Abstract:
Various embodiments of the present invention are illustrated in the present disclosure. A first embodiment is a safety cover for a deadbolt of a door. The cover includes a housing having a first open end and a second open end. The housing is mounted to the door and positioned to substantially surround the deadbolt with the first open end and to contain a deadbolt actuator knob of the deadbolt within a cavity formed from the housing. The safety cover includes a cap mountable, via the second open end, into snug mating engagement with the interior of the housing. The cap is positioned such that upon actuation the cap slides axially within the housing until an inner wall of the cap meets the deadbolt actuator knob and wherein upon further actuation the inner wall grips and rotates the deadbolt actuator knob.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61036471, filed on Mar. 14, 2008 and entitled “Child Resistant Device for Deadbolt Locks,” which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to safety devices for door locks. More particularly the present invention relates to safety covers for deadbolt locks. 
       BACKGROUND SECTION 
       [0003]    Conventional deadbolt locks found on doors, particularly exterior doors, are typically of two types: those with deadbolt actuator knobs and those without. A deadbolt actuator knob is a mechanism on the interior side of the lock that can be manually turned to lock and unlock the deadbolt. Commonly, a key opening is found on the exterior side of the lock so as to receive a key that can open and close the lock. For those locks that do not have deadbolt actuator knobs, the interior side of the lock will often include a second key opening for receiving a key. Actuator knobs have been found to be useful. However, they also pose a safety risk as children can easily manipulate them thereby allowing the child to unlock the door and potentially exiting a home, unsupervised. Other devices have been created heretofore for addressing similar problems. Notably, Japanese Patent No. JP4076176 to Yutaka and entitled “Push-Pull Turning Lock” (hereinafter, “Yutaka”) describes a custom portion to replace the interior of a lock. This device requires a push or pull actuation to lock or unlock the deadbolt. Yutaka is not meant to be attached to a fully-functional, existing deadbolt lock. Further, different deadbolt lock manufacturers have lock shafts in different locations and with different profiles which means Yutaka would not work with most or all existing deadbolts. 
         [0004]    Other devices have similar or more noteworthy deficiencies in their function and/or design. There remains a need in the marketplace to provide a user-friendly yet effective safety cover for a deadbolt. 
       SUMMARY 
       [0005]    Various embodiments of the present invention are illustrated in the present disclosure. A first embodiment is a safety cover for a deadbolt of a door. The cover includes a housing having a first open end and a second open end. The housing is mounted to the door and positioned to substantially surround the deadbolt with the first open end and to contain a deadbolt actuator knob of the deadbolt within a cavity formed from the housing. The safety cover includes a cap mountable, via the second open end, into snug mating engagement with the interior of the housing. The cap is positioned such that upon actuation the cap slides axially within the housing until an inner wall of the cap meets the deadbolt actuator knob and wherein upon further actuation the inner wall grips and rotates the deadbolt actuator knob. 
         [0006]    A second embodiment of the present invention is a child safety cover for a door lock, the door lock having an actuator knob. The cover includes a housing and a cap mountable into snug mating engagement with an interior of the housing. The cap is positioned such that upon actuation the cap slides within the housing until the cap meets the actuator knob and wherein upon further actuation the cap rotates the actuator knob. 
         [0007]    A third embodiment of the present invention is a safety cover for a deadbolt of a door. The cover includes means for confining a thumb-turn of the deadbolt within a cavity and means for actuating the thumb-turn. The means for actuating snugly engages the means for confining at an open end of the means for confining. The means for actuating is positioned to slide axially within the means for confining and upon meeting the thumb-turn effectively rotates the thumb-turn. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. 
           [0009]      FIG. 1  illustrates an exploded perspective view of a first embodiment of the safety cover mounted to a door. 
           [0010]      FIG. 2  illustrates a perspective view of the safety cover mounted to the door. 
           [0011]      FIG. 3  illustrates a front view of the housing of the safety cover mounted to the door. 
           [0012]      FIG. 4  illustrates a sectional view of the first embodiment of the safety cover. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details. 
