Patent Publication Number: US-7581423-B2

Title: Protective cover for a lock

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/677,459, filed May 3, 2005, the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a protective cover for a lock, and more particularly to a flexible cover for a padlock adapted to enhance corrosion resistance of the lock body and to seal openings from moisture and other contaminants. 
     BACKGROUND OF THE INVENTION 
     Due to the many outdoor uses of padlocks, protective covers have been proposed to minimize the exposure of the padlock, particularly the keyway and the internal components of the padlock, to moisture and other contaminants, in an effort to extend service life by minimizing corrosion or oxidation of metallic lock components and damage caused by contamination. Previously proposed covers have been provided with a top portion to be fitted over the top end of the lock body, with openings to accommodate the shackle, and a bottom portion to be fitted over the bottom end of the lock body. However, the presence of a slit between the shackle openings, or sealing surfaces that deflect downward towards the shackles, may allow moisture to accumulate on the top portion of the cover and eventually seep past the cover and into the shackle holes. 
     To open the lock, the bottom portion of the previously proposed covers may be removed to access the keyway, or the bottom portion may be provided with an opening to access the keyway without removing the bottom portion. The opening in some proposed covers has been limited to a slit in the flexible bottom portion, allowing the material at the slit to be pressed open when a key is pressed against the slit for insertion in the keyway, or allowing the slit to be opened by squeezing the ends of the cover, similar to the operation of a plastic coin purse. After the key is removed from the lock, the slit contracts to its original form. However, this type of slit in the bottom cover may still allow moisture or other contamination to enter the keyway through the slit, particularly if repeated unlocking of the lock has resulted in plastic deformation of the cover material, causing the slit to widen. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a protective cover for a lock, in which exposure of the internal and external surfaces of the lock body to moisture and contamination are minimized. 
     In one embodiment, a protective cover for a keyway disposed on an end surface of a lock is provided. A housing is adapted to be assembled over the lock end surface. The housing includes an opening that surrounds the keyway. At least one door is disposed in the housing opening. The door includes an edge for aligning with the keyway in a key insertion position. When a key is pressed against the door, the door moves away from the keyway, providing a key opening in the housing opening for insertion of the key into the keyway. At least one door biasing member engages the door and biases the edge of the door toward the keyway. The door is mounted on a pivot member disposed in the housing opening such that the pivot member and door pivot within the opening when the key is inserted into the keyway and turned in the lock. At least one pivot biasing member engages the pivot member to hold the edge of the door in alignment with the keyway when the keyway is in the key insertion position. 
     In another embodiment, a protective cover is provided for a padlock having a lock body with a top end, a bottom end, and vertical sides therebetween, a keyway disposed on the bottom end, and a shackle extending from first and second shackle holes in the top end. The protective cover includes a top cover member sized to fit over the top end of the lock body. The top cover member has an upper portion for covering the top end and a side wall portion for covering at least a portion of the vertical sides of the lock body. The upper portion includes first and second shackle hole openings that align with the first and second shackle holes for receiving the shackle. First and second annular shackle seals are sized to fit around first and second legs of the shackle, and an outer portion of each of the first and second shackle seals is adapted to be retained in the first and second shackle hole openings of the top cover member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will be more fully understood by reference to the following detailed description of the invention and the accompanying drawings. The drawings represent exemplary embodiments of the present invention and are included for illustrative purposes in order to facilitate understanding of the description. Other embodiments of the present invention contemplated by the description are included within this application. 
