Patent Publication Number: US-7591103-B2

Title: Window sash tilt latch

Description:
The present disclosure relates to a window sash assembly that includes a window sash and a tilt latch at a corner of the window sash, and to a tilt latch for such an assembly. 
   BACKGROUND AND SUMMARY OF THE DISCLOSURE 
   In windows for various applications such as home applications, it is desirable to provide the moveable sash or sashes with tilt latches at opposed sides of the sash. These tilt latches permit the sash to be tilted away from the window frame to facilitate cleaning for example. The tilt latch typically is positioned in a slot at a corner of the sash frame. An objective of the present disclosure is to provide a window sash assembly, and a tilt latch for a window sash assembly, in which the tilt latch is constructed to minimize movement of the latch housing with respect to the sash frame after the latch has been assembled to the frame. 
   The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other. 
   A window sash assembly in accordance with an aspect of the present disclosure includes a window sash having an upper rail and at least one side rail that form a corner of the window sash. A slot at the window sash corner opens laterally outwardly from the corner and is defined in part by opposed linear tracks on the upper rail. A tilt latch is disposed in the slot, and includes a housing having opposed sidewalls and outwardly extending ledges overlying the sidewalls slidably received over the tracks on the upper rail. A flexible resilient spring element on each sidewall is spaced from the associated ledge such that the tracks on the rails are slidably received between the ledges and the spring elements. The spring elements preferably comprise at least one arcuate spring, most preferably a plurality of arcuate springs, on each sidewall of the housing with concave portions opposed to the ledge. The housing preferably is of molded plastic construction, and the arcuate springs preferably are integrally molded with the housing. 
   A window sash assembly in accordance with another aspect of the present disclosure includes a window sash having an upper rail and at least one side rail that form a corner of the window sash. A slot at the corner of the window sash opens laterally outwardly from the corner, and is defined in part by an edge of the side rail. A tilt latch is disposed in the slot and includes a housing having a retainer with a stepped profile in engagement with the edge of the side rail to retard removal of the latch from the slot. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The disclosure, together with additional objects, features advantages and aspects thereof, will best be understood from the following description, the appended claims and the accompanying drawings, in which: 
       FIG. 1  is a perspective view of a window having a sash in accordance with an exemplary embodiment of the disclosure; 
       FIG. 2  is a fragmentary exploded perspective view of a corner of the window sash in  FIG. 1 ; 
       FIG. 3  is a top plan view of the tilt latch in  FIG. 2 ; 
       FIG. 4  is a side elevational view of the tilt latch in  FIG. 3 ; 
       FIG. 5  is an opposing side elevational view of the tilt latch in  FIG. 3 ; 
       FIG. 6  is a fragmentary sectional view taken substantially along the line  6 - 6  in  FIG. 5 ; 
       FIG. 7  is a fragmentary sectional view taken substantially along the line  7 - 7  in  FIG. 3 ; 
       FIG. 8  is a fragmentary sectional view on an enlarged scale of a portion of  FIG. 7 ; and 
       FIG. 9  is a fragmentary exploded perspective view of a modification to the tilt latch in  FIG. 2 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1  illustrates a building window  20  that includes a generally rectangular outer frame  22 , and an upper sash  24  and a lower sash  26  disposed within frame  22 . Window  20  illustrated in  FIG. 1  is a so-called double-hung window in which both upper sash  24  and lower sash  26  are mounted for movement within outer frame  22 . However, the subject matter of the present disclosure is equally useful in a window assembly in which only one sash  26  is moveable. Sash  26  includes an upper rail  28  and a pair of side rails  30 , 32 . A tilt latch  34 , 36  is positioned at each corner of upper rail  28  with respective side rails  30 , 32 . Tilt latches  34 , 36  are mirror images of each other, and tilt latch  36  will be described in detail in conjunction with  FIGS. 2-8 . 
