Abstract:
A door lock assembly includes a cam attached to a handle for rotating a rotary drive in response to rotation of the handle. The rotary drive has a driven part rotated by the cam, and a drive part opposite to the driven part. A latch operator is rotated by the drive part so that a latch operating spindle connected to the latch operator can retract a latch. A slide plate is controlled by a key-operated lock unit to prevent or permit rotation of the cam and the latch operating spindle. The door lock assembly is simple in construction and can be assembled easily.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority of Taiwanese Utility Model Application No. 095219765 filed on Nov. 8, 2006. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a door lock assembly, more particularly, to a door lock assembly for a fireproof door, which has a cam associated with a handle to transmit movements to a latch operating spindle. 
         [0004]    2. Description of the Related Art 
         [0005]    According to construction laws, it is required that a fireproof door be installed in a staircase on each floor of a building. In order to prevent fire from moving from one floor to an adjacent floor, the fireproof door is normally closed. However, for emergency exit or safety purposes, the fireproof door is provided with a door latch device which can be readily operated from the inside of the door. Generally, a door latch installed at the inside of the door includes a handle frame installed on the middle of the door. By pressing a handle disposed inside the handle frame, the door can be unlatched and opened. The fireproof door is further provided with a door lock assembly which includes a handle and a key-operated lock. The user may operate the handle and the key-operated lock from the outside of the door to lock or unlock the door. Examples of door lock assemblies for fireproof doors are disclosed in U.S. Pat. Nos. 5,445,423, 5,516,161, 5,658,026, 5,664,816, and 7,181,940. 
       SUMMARY OF THE INVENTION 
       [0006]    An object of the present invention is to provide a door lock assembly for a fireproof door, which has a simple construction and which can be assembled easily. 
         [0007]    According to one aspect of this invention, a door lock assembly comprises: a housing; a handle connected to the housing; a cam attached to the handle inside the housing and rotatable along with the handle; a rotary drive disposed rotatably in the housing and having a driven part rotated by the cam, and a drive part opposite to the driven part; a latch operator disposed rotatably in the housing and driven by the drive part of the rotary drive; and a latch operating spindle adapted to operate a latch and connected to the latch operator for rotation along with the latch operator. 
         [0008]    According to another aspect of the invention, a door lock assembly comprises: a housing having two aligned support rods; a handle connected to the housing; a latch operating spindle adapted to operate a latch; a cam attached to the handle inside the housing for transmitting rotation of the handle to the latch operating spindle; a key-operated lock unit provided in the housing; a slide plate disposed movably between the cam and the lock unit and movable between a locking position that limits the handle from rotation, and an unlocking position that permits the handle to rotate. The slide plate has two aligned guide holes respectively receiving the support rods in a slidable relationship. A coiled spring is sleeved around one of the support rods and resiliently positions the slide plate. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which: 
           [0010]      FIG. 1  is an exploded view of the first preferred embodiment of the present invention; 
           [0011]      FIG. 2  is a perspective view of the first preferred embodiment in which a cover plate is removed; 
           [0012]      FIG. 3  is a plan view of a first preferred embodiment in an unlocking position; 
           [0013]      FIG. 4  is the same view as  FIG. 3 , but showing that a cam is rotated; 
           [0014]      FIG. 5  is the same view as  FIG. 3 , but showing a locking position of the first preferred embodiment; 
           [0015]      FIG. 6  is an exploded view of the second preferred embodiment in which a slide; 
           [0016]      FIG. 7  is a perspective view of the second preferred embodiment in which a cover plate is removed; 
           [0017]      FIG. 8  is a plan view of the second preferred embodiment in the unlocking position; and 
           [0018]      FIG. 9  is the same view as  FIG. 8 , but showing the locking position of the second preferred embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification. 
         [0020]    Referring to  FIGS. 1 and 2 , there is shown a door lock assembly according to a first embodiment of the present invention, which includes a housing  100  composed of an inner case  1  and an outer case  10 . A cover plate  9  is connected to the inner case  1 . The inner case  1  is provided with two guide rods  11 , two screw rods  12 , two support rods  13 , a handle hole  16 , a passage hole  17  and a tubular flange  19 . The outer case  10  surrounds the inner case  1 , and has a handle hole  102  aligned with the handle hole  16 . 
         [0021]    The door lock assembly further includes a handle  8 , a cam  2 , a rotary drive  3 , a latch operator  4 , a latch operating spindle  5 , a slide  6 , and a key-operated lock unit  7 . 
         [0022]    The handle  8  is connected to the housing  100 , and has a grip portion  84  and a tubular body  85 . The tubular body  85  has one end that is formed with two spaced apart lugs  81  and a groove  82  and that extends through the handle holes  102  and  16  of the outer and inner cases  10  and  1 . 
