Abstract:
A window securing device ( 36 ) for use in a double-hung sash window assembly having upper and lower sash window frames ( 14,16 ) installed for relative overlapping vertical sliding movement, said upper sash frame ( 14 ) having a recess into the interior of a vertical facial member of the window. The device ( 36 ) includes a housing ( 38 ) having a front faceplate opening ( 51 ) into a cavity ( 50 ) therein and a means for retaining the housing ( 38 ) in the recess with the faceplate ( 42 ) covering the edges of the recess. A pawl ( 40 ) mounted in the cavity ( 50 ) of the housing ( 38 ) is spring biased into an extended position where the lowermost arresting edge protrudes through the opening ( 51 ). In effect, the extended pawl ( 40 ) blocks the pathway of a top portion of the lower sash ( 16 ) for preventing further upward movement thereof. With the pawl ( 40 ) in the extended position, the uppermost contact edge ( 46 ) of said pawl ( 40 ) is configured for abutting against an inside edge ( 52 ) of the top of the opening ( 51 ) in said faceplate ( 42 ). A substantial portion of the upward force associated with the lifting of the lower sash ( 16 ) against the arresting edge is transferred into the upper sash frame for enhanced resistance.

Description:
DESCRIPTION 
     This is a continuation of copending application Ser. No. 09/504,112, now U.S. Pat. No. 6,364,375, filed Feb. 15, 2000, which is incorporated herein by reference and made a part hereof, and upon which a claim of priority is based. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to a window stop, and more particularly to an improved window securing device for preventing or limiting movement of a window sash. 
     BACKGROUND OF THE INVENTION 
     Double-hung windows are one of the most common kinds of windows for residential and other structures. Typically, a double-hung window assembly consists of a window frame and a pair of window sashes. The lower sash resides immediately inward of the upper sash so that the sashes overlap and vertically slide parallel to one another along guide rails of the master window jamb of the window assembly. Although window sashes are traditionally made exclusively of wood, such window sashes can be formed of extruded plastic frame members or metal frame members joined at the corners, for example, to form a generally rectangular frame in which the glazing is installed. 
     Most double-hung windows include a locking mechanism located at the point where the sashes meet when the window assembly is closed. A latch mechanism is fixed on the header of the lower sash and the corresponding latch-receiving mechanism is fixed on the sill of the other sash. When the window sashes are in the closed position, the lock may be secured to prevent any movement of the sashes. The problem associated with these locks is that they are typically difficult to secure either because of the tight tension of the mechanism or the need to align the lock with the latch perfectly before securing. Such locks also fail to provide the user an option to open the window slightly to allow ventilation, while also inhibiting egress in or out through the window. 
     To limit the relative movement of the sashes, stop or limit devices known as “sash locks” or “window stops” have been developed to solve the above problems. Sash locks in various designs and forms are now available. Typically, the designs include a pawl pivotally mounted in a housing in a stile member of the upper sash. A spring biases the pawl toward an extended position, whereby the pawl is configured to engage the header member of the lower sash to limit movement thereof. An upper rear surface of the pawl is engageable with a back wall of the housing in cooperation with a pivot post or lug to serve to limit rotation of the pawl. 
     Over-rotation of the pawl has been a problem with this type of sash lock. Occasionally, the lower sash or the user may engage the pawl in such a way that it does not properly engage the back wall of the housing. It has also been found that in applications where large forces are applied to prior art pawls, the back wall of the housing can deform under the increased horizontal force against the back wall imposed by the pawl, and allow the pawl to slide along the back wall and over-rotate, permitting the window to open. Tremendous stress is also exerted on the pivot post or lug that may also result in failure during engagement with the lower sash. In both incidents, over-rotation occurs and the stop fails to adequately limit movement of the lower sash. 
     Another problem encountered by prior art sash locks is the existence of a gap between the lower end of the pawl and housing when the pawl is extended. This gap allows dust and debris to collect within the cavity over time. Eventually the cavity of the housing becomes impacted with dirt, whereby the proper functioning of the sash lock is impeded. With respect to the manufacture of sash locks, typically, prior art sash lock housings are composed of two or more parts that require assembly. Sash locks incorporating such housings cost more to produce than if unitary housings were utilized. 
     Accordingly, there is a need for an improved window stop, wherein the stop is simple to manufacture, stronger and more durable, less prone to failure, and cost effective to produce. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a window securing device for use in a double-hung window assembly having upper and lower sash window frames installed for vertical reciprocal sliding movement relative to each other. The stile member of the upper sash has a recess on the front surface for installing the device into the recess. 