         FIG. 1  is a front view of a padlock with a protective cover; 
         FIG. 2  is a cross-sectional view of a padlock with a protective cover; 
         FIG. 3  is an exploded perspective view of a padlock with a protective cover; 
         FIG. 4  is a perspective view of the padlock and protective cover of  FIG. 3 ; 
         FIG. 5  is a perspective view of a shackle seal; 
         FIG. 6  is an enlarged partial cross-sectional view of the padlock, protective cover, and shackle seal of  FIG. 2 ; 
         FIG. 7  is a bottom view of a protective cover with a keyway door assembly for a lock; 
         FIG. 8A  is a perspective view of a keyway door assembly for a lock; 
         FIG. 8B  is an exploded perspective view of the keyway door assembly of  FIG. 8A ; 
         FIG. 9A  is a perspective view of a protective cover with a keyway door assembly for a lock; 
         FIG. 9B  is an exploded perspective view of the protective cover of  FIG. 9A ; 
         FIG. 9C  is a perspective view of the door retaining member of  FIG. 9A ; 
         FIG. 10  is a perspective view of the protective cover of  FIG. 9A , with a key inserted through the keyway door assembly and the keyway door assembly pivoted to an unlocked position; 
         FIG. 11  is a perspective view of the protective cover of  FIG. 9A , with the keyway door assembly returned to a locked position; 
         FIG. 12A  is a perspective view of a protective cover with another keyway door assembly; 
         FIG. 12B  is an exploded perspective view of the protective cover of  FIG. 12A ; 
         FIG. 13A  is a top view of a protective cover with another keyway door assembly; 
         FIG. 13B  is an exploded side perspective view of the protective cover of  FIG. 13A ; 
         FIG. 14  is a bottom perspective view of another keyway door assembly; 
         FIG. 15  is an exploded perspective view of a padlock and a protective cover having top and bottom portions, in which the bottom portion has a detachable bottom plate; 
         FIG. 16  is a top view of a detachable bottom plate; and 
         FIG. 17  is a top view of another detachable bottom plate. 
     
    
    
     DETAILED DESCRIPTION 
     The Detailed Description of the Invention merely describes preferred embodiments of the invention and is not intended to limit the scope of the claims in any way. Indeed, the invention as described by the claims is broader than and unlimited by the preferred embodiments, and the terms in the claims have their full ordinary meaning. 
     The present invention provides a protective cover for a lock, such as, for example, a padlock. The protective cover may serve any one or more of a variety of purposes, such as, for example, improving impact resistance for one or more lock components, providing color coding or other visual identification for one or more locks, providing corrosion resistance for external surfaces of the lock, or providing external seals to minimize or eliminate the entry of moisture, debris, or other contaminants into the lock through cracks, seams, or other openings in the lock, such as, for example, a keyway or shackle holes. 
       FIGS. 1-4  illustrate a padlock  10  with a protective cover  50  according to an exemplary embodiment of the invention. While the figures illustrate the use of the exemplary protective cover with a padlock, any one or more of the features of the exemplary embodiments may be used on different types of locks, including, for example, combination locks, tool locks, shackle-less locks, etc. The padlock  10  includes a lock body  20 , a shackle  30  extending from shackle holes  24 ,  25  disposed in a top end  22  of the lock body  20 , and a keyway  28  extending from a bottom end  26  of the lock body  20  through a cylinder  29  disposed in the lock body. The shackle  30  includes a longer shackle leg  34  that remains engaged with the shackle hole  24  when the lock is in use, and a shorter shackle leg  35  that is withdrawn from shackle hole  35  when the padlock in unlocked. To unlock the padlock  10  of the exemplary embodiment, a key (not shown) is inserted through the keyway  28  into the cylinder  29 , and the key is turned to rotate the cylinder  29  from a locked position to an unlocked position, thereby releasing the shackle  30  for withdrawal of the shorter shackle leg  35 . To remove the key, the exemplary embodiment may require that the key, and with it, the cylinder  29 , be turned back to the locked position to release the key for withdrawal. 
     The protective cover  50  of the exemplary embodiment includes a top cover member  60  and a bottom cover member  70 . However, other embodiments of the invention include one piece protective covers assembled over the top portion or the bottom portion of a lock. The top and bottom cover members  60 ,  70  may be provided in a resilient, flexible material, such as, for example, polymers such as nylon or polypropylene, or elastomers such as Santoprene®. The use of a flexible material may allow one or both of the top and bottom cover members  60 ,  70  to be sized to provide a slight interference fit between the cover and the lock body  20 , to provide a stronger grip and a tighter seal between the cover  50  and the lock body  20 . In one embodiment, one or both of the top and bottom cover members  60 ,  70  may be constructed from two or more different materials, such as, for example, inner and outer layers of polymeric material molded with a two-shot molding process. In an exemplary embodiment, the top cover may be provided with an inner layer of glass filled, impact copolymer polypropylene and an outer later of Santoprene®, a thermoplastic elastomer that adheres well to polypropylene; and the bottom cover may be provided in rubberized nylon, a durable, impact resistant material. 
