Patent Publication Number: US-7712340-B2

Title: Lock structure

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the invention 
   The present invention relates to an improvement on a lock structure, more particularly one, which includes a lock body, and a locking crutch to cooperate with the lock body to lock an object; the lock body is equipped with two movable engaging plates, and the locking crutch has two grooves to receive respective ones of the movable engaging plates so that the lock can be firm in the locking configuration. 
   2. Brief Description of the Prior Art 
   A variety of locks are available for helping to prevent thievery, e.g. door locks, combination locks, and cable locks, which are mainly used for locking bicycles and motorcycles. And, the industry have recently developed electromagnetic locks, chip locks, and voice-controlled locks, which are more advanced than the above-mentioned conventional locks, and can&#39;t be easily opened by unauthorized persons. Moreover, stronger locks are also available, which are made of saw-resistant materials so as not to be damaged with saws. 
   A currently existing saw-resistant lock is available, which includes a lock body consisting of several metallic plate parts. The plate parts have already undergone heat treatment to increase their strength, and are positioned on above another. Therefore, it is relatively difficult for thieves to damage the lock with a saw. 
   However, it takes relatively much cost, labor and time to manufacture the saw-resistant lock because all of the metallic plate parts have to be subjected to heat treatment, and then stacked and fastened together by means of rivets. 
   To overcome the above-mentioned problems, the inventor of the present invention developed an improvement on a saw-resistant lock, which has been filed for U.S. patent application with application Ser. No. 11/979,652. The saw-resistant lock includes a lock body, a lock core held in a core holding hole of the lock body. The lock body has several pin holes on a periphery portion thereof, and saw-resistant pins are inserted in the pin holes of the lock body respectively; the saw-resistant pins have already undergone heat treatment to have high strength. Therefore, the present lock has a lower manufacturing cost, and is easier to assembly than the above-mentioned saw-resistant stacked-plate lock. 
   However, besides having saw-resisting capability, a lock should be very firm in the locking configuration and smoothly operable without the possibility of its locking crutch being interfered with when moving relative to the lock body. Therefore, it is a main object of the present invention to provide an improvement on a lock, which has a good saw-resisting capability, and is smoothly operable, and relatively easy to assemble as compared with the above-mentioned saw-resistant stacked-plate lock. 
   SUMMARY OF THE INVENTION 
   A lock in accordance with an embodiment of the present invention includes a lock body, a key-operated lock core in a middle hole of the lock body, two spring-biased movable plates slideable on a recessed portion of the lock body, and a locking crutch capable of being fastened to the lock body with the spring-biased movable plates. The lock body has crutch embedding holes on two sides of the middle hole. The lock core has a plate part, and force will be applied to the movable plates through the plate part of the core when the core is turned. The locking crutch has a groove on each of two ends thereof to engage a corresponding said movable plate. The movable plates will be spring-biased towards the crutch embedding holes to engage the locking crutch as soon as the lock core is turned to the locking position; thus, the locking crutch and the body together form a loop. The movable plates will be forced to disengage from the locking crutch by the plate part of the lock core when the lock core is turned to the unlocking position. 
   Furthermore, several saw-resistant pins are inserted in receiving holes formed on a periphery of the lock body; thus, the lock is prevented from being damaged with a saw. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood by referring to the accompanying drawings, wherein: 
       FIG. 1  is an exploded perspective view of the present invention, 
       FIG. 2  is a perspective sectional view of the present invention, 
       FIG. 3  is a sectional view of the present invention, 
       FIG. 4  is a sectional view of the lock of the present invention, taken when the lock is being moved to an opened configuration, 
       FIG. 5  is a horizontal sectional view of the present invention, and 
       FIG. 6  is a horizontal sectional view of the present invention in the opened configuration. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a preferred embodiment of a lock structure of the present invention includes: 
   a lock body  1 ; the lock body  1  has a lock hole  11  on a middle portion, and crutch embedding holes  12  on two sides of the lock hole  11 ; the lock body  1  further has a receiving recessed portion  13  on an upper side thereof, which adjoins upper ends of the lock hole  11  and the crutch embedding holes  12 ; the lock body  1  has several pin receiving holes  14  and fixing holes  15  on a periphery thereof; 
   a lock core  2  held in the lock hole  11  of the lock body  1 ; the lock core  2  has a plate part  21  at a front end thereof; 
   a locking crutch  3 ; the locking crutch  3  can be embedded in the crutch embedding holes  12  of the lock body  1  at two ends thereof; the two ends of the locking crutch  3  each have a groove  31  thereon, and both the grooves  31  are parallel to each other; 
   first and second movable plates  4 , which are held in the receiving recessed portion  13  of the lock body, and biased towards the crutch embedding holes  12  of the lock body  1  with elastic elements  43  so that the crutch embedding holes  12  are normally partially covered with respective ones of the movable plates  4 ; each of the movable plates  4  has first and second joining protrusions  41  and  42 ; one of the elastic elements  43  is joined at two ends thereof on the first joining protrusion  41  of the first movable plate  4  and the second joining protrusion  42  of the second movable plate  4  while the other elastic element  43  is joined at two ends thereof on the second joining protrusion  42  of the first movable plate  4  and the first joining protrusion  41  of the second movable plate  4 ; furthermore, each of the movable plates  4  has a stopping plate part  44  to cooperate with the lock core  2 ; 
