Abstract:
An improved electronic lock requires a low power and consumes less electricity including an outer frame, an inner frame, a lock axle unit and a power unit. The outer frame is fastened to the outer side of a lock stile of a door. The outer frame has an outer handle, a keypad and a key way located on the exterior, and has the interior for housing the lock axle unit and the power unit to couple with the inner frame. The power unit includes a motor, a spring, a sleeve, a sliding plate and a retain plate. The power unit is coupled with a L-shaped lever to generate lever movements. Users may enter an electronic password to activate the motor to perform locking and unlocking function. The construction greatly reduces electric power: consumption of batteries, and lowers electric voltage, and increase the durability of the batteries.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an improved electronic lock and particularly an improved electronic lock that employs a small power motor to drive the lock to reduce electric power consumption and voltage, and to increase the durability of batteries. 
     2. Description of the Prior Art 
     Conventional electronic locks generally employ only an electronic password to control unlocking of the lock. Such a design has many drawbacks in practical use, notably: 
     1. As the electronic lock controls unlocking and locking mainly through electronics, and it generally does not have keys for backup, in the event of power shortage, malfunction of electric circuits, or users forget the password, users cannot unlock the electronic lock by themselves. They have to ask the locksmith for help. It is not convenient and incurs extra cost. 
     2. Conventional electronic locks do not have well designed battery chambers. In the event of battery power running out, the whole electronic lock has to be disassembled for replenishing the batteries. It is not only inconvenient, parts (such as screws) are easily get lost during disassembly. In addition, electric circuits are easy to be damaged due to inadvertent disassembly. 
     In order to remedy the disadvantages mentioned above, Applicant has proposed a solution entitled: “Improved electronic lock” (U.S. Pat. No. 5,960,656). Although that patent can overcome the problems of conventional electronic locks, it uses solenoid valve as the main driving source. Such a design creates the following problems: 
     1. The operation of the solenoid valve requires sufficient electric power to generate the required magnetic force. When using batteries as the power supply for the electronic lock, the electric power of the batteries is consumed continuously. Hence its reliability is risky. 
     2. The solenoid valve requires electric power of 12V, and a step-up circuit is needed to boost the voltage from 12V to 50V. It consumes a lot of electric power. 
     SUMMARY OF THE INVENTION 
     In view of aforesaid disadvantages, the object of the invention is to provide an improved electronic lock that employs a motor as the power supply. The motor can function accurately at a low voltage, thus effectively overcomes the disadvantages of power draining that occurs to the solenoid valve. And durability of the batteries also increases. 
     The electronic lock according to the invention mainly includes an outer frame, an inner frame, a lock axle unit and a power unit. 
    
    
     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the invention. 
     FIG. 2 is an exploded view of the invention. 
     FIG. 3 is a schematic view of the invention in an operating condition, locked in a normal circumstance. 
     FIG. 4 is a fragmentary cross section according to FIG.  3 . 
     FIG. 5 is a schematic view of the invention in another operating condition, for unlocking. 
     FIG. 6 is a fragmentary cross section according to FIG.  5 . 
     FIG. 7 is a schematic view of the invention in yet another operating condition, for unlocking. 
     FIG. 8 is a cross section of the invention, showing locked in a normal circumstance. 
     FIG. 9 is a cross section of the invention, showing an unlocking circumstance. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, the electronic lock of the invention mainly includes an outer frame  1  fastening to a locking dock  11 . The locking dock  11  has screw struts  111  located on one side to run through the lock stile from the outer side of a door to fasten to an inner frame  2  of the lock located on the inner side of the door. 
     The outer frame  1  includes a keypad  12 , a circuit board  13  located in the interior of the keypad  12 , and an outer handle  14  located on a lower section thereof. The outer handle  14  houses a lock core  19  therein (also referring to FIG. 8) and has a shaft opening  141  for coupling with a front rod  31  and a stub  334  of a front connection disc  33  of a lock axle unit  3 , and is movable therewith. In the interior of the outer frame  1  below the circuit board, there are a barrel seat  15 , a motor seat  16  and a lock axle compartment  17  for housing a power unit  4  and the lock axle unit  3 . 
