Abstract:
A sash latch for use in a sash of a window frame. The latch comprising a housing installed in the sash of the window frame, the housing containing a retractable slide, a pillar formed in the housing, and an extension at an end of the slide. The slide is movable to engage the extension with the window frame to prevent the sash from moving within the window frame. A slot is formed in a side of the slide wherein when a force is applied to the sash, the slide and the housing are deformed such that the pillar is received by the slot and prevents the slide from moving and disengaging the extension from the window frame.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority to U.S. Provisional Application No. 61/746,222 filed on Dec. 27, 2012 and U.S. application Ser. No. 14/142,585 filed on Dec. 27, 2013. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a sash latch for engagement with a side jamb of a window. 
       BACKGROUND 
       [0003]    During inclement or windy weather, it can be dangerous to open a window. The force of the wind against the exterior of a window can cause the window sash to fly inward due to structural failure of the window. A pressure differential between the inside and outside of a structure can also cause a window sash to move unexpectedly and with great force. In most situations, tilt latches will remain extended, keeping the sash in place. But under some extreme conditions, the various window components deform to a degree that the tilt latches retract, putting higher stresses on the other window hardware which can lead to further failures and the sash is free to swing inward, causing damage or death. 
         [0004]    It would be beneficial to automatically prevent a window from tilting during inclement, windy, or pressure differential conditions that might present a danger of a sudden, forceful window failure or movement. An automatic lock would prevent the window from tilting inward under such conditions. 
       SUMMARY 
       [0005]    A deformable tilt latch contains a slot to receive a pillar. When the pillar is received by the slot, the latch cannot be retracted or moved so as to allow the window to be tilted inward from the window frame. The tilt latch is made of a deformable material. The deformable material deforms when a pressure or force is applied to the exterior of the window. When the deformable tilt latch deforms, the pillar is received in the slot, preventing the latch from operating and, thus, preventing the window from being suddenly or forcefully tilted inward by forces of nature. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0006]      FIG. 1A  is a perspective view of a tilt latch of an embodiment of a latch installed within a corner of a window sash; 
           [0007]      FIG. 1B  is a cross sectional view of an alternative embodiment of a latch installed atop the window sash and detailing interaction with the window frame; 
           [0008]      FIG. 2A  is a larger perspective view of the embodiment of the latch shown in  FIG. 1A ; 
           [0009]      FIG. 2B  is a perspective view of the embodiment of the latch shown in  FIG. 1B ; 
           [0010]      FIG. 3  is a plan view of the embodiment of the latch illustrated in  FIG. 2B ; 
           [0011]      FIG. 4  is an elevation view of the embodiment of the latch illustrated in  FIG. 2B ; 
           [0012]      FIG. 5  is a cross sectional view of  FIG. 3  taken along line  5 -- 5  detailing the two piece assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1A  illustrates a first embodiment of a latch  1  installed into a corner of a window sash  2 . Protruding outwardly from the latch  1  is an extension  3  that extends into an opening of a window frame or side jamb (not shown) to prevent the window sash  2  from inadvertently opening/tilting into the interior of the building.  FIG. 1B  is an alternative embodiment of the latch  1  illustrated in  FIG. 1A . As with the first embodiment, the alternative embodiment latch  110  is disposed within a top corner  111  of a window sash  112  with a latch extension  114  shown positioned within an opening  118  of a window frame  122  shown in a cross sectional view. The latch extension  114  includes a generally planar edge  124  with serrations  126  that when inserted into the opening  118  in the window frame  122  engage a wall member  130  of the window frame  122 .  FIG. 1B  further illustrates a notch  134  within the extension  114  on the side opposite the serrations  126 . 
         [0014]    When under a heavy wind load the sash extension  114  can exert tremendous pressure on the frame  122 . At times, the force applied by very strong winds may cause the upper sash member  140  to flex to such a degree that the center of the sash  140  moves slightly toward the interior of the building causing the outer ends of the upper sash member  140 , constrained by the window frame  122 , to rotate ever so slightly causing the notch  134  to receive the outwardly extending flange members  144  that comprise an edge of the opening  118 . Once the flange member  144  is engaged within the notch  134  it is far less likely that the slightly rotated latch extension  114  can slide past the edge  148  of the opening  118 . The notch  134  and flange member  144  combination serves as a second mechanism, in combination with the serrated edges  126  on the extension  114 , to prevent the inadvertent rotation/opening of the window under high wind load conditions. The very edge  119  of flange member  144  is in close proximity to the notch  134  so that when the flexure of the sash does occur the edge  119  is received into the notch  134  thereby preventing opening of the window. The extension  114  is able to pass through the opening  118  without interference with the edge  119  and contact between the notch  134  and edge  119  only occurs under heavy load conditions. 