   an upper cover  5 , which is secured on the upper side of the lock body  1  to cover the movable plates  4  and the elastic elements  43 ; the upper cover  5  has two receiving recessed portions  51  to receive the elastic elements  43  respectively; the upper cover  5  further has fixing holes  52 , which are aligned with respective ones of the fixing holes  15  of the lock body  1 ; 
   several saw-resistant pins  6 , which are inserted in the pin receiving holes  14  of the lock body  1  to prevent the lock from being damaged with a saw; the saw-resistant pins  6  have undergone heat treatment to increase their strength; 
   a bottom cover  8  secured on a bottom of the lock body  1  to cover the lock core  2 ; the bottom cover  8  has a keyway for a key to pass through, and several fixing holes  81 ; 
   several fixing pins  7 , which are used to fasten the bottom cover  8 , the lock body  1  and the upper cover  5  together; the fixing pins  7  have undergone heat treatment; the fixing pines  7  each have a truncated-cone shaped stopping portion  71  at a lower end, and a riveting hole  72  at an upper end; each of the fixing pins  7  is inserted in corresponding fixing holes  81 ,  15  and  52  in sequence so that the truncated-cone shaped stopping portion  71  contacts the bottom cover  8 , and the riveting hole  72  sticks out from the fixing hole  52 ; the upper ends of the fixing pins  7  are hammered to closely come into contact with the upper cover  5 ; and 
   a shell  9  positioned around the lock body  1 ; the shell  9  has a connecting hole  91 , to which the lock body  1  is firmly connected; the shell  9  has two through holes  92 , which face the crutch embedding holes  12  of the lock body  1  respectively to allow two ends of the locking crutch  3  to pass through, as shown in  FIGS. 3 and 4 . 
   In addition, the lock body  1  is a piece of hard plastic. The fixing holes  15  of the lock body  1  become gradually narrower towards one end, and have a smaller diameter than the fixing pins  7 . And, the pin receiving holes  14  of the lock body  1  have a smaller diameter than the saw-resistant pins  6  so that the saw-resistant pins  6  can be closely in contact with the lock body  1 . 
   Referring to  FIGS. 1 and 2 , in assembly, the lock core  2  is placed in the lock hole  11  of the lock body  1 , with the plate part  21  being held in the upper section of the lock hole  11 . And, the movable plates  4  are placed in the receiving recessed portion  13  of the lock body  1 , and the elastic elements  43  are joined to the movable plates  4  so that the movable plates  4  are usually spring-biased towards corresponding said crutch embedding holes  12  so as to cover at least a portion of a corresponding said crutch embedding hole  12 ; thus, the movable plates  4  will be each detained in a corresponding said groove  31  of the locking crutch  3  if the locking crutch  3  is inserted in the crutch embedding holes  12  of the lock body  1 . Therefore, the movable plates  4  will be forced to move away from the corresponding crutch embedding holes  12  by the plate part  21  of the lock core  2  if the lock core  2  is turned to an opening position, thus allowing the locking crutch  3  to move relative to the lock body  1  for the present lock to open. When the lock core  2  is turned to a locking position, the movable plates  4  will be forced to move onto corresponding said crutch embedding holes  12  by the elastic elements  43 ; thus, the movable plates can engage corresponding said locking crutch grooves  31  to prevent the locking crutch  3  from moving relative to the lock body  1 , and in turn the lock is fixed in the locking configuration. Next, the upper cover  5  is positioned over the upper side of the lock body  1  to cover the movable plates  4  and the elastic elements  43 , with the elastic elements  43  being held in the receiving recessed portions  51  of the upper cover  5 . The bottom cover  8  is positioned under the bottom of the lock body  1 , and the fixing pins  7  are passed through the fixing holes  81 ,  15  and  52  to fasten the bottom cover  8 , the lock body  1 , and the upper cover  5  together. 
   Referring to  FIG. 3  to  FIG. 6 , as soon as the lock core  2  is turned to the opening position, the plate part  21  will push the stopping plate parts  44  of the movable plates  4  so that the elastic elements  43  are compressed, and the movable plates  4  disengage from the grooves  31  of the locking crutch  3 . Consequently, the lock can be opened by means of moving the locking crutch  3  relative to the lock body  1 . As soon as the lock core  2  is turned to the locking position, the elastic elements  43  will force the movable plates  4  to engage the grooves  31  of the locking crutch  3  again; thus, the lock body  1  and the locking crutch  3  together form a loop for allowing the present lock to be fixed in the locking configuration. 
   From the above description, it can be seen that the present invention has the following advantages: 
   1. The locking crutch has an engaging groove on each of two ends thereof, and the lock body of the present invention has two movable plates, which are held and capable of sliding in the upper receiving recessed portion of the lock body to engage the grooves of the locking crutch respectively. Therefore, the lock of the present invention can be more smoothly operated than conventional locks that have a locking crutch with single engaging groove. 
   2. For the above reason, the lock of the present invention can be more firmly fixed in the locking configuration. 
   3. The lock body of the present invention is protected against sawing by means of the saw-resistant pins, which are inserted in the periphery portion, and have already undergone heat treatment. Therefore, while having the same saw-resistant capability, the present lock body has relatively low manufacturing and assembling cost as compared with the prior art, which comprises several stacked metallic plates having already undergone heat treatment. 
   4. The fixing pins have also undergone heat treatment, and therefore can help prevent the lock from being damaged with a saw after they are joined to the bottom cover, the lock body and the upper cover.