     The inner frame  2  is installed on the inner side of the lock stile of the door, and has a battery chamber  211  located on an upper side for housing batteries and an inner handle  22  for users to control extension and retraction of the latch bolt  51  of a latch assembly  5 . 
     The invention has the following characteristics: 
     The lock axle unit  3  is housed in the lock axle compartment  17  of the outer frame  1 , and includes: 
     a front rod  31  coupling with a first spring  311  and running through a front retain plate  32  and a first round opening  333  of the front connection disc  33 , and having one end movable forwards when pressed by an inserting key and other end pushing a linkage block  34 ; 
     a front retain plate  32  being fastened to the outer frame  1  by coupling screw bolts A through apertures  321  formed thereon with screw holes B located on the outer frame  1 . The front retain plate  32  has at least one strut  322  for fastening to a rear retain plate  37  through screw bolts A. In the center of the front retain plate  32 , there is a second round opening  323  to allow a stub  334  located on the front connection disc  33  to run through. Below the second round opening  323 , there is a first arched slot  324  which has a first notch  325  located on the bottom rim in the middle thereof. On the left and lower corner of the front retain plate  32 , there is a hole  326  pivotally engaging with a stub shaft  352  of a coupling barrel  353  of a L-shaped lever  35 ; 
     a front connection disc  33  having four first grooves  331  formed on the perimeter thereof and an indented straight trough  332  formed in the center of the front side. The first round opening  333  is formed on the bottom of the trough  332  to communicate with the stub  334  located on other side of the front connection disc  33 ; 
     a linkage block  34  having an aperture  341  formed in the center thereof to allow a pintle  361  located on a rear connection disc  36  to pass through. The linkage block  34  is pressed by a second spring  342  in normal conditions to wedge in the straight trough  332  of the front connection disc  33 ; 
     a L-shaped lever  35  being located between the front retain plate  32  and the rear retain plate  37 , and having a vertical section  350  and a bottom section  354 . The L-shaped lever  35  further has a coupling barrel  353  located at the corner with two ends formed respectively a stub shaft  352  to engage respectively with the hole  362  on the front retain plate  32  and another hole  375  formed on the rear retain plate  37  such that the L-shaped lever  35  is turnable about a constant axis. The top end of the vertical section  350  is extended to form an U-shaped fender  355  which has a notch  351  to allow the spindle  412  of a motor  41  to pass through; 
     a rear connection disc  36  having four second grooves  362  formed on the perimeter thereof and a cylindrical strut  363  located in the center of the front side. The cylindrical strut  363  has an aperture  364 . The cylindrical strut  363  may couple with a coupling hole  391  formed in a linkage rod  39  which has an aperture  393  formed on one end thereof, then a pin  392  may be inserted into the hole  393  and the aperture  364  to fasten the rear connection disc  36  to the linkage rod  39 . The rear connection disc  36  further has a cross straight trough  365  corresponding to the straight trough  332  of the front connection disc  33 . The pintle  361  is located in the center of the cross straight trough  365  for passing through the aperture  341  formed on the linkage block  34 ; 
     a rear retain plate  37  having apertures  371  for fastening to the struts  322  of the front retain plate  32  by means of the screw bolts A to couple with the front retain plate  32 . The rear retain plate  37  has a third round opening  372  and a second arched slot  373  located below the third round opening  372 . The second arched slot  373  has a second notch  374  located on the bottom rim in the middle thereof. On the left and lower corner of the rear retain plate  37 , there is another hole  375  pivotally engaging with the stub shaft  352  of the coupling barrel  353  of the L-shaped lever  35 ; 
     a latch bolt  38  running through the arched slots  324  and  373  of the front and the rear retain plates  32  and  37  and is fastened to a nut  381  so that the latch bolt  38  may slide to the left and the right in the arched slots  324  and  373 , and move the front and the rear connection discs  33  and  36 . The latch bolt  38  is located in the notches  325  and  374  of the arched slots  324  and  373  in normal conditions; and 
