Patent Document

CROSS-REFERENCES TO RELATED APPLICATIONS 
     The applicant wishes to claim the benefit of U.S. Provisional Patent Application No. 60/275,739, dated Mar. 14, 2001 for RETRACTABLE CABLE LOCK WITH RESET MECHANISM in the names of Cornelius McDaid, Jason A. Morris, and Donald H. Warren. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to locks, more particularly, to a mechanism that prevents accidental resetting of the combination of a retractable wire lock. 
     2. Description of the Related Art 
     A popular wire lock on the market today is a portable model with a thin, retractable wire, as disclosed in U.S. Pat. No. 4,896,517, issued to Ling. The wire, with a locking head, extends from a wire hole on the top surface of the lock casing. At the opposite end of the top surface is a locking hole into which the locking head is inserted. Between the two holes is a set of coaxial combination dials. When the correct combination is set, the locking head can be snapped into the locking hole. If the combination is changed from the correct combination, the locking head is secured in the locking hole. 
     The lock is designed so that the user can reset the combination. The combination is reset by first setting the current correct combination, and then pushing the locking head down into the wire hole until it hits a stop. The user then sets the new combination and pulls the locking head from the wire hole. Now the new combination is locked in and must be used to operate the lock. 
     The problem with this mechanism that is addressed by the present invention is that it is relatively easy to change the combination without realizing it. The typical problem scenario is that the user finishes using the lock and leaves the dials set to the correct combination. Then the lock is dropped into a bag or other container. The lock is either dropped onto its top edge or another item is dropped on top of the lock, pushing the locking head into the wire hole. While rummaging around in the bag for the lock or some other item, one or more of the dials are inadvertently turned. The next time the lock is used, the user pulls the locking head from the wire hole, resetting to the new combination. Up to this point there would be no real problem, except that the user most likely is not going to look at the combination dials because she already “knows” what the combination is. So the user snaps the locking head into the locking hole and spins the dials off the correct combination without looking. Now, the combination has been set to something other than what the user thinks it is, but doesn&#39;t realize it until she later tries to open the lock. At this point, since the user does not know the current correct combination, the only way to release the device being secured is to cut the wire, thereby destroying the lock. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a retractable wire lock in which it is much more difficult than in similar locks of the prior art to inadvertently reset the combination. 
     The present invention is an improvement of an existing lock described in U.S. Pat. No. 4,896,517 (the &#39;517 patent), incorporated herein by reference. The present invention replaces the combination reset mechanism of the &#39;517 lock with one of two embodiments. The combination is reset by pushing an internal reset block inwardly. In the lock of the &#39;517 patent, the reset block is pushed inwardly by pushing the locking head into the wire hole in the casing. A tapered surface on the locking head contacts an inclined surface of the reset block, pushing the reset block inwardly. 
     In one embodiment of the present invention, the &#39;517 reset block is replaced by a reset block that has a reset button. The reset button extends from the reset block out of the casing. In order to reset the lock combination, the user presses and holds the reset button, sets the new combination, then releases the reset button. 
     The second embodiment also replaces the &#39;517 block with a reset block that has a reset button. In addition, the second embodiment employs the locking head to hold the reset block in the reset position so that the user does not have to continually press the reset button during the reset procedure. The reset block has an arcuate cavity around the locking head. A flat shoulder on the lower portion of the locking head sits on a ledge on the surface of the cavity, preventing the locking head from being pushed into the wire hole. Pressing the reset button disengages the ledge from the locking head, allowing the user to push the locking head into the wire hole, which now holds the reset block in the reset position. After the new combination has been set, the user pulls the locking head from the wire hole, causing the reset block to return to its normal position, setting the new combination. 