     In the exemplary embodiment of  FIGS. 1-4 , a side wall portion of the top cover member  60  overlaps a side wall portion of the bottom cover member  70  when assembled to the lock body  20 . Alternatively, the bottom cover member could overlap the top cover member (not shown). The elimination of an open seam or gap between the top cover member  60  and bottom cover member  70  further minimizes the potential entry of moisture and other contaminants past the cover  50  and onto the lock body and its openings. As shown in  FIGS. 3 and 4 , the bottom cover member  70  may be provided with a ridgeline  76  between a thicker lower portion of the side wall and a thinner upper portion of the side wall. The ridgeline  76  provides coverage for the inner layer of material of the top cover member (if two layers of material are used), and also provides a flush seam between the overlapping cover members. As shown in  FIGS. 2 and 3 , the top and bottom cover members  60 ,  70  may be provided with one or more slots  62  and locking tabs  72  for holding the top and bottom cover members  60 ,  70  together on the lock body  20 , and preventing the bottom cover member  70  from sliding down or off the body  20 . While the exemplary embodiment provides slots  62  on each end of the top cover member  60  and corresponding locking tabs  72  on each end of the bottom cover member  70 , one or more slots may be provided on the bottom cover member  70  with one or more locking tabs on the top cover member  60 . Further, other means of connecting the top and bottom portions may be provided, such as, for example, snaps, clips, or other fasteners. 
     Flexible shackle seals may be provided at the shackle holes to minimize the entry of moisture and other contamination past the top cover member  60  and the shackle  30  and into the shackle holes  24 ,  25  in the lock body  20 . For example, the shackle seals may be shaped to prevent moisture or contaminants from collecting around the edges of the shackle holes. In an exemplary embodiment, as shown most clearly in  FIGS. 3 ,  5  and  6 , a pair of annular shackle seals  80  are provided for installation around shackle legs  34 ,  35  and retention in shackle openings  64 ,  65  in the top cover member  60 . Each shackle seal  80  may be provided with a circumferential slot or groove  85  around the outside diameter of the seal  80 , which receives a corresponding inner edge of the shackle opening  64 ,  65  for interlocking engagement. The cover member  60  may be provided with undercuts  66  formed around the edges of the shackle openings  64 ,  65  for retaining the shackle seals  80 . 
     The shackle seals  80  may be further provided with a contoured, generally frustoconical upper surface  83 , which overhangs the groove  85  to prevent moisture or contamination from seeping past the groove  85  and beneath the cover  60 . The frustoconical shape of the upper surface also prevents moisture from collecting or pooling around the shackle legs  34 ,  35  on the top cover member  60 . Further, a tight interference fit between the inner edge of the upper surface  83  and the shackle leg  34 ,  35  enables the shackle seal to wipe or scrape away moisture and contaminants from the outer surfaces of the shackle legs  34 ,  35  when the shackle  30  is returned to locking engagement with the lock body  20 . Further still, a contoured inner diameter  88  of the shackle seal  80 , as shown in  FIG. 6 , may be provided to allow for a gap between the shackle leg  34 ,  35  and the base of the shackle seal  80 , allowing the seal  80  to float and flex in the shackle openings  64 ,  65  to accommodate variations in shackle leg size, roundness, and spacing. In assembling an exemplary embodiment of the protective cover to a corresponding padlock, the shackle seals  80  may be pressed or snapped into the shackle openings  65  of the top cover member  60  prior to assembly of the top cover member over the lock body. The shackle seals may be provided in a flexible material, such as, for example, an elastomer. In an exemplary embodiment, the shackle seals are provided in Hytrel®, a polyester elastomer known for its chemical resistance properties. 
     The bottom cover member  70 , or any protective cover over a lock end surface on which a keyway is disposed, may be provided with a fixed opening for access to the keyway in both locked and unlocked positions. The cover member may also be provided without an opening, thereby requiring removal of the cover member prior to unlocking. However, to further minimize access to the opening by moisture and other contaminants, a movable keyway door may be provided, which covers the keyway when the cover member is assembled to the lock, but may be opened to provide a key opening to permit access to the keyway when unlocking the lock. In some applications, it may be advantageous to limit movement of the door to a direction substantially parallel with the surface of the lock, such as sliding or pivoting movement to minimize the required gap between the door and the keyway. Further, the use of a movable rigid door, instead of a deformable slot, may allow for longer service life for the cover, as gradual plastic deformation of a slot-like opening may result in a larger opening for moisture and contaminants to enter. The exemplary embodiments of  FIGS. 7-17  illustrate mechanisms for providing a movable rigid keyway door that may be opened to allow for insertion of a key into the keyway. 