         [0023]    The cam  2  has two slots  23  for extension of the respective lugs  81  formed at one end of the tubular body  85 . A locking ring  27  is engaged in the groove  82  so that the cam  2  is rotatable along with the handle  8  within the housing  1 . The cam  2  has two opposite tongues  22  extending in an axial direction of the cam  2 . A torsion spring  24  is disposed in the inner case  1  around the tubular flange  19  of the inner case  1 , which in turn extends around the end of the tubular body  85 . The torsion spring  24  has two legs  25  supported on the respective second screw rods  12 . Each leg  25  is engageable with one of the tongues  22  to apply a returning force to the cam  2 . Therefore, when the handle  8  is rotated by an angle, it can return to its original position. A protrusion  21  is formed on a lug portion  20  of the cam  2 . 
         [0024]    The rotary drive  3  is disposed in the housing  100  and has a central hole  31 . The rotary drive  3  is sleeved rotatably around one of the support rods  13  fixed to the inner case  1  substantially in parallel with the latch operating spindle  5  and disposed between the latch operating spindle  5  and the handle  8 . The rotary drive  3  further has a driven part  32 , and a drive part  33  disposed on two sides of the support rod  13 . The driven part  32  overlaps with the lug portion  20  of the cam  2 , and has an engaging groove  320  engaging the protrusion  21  of the cam  2  so that the rotary drive  3  can be rotated by the cam  2 . The drive part  33  also has an engaging groove  330 . 
         [0025]    The latch operator  4  is disposed rotatably in the housing  100 , and is configured as a U-shaped plate having two holes  41 , and a pair of spaced apart lobe portions  40 . The latch operating spindle  5  is fixed in the holes  41  for rotation along with the latch operator  4 . The latch operating spindle  5  passes through a spindle hole  62  in the slide plate  6 , and extends rotatably into the passage hole  17  in the inner case  1  and a first slot  91  in the cover plate  9 . A latch operating end  51  of the latch operating spindle  5  is connected to a latch mechanism (not shown). 
         [0026]    The lobe portions  40  overlap with the drive part  33  of the rotary drive  3 . A protrusion  42  is provided on the lobe portions  40  to engage the engaging groove  330  of the drive part  33  so that the latch operator  4  can be driven by the drive part  33 . Preferably, the protrusion  42  is configured as a pin  42  that has two ends respectively inserted into two holes  43  (only one is shown) in the lobe portions  40  so that the protrusion or pin  42  is held by the lobe portions  40 . The drive part  33  extends inbetween the lobe portions  40  to engage the protrusion or pin  42 . 
         [0027]    The cover plate  9  is further provided with two second slots  92 , and screw holes  96 . The cover plate  9  is secured to the inner case  1  by using screws  94  connected to the respective screw holes  96  and the screw holes in the respective guide rods  11  and screw rods  12 , thereby covering the cam  2 , the rotary drive  3 , the latch operator  4 , and the slide plate  6 . The latch operating end  51  of the latch operating spindle  5  extends through the first slot  91 . Two mounting screw rods  93  extend through the respective second slots  92  and are attached respectively to screw holes in the support rods  13 . 
         [0028]    The housing  100  further has two screw holes  14  (only one is shown), a lock hole  15  and a curve slide hole  18  all of which are formed in the inner case  1 , and a lock hole  101  formed in the outer case  10 . A curve slide hole  95  is formed in the cover plate  9  in alignment with the slide hole  18 . 
         [0029]    The lock unit  7  is disposed in the lock holes  101  and  15 , and has a key plug  71 , a key hole  72  formed in the key plug  71 , two diametrically opposite engaging elements  74 , and a transmitting member  73  rotatable along with the key plug  71 . The transmitting member  73  has a radially projecting transmitting tab  731 . An operating key (not shown) can be inserted into the key hole  72  and a hole  730  of the transmitting member  73  to rotate the key plug  71  and the transmitting member  73 . The engaging elements  74  interlock with respective retaining elements  77  of retaining plates  76  which are secured to the inner case  1  on two sides of the lock hole  15  by means of screws  75  and the screw holes  14 . 
         [0030]    The slide plate  6  is disposed movably between the lock unit  7  and the cam  2 . The slide plate  6  has two aligned guide holes  61  on two sides of the spindle hole  62 . The support rods  13  extend through the respective guide holes  61  such that the slide plate  6  is slidable with respect to the support rods  13 . The spindle hole  62  receives one end of the latch operating spindle  5 . The slide plate  6  further has an engagement part  63  formed on an upper edge thereof, and two abutment parts  64  formed on a lower edge thereof and abutting against the cam  2 . 
         [0031]    The slide plate  6  is resiliently positioned by a coiled spring  54 . The coiled spring  54  is sleeved around the support rod  13  above the latch operator  4 . One end of the coiled spring  54  is in abutment with the cover plate  9 . Another end of the coiled spring  54  has a positioning ring  55  connected thereto. The ring  55  tapers slightly toward the guide hole  61  formed above the spindle hole  62 , and extends partially into the guide hole  61 . The guide hole  61  substantially resembles a figure of eight, and has two inwardly extending projections  611  to engage the positioning ring  55 . The guide rods  11  are disposed on two sides of the slide plate  6  to guide the sliding of the slide plate  6 . 
