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RELATED APPLICATION 
       [0001]    The present application claims the benefit of U.S. Provisional Application No. 60/986,872, filed Nov. 9, 2007 and entitled “POSITIVE ACTION LOCK FOR SLIDING WINDOWS,” the disclosure of said application being hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to windows, and more specifically, to latching mechanisms for sliding windows. 
       BACKGROUND OF THE INVENTION 
       [0003]    Double hung and other sliding sash type windows are very common. Typically, a latch or locking mechanism is used to secure the sashes in place to inhibit unintentional opening of the sashes and unauthorized entry to the structure. 
         [0004]    One very common mechanism used to lock sashes together is the so-called check rail lock, which includes a sweep cam attached to a rotatable handle. The check rail lock is mounted on one of the sashes, usually the lower sash of a double-hung window proximate the center of the sash rail. A keeper structure is mounted on the other sash proximate the check rail lock. As the handle is rotated in either direction, the sweep cam is rotated into or out of engagement with the keeper in order to enable locking or opening of the window as desired. These check rail lock devices are simple and relative easy to operate. A drawback of these devices, however, is that the handle can be rotated so that the sweep cam is extended even when the sash is open. When the sash is closed with the sweep cam in such position, the extended position of the sweep cam prevents full closure of the sash. The operator of the window may not notice the window is not fully closed and latched. In addition, the sweep cam may strike and damage the other sash. One example of a check rail lock type mechanism is disclosed in U.S. Pat. No. 6,478,347. 
         [0005]    Another prior mechanism includes a sliding latch bolt that may be mounted on one sash and that is selectively engageable with a keeper mounted on the other sash. A drawback with these mechanisms, however, is often that the bolt must be held in a retracted position as the window is operated. In other cases where a mechanism for holding the bolt in a retracted position is employed, the bolt either releases as soon as the window is raised or must be manually released with a separate catch or button. In such cases, the window may fail to close fully and may not be noticed by the operator of the window. In addition, such bolt systems are relatively complex, requiring an undesirable number of components, which in turn increases manufacturing costs and the size of the assembly, and limits the window systems capable of employing these locks. 
       SUMMARY OF THE INVENTION 
       [0006]    A sliding window can be equipped with a latch or lock mechanism. The lock mechanism can include a lock housing mounted on a sliding sash of a window assembly opposite a keeper. The bolt of lock mechanism can be received in the keeper to latch the sashes together. To open the window, the lock mechanism is disengaged from the keeper by grasping a finger pull on a handle and pulling outwardly away from window. The latch handle slides outwardly and pulls the bolt out of the keeper. With the bolt in this position, the sash may be slid upwardly to open the window. When the lock mechanism is unlocked, a portion of a trigger shifts from a position within the lock base to a forward position projecting from the lock base. To close the window, the sash is slid downward. The keeper contacts the trigger, releasing the bolt. A biasing spring urges the bolt forwardly so that it is once again engaged in the keeper and the sashes are latched together as before. 
         [0007]    A lock mechanism for a sliding window includes a lock housing and a keeper. Lock housing includes a lock base defining an opening or channel therein, a trigger slidably disposed in the base and operably coupled with a bolt. The bolt is selectively positionable between an extended position wherein a portion of the bolt extends outwardly from the housing through the opening and a retracted position wherein the bolt is contained in the housing. A biasing element is operably coupled to the bolt and arranged to bias the bolt toward the extended position. The trigger can comprise a single part movable within housing between a first position wherein a portion of the trigger extends outwardly from the housing and a second position wherein at least a portion of the trigger retreats back into and is contained in the housing. When the extended trigger comes into contact with the keeper, the trigger releases the bolt so it can engage the keeper, which locks the lock housing to the keeper. The lock mechanism can be released by pulling back on a handle disposed on a cover of lock base. 