     In the exemplary embodiment of  FIG. 7 , a pair of doors  130  are provided for covering the keyway of the lock. In an exemplary embodiment, as shown in  FIGS. 8A and 8B , the doors  130  may be slidably mounted in a pivot member or door retaining member  120 . The door retaining member  120  is aligned with an opening  173  of a cover member  170  such that the doors  130  cover a keyway of a lock when the cover member  170  is assembled to the lock. The opening  173  may be a cut-out in the cover member  170 , limited in size and/or shape as required by the range of motion of the key within the lock, as shown in  FIG. 7 . The door retaining member  120  includes door biasing members, such as, for example, compression springs  125 , shown in  FIGS. 8A and 8B , which bias the doors  130  towards each other in a closing direction. The doors  130  of the exemplary embodiment are provided with inner edges  132  facing away from the keyway. When a key (not shown) is pressed against the doors  130 , the force applied overcomes the biasing forces of the door biasing members  125 , pushing the doors  130  apart to provide an opening for the key, and access to the keyway. 
     Many different mechanisms may be provided to enable the doors to open against the door biasing members when the key is pressed against the door or doors, such as, for example, a small gap adjacent to the door edge into which a pointed end of the key may be received, or a hinge on each door to allow the doors to tilt in toward the lock body to provide a key opening. In one embodiment, as shown in  FIGS. 8A and 8B , the edges  132  of the doors  130  may be chamfered, such that an axial force applied to the chamfered surfaces may be directed to provide lateral movement of the doors  130  in an opening direction. While the chamfered portions of the edges  132  of the illustrated embodiment are flat surfaces extending from outer surfaces of the doors at about a 45° angle, the chamfered surface may take any of a wide variety of contours and/or angles sufficient to direct an axial force applied to the doors to provide lateral movement of the doors in an opening direction. Further, while the exemplary embodiments illustrated in  FIGS. 7-17  is a two door design, other embodiments of the invention may be provided with only one door, or with more than two doors (not shown). 
     The doors may be provided in a relatively hard, wear resistant material that is resistant to damage or deformation. In an exemplary embodiment, the door or doors are provided in a glass filled nylon, such as, for example, a 33% glass filled nylon. 
     In the exemplary embodiment of  FIGS. 8A and 8B , the door retaining member  120  includes a slot  127  that aligns with the chamfered edges  132  of the doors  130 , to allow a key to be inserted through the door retaining member  120 , while providing a base  128  to support the doors  130 . A ridge  129  is provided at each end of the slot  127  to provide a positive stop for each door  130  in the closed position, thereby preventing the door biasing members  125  from forcing the doors  130  to overlap or misalign in the door retaining member  120 . The door retaining member may be provided in a relatively hard, wear resistant material that is resistant to damage or deformation. In an exemplary embodiment, the door retaining member is provided in a glass filled nylon, such as, for example, a 33% glass filled nylon. 
     To allow the inserted key to be turned in the lock, the door retaining member  120  may allow for sufficient slideable movement of the doors  130  against the door biasing members  125  to provide a key opening wide enough (i.e., the width of a key blade) for the key to fully rotate between the edges  132  of the doors  130 . However, to minimize the size of the key opening and resulting exposure of the lock during use of a key, as shown in  FIGS. 9A-11 , the door retaining member  220  may be permitted to pivot with respect to the cover member  270  when the key is inserted past the doors  230  and turned with the keyway, substantially limiting the key opening to the thickness of the key blade. To prevent the door retaining member  220  from being loose in the cover member  270  and misaligning with the keyway when the key is not inserted, one or more recesses or detents  222  and corresponding pivot biasing members  210  may be provided to hold the door retaining member  220  such that the retaining member slot  227  ( FIG. 9C ) and the edges of the doors  230  are in alignment with the keyway in a locked position prior to key insertion and rotation. The pivot biasing members  210  may be retained in corresponding recesses in the cover  270 , as shown in  FIGS. 9A-11 . The pivot biasing members  210  engage the detents  222  when the door retaining member  220  is aligned with the locked position of the keyway, as shown in  FIGS. 9A and 11 . This engagement requires deliberate turning force of a key A ( FIG. 10 ) in the keyway to disengage the pivot biasing members  210  from the detents  222  and pivot the door retaining member  220 . While  FIGS. 9A-11  show detents  222  in the door retaining member  220  and corresponding flat wire spring pivot biasing members  210 , another embodiment may be provided with one or more detents disposed on a surface of the cover member and one or more corresponding pivot biasing members disposed on the door retaining member. 
