Abstract:
An asymmetric carrier for an interconnected lock assembly mounted in a door comprising a carrier body having a rack fixably attached to the carrier body. The carrier body has an asymmetric cam surface on at least one side of the carrier body. The asymmetric cam surface is engageable by a cam of the interconnected lock assembly in either a clockwise or counter clockwise direction to move the carrier body in a vertical direction. The cam imparts a horizontal resultant force on the carrier body in the same direction and in generally the same magnitude, regardless of rotational direction of the cam.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates generally to interconnected lock assemblies used to secure doors. More particularly, the present invention relates to an interconnected lock assembly with an asymmetric carrier component which provides equal carrier loads and motion for equivalent rotational distances of a cam, regardless of the direction of rotation.  
         BACKGROUND OF THE INVENTION  
         [0002]    An interconnected lock assembly is characterized by an inside handle, either knob or lever, which simultaneously retracts both a deadlatch and a deadbolt. Such a lock assembly is commonly found in public accommodations such as hotels and motels in which, for security purposes, the occupant wishes to set both a deadlatch and a deadbolt. The same type of lock assembly may also be found in a residential or other environments. It is particularly important that both locks be retracted by the turning of a single inside operating member as it has been found that in the event of a fire or other panic situation it is desirable that the occupant only need turn a single knob or lever to operate all of the lock mechanisms in a particular door.  
           [0003]    Such interconnected lock assemblies have been on the market for a number of years. Some interconnected lock assemblies are designed such that the rack or rack carrier component may move to different heights when the handles are rotated by equal amounts in opposite directions. One prior art device uses a rack with a flat surface interfacing a symmetric cam which raises the rack by equal amounts for equal rotational distances of the handles, regardless of the direction of rotation.  
           [0004]    One problem with interconnected lock assemblies is that the rack or rack carrier component, depending on the design, is subjected to different loads when the lower handles are rotated in different directions. This can result in increased wear of the rack, rack carrier, and of the interconnect mounting bracket, or carrier interface. This can result in increased play in the interconnect components, leading to premature failure of the interconnect lock.  
           [0005]    The foregoing illustrates limitations known to exist in present interconnected lock assembly designs. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.  
         SUMMARY OF THE INVENTION  
         [0006]    It is therefore an object of the present invention to provide an interconnected lock assembly with an asymmetric carrier component which provides equal carrier loads and motion for equivalent rotational distances of a cam, regardless of the direction of rotation. This and other objects of the present invention are provided by an asymmetric carrier for an interconnected lock assembly mounted in a door comprising a carrier body having a rack fixably attached thereto. The carrier body has an asymmetric cam surface on at least one side of the carrier body. The asymmetric cam surface is engageable by a cam of the interconnected lock assembly in either a clockwise or counter clockwise direction to move the carrier body in a vertical direction. The cam imparts a horizontal resultant force on the carrier body in the same direction and in generally the same magnitude, regardless of rotational direction of the cam. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is an exploded perspective view of the interconnected lock assembly with asymmetric carrier of the present invention;  
         [0008]    [0008]FIG. 2 is a perspective view of the assembled interconnected lock assembly in accordance with the present invention of FIG. 1;  
         [0009]    [0009]FIG. 3A is a side elevational view of the assembled interconnected lock assembly with keyless exit, shown without the escutcheon and the inside handle, showing counter-clockwise rotation of the cam in accordance with the present invention of FIG.  
         [0010]    [0010]FIG. 3B is a side elevational view of the assembled interconnected lock assembly with keyless exit, shown without the escutcheon and the inside handle, in accordance with the present invention of FIG. 1;  
         [0011]    [0011]FIG. 3C is a side elevational view of the assembled interconnected lock assembly with keyless exit, shown without the escutcheon and the inside handle, showing clockwise rotation of the cam in accordance with the present invention of FIG. 1;  
         [0012]    [0012]FIG. 4A is a detail view of the cam engaging the asymmetric cam surface of the carrier component in a clockwise direction showing the resultant forces on the asymmetric cam surface, in accordance with the present invention of FIG. 1; and  
         [0013]    [0013]FIG. 4B is a detail view of the cam engaging the asymmetric cam surface of the carrier component in a counter-clockwise direction showing the resultant forces on the asymmetric cam surface, in accordance with the present invention of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0014]    Referring now to the drawings, wherein similar reference characters designate corresponding parts throughout the several views, there is generally indicated at  10  an adjustable interconnected lock assembly with asymmetric carrier of the present invention. Referring specifically to FIGS. 1 and 2, lock assembly  10  comprises a first or lower interconnected lock assembly  18  comprising outside housing assembly  12 , rose  14 , and outside handle, or knob/lever  16 , attached from the outside of a door (not shown) through a first or lower bore in the door, and through a back plate assembly  20  positioned on the inside of the door, to inside housing assembly  22 . Interconnect cam  24 , escutcheon  28  with attached thumbturn  32 , and inside handle, or knob/lever  26  are attached to inside housing assembly  22  on the inside of the door. Although not shown, a latch assembly could be operably connected between outside housing assembly  12  and inside housing assembly  22 . Interconnected lock assembly  10  also comprises a second or upper interconnected lock assembly  40  comprising a deadbolt housing assembly  42  and a deadbolt latch assembly  44 . Deadbolt housing assembly  42  is attached from the outside of the door through a second or upper bore and operably connected to deadbolt latch assembly  44 , and through back plate assembly  20  and secured thereto by deadbolt plate  46  and mounting screws  48 . Deadbolt latch assembly  44  includes a deadbolt  90 , movable between an extended and a retracted position. Deadbolt housing assembly  42  is operably connected to a deadbolt pinion  50  which engages a deadbolt rack  52  connected to back plate assembly  20  as discussed in detail below. The lower interconnected lock  18  and upper interconnected lock  40  are standard configurations that are well-known in the art, and as such, the workings of these locks will not be described in detail, except as they relate to the present invention.  
