Patent Publication Number: US-2007107479-A1

Title: Apparatus for securing a deadbolt

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to door security devices and more particularly to an apparatus for securing an extended deadbolt.  
      2. Background  
      Deadbolts have been used to secure doors for some time. They provide much greater protection than the sole reliance on the conventional latch bolt employed by almost every door. Once a deadbolt has been extended into the adjacent wall, the door becomes extremely difficult to open provided the deadbolt has been secured to the door and as long as the area of the wall receiving the extended deadbolt is sufficiently sturdy. Assuming both requirements are met, there are two remaining security issues on the outside of the door: 1) an unauthorized key capable of retracting the deadbolt from the outside; and 2) tools capable of “picking” a lock from the outside. Additionally, there are security issues from inside the door. Young children (e.g. at daycare or at home) may want to wander outside unsupervised and simply retract the deadbolt by turning the thumb latch and then simply open the door.  
      The reasons a key&#39;s use might be unauthorized are almost as diverse as human behavior. A landlord could change tenants but forget to collect the deadbolt key from the old tenant. A couple could have so recently become estranged that the remaining spouse simply didn&#39;t have time to change the locks. Keys are sometimes stolen and master keys may sometimes be used by professional criminals and others.  
      What is needed is an apparatus which will prevent the use of a key for retraction of an extended deadbolt. Further, it would be helpful if such an apparatus had low cost, and was portable for installation. Further, an apparatus is needed which makes it more difficult for an unauthorized person, such as a child, to retract the deadbolt from the inside by simply turning the thumb latch.  
     SUMMARY OF THE INVENTION  
      The apparatus of the present invention solves the problems identified above (at least for a single-cylinder deadbolt assembly). It provides a solution for the problem of unauthorized use of a key or tools used to pick locks with low cost, portability and ease of installation.  
      The present invention provides an apparatus for mounting on a door or other structural substrate from the inside for adaptive use with a single-cylinder deadbolt assembly. The deadbolt assembly includes a deadbolt, a security faceplate and a thumb latch, with the security faceplate and thumb latch mounted on the security side of the door. The deadbolt assembly is designed for operational rotation of the thumb latch on the security side of the door or use of a key on the key side of the door, causing the deadbolt reversibly to extend or retract from the door and engage or disengage, respectively, a wall or other structure adjacent the door, so that the door cannot be opened without exceptional force when the deadbolt is extended into the wall.  
      The apparatus includes a frame mounted on the security side of the door, including an engaged-fixing site and a retracted-fixing site. A security member is operatively associated with the frame, having a thumb latch-engaging member formed on a first end, and a second end formed distal the first end, the first end and second end defining an axial length of the security member. A fixing member, such as a screw, is operatively associated with the frame and security member.  
      When the security member has been positioned so that the thumb latch-engaging member is in a retracted position relative to the thumb latch, and the fixing member is fixed in the retracted-fixing site, it prevents axial shifting of the security member relative to the frame. The security member is thus positioned not to restrict the thumb latch from operational rotation and therefore the deadbolt may be reversibly extended or retracted by means of a key from the key side.  
      But when the deadbolt has been placed in the extended position and the thumb latch has consequently been operationally rotated to its corresponding position the apparatus may then be operationally engaged. To do so, the security member is positioned so that the thumb latch-engaging member is in an extended position relative to the thumb latch, and the fixing member is reversibly fixed in the engaged-fixing site so as to fix the security member and prevent axial shifting of the security member relative to the frame. In this fashion the thumb latch-engaging member of the security member restricts the thumb latch from operational rotation. Therefore the deadbolt may not be retracted by means of a key or any other tools used to pick locks from the key side of the door. However, the security member is also easily retractable in order to allow for the quick operation of the thumb latch. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1   a  is an isometric view of the inventive apparatus shown mounted on the interior side of a door engaged with a thumb latch;  
       FIG. 1   b  is an isometric view of the exterior side of the door;  
       FIG. 2  is the front view of  Fig. 1   a  with the apparatus shown in retracted mode;  
       FIG. 3   a  is a perspective view of the frame;  
       FIG. 3   b  illustrates the mounting side of the frame;  
       FIG. 4  is an exploded perspective view of the security member and screw;  
       FIG. 5  is a side view of a security member included in the apparatus;  
       FIG. 6  is another side view of the security member illustrating the shape of the thumb latch-engaging member thereof;  
       FIG. 7  is an end view of the security member;  
       FIG. 8  is a side view of a frame included in the apparatus, illustrating a channel formed therein; and  
       FIG. 9  is an end view of the frame. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to the figures in general and  Fig. 1   a  in particular, an apparatus  10  (also known commercially as the Lock Jaw™), is shown in operative association with a deadbolt assembly  12  (partially shown), a door  14  (or other substructural substrate), a doorjamb  16 , adjacent wall or similar structure  18 . Apparatus  10  includes a frame  20  a security  22  and a fixing member or screw  24 . The apparatus  10  is shown in extended mode while in  FIG. 2  apparatus  10  is shown in a retracted mode, both of which will be discussed in detail below.  
