Patent Publication Number: US-6666054-B1

Title: Remote-controlled door lock

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a remote-controlled door lock, particularly to one provided with a braking device capable of being controlled by a remote controller to restrict a latch-bolt assembly in a locked position. When a circuit board receives a locking sign from the remote controller, the circuit board will actuate a motor of the braking device to turn a driving gear to rotate a gear rack of a slide block that is meshed with the driving gear to move a retaining member that is disposed at a bottom of the slide block upwards to be engaged with a through hole of the latch-bolt assembly without moving into a slide slot that extends from the through hole and has a width smaller than a diameter of the retaining member so as to restrict the latch-bolt assembly in a locked position, whereby even though dead bolts of a lock base are unlocked, the door lock cannot be completely unlocked without using the remote controller to actuate the braking device to relieve the latch-bolt assembly from being locked, thus achieving a best effect of anti-theft. 
     2. Description of the Prior Art 
     A conventional key-operated door lock, as shown in FIG. 1, includes a case body  10  provided with a lock base  11 , a pull plate  12  and a latch-bolt assembly  13  disposed therein. The lock base  11  has dead bolts  110  provided at one side thereof and capable of extending out of through holes  100  formed in a sidewall of the case body  10 . The lock base  11  further has two lock cores  111  respectively disposed in an inner and an outer sides thereof and each provided with a keyhole  112 . The pull plate  12  is disposed in the outer side of the case body  10  and has a fixing plate  120  extending into a slide groove  101  of the case body  10  and attached relatively to a fixing plate  102  of the case body  10 . One end of the latch-bolt assembly  13  extends through the fixing plate  102  of the case body  10  to be secured to the fixing plate  120  of the pull plate  12 . A spring  130  is sleeved on the latch-bolt assembly  13  adjacent to the end thereof. The other end of the latch-bolt assembly  13  is provided with a stop member  131  capable of extending out of a through hole  103  formed at the sidewall of the case body  10 . When a key is inserted in the keyhole  112  of one of the lock cores  111  to turn, the dead bolts  110  and the stop member  131  will move back into the case body  10 , thus unlocking the conventional key-operated door lock. 
     However, such a conventional key-operated door lock only using a key to lock the dead bolts  110  can be easily pried unlocked by thefts with simple picking tools or special tools, thus losing the anti-theft function. 
     SUMMARY OF THE INVENTION 
     The main purpose of the invention is to offer a remote-controlled door lock having a best effect of anti-theft. 
     The main feature of the invention is to provide a case body having a battery base, a circuit board and a braking device disposed therein, the braking device located above a latch-bolt assembly and having a fixed base, two slide rails disposed in the fixed base, a motor disposed at an outer sidewall of the fixed base and having a shaft with one end extending into the fixed base, a driving gear disposed on the end of the shaft of the motor, a slide block disposed in the fixed base and having one end placed between the two slide rails and the other end provided with an inner surface formed as a gear rack capable of being meshed with the driving gear, a connecting rod fixed at a bottom of the slide block and having a retaining member disposed at a lower end thereof; and, 
     a latch-bolt assembly having a through hole formed thereon, and a slide slot extending from the through hole and having a width smaller than a diameter of the retaining member. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     This invention will be better understood by referring to the accompanying drawings, wherein: 
     FIG. 1 is a schematic sectional view of a conventional door lock; 
     FIG. 2 is a perspective view of a first preferred embodiment of a remote-controlled door lock in the present invention; 
     FIG. 3 is a sectional view of the remote-controlled door lock in the present invention, showing a driving gear meshed with a gear rack of a slide block; 
     FIG. 4 is a schematic sectional view of the first preferred embodiment of the remote-controlled door lock in the present invention being in a locked status; 
     FIG. 5 is a schematic sectional view of the first preferred embodiment of the remote-controlled door lock in the present invention being in an unlocked status; 
     FIG. 6 is a perspective view of a second preferred embodiment of the remote-controlled door lock in the present invention; 
     FIG. 7 is a schematic sectional view of the second preferred embodiment of the remote-controlled door lock in the present invention being in a locked status; and, 
     FIG. 8 is a schematic sectional view of the second preferred embodiment of the remote-controlled door lock in the present invention being in an unlocked status. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A first preferred embodiment of a remote-controlled door lock in the present invention, as shown in FIGS. 2 and 3, mainly includes a case body  2  provided with a lock base  3 , a latch-bolt assembly  4 , a battery base  5 , a circuit board  6 , and a braking device  7  therein. 
     The lock base  3  has two dead bolts  30  capable of extending out of a sidewall of the case body  2 . 
     The latch-bolt assembly  4  has an engagement block  40  disposed at one end thereof and capable of extending out of the sidewall of the case body  2 , a through hole  41  formed thereon, and a slide slot  42  extending from the through hole  41  and having a smaller width. 
     The battery base  5  can accommodate batteries  50  therein. 