     Other objects of the present invention will become apparent in light of the following drawings and detailed description of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and object of the present invention, reference is made to the accompanying drawings, wherein: 
     FIG. 1 is a top cross-sectional view detailing the first embodiment of the combination reset mechanism of the present invention; 
     FIG. 2 is a front cross-sectional view detailing the combination reset mechanism of FIG. 1; 
     FIG. 3 is a top cross-sectional view detailing the second embodiment of the combination reset mechanism of the present invention in the normal position; 
     FIG. 4 is a front cross-sectional view detailing the combination reset mechanism of FIG. 3; and 
     FIG. 5 is a front cross-sectional view detailing the combination reset mechanism of FIG. 3 in the reset position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As indicated above, the present invention is an improvement of an existing lock. The lock is described in detail in U.S. Pat. No. 4,896,517, incorporated herein by reference. This specification will first summarize the &#39;517 patent and then describe in detail the improvement of the present invention. 
     Referring to the figures of the &#39;517 patent, the lock of the &#39;517 patent includes a casing  1 , a wire means  2 , a plurality of dials  3 , a plurality of sleeves  4 , a locking head latch  5 , a resilient impinger  6 , and a wire clutch means  7 . 
     The casing  1  contains the internal components of the lock. The lower part of the casing  1  has space for the wire means  2 . The wire means  2  includes a wire rope  21  wound on a spring-loaded reel  22 . As the wire rope is pulled from the reel  22 , the spring  23  is wound. When the wire rope  21  is released, the spring  23  unwinds, rotating the reel  22  to rewind the wire rope  21  back onto the reel  22 . A locking head  24  is permanently attached to the outer end of the wire rope  21 . 
     The wire clutch means  7  retains the wire rope  21  at the length pulled from the reel  22 . A pushbutton  71  operates a pawl  73  that engages teeth  221  on the reel  22 . It also operates a bifurcate portion  78  for straightening the wire rope  21  within the casing  1 . 
     The upper part of the casing  1  has a vertical wire hole  12  from which the locking head  24  of the wire  21  is pulled, a vertical locking hole  13  into which the locking head  24  is inserted for locking, and a horizontal latch hole  14  in the side wall adjacent to the locking hole  13  for the latch pushbutton  51  that releases the locking head  24  from the locking hole  13 . The spring-loaded impinger  6  sits in the lower end of locking hole  13 . When the locking head  24  is pushed into the locking hole  13 , it pushes against the impinger  6 , compressing the impinger spring  62 . When in this position, the impinger  6  prevents the clutch button  71  from operating. When the latch pushbutton  51  releases the locking head  24 , the spring  62  causes the impinger  6  to push the locking head  24  from the locking hole  13 . 
     Each combination dial  3  is an annular ring  31  with a plurality of grooves  321  formed in the bore. Each groove  321  is engageable with a tooth  41  formed on a surface of a sleeve  4 . Each sleeve  4  includes a central hole  40  for slidably engaging a cylindrical rod  50  of the locking head latch  5  and a recess  42  in the central hole  40  engageable with a key  56  protruding from the cylindrical rod  50 . The locking head latch  5  includes a latch pushbutton  51 , a locking aperture  52  into which the locking head  24  is inserted, and a cylindrical rod  50  formed on a inner portion of the locking head latch  5  slidably engageable with a central hole  40  of the sleeve  4 . The edge of the locking aperture  52  engages a neck portion  243  of the locking head  24  to secure the locking head  24  into the locking hole  13 . 
     The combination dial grooves  321  are engaged with the sleeve teeth  41 . When the combination dial  3  is rotated, the sleeve  4  also rotates. When the sleeves  4  are rotated so that the recesses  42  are all aligned with the cylindrical rod keys  56 , the latch pushbutton  51  can be pushed inwardly, moving the edge of the locking aperture  52  from the locking head neck portion  243 , releasing the locking head  24  from the locking aperture  52 . A spring  55  biases the latch pushbutton  51  outwardly. 
     The present invention involves the combination reset mechanism of the lock. In the lock of the &#39;517 patent, a sliding block  15  is movable inwardly when inward pressure is applied. When the sliding block  15  is so moved, it pushes the sleeves  4  inwardly until the sleeve teeth  41  disengage from the combination dial grooves  321 , while straddling the locking latch cylindrical rod  50 . Now the combination dials  3  can be rotated to a new combination. When the inward pressure is removed from the sliding block  15 , the pushbutton bias spring  55  causes the sliding block  15  to move back to its normal position and also causes the sleeve teeth  41  to reengage with the combination dial grooves  321 , setting the new combination. 
