 1  shows perspective view of the doorlock device in accordance with the present invention. 
     As to outer constitution, the doorlock device comprises a housing  200  including PTC receiving part  500  which receives PTC(positive temperature coefficient) and switch contact point part  500 , a cover  300  combined with the housing and including a latch opening  310  through which a latch is inserted, a latch slide part  400  which is combined with the upper part of the cover to be pushed by the inserted latch and includes a latch slider spring  410  for elastically supporting the latch slider, and a locker withdrawal part  900  which separates a movable plate and a fixed plate by forcibly withdrawing the protruded locker  800  through operation of a torsion spring which is elastically supported upon abnormal withdrawal of the latch. 
     Hereinafter the inner constitution of the doorlock device is described in detail. 
       FIGS. 2 and 3  show perspective views of the disassembled doorlock device of the present invention. 
     The doorlock device of the present invention comprises a housing  200  in which PCT receiving part  550 , contact point part  500 , solenoid  600 , a cam housing  700  moved by the solenoid and a locker moved by the cam housing  700  are provided; a cover  300  which is combined with the housing  200 , includes a latch opening  310  through which a latch  100  is inserted and locker opening  301  through which the locker  800  is vertically moved in and out; a latch slider  400  which is pushed by the inserted latch  100  and elastically supported by a latch slider spring  410  provided on the upper surface of the cover  300 . Further, in the doorlock device are provided a locker withdrawal part  900  which is combined with the cover through hinge-joint and is rotated by the insert of the latch  100  about the hinge-joint, a torsion spring which elastically supports the locker withdrawal part  900  against the direction in which the latch  100  is inserted, and a protrusion  910  in the upper area of the locker for forcibly withdrawing the locker  800  through the operation of the torsion spring upon the abnormal withdrawal of the latch. 
     An ordinary-skilled person of the art could easily design the constitution of the torsion spring, which elastically supports the locker withdrawal part  900 , and thus it is not shown in the drawings. 
     In the PTC receiving part  550 , solenoid contact points (a) and (b) are arranged and PTC  551  is placed between the solenoid contact points (a) and (b). 
     In the contact point, part  500 , bimetal contact point (c), the other contact point (d) of the solenoid, contact point (e) and fixed plate contact point (f) is arranged, respectively. 
     In the one end of the bimetal contact point (c), the bimetal  570  and movable plate  510  is arranged, respectively, and PTC  560  is placed between the movable plate  510  and the bimetal  560 . 
     The PTCs  551 , 560  is a semiconductor which conducts electricity below predestined temperature and cut the electricity when heated over predestined temperature due to drastic increase of resistance, respectively, and thus functions as a switch which is short-circuited when electrical flow increases drastically. 
     The solenoid  600 , which is connected at the solenoid contact points (a) and (b) and is activated by the contact point (e), comprises a solenoid case  630  and a solenoid plunger  610  placed in the center of a bobbin  620 , upon which electric wire is wound. 
     The one end of the solenoid plunger  610  is received in a cam housing  700 , in which a push cam  710  and a rotation cam  720  which rotates according to the reciprocating movement of the push cam is placed, respectively. 
     On the one end of the rotation cam  720 , an eccentric part  721  is formed eccentrically relative to shaft axis of the rotation cam  720  and a rotation cam spring  720  is provided to elastically support the push cam and the rotation cam. A slider  750  is provided to engage the outer contacting surface of the eccentric part  721 . 
     A slider spring  751  is provided to have the slider  750  contact with the eccentric part  751  of the rotation cam  720  at any time and the slider  750  is arranged in oblique angle with a locker  800 . 
     In the locker  800 , movable plate insert  810  is provided, in which the locker withdrawal part  511  of the movable plate is inserted and placed. 
     A cover  300  is placed upon the upper part of the housing  200  and combined with the housing to secure the above-described components in their position, in which a locker opening  301  through which the locker  800  provided in the housing  200  is moved in and out in accordance with its longitudinal movement. In the upper part of the cover  300 , a latch slider  400  is placed. 
