Abstract:
A fire door lock includes a base assembly including first and second slide blocks, a locking control assembly including a movable seat forming a groove and a tongue control plate movably mounted to one side of the locking control assembly, and a winglet assembly including first and second winglets both having a boss movably received in the groove of the movable seat and both being respectively and rotatably coupled to the first and second slide blocks. Thus, when the movable seat is driven by a handle, the movable seat moves the first and second slide blocks to withdraw first and second latch bars to unlock the fire door and when the fire door is closed, the tongue control plate is actuated to allow the movable seat to return to the locked condition and the first and second latches and a tongue are stretched out to realize three-directional locking.

Description:
BACKGROUND OF THE INVENTION 
   (a) Technical Field of the Invention 
   The present invention relates to a fire door lock, and in particular to a fire door lock comprising a movable seat, which when actuated and moved by a handle bar, moves first and second slide blocks and a lock tongue inward to further drive first and second latch bars inwards to unlock the fire door, and which, when the door is closed and a tongue control plate is brought into contact with an external fixture and thus actuated, automatically returns to the original locked position to stretch the first and second latch bars outward to secure the fire door and also cause a tongue holder seat to abut against and maintain the tongue in the locked condition thereby realizing a three-directional locking of the fire door. 
   (b) Description of the Prior Art 
   Fire door locking mechanisms are known, such as Taiwan Patent Publication No. 568161, which discloses in  FIG. 11  of the attached drawings thereof a central locking mechanism  3  and upper and lower locking mechanisms  4 ,  6  that are coupled to the central locking mechanism  3 , and a transmission mechanism  9  that is coupled to the central locking mechanism  3  so that when an operating handle bar is depressed, the transmission mechanism  9  drives the central locking mechanism  3 , which in turn drives the upper and lower locking mechanisms  4 ,  6  to operate in a simultaneous manner for locking and unlocking a fire door. 
   The conventional device, although effective in overcoming the drawback of other known fire door mechanism that no upper and lower vertical latching are included. However, such a conventional device does not include horizontal latching or locking so that when the fire door can be broken in by breaking a middle portion of the door. Thus, further improvement is needed. 
   Other prior art references, such as U.S. Pat. No. 7,144,050, suffer the same drawback. 
   Thus, it is desired to provide an improved fire door lock that enhances security of the fire door, while maintaining easy operation by a user to open the door. 
   SUMMARY OF THE INVENTION 
   The primary purpose of the present invention is to provide a fire door lock comprising a base assembly, which comprises a bottom plate on which first and second slide blocks are slidably mounted, a locking control assembly, which comprises a movable seat forming a groove and a tongue control plate movably mounted to one side of the locking control assembly, and a winglet assembly, which comprises first and second winglets, which both have a boss movably received in the groove of the movable seat and both being respectively and rotatably coupled to the first and second slide blocks. Thus, when the movable seat is driven by an operating handle bar, the movable seat is driven to move the first and second slide blocks to withdraw first and second latch bars to thereby unlock the fire door. When the fire door is closed, the tongue control plate is hit and acted to allow the movable seat to return to the locked condition and the first and second latches and a tongue are stretched out to realize three-directional locking. 
   The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
   Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing a fire door lock constructed in accordance with the present invention; 
       FIG. 2  is an exploded view of the fire door lock of the present invention; 
       FIG. 3  is an exploded view of a base assembly of the fire door lock of the present invention; 
       FIG. 4  is an exploded view of a locking control assembly of the fire door lock of the present invention; 
       FIG. 5  is a perspective view, partially broken, of the locking control assembly of the fire door lock of the present invention; 
       FIG. 6  is a schematic view illustrating the base assembly before the fire door lock is operated; 
       FIG. 7  is a side elevational view of the locking control assembly before the fire door lock is operated; 
       FIG. 8  is a cross-sectional view of the locking control assembly before the fire door lock is operated; 
       FIG. 9  is a perspective view illustrating the operation of the fire door lock of the present invention; 
       FIG. 10  is a schematic view illustrating the base assembly after the fire door lock is operated; 
       FIG. 11  is a side elevational view of the locking control assembly after the fire door lock is operated; 
       FIG. 12  is a cross-sectional view of the locking control assembly after the fire door lock is operated; and 
       FIG. 13  is a perspective view illustrating the fire door lock of the present invention mounted to a fire door panel. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
   With reference to the drawings and in particular to  FIGS. 1-3 , a fire door lock constructed in accordance with the present invention comprises a base assembly  2 , which comprises a bottom plate  3  and first and second latch bars  35 ,  36 . The bottom plate  3  forms at least one fixing hole  38  and two mounting holes  391 ,  392 , which will be referred to as fifth and sixth mounting holes, respectively. The bottom plate  3  also forms first and second slide racks  31 ,  32  and comprises first and second slide blocks  33 ,  34 , which are respectively and slidably received in the first and second slide racks  31 ,  32 . The first slide block  33  forms a first notch  332  and a first slot  331  and similarly, the second slide block  34  forms a second notch  342  and a second slot  341 . The first latch bar  35  is securely coupled to the first notch  332  of the first slide block  33 , while the second latch bar  36  is securely coupled to the second notch  342  of the second slide block  34 . 