      Referring to  FIG. 3   a  frame  20  (of apparatus  10 ) is shown in perspective to be hollow and cylindrical in shape. Frame  20  presents a top end  26  at one end of frame  20  and a bottom  28  at the other end thereof Frame  20  also has a mounting side  30  (see  FIG. 3   b ), and an opposite facing distal side  32 . Distal side  32  includes portions forming a channel  34  which begins proximal to top  26  and ending about half way down distal side  32 . The cylindrical shape of frame  20  presents an axial direction as indicated at reference numeral  36 .  
      Referring to  FIG. 3   b , mounting side  30  includes an engaged-site hole  38  and a retracted-site hole  40 .  
      Engaged-site hole  38  along with the lower most portion of channel  34  (see  FIG. 3   a ) together make up an engaged-fixing site. Analogously, retracted-site hole  40  and upper most portions of channel  34  together form retracted-fixing site. Note that the retracted-site hole  40  is in substantial alignment with the top of channel  34  and that the engaged-site hole  38  is substantial alignment with the bottom of channel  34  (see  FIG. 8 ).  
      Referring to  FIG. 4 , security member  22  is shown in perspective with fixing member  24 . Security member  22  is received within the hollow volume of frame  20  to allow axial shifting of security member  22 . Security member  22  has a thumb latch-engaging member  42  formed on a first end  44  thereof and a second end  46  formed distal from first end  44 . First end  44  and second end  46  define the same axial length  36  as noted in  FIG. 3   a . Thumb-latch-engaging member  42  includes two flat wide tines  48  downwardly extending in axial direction  36 . Tines  48  form an arcuate invagination  50  (see also  FIG. 6 ) adapted for engagement with a thumb latch  52  (see  FIG. 1   a ).  
      Security member  22  also includes portions forming a threaded bore  54  (see also  FIGS. 5 and 6 ) which alternatively forms a portion of both the engaged-fixing site and the retracted-fixing site in a fashion to be explained below.  
      Still referring to  FIG. 4 , fixing member  24  is a threaded screw including a threaded portion  56  for mating engagement with threaded bore  54 . Screw  24  also includes a shaft  58 , a flange  60  and a head  62 . In this fashion fixing member  24  maybe reversibly removed from threaded bore  54 , although it will readily be appreciated that the other means of fixing security member  22  relative to frame  20  to prevent axial shifting along axis  36  maybe utilized, such as a cotter pin or the like.  
      Referring to  FIG. 1   b , deadbolt assembly  12  (partially shown) is a single-cylinder deadbolt device. In other words, a key  64  may only be used on the outside or key side  65  of door  14  at a keyhole  66  disposed in an outside faceplate  68 .  
      With reference to  Figs. 1   a  and  1   b , assembly  12  is installed on door  14  with outside security faceplate  66  (see  FIG. 1   b ), as well as thumb latch  52  and an inside security faceplate  70  on an interior or security side  72  of door  14  ( FIG. 1   a ). In other words, the security side  72  of door  14  would normally be thought of as located in the interior of a room or a house or the like, while key side  72  of door  14  ( FIG. 1   b ) would normally be exterior or even outdoors. In summary, deadbolt assembly  12  includes outside faceplate  66  on key side  77  of door  14 , as well as keyhole  68  for use in retracting or extending a deadbolt  74  which is shown in phantom in the extended mode in  FIG. 1   a , while also shown in retracted mode in  FIG. 2 . Deadbolt  74 , as is well-known in the art, lends security to door  14  by its extension into mortise  76  formed within portions of door  14 , doorjamb  16  and wall  18  ( FIG. 1   a ).  
      Door  14  (or substructural substrate, a gate, window or other portal) includes security side  72  and key side  65  as previously mentioned. Door  14  also includes knob  80   a  on the security side  72  ( FIG. 1   a ) and another knob  80   b  on the key side  65  ( FIG. 1   b ). Door jamb  16  is conventionally installed and well-known in the art. Installment of apparatus  10  will now be discussed.  
      Referring to  FIG. 1   a  for installation of apparatus  10 , first deadbolt assembly  12  is previously installed to be capable of both the extended mode shown in  FIG. 1   a  and the retracted mode shown in  FIG. 2 . In other words, deadbolt  74  is capable of being extended for security purposes or it can also be retracted so that door  14  can be simply opened with door knob  80   a  or  80   b , respectively from either the inside or the outside (assuming any locking mechanism for knobs  80   a  and  80   b  have not otherwise been engaged). Next, deadbolt assembly  12  is placed in extended mode as illustrated in  FIG. 1   a.    
      For the next step of installation, apparatus  10  must be lined up in orientation to thumb latch  52 . Obviously if door knob  80   a  is located above faceplate  70  rather than below it, as shown in  FIG. 1   a , then the vertical orientation of apparatus  10  would be beneath thumb latch  52  rather than as shown.  