     a linkage rod  39  having a coupling hole  391  formed on one end thereof to couple with the cylindrical strut  363  of the rear connection disc  36  and is fastened by the pin  392 , and other end running through a square opening  52  of the latch assembly  5  to engage with the inner handle  22  to link the movement between the latch bolt  51  of the latch assembly  5  and the inner handle  22  of the inner frame  2 ; 
     The power unit  4  is housed in the barrel seat  15  and the motor seat  16  of the outer frame  1 , and includes: 
     a motor  41  being housed in the motor seat  16  of the outer frame  1  and fastened by a lid  411 . The spindle  412  of the motor  41  may turn in one direction or in a reverse direction depending on the polarity of the input electric power supply. Therefore a pintle  413  mounted on the spindle  412  may move along the helical path of a third spring  43  housed in a sleeve  44  to move the sleeve forwards or rearwards; 
     a sliding plate  42  coupled an opening  441  of the sleeve  44  to prevent the third spring  43  from dropping out having a round hole  421  in the center to allow the spindle  412  of the motor  41  to pass through, and a jutting flap  422  extended from one side thereof to wedge in a retain slot  451  formed on a retain plate  45 ; 
     a third spring  43  housed in the sleeve  44  having two ends engaged with a wedge slot  442  of the sleeve  44 ; 
     a sleeve  44  being hollow for housing the third spring  43  and having a wedge slot  442  formed on one side thereof; and 
     a retain plate  45  fastened to an upper section of the barrel seat  15  of the outer frame  1  to cover the sleeve  44 . The retain plate  45  has a retain slot  451  for limiting the forward and rearward moving displacement of the jutting flap  422  of the sliding plate  42 . 
     By means of the construction set forth above, referring to FIGS. 3,  4  and  8 , when the electronic lock of the invention is locked in normal conditions, the linkage block  34  of the lock axle unit  3  is pushed by the second spring  342  in the normal conditions and is wedged in the straight trough  332  of the front connection disc  33 , and the latch bolt  38  drops into the notches  325  and  374  of the arched slots  324  and  373  of the front and the rear retain plates  32  and  37  due to gravity. Thus when an user turns the outer handle  14  of the outer frame  1 , only the front connection plate  33  of the lock axle unit  3  is driven. The rear connection plate  36 , linkage rod  39  and the latch bolt  51  of the latch assembly  5  cannot be moved. The electronic lock of the invention cannot be unlocked and is in a locked condition. To unlock the electronic lock of the invention, users may enter the correct password on the keypad  12  on the outer frame  1  to activate the circuit board  13 , and the motor  41  of the power unit  4  is activated and rotates. As the spindle  412  of the motor  41  rotates at a constant location and the sleeve  44  is movable, when the pintle  413  of the spindle  412  rotates along the helical path of the spring  43 , the sleeve  44  is pushed forwards. The U-shaped fender  355  of the L-shaped lever  35  is pushed by front end of the sleeve  44  (as shown in FIG. 6) and moved outwards. As a result, the bottom section  354  is tilted upwards to push the latch bolt  38  upwards into the arched slots  373  and  324 , and the grooves  331  and  362  of the front and rear connection plates  33  and  36  (as shown in FIG.  5 ). In such a condition, when the user turns the outer handle  14  of the outer frame  1 , the front and rear connection plates  33  and  36  and the linkage rod  39  of the lock axle unit  3  are driven to move the latch bolt  51  of the latch assembly  5 , and the lock may be unlocked and opened (as shown in FIG.  7 ). 
     In the event that the user has forgotten the password or battery power in the electronic lock is exhausted, and the electronic lock cannot be activated, the user may insert the key  6  into the key way (as shown in FIGS. 8 and 9) to push the front rod  31  of the lock axle unit  3 . The linkage block  34  may be pushed and moved between the straight trough  332  of the front connection disc  33  and the cross straight trough  365  of the rear connection disc  36  of the lock axle unit  3 . Then the outer handle  14  of the outer frame  1  may be turned to drive the front and the rear connection discs  33  and  36 , and in turn to drive the linkage rod  39  and the latch bolt  51  of the latch assembly  5  to accomplish the unlocking (operations of inserting the key into the key way are known in the art, thus are omitted in the drawings and descriptions). 
     While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiment thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.