     The latch slider  400  comprises a latch insert opening  420  which is in communication with a latch opening  310  through which the latch  100  is inserted, a locker holder  430  which is pushed by the insert of the latch  100  and opens the locker opening  301  thereby the locker  800  protruding to cause the restriction of the latch slider  400 , and a latch slider spring  410  which restores the moved latch slider  400  in its initial position in accordance with the move-in of the locker  800  and the move-out of the latch  100 . 
     A locker withdrawal part  900  is also provided which is combined with the cover  300  through a hinge-joint, thereby the locker withdrawal part  900  rotating by the insert of the latch  100  about the hinge-joint. The locker withdrawal part  900  is elastically supported against the insert of the latch  100  by a torsion spring and includes the protrusion  910  in the upper area of the locker  800  for forcibly withdrawing the latch  800  by the torsion spring upon abnormal withdrawal of the latch. 
     A latch slider fixer  940  is provided on the locker withdrawal part  900  and a fixing recess  440  is provided in the latch slider  400  which engages with the latch slider fixer  940  such that the latch slider  400  is fixed by the locker withdrawal part  900  against normal withdrawal of the latch  100 . 
     Now, the above-mentioned push cam and the rotation cam are explained in detail, which replace the constitutional element of the toothed wheel in the prior art. 
       FIG. 4  shows the perspective view of the push cam and the rotation cam. 
     The push cam  710 , hollowly shaped, includes protrusion  712  and toothed part  711 , and the rotation cam  720  includes oblique angle parts  722  and an eccentric part  721  which is formed eccentric relative to the oblique angle part. 
     Further, the rotation cam  720  is elastically pushed by a rotation cam spring  730  which is provided on the inner surface of the housing  200 , so that the rotation cam  720  engages with the push cam  710 . 
     The oblique angle parts  722  on the rotation cam  720  are arranged in 120° angular distribution along the circumference of the rotation cam  720 , hence the number of them being  3 . 
     Therefore, the solenoid plunger  610  pushes the push cam  710  in the cam housing  700  in response to the control signal of the solenoid  600 , so that the push cam  710  pushes the rotation cam  720  and rotates it by 120° simultaneously. 
     An ordinary-skilled person of the art could modify the rotation direction of the rotation cam  720  caused by the pushing of the push cam  710  appropriately according to the embodiment. 
     The above-described constitution is described in cross-sectional view hereinafter. 
       FIG. 5  shows cross-sectional view of the solenoid and cam housing  700  according to the present invention. 
     The solenoid  600  comprises the solenoid case  630  and the bobbin  620  whereon electric wire is wound and in which the solenoid plunger  610  is placed. 
     When electric signal is inputted to the solenoid  600 , the solenoid plunger  610  pushes the push cam  710  placed in the cam housing  700 . Then, the push cam  710  pushes the rotation cam  720  while rotating it with its toothed part  711  and the protrusion  712  and the oblique angle part  722  of the rotation cam  720 . 
     Now, the operation of the above-described constitution is described. 
       FIG. 6  shows a plane view of the doorlock device of the present invention, while  FIGS. 7 ,  8  and  9 , each showing the A-A′ plane of  FIG. 6 , shows cross-sectional view before the latch is inserted, cross-sectional view when the latch is inserted, and cross-sectional view when locking is activated, respectively. 
     Further,  FIGS. 10 and 11  shows the perspective view of the  FIGS. 8 and 9 , respectively. 
     Although the locker withdrawal part  900  is not shown in  FIGS. 7 ,  8  and  9 , the ordinary-skilled of the art could easily understand of the operation of the constitution with reference to  FIGS. 10 and 11 . 
     In  FIG. 7 , the crest point of the eccentric part  721  is in engagement with the slider  750 . In addition, the slider  750  holds the locker  800 , while the latch slider  400  arranged on the cover  300  is elastically supported by the latch slider spring  410 . 