      Once frame  20  of apparatus  10  has been vertically aligned with thumb latch  52  it must then be checked for positioning in both the extended-security-member mode and retracted-security-member mode of apparatus  10 . In other words, apparatus  10  is shown in  FIG. 1   a  in extended-security-member mode (with security member  22  extended) while apparatus  10  is in retracted-security-member mode (with security member  22  positioned inside frame  20 ) in  FIG. 2 . So the final positioning prior to installment is determined by viewing the vertical extension of security member  22  relative to thumb latch  52 . Once frame  20  position has been determined, apparatus  10  can be affixed to door  14  by glue, adhesive strip or the like applied to mounting side  30  of the frame  20  (see  FIG. 3   b ). Screws or nails could also be used if apparatus  10  were provided with holes in frame  20  or with some kind of mounting plate affixed to frame  20 . But in the preferred embodiment, no such holes are provided because it is assumed it will be more convenient for the user to install by use of adhesive strips, glue or the like.  
      After installment apparatus  10  can easily be de-installed. For example, if glue were to be used a solvent or a heating of the glued surface can be used to remove apparatus  10 . Likewise an adhesive strip might simply be removed by mechanical pressure. The convenience of mounting apparatus  10  is enhanced by the fact that very little mechanical stress will be applied to apparatus  10  in the course of its operation as will be discussed below. In this fashion, apparatus  10  can be taken by a person on a car trip and then easily installed at each hotel room in which the traveler stays and then de-installed when the traveler is checking out of the hotel. The inventive apparatus  10  may thus be used and reused at various locations which is facilitated by the easy portability and light weight.  
      In operation and referring to FIG. . 2 , the apparatus  10  is first placed in retracted-security-member mode, i.e. security member  22  is shifted so that it is received completely within frame  20 . This is done by placing fixing member  24  through the uppermost portion of channel  34  and threading it into bore  54  ( FIG. 4 ) and finally fixing the threaded end  56  ( FIG. 4 ) of fixing member  24  into hole  40  ( FIG. 3   a ). In this fashion, security member  22  is prevented from shifting along axis  36  in a vertical fashion. This constitutes the retracted-security-member mode. Note that the top  46  ( FIG. 4 ) of security member  22  is flush with top  26  ( FIG. 3   a ) of frame  20  in the retracted-security-member mode. In this retracted mode, it will be noted that thumb latch  52  of deadbolt assembly  12  is freely rotated to be placed in retracted deadbolt mode as illustrated in  FIG. 2  or could also be placed in extended mode as shown in  FIG. 1   a  where deadbolt  74  extends beyond door jamb  16  into mortise  78  formed within wall  18 . Since thumb latch  52  is mechanically free to rotate from the horizontal position of the retracted-deadbolt mode to a vertical position of the extended-deadbolt mode, it can be manipulated by either manual adjustment from security side  72  (i.e. inside the room in question) or by manipulation of key  64  on key side  65  (i.e. outside the room in question).  
      The next step in operation is that deadbolt  74  is placed in extended-deadbolt mode by turning thumb latch  52  to the upright, vertical position as shown in  FIG. 1   a . Next security member  22  must be downwardly extended in the following fashion to achieve the extended-security-member mode. First, fixing member  24  must be loosened and removed at least from retracted fixing hole  40  which enables the downward movement of security member  22  relative to frame  20 . In this fashion security member  22  is then downwardly shifted to the position indicated in  FIG. 1   a . Next, fixing member  24  is then rescrewed so that it engages extended-fixing site hole  38  ( FIG. 3   b ). In this fashion the extended-security-member mode is achieved and thus thumb latch engaging member  42  of security member  22  restricts thumb latch  52  since tines  48  prevent any significant rotation of thumb latch  52 .  
      Referring to  FIG. 1   b , it will be readily appreciated that use of key  64 , when placed in keyhole  66  on key side  65  of door  14 , simply will not be able to generate sufficient torque to overcome the restrictive engagement of tines  48  so that thumb latch  52  cannot be turned from key side  65 . In this fashion it will be appreciated that not much mechanical mounting force between apparatus  10  and door  14  will be required to adequately withstand any torque that is physically possible to be exerted by key  64 . Hence when apparatus  10  is in extended-security-member mode as illustrated in  FIG. 1   a , it prevents thumb latch  52  from any operational rotation, key  64  may not be used to retract bolt  74  and therefore anyone trying to enter through door  14  from the outside will not be able to, so long as apparatus  10  remains in extended-security-member mode without exertion of exceptional force.  
      It should be apparent that the invention not only accomplishes the major functions required from such apparatus  10 , but does so in a particularly advantageous manner. It should be equally apparent, however, that various minor and equivalent modifications from the embodiments disclosed herein for illustrative purposes could be employed without departing from the essence of the invention. It is to be understood, therefore, that the invention should be regarded as encompassing not only the subject matter literally defined by the claims which follow, but also technical equivalents thereof