         [0015]    As shown in  FIG. 2A  the first embodiment of the latch  1  contains a movable slide  4  that slidably extends and retracts so as to move the extension  3  of the slide  4  into an opening in a window frame (not shown) and into and out of engagement with a side of, or other fixed member in, the opening in the window frame. When the extension  3  is extended into the window frame, the sash  2  is thus fixed in the window frame and cannot be tilted inward. When the extension  3  is retracted out of the frame, the sash  2  may be tilted inward for cleaning, removal, or other maintenance. 
         [0016]    The latch, as shown in  FIG. 2A  has a finger grip  5  to allow a user to move the slide  4  so that the extension  3  of the slide  4  may be moved into and out of engagement with the window frame. When the user uses the finger grip  5  to move the slide  4  so that the extension  3  is out of engagement with the frame, the window sash  2  may be moved within the window frame. When the slide  4  is moved into engagement with the frame, the window sash is immobilized. The latch further reveals a pillar  8  that serves to limit the flexure of the extension  3  when the latch is placed under a heavy load such as during a strong wind event. The pillar  8  serves to limit the deformation of the latch  1  and particularly the extension  3 . 
         [0017]    As further shown in  FIG. 2A , the slide  4  is movable within a housing  6 . The sash  2 , slide  4  and housing  6  are made of materials such as nylon, vinyl, aluminum, or plastic that deforms slightly when a pressure or other force is applied to an exterior face of the sash  2 . 
         [0018]      FIG. 3  illustrates the thumb depression  155  and thumb backstop  158  disposed within and atop the upper surface  160  of the latch  110 .  FIG. 3  further illustrates the extension  114  with the serrations  126  that engage the opening  118  of the frame.  FIG. 4  illustrates the two piece construction of the latch  110  with forward  162  and rear  164  slots for engagement with the upper surface  168  of the sash when the latch  110  is installed therein. 
         [0019]      FIG. 5  further illustrates the two piece construction of the latch. Specifically, the latch  110  includes an upper member  175  and a lower member  178 . The upper member includes the thumb depression and thumb backstop  158 , the extension  114  and a spring cavity  182  for retaining the spring  186 . The lower member  178  includes the rear support element  190  with an upper surface  191  in contact with the upper member  175  and a plunger arm  192  with an engagement member  196  for engagement with the spring  186  that is housed within the spring cavity  182 . The plunger arm  192  extends slightly into the spring cavity  182  and the first end  200  of the coiled spring  186  wraps around an engagement nub  196  and the second end  204  of the spring  186  is positioned against the stop wall  208  of the spring cavity  182 . The upper and lower members  175 ,  178  are effectively integrated with one another. 
         [0020]    In operation, when the latch is installed in the sash, the user will place their thumb in the thumb depression  155  and push against the thumb backstop  158 . The latch will resist movement backward because the sash upper surface  168  will be inserted into the forward and rear slots  162 ,  164  which respectively restrict movement of the upper and lower members  175 ,  178  to a preset distance. The user will push back on the thumb stop  158  which will cause the upper member  175  to move backward with the thumb pressure and to be resisted by the spring  186  that will be applying a counter pressure against the stop wall  208 . The upper member  175  will slide past the lower member  178  at surface  220  and at the spring cavity surface  224  where the arm  192  slides into the spring cavity  182 . 
         [0021]    As the thumb pressure increases the spring  186  will be further compressed within the spring cavity  182  until the extension  114  is fully retracted from the opening  118  of the window frame  122 . Once fully retracted from the opening  118 , the sash may be rotated to the desired position and the user may release thumb pressure which will cause the spring to expand to its original position within the spring cavity  182  under no load. The upper member  175  is capable of sliding over the lower member  178  for a predetermined distance because the upper member  175  is fabricated with an overhang portion  230  that eliminates any interference between the upper and lower members as they slide past one another at surface  220  and within the spring cavity  182 . The upper member  175  may slide over the lower member  178  until the upper member vertical wall  235  encounters the vertical wall  245  of the lower member  178 . When the spring  186  is fully expanded a cavity  250  is formed between the upper and lower members  175 ,  178  that is completely closed when the extension  114  is fully retracted from the opening in the jamb  118 . 
         [0022]    Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.