Patent Publication Number: US-6334348-B1

Title: Electronic lock

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a lock, and more particularly to an electronic lock. 
     BACKGROUND OF THE INVENTION 
     As shown in FIGS. 1 and 2, an electronic lock of the prior art comprises a housing  1  which is fastened with a base  2  for containing a lock core  3 , a large circular pad  4 , a small circular pad  5 , a retaining pillar  6 , an elastic element  7 , and an electromagnetic element  8 . A handle shaft  9  is fastened pivotally with the housing  1  for mounting thereon the electromagnetic element  8 . The handle shaft  9  is provided in the periphery thereof with a plurality of second engagement projections  91  corresponding to a first engagement projection  61  of the retaining pillar  6 . The elastic element  7  is engaged at one end thereof with the second engagement projections  91 . The handle shaft  9  is fastened with a handle  10  capable of actuating the handle shaft  9  to turn. The elastic element  7  is received at other end thereof in the center of the first engagement projection  61  of the retaining pillar  6 . The retaining pillar  6  is provided at other end thereof with a retaining hole  62  for retaining a retaining projection  31  of the lock core  3 . The retaining projection  31  is fitted into the large and the small circular pads  4  and  5 . The lock core  3  is provided with a lock tongue  11 . When the electromagnetic element  8  is connected with the power source, the small circular pad  5  and the large circular pad  4  are attached to the electromagnetic element  8  such that the retaining pillar  6  is actuated to remain in an action position. In the meantime, the second engagement projection  91  of the handle shaft  9  is completely engaged with the first engagement projection  61  of the retaining pillar  6 , whereas the retaining hole  62  of the retaining pillar  6  is coupled with the retaining projection  31  of the lock core  3 . As a result, the lock core  3  can be actuated to turn by the handle  10  via the handle shaft  9 , the retaining pillar  6  and the retaining projection  31  of the lock core  3 . 
     Such a prior art electronic lock as described above is defective in design in that it can be easily tampered with by an unauthorized person using a magnetic article to bring about an outward displacement of the large and the small circular pads, thereby resulting in the retaining pillar being activated to locate at the action position so as to cause the second engagement projection of the handle shaft to engage the first engagement projection of the retaining pillar. The lock core can be thus turned by the handle to unlock the electronic lock. 
     As shown in FIG. 3, another prior art electronic lock comprises a dish-shaped clutch magnetic collection seat which is a coil ring  2  mounted on the center shaft of an outer seat disk I for attracting the dish-shaped action piece  3  which is mounted on the actuation retainer  4 . The actuation retainer  4  is provided with a retaining seat  5  and is engaged with a receiving seat  6  and a fitting ring  7 . Located between the action piece  3  and the coil ring  2  is a spring  8  which is corresponding in location to another spring  9 . The retaining seat  5  is fastened pivotally with an outer handle  13  in conjunction with a recessed wheel block  11  and a protruded wheel block  12 . A square bolt  14  is joined with the receiving seat  6 . When the magnetic action is at work, the action piece  3  forces the spring  8  to become attached to the coil ring  2 . In the meantime, the actuation retainer  4  is moved to retain the retaining seat  5  so as to turn the outer handle  13 . The motion is imparted to the receiving seat  6  to actuate the square bolt  14  to rotate. As a result, the tongue bolt  15  is unlocked. This prior art electronic lock can be also easily tampered with by an unauthorized person making use of a magnetic object having a greater magnetic force than the electronic lock. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide an electronic lock which cannot be easily tampered with by an unauthorized person. 
     In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by an electronic lock comprising a housing in which an electromagnetic element is disposed. The electromagnetic element is provided with a receiving slot receiving an elastic element which is fitted over a protruded pillar of an actuation block. The actuation block has an arresting ring which is confined to the side of the elastic element. The actuation block is provided with a fitting hole in which the connection shaft of an action piece is received. The action piece is thus located at the outer sides of the electromagnetic element and the actuation block. The connection shaft is provided at other end thereof with a fastening piece for fastening a handle. When the electromagnetic element is connected with the power source, the action piece is attracted to move inwards to urge the actuation block, which is thus forced to move inwards to compress the elastic element. The protruded pillar of the actuation block is then forced into the retaining block of the lock belly so as to control the unlocking of the lock tongue. At this time, the fitting hole of the actuation block is still engaged with the connection shaft. The door can be thus opened by turning the doorknob. When the electromagnetic element is disconnected from the power source, the actuation block is forced by the elastic force of the elastic element to move outward, thereby resulting in the separation of the protruded pillar from the retaining block. The action of the lock tongue thus cannot be controlled. All components of the electronic lock of the present invention must be engaged during the same inward action to unlock the electronic lock. The electronic lock of the present invention cannot be easily tampered with by an unauthorized person using a magnetic object having a magnetic force greater than the magnetic force of the electromagnetic element of the electronic lock. 
    