     The latch  100  passes through the latch opening  310  in the cover  300  to be inserted in the latch insert opening  420  in the latch slider  400  by the closing operation of a door(s) (see FIGS.  8  and  10 ). As the latch  100  is inserted, a holder of the latch  100  comes to in engagement with the latch support  421  in the latch slider  400 , thereby pushing the latch slider  400  in the left direction as in the figs. At the same time, as a result of the insert of the latch  100 , the locker withdrawal part  900  is rotated due to its engagement with the latch  100  and the latch slider fixer  400  gets out of the fixing recess  440  in the latch slider  400 , so that the latch slider  400  is pushed and the protrusion  920  of the locker withdrawal part  900  is displaced above the locker slider  400 . 
     When the latch slider  400  is pushed in the left direction, the locker opening  301  shows up, placed on the cover  300  to pass through the cover  300 , where the locker  800  protrudes. 
     Under the situation where the latch  100  is inserted or the door is closed, in response to the input of the control signal to the solenoid  600 , the solenoid plunger  610  pushes the push cam  710  to push and rotate the rotation cam  720  which is in engagement with the push cam  710 . 
     As a result of the rotation of the rotation cam  720 , the eccentric part  721  is rotated by 120°, then the slider  750 , in engagement with the eccentric part  721 , is pushed in the left direction in the figs, along the circumferential surface of the eccentric part  721  by the slider spring  751 , so that the locker  800  comes to be in contact only with the locker withdrawal part  511  of the movable plate  510 . 
     Under the above-specified situation, when the electric signal is inputted to the bimetal  570  by pushing a push-button on the electric home appliance, the bimetal  570  moves the movable plate  510  in the upward direction, thereby the locker  800  being moved in the upward direction and protruding above the cover  300  (see  FIGS. 9 and 11 ). 
     As a result of the protruding of the locker  800  above the cover  300 , the latch slider  400  is fixed, and thus the latch  100  cannot be withdrawn from the latch opening  310 . 
     When control signal (electric signal) is inputted to the solenoid  600  under the above-specified situation, the rotation cam  720  is rotated by  120 ° while the latch  100  is kept in its locked position. 
     When the second control signal is inputted to the solenoid  600  under the above-specified situation, the rotation cam  720  returns to its initial position pushing the slider  750  with its eccentric part  750 , so that the slider  750  pushes the locker  800  downwards, and thus the latch slider  400  comes to be in free-to-move condition. 
     Now, the locker withdrawal part  900  is described in detail. 
     Although the door is seldom opened by compulsion, it is necessary to consider this seldom case. 
     The latch  100  could be withdrawn not only by compulsion due to its wear or release of the holding means which holds the latch, but also by any force opening the door forcibly. 
     That is to say, abnormal opening of the door often occurs during the use of the electric home appliance, which can result in great danger. 
     Therefore, it is necessary to forcibly separate the movable plate  510  from the fixed plate  520 , so that the operation of the appliance be stopped when the door is abnormally opened during the use of the appliance. 
     One embodiment of the above-specified constitution is described referring to  FIGS. 10 and 11 . 
     As described in the above paragraph, the locker withdrawal part  900  rotated by the insert of the latch  100  is combined with the cover  300  above the latch slider  400  through a hinge-joint and is elastically supported by the torsion spring against the insert direction of the latch  100 . 
     As shown in the figs, the locker withdrawal part  900  which is connected with the cover  300  through hinge hole  930  in the cover  300  and is elastically supported by the torsion spring(not shown in the figs.) against the insert direction of the latch  100 , comprises the protrusion  910  which is formed to protrude for the withdrawal of the locker  800  and a latch engagement part  920  which is rotated by the insert of the latch  100 , resulting in the displacement of the protrusion  910  from the locker opening  920 . 
     Describing the operation of the above-specified constitution, if the latch  100  is forcibly withdrawn under a situation where the latch  100  is inserted, the latch slider  400  is fixed by the locker  800 . In this situation, the locker  800  is kept in its upward protruded position, the movable plate  510  contacts with the fixed plate  910 , and the electric home appliance is in. operation. Therefore, it is needed to forcibly separate the movable plate  920  from the fixed plate  910  to stop the operation of the appliance. 