         [0008]    The disclosed interlinking of the trigger and bolt provides a lock mechanism with relatively few components. As such, the lock mechanism provides increased reliability and allows for the use of relatively small lock housings compared to conventional hardware. The availability of smaller lock housings to contain the components of the lock mechanism means that the lock mechanism can be employed on various window configurations, including vertical and horizontal window orientations. As such, the lock mechanism can be used with top mount, recessed mount, and face mount window systems. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded view of a lock base, bolt and trigger of a lock mechanism according to the present disclosure; 
           [0010]      FIG. 2  is an exploded view of a lock mechanism adapted for a top mounted window system according to the present disclosure; 
           [0011]      FIG. 3  is an exploded view of a lock mechanism adapted for a recess mounted window system according to the present disclosure; 
           [0012]      FIG. 4  is an exploded view of an unlocked lock mechanism according to the present disclosure; 
           [0013]      FIG. 5  is a perspective view of an unlocked lock mechanism prior to disengagement with a keeper according to the present disclosure; 
           [0014]      FIG. 6  is an exploded view of a lock mechanism in a locked position prior to triggering according to the present disclosure; 
           [0015]      FIG. 7  is a perspective view of a locked lock mechanism according to the present disclosure; 
           [0016]      FIG. 8  is an exploded view of a cover housing of a lock mechanism according to the present disclosure; 
           [0017]      FIG. 9  is a perspective view of a handle pull of a lock mechanism according to the present disclosure; 
           [0018]      FIG. 10  is a front view of a handle pull of a lock mechanism according to the present disclosure; 
           [0019]      FIG. 11  is a bottom view of a cover of a lock mechanism according to the present disclosure; 
           [0020]      FIG. 12  is a front view of a trigger of a lock mechanism according to the present disclosure; 
           [0021]      FIG. 13  is a front view of a bolt of a lock mechanism according to the present disclosure; 
           [0022]      FIG. 14  is a top view of a lock mechanism denoting cross-section view  18 - 18  according to the present disclosure; 
           [0023]      FIG. 15  is a top view of a lock mechanism denoting cross-section view  19 - 19  according to the present disclosure; 
           [0024]      FIG. 16  is a top view of a lock mechanism denoting cross-section view  20 - 20  according to the present disclosure; 
           [0025]      FIG. 17  is a top view of a lock mechanism denoting cross-section view  21 - 21  according to the present disclosure; 
           [0026]      FIG. 18  is a cross-section view of a lock mechanism in a trigger position according to the present disclosure; 
           [0027]      FIG. 19  is a cross-section view of a lock mechanism in an engaged lock position according to the present disclosure; 
           [0028]      FIG. 20  is a cross-section view of a lock mechanism in an unengaged unlocked position according to the present disclosure; 
           [0029]      FIG. 21  is a cross-section view of a lock mechanism in an unengaged unlocked position according to the present disclosure; 
           [0030]      FIG. 22  is a top view of a lock base, bolt and trigger of a lock mechanism, without a cover housing, denoting cross-section views  23 - 23  and  24 - 24  according to the present disclosure; 
           [0031]      FIG. 23  is a cross-section view of a lock base, bolt and trigger of a lock mechanism according to the present disclosure; 
           [0032]      FIG. 24  is a cross-section view of a lock base, bolt and trigger of a lock mechanism according to the present disclosure; 
           [0033]      FIG. 25  is an exploded view of a lock mechanism according to the present disclosure; 
           [0034]      FIG. 26  is an exploded view of a lock mechanism in an unlocked position according to the present disclosure; 
           [0035]      FIG. 27  is a perspective view of a lock mechanism in a locked position according to the present disclosure; 
           [0036]      FIG. 28  is an exploded view of a lock mechanism according to the present disclosure; 
           [0037]      FIG. 29  is a perspective view of a keeper of a lock mechanism according to the present disclosure; and 
           [0038]      FIG. 30  is a perspective view of a window system including a lock mechanism according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0039]    In one embodiment, as depicted in  FIGS. 1-24 , lock and latch mechanism  10  generally includes a lock housing  12  and a keeper  22 . Lock housing  12  includes a lock base  14 , trigger  16 , latch bolt  18 , and cover  20 . Lock housing  12  can be disposed along a portion of a sliding window sash  26 , while keeper  22  can be disposed along a portion of other sash  27 , as shown in  FIG. 30 . As depicted in  FIGS. 2-3 , the lock mechanisms disclosed herein can be employed on recessed and top mounting window systems. 
         [0040]    Referring generally to the embodiment of  FIGS. 1-24 , trigger  16  can include a front end portion  30 , head portion  31 , tail portion  32 , tail bulb  34 , pivots  36 , trigger recess  38  and trigger catch  39 . Front end portion  30  provides an engagement or triggering surface that allows lock mechanism  10  to lock even in situations where window sashes are misaligned. Pivots  36  can be rounded at least at their respective ends and extend out a distance laterally from the rear of the head portion  31 . Further, tail portion  32  is generally elongate and narrower than head portion  31 , with tail bulb  34  defining a rounded end for trail portion  32 . Trigger recess  38  is defined in the top of head portion  31  and forms a corresponding trigger catch  39  ( FIG. 12 ) at the bottom of trigger  16 . Trigger  16  can be constructed of relatively flexible materials, such as plastics, metals and other like materials. 