    
     The foregoing objective, features, functions, and advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a schematic view of an electronic lock of the prior art. 
     FIG. 2 shows a partial enlarged view of the electronic lock of the prior art as shown in FIG. 
     FIG. 3 shows a schematic view of another electronic lock of the prior art. 
     FIG. 4 shows an exploded view of an electronic lock of the present invention. 
     FIG. 5 shows a schematic view of the electronic lock of the present invention in combination. 
     FIG. 6 shows a schematic view of the present invention in conjunction with a lock flank. 
     FIG. 7 shows a schematic view of the present invention at work. 
     FIG. 8 shows another schematic view of the present invention at work. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT 
     As shown in FIGS. 4 and 5, an electronic lock embodied in the present invention comprises a housing  10  in which an electromagnetic element is disposed. The electromagnetic element is a coil seat  20  having a coil. The coil seat  20  is provided in the center thereof with a receiving slot  21 , and in the side plate thereof with a hole  22  which penetrates through the receiving slot  21 . The receiving slot  21  is intended to receive a spring  30 . An actuation block  40  is provided with a protruded pillar  41 , a fitting hole  42 , and an arresting ring  43 . The protruded pillar  41  is fitted into the spring  30  and the hole  22  of the coil seat  20  such that the end of the protruded pillar  41  is jutted out of the coil seat  20 . A connection shaft  50  is provided with a stopping ring  51  and is used to dispose an action piece  60  and an outer shield  70 . The connection shaft  50  is inserted into the fitting hole  42  of the actuation block  40  such that the action piece  60  is located outside the coil seat  20  and the actuation block  40 , and that the outer shield  70  contains the coil seat  20 , the actuation block  40 , and the action piece  60 . The connection shaft  50  is further provided with a fastening piece  52  which is provided with a hole  521  corresponding to the hole  81  of a fastening piece  80  fastened with the connection shaft  50 . A handle  90  has a rotary shaft  91  which is received in the holes  521  and  81 . Located between the inner wall of the housing  10  and the fastening piece  80  is a spring  100  which is fitted over the rotary shaft  91  of the handle  90  to enable the handle  90  to return to its original position. 
     As shown in FIG. 6, the electronic lock of the present invention is fastened with a door frame  110  such that the coil seat  20  is fastened with the outer side of a lock flank  120  which is inserted onto the door frame  110 , and that the housing  10  is fastened onto the door frame  110 , and that the protruded pillar  41  of the actuation block  40  is inserted into a hole  121  of the lock flank  120 . The lock flank  120  is provided with a retaining block  122  which is located in the hole  121  for controlling the action of a lock tongue  123 . As shown in FIG. 7, when the control circuit is turned on, the coil seat  20  is connected with the power source. As a result, a magnetic force is brought about by the coil seat  20 . The action piece  60  is attracted by the magnetic force to move inwards to urge the actuation block  40 , thereby causing the arresting ring  43  of the actuation block  40  to compress the spring  30 . The protruded pillar  41  is thus displaced to enter the retaining block  122  of the lock flank  120 . In the meantime, the connection shaft  50  remains in the fitting hole  42  of the actuation block  40 . As the handle  90  is turned, the rotary shaft  91  of the handle  90  actuates the fastening piece  52  and the connection shaft  50  to turn. The motion is imparted to the actuation block  40 . As the actuation block  40  turns, the protruded pillar  41  of the actuation block  40  actuates the retaining block  122  of the lock flank  120  to turn, so as to control the action of the lock tongue  123  to enable the door frame  110  to be opened. 
     As shown in FIG. 8, as soon as the coil seat  20  is disconnected with the power source, the actuation block  40  is forced by the elastic force of the decompressed spring  30  to displace rearward, thereby resulting in the disengagement of the protruded pillar  41  of the actuation block  40  with the retaining block  122  of the lock flank  120 . As a result, the action piece  60  moves backward to return to its original position. 
     The embodiment of the present invention described above is to be regarded in all respects as being merely illustrative and not restrictive. Accordingly, the present invention maybe embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scopes of the following appended claims.