   Referring to  FIG. 7  in particular, tilt latch  36  includes a latch bolt  38  slidably carried within a housing  40  and urged laterally outwardly (with respect to sash  26 ) by a spring  42  captured between latch bolt  38  and housing  40 . Latch bolt  38  preferably has a beveled outer end or nose  44  that engages frame  22  ( FIG. 1 ) to urge the latch bolts laterally inwardly as sash  26  is swung from the open position of  FIG. 1  toward the closed position. Latch  36  is received within a laterally extending slot  46  ( FIG. 2 ) formed at the corner of upper sash rail  28  and side rail  32 . Slot  46  includes a pair of longitudinally extending tracks  48 , 50  that are opposed to each other across slot  46 . Tracks  48  are formed in the contour of rail  28 , which preferably is of extruded metal or plastic construction. An identical slot is formed at the opposing end of rail  28  for receipt of tilt latch  34  ( FIG. 1 ) as previously described. 
   Tilt latch housing  40  preferably is of elongate generally rectangular construction, having a pair of laterally opposed parallel sidewalls  52 , 54  and a top panel  56 . The spaced edges of top panel  56  form ledges  58 , 60  that overlie or overhang sidewalls  52 , 54  respectively. Each sidewall  52 , 54  has a series of longitudinally spaced arcuate openings  62  (FIGS.  2  and  4 - 5 ) adjacent to but preferably spaced from associated ledges  58 , 60 . A flexible resilient continuously curvilinear arcuate spring  64  is integrally molded with housing  40  within each arcuate opening  62 . Each arcuate spring  64  includes an upwardly convex mid portion  66  adjacent to but spaced from the associated ledge  58 , 60 , and end portions  68 , 70  that are molded integrally with the associated housing sidewall  52 , 54 . Thus, the end portions  68 , 70  of springs  64  are fixed with respect to sidewalls  52 , 54  while the mid portion  66  of each spring  64  is free to flex within its associated opening  62 . The mid portions  66  of arcuate springs  64  preferably are uniformly spaced from the associated overlying ledge  58 , 60 . Thus, when latch  36  is slid into slot  46  in  FIG. 2 , the opposed tracks  48 , 50  of slot  46  are received between ledges  58 , 60  and underlying springs  64 . Ledges  58 , 60  slide along the top surfaces of tracks  48 , 50  while the mid portions  66  of springs  64  engage and slide along the bottom surfaces or undersurfaces of tracks  48 , 50 . The resiliency of arcuate springs  64  accommodates tolerance variations in tracks  48 , 50  and in the molding of housing  40 , and help retain latch  36  tightly within slot  46 . 
   A resilient retainer  72  is integrally molded with housing  40 . The head or end  74  of retainer  72  engages the upper inside edge of side rail  32  that forms slot  46 . Head  74  has a free end with a stepped or staircase-shaped profile  76  best seen in  FIGS. 7 and 8 . The purpose of this stepped profile is to provide multiple steps for engagement with the opposing edge of rail  32 . The stepped profile at the end of retainer  72  accommodates tolerance variations in the thickness of rail  32  and in the depth of slot  46  in rail  28 . Housing  40  preferably is of molded plastic construction, and springs  64  (or  64   a  in  FIG. 9 ) are integrally molded with the housing. 
     FIG. 9  illustrates a latch  36   a  that is similar to latch  36  in  FIGS. 2-8  except that the arcuate springs in latch  36   a  are contiguous with each other and form an elongated flexible resilient wavy spring  64   a  on each side of the latch housing. Each wavy spring  64   a  has upper reaches adjacent to ledges  58 , 60 , and are flexibly and resiliently disposed within associated arcuate openings in the sidewalls of the housing. The lower reaches of spring  64   a  are integrally molded with the housing sidewall. 
   There thus has been disclosed a window sash assembly and a tilt latch for a window sash assembly that fully satisfy all of the objects and aims previously set forth. The disclosure has been presented in conjunction with several exemplary embodiments, and a number of modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art in view of the foregoing description. The disclosure is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.