     To retain the door retaining member  220  and doors  230  in the cover  270  during assembly, cover removal, or maintenance of the lock, one or more retaining ribs  274  may be provided in the bottom cover opening to engage the corresponding detents  222  in the door retaining member  220  in an assembly position of the door retaining member  220 , as shown in  FIG. 9B . To accommodate the retaining ribs  274 , an outer circumference of the door retaining member  220  may be provided with a recess  226  to provide clearance for rotation of the door retaining member  220 . 
     In another embodiment, shown in  FIGS. 12A and 12B , the pivot biasing member  310  includes a compression spring  312 , ball  314 , and housing  316 . The spring  312  biases the ball  314  against the door retaining member  320 . The ball is partially received in a corresponding detent  322  of the door retaining member  320  when the door retaining member  320  is positioned to align the edges of the doors  330  with the keyway in the locked position. 
     In still another embodiment, shown in  FIGS. 13A and 13B , the door biasing members comprise flat wire springs  425  retained by the door retaining member  420 . The springs engage raised buttons  435  on rear sides of the doors  430  to bias the doors  430  towards a closed position. Additionally, the pivot biasing member comprises a bent flat wire spring  410  assembled with the cover member  470  and biased against the door retaining member  420  to engage a corresponding detent in the door retaining member  420  when the door edges are aligned with the locked keyway position. 
     In still another embodiment, as shown in  FIG. 14 , the door biasing members comprise flat wire springs  525  retained by the door retaining member  520 . The springs engage rear edges  535  of the doors  530  to bias the doors  530  towards a closed position. 
     As shown in  FIGS. 10-13 , the door retaining member and doors for covering the keyway may be disposed in a bottom cover member  270 ,  370 ,  470  for assembly to a padlock along with a top cover member  60  (see  FIGS. 1-4 ) to which the bottom cover member may be connected. However, the keyway door mechanism as described herein may be provided with any type of cover member for use with many types of locks, including, for example, a door lock, shackle-less lock, or tool lock. Additionally, as used with a padlock or similar type of lock, the keyway door mechanism may be provided in a separate bottom plate  680 , as shown in  FIGS. 15-17 . This bottom plate  680  may be attached to the open bottom of a cover member  670 , as shown in  FIG. 15 , by a slot  675  and locking tab  685  engagement, or by any suitable clips, snaps, fasteners, or other mechanisms (not shown). Alternatively, the bottom plate may be attached directly to the bottom keyway surface of the lock body  20 , and a bottom cover member having an opening aligning with the door mechanism (not shown) may, but need not, be assembled to the lock body  20  over the bottom plate  680 . 
     In one such embodiment, illustrated in  FIG. 16 , the bottom plate assembly  680  includes door retaining member  620 , doors  630 , door biasing member (not shown), and pivot biasing member  610  such as those shown in the embodiment of  FIGS. 12A and 12B . Alternatively, doors may be pivotally connected directly to the bottom plate. In the exemplary embodiment of  FIG. 17 , the doors  730  are pivotally connected to the plate  780  on opposite sides of the opening, with edges  732  angled such that when the doors  730  are pushed open by applying force to the doors, both doors  730  rotate in the same direction and produce a generally rectangular key opening that widens to accommodate the turning of the key. Door biasing members, such as flat wire springs  785  in the exemplary embodiment, are assembled with the bottom plate  780  to bias the doors  730  towards the closed position, causing the doors  730  to automatically close when the key is withdrawn. It should be noted that a door mechanism utilizing one or more pivotally connected doors may also be provided with the bottom cover members  70  of  FIGS. 1-4  and as described above. 
     The detailed description has been provided for clearness of understanding of the present invention and is not intended to unnecessarily limit the scope of the invention. Modifications will be obvious to those of ordinary skill in the art, and such modifications are intended to be included as part of this invention.