   A winglet assembly  4  comprises first and second winglets  41 ,  42 . The first winglet  41  forms first and second mounting holes  45 ,  46  and a first boss  43 . The first mounting hole  45  is rotatably coupled to the fifth mounting hole  391  of the bottom plate  3  by a pivot (not labeled) and the second mounting hole  46  is rotatably coupled to the first slot  331  of the first slide block  33  by a pivot (not labeled). The second winglet  42  forms third and fourth mounting holes  47 ,  48  and a second boss  44 . The third mounting hole  47  is rotatably coupled to the sixth mounting hole  392  of the bottom plate  3  by a pivot (not labeled) and the fourth mounting hole  8  is rotatably coupled to the second slot  341  of the second slide block  34 . 
   Also referring to  FIGS. 2 ,  4  and  5 , a locking control assembly  5  comprises a housing  51 , a movable seat  6 , a tongue holder seat  7 , a holder  74  and a tongue  52 , a tongue control plate  53 , a control plate  54 , and a shaft set  8  that is composed of a number of pins and shafts  81 - 85 . The housing  51  forms at least one housing mounting hole  511 , a control hole  510 , a third elongated hole  512  and fourth, fifth, sixth, and seventh through-holes  513 ,  514 ,  515 ,  516 . The movable seat  6  comprises a positioning bar  61 , a first stop  63 , a groove  62 , and at least one through hole  66 . The movable seat  6  has opposite side walls in which first elongated holes  64  and second elongated holes  65  are formed. The through holes  66  function to couple a connection end  92  of an operating handle assembly  91 , as shown in  FIG. 13 . The tongue holder seat  7  comprises a second stop  72 , first through holes  71 , an anchoring hole  73 , and a third spring  79 . The holder  74  forms holding sections  75 , a first aperture  78  and second trough holes  77 . The tongue  52  forms a (recessed) engaging portion  523 , a first bore  521 , and second bores  522 . The tongue control plate  53  has a third trough holes  531  and a second aperture  532 . The control plate  54  comprises a fourth spring  544 , a third stop  542 , a fourth elongated hole  541 , and a fifth elongated hole  543 . The pivot set  8  comprises a control pin  86 , a first shaft  81 , a second shaft  82 , a third shaft  83 , a fourth shaft  84 , and a fifth shaft  85 . 
   Also referring to  FIG. 13 , which illustrates the fire door lock of the present invention mounted to a fire door panel  9 , the connection end  92  of the operating handle assembly  91  is coupled to the trough holes  66  of the movable seat  6  so that when the operating handle assembly  91  is depressed or actuated, the first and second latch bard  35 ,  36  and the tongue  52  are moved to allow the fire door  9  to open. Further, when the fire door  9  is being closed the tongue control plate  53  is brought into contact with for example a door frame or a fixed article, the movable seat  6  is released to return to the original locked position whereby the first and second latch bars  35 ,  36  secure the fire door  9  and the tongue holder seat  7  is put in abutting engagement with the engaging portion  523  of the tongue  52  to thereby realize securing the fire door at three different orientations. 