         [0014]    Turning now to  FIG. 1 , illustrated is an exploded perspective view of a first embodiment of the safety cover  10  mounted to a door  1 . Door  1  includes a hole  2  for receiving a deadbolt lock (lock cylinder not shown). A deadbolt actuator knob  4  is coupled to the face plate  3  of the lock. As is well understood, the deadbolt actuator knob  4 , or sometimes referred to as a thumb-turn, mates with the lock cylinder upon install. Rotation of the actuator knob  4  initiates a latch  6  (not shown) to move in a lateral position, thus effectively locking or unlocking the deadbolt lock. While a deadbolt lock has been illustrated throughout, it will be appreciated by those skilled in the art that the present invention can be applied to a number of locks wherein a rotatable actuator knob is utilized to lock and unlock the lock. For example, the safety cover illustrated herein may be implemented on a standard door knob with thumb-turn lock. 
         [0015]    A housing  30  of the safety cover  10  is positioned to extend perpendicularly away from the door  1 . Housing  30  is designed to be pressed against the door  1  and the face plate  3  of the lock (illustrated further in subsequent figures). The housing  30  is formed to confine or contain the face plate  3  and actuator knob  4  within a hollow cavity of the housing  30 . A cap  20  of the safety cover  10  is designed to fit within the cavity of the housing  30  thereby preventing immediate access to the actuator knob  4  (See  FIG. 2 ). Once confined by the housing  30 , actuator knob  4  becomes more difficult to access and manipulate, particularly for a child. 
         [0016]    In this embodiment housing  30  is a generally cylindrical shape designed to match the generally circular contour of most deadbolts. Housing  30  is formed such that both ends are open. A first open end allows for the face plate  3  and actuator knob  4  to meet the lock cylinder. A second open end is positioned to receive the cap  20 . 
         [0017]    In other embodiments, housing  30  may take on other shapes, such as a more squared shape, although the interior side wall  31  would preferably remain relatively cylindrical or tubular. 
         [0018]    Housing  30 , in this embodiment, has a protruding section  33  of its side wall. Here, the protruding section  33  is the bottom portion of the housing  33  and is designed to make access more difficult to the cap  20  for children. In other embodiments, the housing  30  may not include the protruding section  33 . 
         [0019]    Two lips  35  extend radially inward from the side wall  31  at the first open end of the housing  30 . In practice, the lips  35  are positioned securely between the door  1  and the face plate  3 , upon mounting of the face plate  3 . As best illustrated in  FIG. 3 , lips  35  are arcuate in shape thus allowing for vertical movement of the housing  30  relative to the face plate  3  and actuator knob  4 . Upon installation, it is preferred that the housing  30  be positioned so as to align the axis of rotation of the cap  20  with the axis of rotation of the actuator knob  4 . In some models of deadbolts, the axis of rotation of the actuator knob  4  may be offset from the center of the deadbolt. In other embodiments, the lips  35  may be formed to allow horizontal variance in the positioning of the safety cover  10  relative to the deadbolt lock. Furthermore, lips  35  may extend 360° from the side wall  31  of the housing  30  thus providing minimal horizontal or vertical variance in the positioning of the housing  30 . 
         [0020]    Friction bumps  37  are formed and extend radially inward from the interior side wall of the housing  30  (as seen in  FIG. 3  and  FIG. 4 ). Upon installation, as the cap  20  is placed within the first open end of the housing  30 , the cap  20  must slide past the friction bumps  37 . Once past, the cap  20  is safely secured. One or more friction bumps  37  could be utilized to secure the cap  20 . In other embodiments, mating threads (not shown) on the housing  30  and the cap  20  could be used to secure the cap  20  into place. A limited number of rotations of the threads would allow the cap  20  to be properly secured (and prohibit the cap °from falling out) yet still allow horizontal movement of the cap  20  as needed (once the threads of the cap  20  pass the mating threads of the housing  30 ). A number of other approaches for retaining the cap  20  within the housing  30  could be utilized aside from the approaches mentioned above. For example, the cap  20  could be snapped into place and remain within the housing  30  until snaps were pressed thus releasing the cap  20  from the housing  30 . 
         [0021]    Housing  30  may be manufactured from a number of materials including durable plastic or rubber. It is envisioned that housing  30  would be molded as a single part, although it may be possible to manufacture the housing  30  into multiple parts and assemble them together. This may be advantageous for manufacturing efficiency or packaging optimization. It should be appreciated by those skilled in the art that the spirit of the invention does not lie in whether the housing  30  is formed of a single piece or multiple pieces assembled together. 