         [0041]    Latch bolt  18  can include sides  40 , front end portion  42 , stop  44 , recess  46 , center groove  48 , catch  50 , and pull apertures  52 . Center groove  48  is flanked by sides  40  to define a recessed area adapted to receive tail portion  32  and catch  39  of trigger  16 . As such, trigger  16  is slidably disposable within and along center groove  48 . Forward advancement of trigger  16  within center groove  48  is limited by the abutment of catch  39  of trigger  16  with catch  50  ( FIG. 13 ) of bolt  18 . Sides  40  of bolt  18  can include rounded leading edges. Bolt  18  can be constructed of a variety materials, including plastics, metals, and other known materials. 
         [0042]    Lock base  14  generally includes lock channel  56 , rear wall  58 , lock base stop  60 , pivot openings  62 , base guides  64 , spring groove  66 , hooks  68 , fastening apertures  70 , and front wall  72 . Lock channel  56  is adapted to receive trigger  16  and bolt  18 , with bolt  18  slidably disposable along the base of the channel  56 . A biasing element or spring  24  is operatively disposed in spring groove  66  between rear wall  58  and the rear of bolt  18  to bias bolt  18  outwardly through lock channel  56 . Accordingly, bolt stop  44  rides along spring groove  66  such that forward advancement of bolt  18  within the channel  56  is limited by the abutment of bolt stop  44  with lock base stop  60 . Trigger  16  is likewise positioned within lock channel  56  when trigger  16  is operably coupled with bolt  18 . Trigger pivots  36  are slidably disposable along base guide  64  and provide a level pivotability for trigger  16  within lock base  14 , as shown in  FIGS. 23-24 . Hooks  68  extend out from lock base  14  to facilitate securement and alignment of lock housing  12  with keeper  22 . 
         [0043]    Housing cover  20  generally includes cover plate  74  and pull  76 , as shown in  FIGS. 8-10 . Cover plate  74  is adapted to cover and couple with lock base  14  by way of retention apertures  84 . Cover plate  74  further includes pull grooves  80  and lock indicia  82 . Pull  76  includes a handle grip or lip  86 , front end portion  88  and posts  90 . Posts  90  are inserted into pull grooves  80  and extend into lock base  14  for engagement with pull apertures  52  of bolt  18  such that pull  76  and bolt  18  slide together. Posts  90  are retained for slidable disposition along pull grooves  80  via post barbs  92 . The interlinking of pull  76  with bolt  18  provides a means for a user to retract bolt  18  from its engagement with keeper  22  by sliding pull  76  rearward along the path of pull grooves  80 . As such, a comfortable finger pull on pull  76  provides positive feedback of the retraction or disengagement of bolt  18  with a snap feeling caused by engagement of catch  39  of trigger  16  with catch  50  of bolt  18 . In turn, the front end portion  88  of pull  76  moves to a rearward position, exposing lock indicia  82 . Lock indicia  82  can include the word “UNLOCKED”, or similar markings denoting disengagement or an unlocked state of bolt  18  from keeper  22 . Because cover housing, and cover plate  74  are removable, end users or manufacturers can change the lock aesthetics with various cover shapes and components according to particular preferences. 
         [0044]    Keeper  22  generally includes hook slots  94 , bolt slot  95 , fastening apertures  96  and ledge portion  97 . Keeper  22  is disposable on top or recessed mounted window systems, as depicted in  FIGS. 2-3 . Hook slots  94  are arranged to receive and align hooks  68  of lock base  14  and bolt slot  95  is arranged to receive latch bolt  18 , as shown in  FIGS. 4-7 . Lock housing  12  and keeper  22 , and their respective components and structures, can be constructed of a variety materials, including plastics, metals, and other known materials. 
         [0045]      FIGS. 14-21  depict various operational configurations for the components of lock mechanism  10 . In use, lock mechanism  10  is mounted on a window assembly  25  that can include sliding sash  26  and other sash  27 . Lock housing  12  is mounted on sliding sash  26  opposite keeper  22  via fastening apertures  70 , with keeper  22  mounted on stationary sash  27  via fastening apertures  96 . When sliding sash  26  is open, lock housing  12  and keeper  22  are disengaged as shown in  FIGS. 16 and 20 . In this configuration, lock mechanism  10  is in the unlocked position, whereby pull  76  is pulled back such that bolt  18  is retracted back into the lock base  14  and out of bolt slot  95  of keeper  22 . Accordingly, sliding sash  26  can be slid away from stationary sash  27  and hooks  68  of lock base  14  can disengage from hook slots  94  of keeper  22 . 