   The first shaft  81  is received in the seventh through hole  516  of the housing  51  and is also rotatably fit into the third through hole  531  of the tongue control plate  53  and the second bores  522  of the tongue  52 , and also extends through the first spring  524 , which is a helical spring in the embodiment illustrated to thereby mount the tongue control plate  53 , the tongue  52 , and the first spring  524  in the housing  51 . The second shaft  82  is movably received in the third elongated holes  512  of the housing  51  and is movably fit into the second elongated holes  65  of the movable seat  6  and the first bore  521  of the tongue  52  to thereby mount the movable seat  6  and the tongue  52  in the housing  51 . Thus, when the movable seat  6  is moved in a rearward direction (that is a direction away from the tongue  52 ) by being actuated by the operating handle assembly  91 , the tongue  52  is moved into the housing  51  and at the same time, the first stop  63  of the movable seat  6  depresses the second stop  72  of the tongue holder seat  7  downward (as illustrated in  FIG. 11 ) due to a camming engagement therebetween to thereby release the abutting engagement between the tongue holder seat  7  and the engaging portion  523  of the tongue  52 . By this, the tongue  52  is allowed to move inward into the housing  51  as demonstrated in  FIG. 12 . Further, the second spring  70  biases the holder  74  in such a way that the holding sections  75  of the holder  74  are moved into engagement with the positioning bar  61  of the movable seat  6  to prevent the movable seat  6  from moving forward and thereby maintaining an unlocked condition. 
   The fifth shaft  85  is received in the fourth through holes  513  of the housing  51  and is movably fit into the first elongated holes  64  of the movable seat  6  and rotatably fit into the first through holes  71  of the tongue holder seat  7  to thereby mount the movable seat  6  and the tongue holder seat  7  in the housing  51 . The third shaft  83  is received in the sixth rough hole  515  of the housing  51  and is movably fit into the fourth elongated hole  541  of the control plate  54  to mount the control plate  54  to an outside surfaced of one side wall of the housing  51 . The fourth shaft  84  is received in the fifth through holes  514  of the housing  51  and is rotatably fit in the second trough holes  77  of the holder  74  and also extends through the second spring  70  and the fifth elongated hole  543  of the control plate  54  to thereby mount the holder  74 , the second spring  74 , and the control plate  54  to the housing  51 . The control pin  86  is fit into the control hole  510  of the housing  51  and is further fit into the first aperture  78  of the holder  74 . The third spring  79  has an end  791  mounted to the anchoring hole  73  of the tongue holder seat  7  and an opposite end  792  attached to the third shaft  83 . 
   Also referring to  FIGS. 3 and 6 , the first boss  43  of the first winglet  41  and the second boss  44  of the second winglet  42  are received in the groove  62  of the movable seat  6 . The first mounting hole  45  of the first winglet  41  is rotatably coupled to the fifth mounting hole  391  of the bottom plate  3  and the second mounting hole  46  of the first winglet  41  is rotatably and movably coupled to the first slot  331  of the first slide block  33 . The third mounting hole  47  of the second winglet  47  is rotatably coupled to the sixth mounting hole  392  of the bottom plate  3  and the fourth mounting hole  48  of the second winglet  42  is movably and rotatably coupled to the second slot  341  of the second slide block  34 . Thus, when the movable seat  6  is moved rearward, the first and second slide blocks  33 ,  34  are driven in a direction into the locking control assembly  5 . And as shown in  FIGS. 9 and 10 , the first and second latch bars  35 ,  36  are also driven to release the fire door  9 . Consequently, both latch bars  35 ,  36  and the tongue  52  are actuated or moved at the same time to release the fire door  9 . 
   When the fire door  9  is closed again, as shown in  FIGS. 5 and 7 , the tongue control plate  53  that is movably arranged outside the housing  51  is brought into contact with and thus stopped by for example a door frame or an opposite door panel so that the control plate  54  is forced rearward, the third stop  542  of the control plate  54 , due to camming action, raises the control pin  86  upward and simultaneously raises the holder  74  upward thereby releasing the engagement between the holding sections  75  of the holder  74  and the positioning bar  61  of the movable seat  6  to allow the movable seat  6  to return to the locked condition as being biased by a spring force of the third spring  79  that has the end  791  fixed to the anchoring hole  73  of the tongue holder seat  7  and the opposite end  792  attached to the third shaft  83 , as shown in  FIGS. 5 and 8 . In this condition, the tongue holder seat  7  is again positioned in engagement with the recessed engaging portion  523  of the tongue  52  and at the same time, the tongue  52  is biased outward by the first spring  524 , to thereby make and maintain the tongue  52  in the locked condition. 
   In addition, as shown in  FIG. 2 , the bottom plate  3  is provided with a lock portion  393 , which comprises a switching block  394  so that when the lock portion  393  is operated with a key for opening the fire door lock, the switching block  394  is rotated and thus moving the movable seat  6 , as shown in  FIG. 10 , thereby realizing opening of the fire door with a key. Since the lock portion  393  is known in the art and constitutes no novel part of the invention, no detail will be given herein. 
   Although the present invention has been described with reference to the preferred embodiment thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims. 
   It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
   While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.