         [0022]    Cap  20 , in this embodiment, has a circular shape to mate snugly within the contour of the interior side wall  31  of the housing  30 . Cap  20  includes an outer face  21  and a side wall  23 . Cap  20  also includes an inner face  22 , which is best illustrated in  FIG. 4 . 
         [0023]    A protrusion  25  may be formed from the outer face  21  to provide for a user to more easily rotate the cap  20  when necessary. The protrusion  20 , in this embodiment, is a narrow, generally rectangular protrusion. The protrusion  20 , however, could take on a number of different shapes without departing from the spirit of the invention. Alternatively, cap  20  may not have a protrusion  20  at all. 
         [0024]    Cap  20  may be manufactured of a number of materials most preferably durable plastic or rubber. It is envisioned that cap  20  may be generally opaque or generally transparent. In some embodiments, some transparency in the cap  20  may allow a user to see the position of the actuator knob  4 . Cap  20  may be formed of a singular part or formed of multiple parts and assembled together. For example, the inner face  22  of the cap  20  may be positioned within a recess of the cap  20  (as best illustrated in  FIG. 4 ) and still provide the necessary functionality. The inner face  22  may be manufactured from different material than the cap  20 . For example, the inner face  22  may be made from a material with a higher coefficient of friction than the material from which the cap  20  is made. 
         [0025]    In practice, once the housing  30  is properly mounted between the door  1  and the face plate  3  of the deadbolt lock, the cap  20  can be positioned with the second open end of the housing  30  so as to effectively seal the actuator knob  4  within the safety cover  10 . As mentioned, the cap  20  may be inserted into the second open end of the housing  30  such that the cap  20 , with some force, slides past the friction bumps  37 . Once in position, a user can effectively lock or unlock the deadbolt lock by pushing the cap  20  toward the door  1 , until the inner face  22  meets the actuator knob  4 . As visible in  FIG. 4  some space is provided to allow for the axial movement of the cap  20 , within the housing  30 . 
         [0026]    Once the inner face  22  of the cap  20  meets the actuator knob  4 , the user can then rotate the cap  20  in order to rotate the actuator knob  4  in either the clockwise or counter-clockwise direction. The material in which the cap  20 , and in particular the inner face  22  of the cap  20 , is manufactured is important. The material should effectively “grip” the actuator knob  4 , thus a material with considerable friction is preferable. Although not illustrated in these embodiments, protrusions may extend from the inner face  22  of the cap  20  in order to effectively grip the actuator knob  4 . 
         [0027]    It should be appreciated by those skilled in the art that the embodiments of the present invention make it more difficult for a child to unlock (or lock) a deadbolt lock, by adding some complexity to the process of rotating the actuator knob  4 . One of the primary features of the present invention is that the safety cover  10  is a wholly separate device from the lock itself, thus not requiring much for installation. It should be noted that the present invention, upon installation does not affect a user in his or her ability in locking or unlocking the deadbolt lock from the outside (ie., with a key), as the safety cover  10  provides no resistance to the actuator knob  4  when no user force is applied. 
         [0028]    The embodiments as illustrated herein do not include any means for resetting the cap  20  away from the actuator knob  4 , once a user completes the task of rotating the knob  4 . As illustrated in the figures there is sufficient space for the cap  20  to retreat once any user force is removed. However, in other embodiments, approaches for forcing the cap  20  to retreat away from the actuator knob  4  could be implemented. For example, a compression spring placed between the cap  20  and the door  1  and contained within the cavity formed by the housing  30  could effectively apply a force that would reset the cap  20  away from the actuator knob  4 . Alternatively, the housing  30  could be designed with a generally conical shape with diameter decreasing towards the end mated with the door  1 . In this case, the cap  20  may have spring fingers integrated within that would meet the conical shape of the housing  30 , and with force from a user continue to allow axial movement of the cap  20  towards the actuator knob  4 . Upon removal of this force, the cap  20  would retreat back away from the actuator knob  4 . 
         [0029]    It should be emphasized that the above-described embodiments of the present invention, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention and protected by the following claims.