         [0015]    Referring now to FIGS.  3 A- 3 C, interconnected lock  10  shown with escutcheon  28  and inside handle  26  removed. Back plate assembly  20  comprises an asymmetric carrier component  54  vertically movable on, and slidably attached to a back plate  56  by a plurality of tangs  58 . Deadbolt rack  52  is oriented vertically and fixedly attached to carrier component  54  such that it engages pinion  50 . Thumbturn  32  is pivotally attached to deadbolt rack  52  such that rotation of thumbturn  32  in one direction lowers deadbolt rack  52  and rotation of thumbturn  32  and the other direction raises deadbolt rack  52 . Conversely, movement of deadbolt rack  52  causes rotation of thumbturn  32  in a corresponding manner. The rack  52  attached to carrier component  54  causes deadbolt pinion  50  to rotate as carrier component  54  moves either upward or downward. Driver bar  60  co-rotates with deadbolt pinion  50 . Rotation of driver bar  60  causes retraction and extension of deadbolt  90  of deadbolt latch assembly  44  in a standard fashion. Accordingly, as carrier component  54  moves upward, deadbolt  90  of deadbolt latch assembly  44  is retracted, allowing the door to be opened.  
         [0016]    Interconnected lock  10  is adjustable in that upper lock assembly  40  can move up or down to properly fit the upper bore of the door. Deadbolt plate  46  is movable within a slot  62  in back plate  56  to allow the proper positioning of upper lock assembly  40 . Upper lock assembly  40  is then secured to deadbolt plate  46  by mounting screws  48  which secure upper lock assembly  40  in a fixed position. Deadbolt assembly  42  is operably connected to deadbolt pinion  50  by driver bar  60  which is co-rotatingly attached to deadbolt pinion  50 .  
         [0017]    Referring now to FIG. 3B, asymmetric carrier component  54  is shown in a lowered, or locked position. When carrier component  54  is in a lowered, or locked position, an asymmetric cam surface  64  of carrier component  54  engages cam  24 . Cam  24  is attached to inside knob/lever  26  in a co-rotating manner such that rotation of inside knob/lever  26  rotates cam  24  which engages asymmetric cam surface  64 , causing carrier component  54  to move vertically, upwardly to a raised, or unlocked position.  
         [0018]    Referring again to FIG. 3B, cam  24  a shown in a neutral position in which cam  24  is angled at an angle corresponding to asymmetric cam surface  64 . When inside handle  26  is rotated in a counter-clockwise direction, as shown in FIG. 3A, cam  24  also rotates, forcing carrier component  54  upward to an unlocked position. Deadbolt rack  52  moves along with carrier component  54 , causing thumbturn  32  to rotate to an unlocked position. Although not shown, movement of carrier component  54  from a lowered position to a raised position retracts deadbolt  90  from a locked position to an unlocked position in a standard manner.  
         [0019]    Similarly, when inside handle  26  is rotated in a clockwise direction, as shown in FIG. 3C, cam  24  also rotates, forcing carrier component  54  upward to an unlocked position. Deadbolt rack  52  moves along with carrier component  54 , causing thumbturn  32  to rotate to an unlocked position. Again, movement of carrier component  54  from a lowered position to a raised position retracts deadbolt  90  from a locked position to an unlocked position in a standard manner.  
         [0020]    Asymmetric cam surface  64  of asymmetric carrier component  54  is designed such that equal amounts of rotation of inside handle  26  results in equal amounts of vertical movement H of asymmetric carrier component  54  as shown in FIGS. 4A and 4B. In addition, the resultant forces, in the vertical direction Fv and the horizontal direction FH, imparted by cam  24  on asymmetric cam surface  64  of asymmetric carrier component  54  are also equivalent in direction and magnitude, irregardless of rotational direction of inside handle  26 . As a result, carrier component  54  is consistently actuated in the same manner every time inside handle  26  is rotated. This results and less wear of the carrier component  54 , rack  52 , pinion  50 , and mounting bracket  56 , as well as other associated parts of the interconnected lock  10  in comparison to standard carriers or racks which have opposed horizontal resultant forces when the handle is rotated in opposite directions. The design of interconnected lock  10  can be optimized to handle the single direction of resultant horizontal forces in the manner extending the operational life of the lock  10 .  
         [0021]    Movement of carrier component  54  from a locked position to an unlocked position, and vice versa, can be accomplished by either rotating inside knob/lever  26 , rotating thumbturn  32 , or by turning a key to rotate the rotating driver bar  60  of deadbolt assembly  42 .  
         [0022]    Although the present invention has been described above in detail, the same is by way of illustration and example only and is not to be taken as a limitation on the present invention. Accordingly, the scope and content of the present invention are to be defined only by the terms of the appended claims.