         [0046]    When the sliding sash  26  is moved into a closed position, lock housing  12  engages keeper  22 , as depicted in  FIGS. 14-15  and  18 - 19 . In this position, bolt  18  is initially in the retracted position within lock base  14  and at least the front end portion  30  of trigger  16  extends out from front wall  72  of lock base  14 . Trigger pivots  36  abut portions of respective base guides  64 . In addition, bolt catch  50  is captured by trigger catch  39  and the trigger pivots  36  bear against base guides  64  to prevent the bolt  18  from advancing forward out of the lock base  14 . Pivots  36 , while seated within base guides  64 , also provide trigger  16  a level of pivotability within the lock channel  56 . As such, the force of the tail end of retracted bolt  18  against tail bulbs  34  biases the trigger catch  39  down onto bolt catch  50  to further assist in retaining bolt  18  in the retracted position. 
         [0047]    As the front end portion or leading edge  30  of trigger  16  abuts or otherwise contacts top ledge  97  of keeper  22  ( FIG. 18 ), biasing spring  24  propels bolt  18  forward into keeper  22 . As a result, trigger  16  is retracted back a distance into lock base  14  and the leading edge  30  of trigger  16  can remained pressed against keeper  22 , as shown in  FIG. 19 . The bolt  18  is able to advance into keeper  22  because as trigger  16  abuts keeper  22 , trigger  16  pivots or shifts up until trigger catch  39  releases bolt catch  50 , allowing biasing spring  24  to act on bolt  18 . The front end portion or leading edge  42  of bolt  18  then engages bolt slot  95  of keeper  22 . Bolt stop  44  abuts lock base stop  60  of lock base  14  to limit the distal extension of bolt  18  into bolt slot  95 . The front end  42  of bolt  18  or a portion of bolt slot  95  can be radiused or chamfered to aid in proper coupling of the sashes, even in cases of misalignment. This locked configuration of lock housing  12  with keeper  22  is indicated by the pull  76  moving to the locked position, covering lock indicia  82  ( FIG. 15 ). 
         [0048]    To unlock the lock mechanism  10  when the sliding sash  26  is secured to the other sash  27 , pull  76  is pulled rearward with respect to housing cover  74  using lip  86 , as depicted in  FIGS. 16-17  and  20 - 21 . As pull  76  slides rearward, bolt  18  is pulled out of keeper  22  against the bias of spring  24  until bolt  18  is substantially within lock base  14 . Specifically, the linking of pull  76  and bolt  18  causes bolt  18  to retreat as pull  76  is slid rearward. As bolt  18  retracts, trigger  16  also retracts until tail end  34  of trigger  16  hits rear wall  58  of the lock base, preventing trigger  16  from retracting further. Bolt  18 , however, continues to be retracted further until trigger catch  39  captures bolt catch  50  to secure bolt  18  within the lock base  14 . When bolt  18  is slid backward into the lock base  14 , biasing spring  24  causes trigger  16  to slide forward upon clearing keeper  22  such that front end portion  30  of trigger  16  extends out from the front wall  72  of lock base  14 . With bolt  18  in this position, sliding sash  26  may be slid along its track  28 , and hooks  68  of lock base  14  disengage hook slots  94  of keeper  22 , thereby opening the window. In this position, front end  88  of pull  76  exposes the lock indicia  82  provided on cover plate  74  ( FIG. 17 ). 
         [0049]    In another embodiment, as depicted in  FIGS. 25-29 , a lock mechanism  110  generally includes a lock housing  111  and a keeper  114 . Lock housing  111  generally includes a lock base  112 , trigger  115 , bolt  116 , housing cover  118 , and handle  120 . Lock base  112  generally includes front wall  122 , rear wall  124 , and top wall  126 . Rear wall  124  defines lock aperture  128 , trigger apertures  130 , and cover hook apertures  132 . Top wall  126  defines a central aperture  134 . 
         [0050]    Trigger  115  can include a pair of lobes  136  that are received within trigger apertures  130  of base  112 . Twin lobes  136  provide a pair of triggering surfaces, which allows lock mechanism  110  to lock even in situations where window sashes are misaligned. A bolt aperture  138  having bolt guides  140  is defined through trigger  115 . Trigger  115  rests within central aperture  134  of lock base  112  and is slidably disposable therein. Bottom surface  142  of trigger  115  is offset from bottom surface  144  of lock base  112 , providing clearance for uneven mounting surfaces and allowing trigger  115  to slide forward and backward relative to lock base  112 . Trigger  115  can be a single injection molded plastic part, which reduces the part count and costs of lock mechanism  110  and minimizes the force needed to activate the lock. 