     The braking device  7  located above the latch-bolt assembly  4  has a fixed base  70 , two slide rails  71  disposed in the fixed base  70 , a motor  72  disposed at an outer sidewall of the fixed base  70  and having a shaft with one end extending into the fixed base  70 , a driving gear  73  disposed on the end of the shaft of the motor  72 , a L-shaped slide block  74  disposed in the fixed base  70  and having one end placed between the two slide rails  71  and the other end provided with an inner surface formed as a gear rack  75  capable of being meshed with the driving gear  73  (as shown in FIG.  3 ), a connecting rod  76  fixed at a bottom of the slide block  74  and having a retaining member  77  disposed at a lower end thereof and having a diameter larger than the width of the a slide slot  42  of the latch-bolt assembly  4 . 
     In locking, as shown in FIG. 4, firstly, insert a key (not shown) into the lock base  3  to turn and move the dead bolts  30  of the lock base  3  outwards to be inserted into and engaged with an engagement hole of a doorframe (not shown), by which a common locking movement is completed. Secondly, press down a locking button of a remote controller (not shown) to send a locking sign to the circuit board  6  to actuate the motor  72  of the braking device  7  to turn the driving gear  73  clockwise to rotate the gear rack  75  of the slide block  74  that is meshed with the driving gear  73  to move the slide block  74  upwards so that the retaining member  77  of the connection rod  76  will follow the upward movement of the slide block  74  to be inserted into and engaged with the through hole  41  of the latch-bolt assembly  4  and is limited in the through hole  41  without moving into the slide slot  42  because the width of the slide slot  42  is smaller than the diameter of the retaining member  77  so as to restrict the latch-bolt assembly  4  in a locked position without moving back into the case body  2 , by which even though the dead bolts  30  of the lock base  3  are unlocked by the key, the door lock of the present invention is still unable to be completely unlocked without using the remote controller to actuate the braking device  7  to relieve the latch-bolt assembly  4  from being locked, thus achieving a best effect of anti-theft. 
     In unlocking, as shown in FIG. 5, firstly, press down an unlocking button of the remote controller to send an unlocking sign to the circuit board  6  to actuate the motor  72  of the braking device  7  to turn the driving gear  73  counterclockwise to rotate the gear rack  75  of the slide block  74  that is meshed with the driving gear  73  to move the slide block  74  downwards so that the retaining member  77  will follow the downward movement of the slide block  74  to be disengaged from the through hole  41  of the latch-bolt assembly  4 , and the connecting rod  76  will be remained in the through hole  41  and can slide into the slide slot  42  because the diameter of the connecting rod  76  is smaller than the width of he slide slot  42 , by which the latch-bolt assembly  4  can move back into the case body  2 . Secondly, insert the key into the lock base  3  to turn and move the dead bolts  30  of the lock base  3  inwards to be disengaged from the engagement hole of the doorframe, by which the unlocking movement of the door lock of the present invention is completed. 
     Moreover, a second preferred embodiment of the remote-controlled door lock in the present invention, as shown in FIG. 6, mainly has a stop plate  43  instead of the through hole  41  and the slide slot  42  of the latch-bolt assembly  4  to be designed as a stop plate  43 . The stop plate  43  is disposed on the latch-bolt assembly  4  and for being stopped by the retaining member  77  of the braking device  7 . 
     In locking, as shown in FIG. 7, firstly, insert the key into the lock base  3  to turn and move the dead bolts  30  of the lock base  3  outwards to be inserted into and engaged with the engagement hole of the doorframe, by which a common locking movement is completed. Secondly, press down the locking button of the remote controller to send a locking sign to the circuit board  6  to actuate the motor  72  of the braking device  7  to turn the driving gear  73  counterclockwise to rotate the gear rack  75  of the slide block  74  that is meshed with the driving gear  73  to move the slide block  74  downwards so that the retaining member  77  of the connecting rod  76  will follow the downward movement of the slide block  74  to be located behind the stop plate  43  of the latch-bolt assembly  4  to stop the latch-bolt assembly  4  so as to restrict the latch-bolt assembly  4  in a locked position without moving back into the case body  2 , by which even though the dead bolts  30  of the lock base  3  are unlocked by the key, the door lock of the present invention is still unable to be completely unlocked without using the remote controller to actuate the braking device  7  to relieve the latch-bolt assembly  4  from being locked, thus achieving a best effect of anti-theft. 
     In unlocking, as shown in FIG. 8, firstly, press down an unlocking button of the remote controller to send an unlocking sign to the circuit board  6  to actuate the motor  72  of the braking device  7  to turn the driving gear  73  clockwise to rotate the gear rack  75  of the slide block  74  that is meshed with the driving gear  73  to move the slide block  74  upwards so that the retaining member  77  will move upward by following the upward movement of the slide block  74  so as not to stop the stop plate  43  of the latch-bolt assembly  4 , any more and allow the latch-bolt assembly  4  to move back into the case body  2 . Secondly, insert the key into the lock base  3  to turn and move the dead bolts  30  of the lock base  3  inwards to be disengaged from the engagement hole of the doorframe, by which the unlocking movement of the door lock is completed. 
     While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.