         [0032]    To place the slide plate  6  in a locking position or an unlocking position, the lock unit  7  controls and moves a pin  78  that extends transversely of the slide plate  6 . The pin  78  has two ends extending movably through the curve slide holes  18  and  95  in the inner case  1  and the cover plate  9 . The slide holes  18  and  95  are proximate to the upper edge of the elide plate  6 . The pin  78  is pushed by the transmitting tab  731  to slide along the slide holes  18  and  95  so as to engage the engagement part  63  of the slide plate  6  (see  FIG. 5 ), or to disengage from the engagement part  63  (see  FIG. 3 ). When the pin  78  engages the engagement part  63 , the slide plate  6  is in the locking position (see  FIG. 5 . When the pin  78  disengages from the engagement part  63 , the slide plate  6  is in the unlocking position (see  FIG. 3 ). 
         [0033]    The pin  78  is biased by an elongate spring plate  79  which is disposed in the vicinity of the pin  78  and the slide holes  18 ,  95 , and which has two ends respectively supported on the guide rods  11 . 
         [0034]    Referring to  FIGS. 3-5  in combination with  FIGS. 1 and 2 , when the door lock assembly installed on a door is in its locking position, the key plug  71  and the transmitting member  73  may be rotated by a key (not shown) to push the pin  78  to disengage from the engagement part  63  so that the slide plate  6  permits the cam  2  and the handle  8  to rotate. At this time, the handle  8  can be rotated to move the cam  2  which in turn rotates the driven part  32  of the rotary drive  3 . As a result, the drive part  33  rotates the latch operator  4  and the latch operating spindle  5  as shown in  FIG. 4 , thereby unlatching the door and permitting the door to open. 
         [0035]    When the door lock assembly is in an unlocking position, the key plug  71  and the transmitting member  73  may be rotated by the key to push the pin  78  to engage the engagement part  63  (see  FIG. 5 ). At this time, because the pin  78  engages the engagement part  63 , the slide plate  6  is limited from moving upward so that the abutment part  64  which is in abutment with the cam  2  prevents the cam  2  and the handle  8  from rotation. As a result, the handle  8  cannot be rotated and the door cannot be unlatched. 
         [0036]    Referring to  FIGS. 6-9 , there is shown the second preferred embodiment of the present invention in which the slide plate  6 ′ is used in place of the slide plate  6  of the first preferred embodiment. The slide plate  6 ′ does not have the engagement part  63  and the abutment part  64 . Furthermore, no slide holes  18  and  95  are provided in the inner case  1  and the cover plate  9 . However, the pin  65  is formed on the slide plate  6 ′, and a locking part  66  is provided in the slide plate  6 ′. 
         [0037]    The locking part  66  is configured as a constricted hole section  66  formed in the spindle hole  62  of the slide plate  6 ′. The latch operating spindle  5  further has a detent portion  52  opposite to the latch operating end  51 . The detent portion  52  extends into the spindle hole  62  and is engageable with the constricted hole section  66 . When the lock unit  7  moves the pin  65 , the slide plate  6 ′ is moved between its locking position in which the locking part  66  engages the detent portion  52  (see  FIG. 9 ) and its unlocking position in which the locking part  66  disengages from the detent portion  52  (see  FIG. 8 ). 
         [0038]    When the door lock assembly is in its unlocking position and when the key plug  71  and the transmitting member  73  are rotated, the transmitting tab  731  moves upward the pin  65  and the slide plate  6 ′ so that the locking part  66  disengages from the detent portion  52  as shown in  FIG. 8 . The slide plate  6 ′ is therefore in its unlocking position that permits the latch operating spindle  5 , the latch operator  4 , the rotary drive  3 , the cam  2  and the handle  8  to rotate. 
         [0039]    When the door lock assembly is in its locking position and when the key plug  71  and the transmitting member  73  are rotated, the transmitting tab  731  moves downward the pin  65  and the slide plate  6 ′ so that the locking part  66  engages the detent portion  52  as shown in  FIG. 9 . The slide plate  6 ′ is therefore in its locking position that prevents the latch operating spindle  5 , the latch operator  4 , the rotary drive  3 , the cam  2 , and the handle  8  from rotating. 
         [0040]    While the preferred embodiments described hereinbefore are provided with the components, such as, the key-operated lock unit  7 , the pins  78 ,  65  and the slide plates  6 ,  6 ′, the present invention should not be limited thereto. The present invention may be embodied by dispensing with those components. In this case, the door lock assembly of the present intention is operated without using any key. The latch operating spindle  5  can control a latch (not shown) when operated by the handle  8  through the cam  2 , the rotary drive  3 , and the latch operator  4 . 
         [0041]    While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.