     As shown in the figs, if the latch  100  is withdrawn abnormally, the locker withdrawal part  900  restores to its initial position and its protrusion  910  strikes on the locker  800 , thereby withdrawing the locker  800  into the cover  300 . Then, as the locker  800  is withdrawn into the cover  300 , it separates the movable plate  510  from the fixed plate  520 . 
     Hence, the electric home appliance comes to stop. 
     At this time, the latch slide  400  can be held by the protrusion  910  of the locker withdrawal part  900 , but it is again held by the latch  400  as the latch  400  is inserted again. 
     If the latch  100  is withdrawn by normal operation, the latch slide  400  operates first to returns to its initial position, so that the protrusion  910  of the locker withdrawal part  900  comes to in engagement with the upper surface of the latch slider  400 . 
       FIGS. 12 ,  13  and  14  shows perspective view of another embodiment of the locker withdrawal part, perspective view illustrating the operation of the locker withdrawal part of  FIG. 12  when the latch is inserted and when the latch is forcibly withdrawn, respectively. 
     As shown in the figs, the locker withdrawal part  901  is combined with the cover  300  through a hinge-joint in a manner that its hinge joint hole  931  is in communication with hinge joint protrusions  932 , 933  which are shaped to protrude on the cover  300 . Further, the locker withdrawal part  901  comprises in its underpart a rib engagement part  921  which corresponds to a front rib  960  and a rear rib  961  each of which is formed on the latch slider  400  to have a predestined angle, and a protrusion  911  which strikes on the head surface of the locker  800 . Further, the locker withdrawal part  901  is elastically supported by a torsion spring, which is not shown in the figs, because an ordinary-skilled person of the art could easily understand its structure and design it. 
     Now, the operation of the above-described constitution is described. 
     As mentioned, the front rib  960  and the rear rib  961  is fixed and attached to the latch slider  400  and an angular surface with predestined angle, respectively. 
     The rib engagement part  921  of the locker withdrawal part  901  slides on the angular surfaces along their respective angle, thereby the locker withdrawal part  901  rotating about the hinge-joint. That is, as the latch  100  is inserted, it pushes the latch slider  400 , so that the rib engagement part  921  of the locker withdrawal part  901  slides on the angular surface of the front rib  960  along its angle, thereby the locker withdrawal part  901  being rotated (see  FIG. 13 ). 
     Under the above-specified situation, when the electric home appliance is operated, the locker  800  protrudes. If the normal control signal is inputted, the locker  800  is restored to its initial position by being withdrawn into the cover, the appliance stops operating, and the latch slider  400  is pushed by the latch slider spring  410 , so that the rib engagement part  921  of the locker withdrawal part  901  slides on the angular surface of the rear rib  961  along its angle, thereby the locker withdrawal part  901  being rotated about the hinge-joint. 
     Further, when the latch  100  is inserted on the input of the normal control signal, the locker opening  301  (see  FIG. 3 ) is spaced from the locker holder  430  (see  FIG. 3 ) by distance D. 
     In case the latch  100  is forcibly withdrawn on the input of the abnormal control signal, the latch slider  400  is pushed by the latch slider spring  401  and is displaced by the distance D. Thus, the rib engagement part  921  which is in engagement with the front rib  960  is lowered by the torsion spring (not shown in the figs.) and the protrusion  911  strikes on the head surface of the locker  800 , so that the movable plate  510  (see  FIG. 3 ) is separated from the fixed plate  520  (see  FIG. 3 ), hence the appliance stops operating, 
     The rib engagement part  921  of the locker withdrawal part  901  can be formed in another shape, desirably further includes a wheel component which can rotate. 
     Further, if the rib engagement part  921  includes a rotatable wheel component, the shape of the front rib  960  and the rear rib  961  is to be modified in accordance with the shape of the rib engagement part  921 , which of course falls within the scope of the present invention. 
     Further, the eccentric part in the rotation cam can be formed in a multi-eccentric shape or other shape, not limited to the eccentric part of the rotation cam shown in the figs, and described in the above, which is formed to be eccentric only in one direction. 
     Therefore, the eccentric part of the rotation cam can have various shape, and thus the scope of the present invention should not be limited or narrowed to the above-described embodiment.