         [0051]    Bolt  116  has wings  146  extending laterally from each side, and is slidably disposable in bolt aperture  138  of trigger  115 , with wings  146  resting along bolt guides  140 . Bolt  116  includes a tapered leading edge  148 . Biasing spring  150  is disposed between rear surface  152  of bolt  116  and inside surface  154  of front wall  122  to bias bolt  116  outwardly through lock aperture  128 . 
         [0052]    Housing cover  118  includes hooks  156  that engage apertures  132  of lock base  112 . This allows cover  118  to be easily removed from lock mechanism  110 . Handle  120  includes a grip  158  in its upper surface  160  that provides a means for sliding handle  120  between a locked position and an unlocked position. Post  162  extends downwardly from handle  120  and is flanked by a pair of guides  164 . Handle  120  is slidably disposed on housing cover  118  with post  162  extending through slot  166  and guides  164  through guide slots  168 . Post  162  engages bolt  116  so that bolt  116  and cover  118  slide together. 
         [0053]    Keeper  114  includes hooks  170  that engage slots  172  in lock base  112  to secure keeper  114  to lock base  112 . A bolt slot  174  is defined in keeper  114  to engage bolt  116  when lock mechanism  110  is in the locked position. 
         [0054]    In use, lock mechanism  110  is mounted on a window assembly  25 . Lock housing  111  is mounted on a sliding sash  26  opposite keeper  114  mounted on a stationary sash  27 . When sliding sash  26  is open, lock housing  111  and keeper  114  are disengaged as shown in  FIG. 26 . Lock mechanism  110  is in the unlocked position, whereby handle  120  is slid away from housing cover  118  and bolt  116  is retracted into the lock housing  111 , such that it does not project outwardly from lock aperture  128 . Lobes  136  of trigger  115  project outwardly through trigger apertures  130  of lock base  112 . In addition, various forms of lock indicia can be provided with housing cover  118  to indicate locked or unlocked states for the lock mechanism  110 . 
         [0055]    When the sliding sash  26  is closed, the lock housing  111  engages the keeper  114 , as depicted in  FIG. 27 . The lobes  136  of trigger  115  are contacted by keeper  114 , which allows biasing spring  160  to propel lock bolt  116  forwardly into keeper  114  and causes lobes  136  to retract into lock housing  111 , as shown in  FIG. 28 . A leading edge  148  of bolt  116  engages bolt slot  174  of keeper  114 . The upper surface  176  of bolt slot  174  can be radiused ( FIG. 29 ) to aid in proper horizontal alignment of the sashes. This locked configuration of lock housing  111  and keeper  114  is indicated by the handle  120  moving to the locked position depicted in  FIGS. 27-28 . 
         [0056]    To unlock the sliding sash  26 , handle  120  is pulled way from housing cover  118  using grip  158 . As handle  120  slides outwardly, bolt  116  is pulled out of keeper  114  against the bias of spring  160  until bolt  116  is substantially within base  112 . With bolt  116  in this position, sliding sash  26  may be slid upwardly along track  28  to disengage keeper hooks  170  from slots  172  and open the window  26   a.  When bolt  116  is slid backward along bolt guides  140  of trigger  115 , biasing spring  160  cause trigger  115  to slide forwardly such that lobes  136  extend outwardly through trigger aperture  130 , allowing lock mechanism  110  to be relocked when the window is closed again. 
         [0057]    It will be appreciated that the various components of lock mechanism  10 ,  110  may be made from any materials suitable in strength and durability. Lock base  14 ,  112  can be constructed from, for example, die-cast metal, while bolt  18 ,  116 , housing cover  20 ,  118  and pull handle  76 ,  120  can be constructed of, for example, polymer blends. Moreover, it will be appreciated that lock mechanism  10 ,  110  may be used with any sliding window or opening, including without limitation, double hung windows and laterally sliding windows having one, two, or any other number of sliding sash assemblies. 
         [0058]    The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof. Therefore, the described embodiments should be considered in all respects as illustrative and not restrictive with the appended claims defining the scope of the invention.

Summary:
A sliding window system can be equipped with a latch or lock mechanism. The lock mechanism can include a lock base mounted on a sliding sash of a window assembly opposite a keeper. The latch bolt of lock mechanism can be received in the keeper to latch the sashes together. A trigger is operably coupled with the latch bolt. To open the window, the lock mechanism is disengaged from the keeper by grasping a pull handle and pulling outwardly away from the window. As a result, the bolt moves to a retracted position within the lock base and a portion of the trigger extends out of the lock base, with the window capable of movement into an open position. When closing the window, the trigger contacts the keeper, releasing the bolt under the bias of a spring into the keeper, thus locking the window.