Patent Publication Number: US-6338261-B1

Title: Lock with a replaceable cylinder

Description:
FIELD OF THE INVENTION 
     The present invention relates to a lock which has a cylinder connected with a locking bar by a pin, the cylinder and/or the locking pins in the cylinder can be easily replaced. 
     BACKGROUND OF THE INVENTION 
     A conventional lock includes a case having a cylinder rotatably received in the case, a plurality of locking pins movably received in the casing and biased by springs. The locking pins radially extend into the cylinder so as to be located between the boundary surface between the case and the cylinder when the lock is in locked position. The cylinder has a key hole for receiving a key therein, the key has serrations on a side thereof so that when the key is inserted into the key hole, the locking pins are pushed into the case by the insertion of the serrations, and when the key is completely engaged with the key hole in the cylinder, the locking pins are pushed by the springs and engaged with the serrations so that the boundary surface will not be stopped by the locking pins. Therefore, when rotating the key, the cylinder is rotated to disengage the shackle or the like to unlock the lock. The case generally is made of steel and the cylinder is generally made of copper which is softer than the steel, so that the cylinder and/or the locking pins will be worn out and this could affect the precision of the locking pins in the unlock positions. That is the reason why the cylinder of a used lock is difficult to be rotated. 
     The present invention intends to provide a lock whose cylinder and/or locking pins can be easily replaced while the case is remained the same. The present invention provides a way to resolve the inherent disadvantage of the conventional lock. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided a lock comprising a case which has slot and a recess and a passage are respectively defined in the case and communicate with the slot. A locking bar extends through an engaging hole in the case and which communicates with the passage. A sleeve is connected to a base member, and both the sleeve and the base member are received in the engaging hole by a bolt. The locking bar extends through the sleeve and has an elongated head which is engaged with the recess in the case. A plurality of chambers are defined radially through the sleeve and the base member, each chamber having a tube and a locking pin, both of the tube and the locking pin are biased by a spring received in the chamber in the base member. A cylinder has a key hole and is rotatably received in the sleeve. The cylinder is connected to the locking bar by a pin. 
     The object of the present invention is to provide a lock whose cylinder can be independently replaced regardless of the case. 
     Another object of the present invention is to provide a lock whose locking pins in the cylinder can be replaced regardless of the cylinder. 
     These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of the lock in accordance with the present invention; 
     FIG. 2 is a side elevational view, partly in section, of the lock in accordance with the present invention, wherein the lock is in an unlock status; 
     FIG. 3 is a side elevational view, partly in section, of the lock in accordance with the present invention, wherein the lock is in a locked status; 
     FIG. 4 is a cross-sectional view to show the elongated head of the locking bar and the narrow neck portion in the recess of the case when in an unlock status; 
     FIG. 5 is a cross-sectional view to show the elongated head of the locking bar and the narrow neck portion in the recess of the case when in a locked status; 
     FIG. 6 is a cross-sectional view to show the locking pins located between the cylinder and the sleeve when in a locked status; 
     FIG. 7 is a cross-sectional view to show the locking pins are pushed to allow the cylinder rotatable relative to the sleeve when in an unlock status, and to show the locking bar is disconnected from the cylinder; 
     FIG. 8 is a cross-sectional view to show the locking pins together with the cylinder are removed from the sleeve with the movement of the key; 
     FIG. 9 is a cross-sectional view to show the new locking pins together with the cylinder are to be inserted into the sleeve by pushing a new key in the case; 
     FIG. 10 is a cross-sectional view to show the new locking pins, the cylinder and the new key are inserted in to sleeve and the locking bar is connected to the cylinder; 
     FIG. 11 is a cross-sectional view to show the new key is removed from the sleeve, and 
     FIG. 12 is an illustrative view to show the lock of the present invention is used to lock two members. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 to  3 , the lock in accordance with the present invention comprises a case  10  having a slot  11  defined in a side thereof so that when locking two members as shown in FIG. 12, a tongue  31  as shown in FIGS. 2 and 3 of the two members can be inserted from the slot  11 . The slot  11  is defined by a first inside and a second inside, a recess  17  defined in the first inside and having a narrow neck portion, and a passage  12  defined through the second inside. An engaging hole  14  is defined in the case  10  and communicates with the passage  12 . The narrow neck portion in the recess  17  is defined by two positioning bars  171  respectively located in the recess  17 . 
     A sleeve  23  is connected to a base member  22  so as to form an “8” shaped member which is removably received in the engaging hole  14 . A notch  221  is defined in the base member  22  and a threaded hole  15  is defined through the case  10  and communicates with the engaging hole  14  in the case  10 . A bolt  16  threadedly extends through the threaded hole  15  and is engaged with the notch  221  so that the sleeve  23  and the base member  22  are retained in the case  10 . A cylinder  21  has a key hole  210  and is rotatably received in the sleeve  23 . The cylinder  21  is connected to a second end of the locking bar  211  by a pin  212 . The notch  221  is a long notch so that when the key  100  is not yet inserted into the cylinder  21 , the base member  22  is stopped by the bolt  16  at one of two ends of the notch  221  as shown in FIG.  2 . When inserting the key  100 , the base member  22  is inserted into the case  10  and the bolt  16  contacts the other end of then notch  221 , and the locking bar  211  is inserted into the recess  17  as shown in FIG. 3. A locking bar  211  has a first end with a groove  213  and an elongated head  214 , and the locking bar  211  is received in the sleeve  23  so that the elongated head  214  is received in the recess  17  in the case  10  and an inner periphery defining the narrow neck portion is engaged with the groove  213  in the locking bar  211  as shown in FIGS. 4 and 5. The elongated head  214  has two sides which are located between the two positioning bars  171  when the lock is in unlock status. On the contrary, when the locking bar  211  is rotated to let the two ends of the elongated head  214  be engaged with the two positioning bars  171 , the lock is locked. Further referring to FIG. 6, a plurality of chambers  24  are defined radially through the sleeve  23  and the base member  22 , each chamber  24  having a tube  217  and a locking pin  218 , and both of the tube  217  and the locking pin  218  being biased by a spring  216  received in the chamber  24  in the base member  22 . 
     Referring to FIG. 7, when the correct key  100  inserted into the cylinder  21 , the serrations of the key  100  push the locking pins  218  to compress the springs  216  so that the locking pins  218  are located to allow the cylinder  21  rotatable relative to the sleeve  23 . Therefore, the elongated head  214  of the locking bar  211  is rotated so that the locking bar  211  can be removed from the recess  17  to unlock the lock. 
     If the base member  22  and the sleeve  23  are to be replaced, the bolt  16  is first removed, and the locking the base member  22  and the sleeve  23  can be easily removed from the case  10  and replaced. 
     Referring to FIG. 8, if the cylinder  21  is to be replaced, the pin  212  is first removed and the locking bar  211  is disengaged from the cylinder  21 , so that the cylinder  21  can be removed from the sleeve  23  together with the key  100 . Therefore, the cylinder  21  can be replaced. Referring to FIGS. 9 to  11 , a new cylinder  21 ′ and/or new locking pins  218 ′ can be cooperated with a new key  100 ′, and all of them are inserted into the sleeve  23  so that the cylinder  21 ′ and/or the locking pins  218 ′ are inserted in the original case  10 . 
     Accordingly, the lock of the present invention involves a feature which allows the user to change the cylinder  21 , the locking pin  218  or the key  100  while the case  10  is remained the same. 
     While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope and spirit of the present invention.