     In the lock of the &#39;517 patent, inward pressure on the sliding block  15  is provided by the locking head  24 . The locking head  24  includes a cylindrical portion  240  with a lower tapered surface  244  circumferentially formed on a lower portion of the cylindrical portion  240 . The lower tapered surface  244  is tangentially engageable with an upper inclined surface  151  of the sliding block  15 . When the locking head  24  is pushed into the wire hole  12 , the locking head lower tapered surface  244  contacts the sliding block upper inclined surface  151 , pushing the sliding block  15  inwardly. As indicated above, there is an inherent problem with this design. If the locking head  24  is accidentally pushed into the wire hole  12 , the combination could be inadvertently changed. 
     In one embodiment on the present invention, the reset mechanism of the &#39;517 patent described above is replaced with the mechanism of FIGS. 1 and 2. In this mechanism, the locking head  24  is not used to reset the combination. The sliding block  15  of the &#39;517 patent is replaced by a reset block  500 . The reset block  500  has a leg  502  extending through a hole  504  in the side wall of the casing  1  adjacent to the wire hole  12  to a reset button  506  outside of the casing  1 . Rather than pushing the locking head  24  into the wire hole  12  to reset the lock combination, the user pushes the reset button  506 . This has the effect of pushing the sleeves  4  inwardly until the sleeve teeth  41  disengage from the combination dial grooves  321 . As with the &#39;571 patent, the combination dials  3  can be rotated to a new combination. When the user releases the reset button  506 , inward pressure is removed from the reset block  500 . The latch pushbutton bias spring  55  causes the reset block  500  to move back to its normal non-reset position and also causes the sleeve teeth  41  to reengage with the combination dial grooves  321 , setting the new combination. 
     In the second embodiment of the present invention, the reset mechanism of the &#39;517 patent is replaced with the mechanism of FIGS. 3-5. One characteristic of the first embodiment described above is that the user must maintain pressure on the reset button  506  during the reset procedure. The reset mechanism of this second embodiment removes that requirement by using the locking head  24  to hold the reset block  550  in the reset position while the user resets the combination. 
     The reset block  550  has an arcuate cavity  552 . The reset button  556  is an extension of one of the legs  554  of the cavity  552 . A portion of the inner surface of the cavity  552  is stepped to form a ledge  558 . This embodiment also replaces the lower tapered surface  244  of the locking head  24  of the &#39;517 patent with a flat shoulder  560  formed between the larger cylindrical portion  564  and the smaller cylindrical portion  566 . When the reset block  550  is in its normal non-reset position and the locking head  24  is pushed into the wire hole  12 , the locking head shoulder  560  contacts the ledge  558 . This cooperation between the shoulder  560  and ledge  558  prevents the locking head  24  from being pushed any farther into the wire hole  12 , as in FIG.  4 . When the reset button  556  is pressed, the ledge  558  slides inwardly, removing the ledge  558  from the path of the locking head shoulder  560 , and allowing the user to push the locking head  24  further into the wire hole  12  to a reset hold position, as in FIG.  5 . If the reset button  556  is then released, the portion  568  of the arcuate cavity  552  below the ledge  558  contacts the larger cylindrical portion  564  of the locking head  24 , thereby holding the reset block  550  in the reset position. Optionally, a protrusion  562  at the lower part of the arcuate cavity  552  cooperates with the locking head shoulder  560  to prevent the locking head  24  from being pushed into the wire hole  12  beyond the reset hold position. After the new combination has been set, the user pulls the locking head  24  from the wire hole  12 . The pushbutton bias spring  55  pushes the reset block  550  back to its non-reset position, causing the sleeve teeth  41  to reengage with the combination dial grooves  321  and fixing the new combination. 
     Thus it has been shown and described a retractable wire lock with secure reset mechanism which satisfies the objects set forth above. 
     Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

Technology Category: 4