     The window securing device includes a housing that is configured to be securely retained in the recess provided in the stile of the upper sash so that the faceplate of the housing protrudes slightly ahead of the stile&#39;s surface. The faceplate has an opening that is continuous with an interior cavity of the housing. 
     A pawl is disposed in the cavity and is configured to move between a retracted position and an extended or securing position. In the securing position, an end of the pawl projects from the opening in the faceplate and is configured to engage an exterior surface of the header of the lower sash to prevent upward vertical movement thereof. The pawl is spring biased to a normally protruding securing position and is movable to a retracted position in the housing. A spring is mounted directly on the pawl via one end that engages the pawl, and the other end of the spring engages the back wall of the housing. 
     In the securing position, the pawl engages the lower sash frame and prevents further relative sliding movement of the sash frames. The pivotally mounted pawl is manually retractable into the cavity to disengage the lower end of the pawl from the lower sash frame header. The faceplate and the retaining studs are cooperatively engageable to releasably maintain the lower end of the pawl in the retracted position. When the pawl is retracted, relative sliding movement between the sash frames can occur. 
     In one embodiment of the present invention, the pawl includes a contact edge proximate to its upper end for preventing the pawl from overextending when the lower sash window is intercepted. It transfers and directs the vertical force originating from the sash window into the stile of the upper window sash. This design is more efficient and superior over those that utilize the back wall and the pivot lug to absorb the force. 
     In another embodiment of the present invention, the pawl also includes a dust tab extending from the lower end of the pawl. The dust tab is a small protrusion that closes the gap between the lower end of the pawl and the lower end of the opening to prevent dust and debris from entering the cavity of the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various details of embodiments of the invention will be described below in association with the accompanying drawings, in which like items are identified by the same reference designation, wherein: 
     FIG. 1 is a partial perspective view of a portion of a window sash assembly having a window securing device in a securing position embodying the invention installed in an upper window sash frame of the assembly; 
     FIG. 2 is a partial perspective view of a portion of the window sash assembly having the window securing device shown in FIG. 1 in a retracted position; 
     FIG. 3 is a perspective view looking toward the front and right side of a housing without a pawl of the window securing device for an embodiment of the invention; 
     FIG. 4 is a right side elevational view of the housing, the left side elevational view being a mirror image thereof; 
     FIG. 5 is a top plan view of the housing; 
     FIG. 6 is a perspective view looking toward the left side of a pawl of the window securing device for one embodiment of the invention; 
     FIG. 7 is a right side elevational view of the pawl of FIG. 6; 
     FIG. 8 is a longitudinal cross-sectional view of the housing of the window securing device showing an associated pawl in its retracted position in one embodiment of the invention; 
     FIG. 9 is a longitudinal cross-sectional view of the housing of the window securing device showing the pawl of FIG. 8 in its securing or extended non-retracted position; and 
     FIG. 10 is a right side elevational view of an alternative embodiment of a pawl including an integral spring element. 
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. 
     Referring to the drawings, FIGS. 1 and 2 partially illustrate a representative window of a portion of a double-hung window sash assembly. Such an assembly includes a pair of double-hung upper and lower sashes  14  and  16  and fitted with suitable glazing  21 , such as shown with upper sash  14 . The sashes  14  and  16  are mounted within a main jamb frame (not shown) for vertical slidable movement therein. The construction of the main jamb is not critical for achieving the advantages of the invention so that a description thereof is deemed unnecessary. 
     Both the frame and sashes  14  and  16  can be formed of different materials, such as metal or strong and rigid plastic materials well known in this field. The sashes  14  and  16  preferably are fabricated from elongated framing members of hollow configuration in cross section. Each sash  14 , 16  is generally rectilinear in configuration, but for purposes of describing the present invention, only the side member or stile  15  of the upper sash  14  and the upper member or header  17  of the lower sash  16  is relevant. The stile  15  has a front exterior surface  18  and the header  17  has a top exterior surface  19 . 
     The window securing device of the invention is designated generally by the reference character  36  and is shown installed in the stile  15  in FIGS. 1 and 2. The window securing device  36 , is especially useful for permitting limited opening of the window sash  16 . The exact vertical placement of the securing device  36  in the stile  15  is determined by how much vertical movement of the sash  16  is desired before the header surface  19  is intercepted by the securing device  36 . Preferably, two securing devices  36  are installed on the window assembly one in each stile  15  of the upper sash  14  and at the same elevation to gain optimum security. 
     FIG. 1 illustrates the securing device  36  in a protruded, securing position. A pawl  40  is extended through the opening  51  and fixed in this position to block the pathway of the lower sash  16  as described hereinbelow. When the sash  16  is moved vertically up towards the securing device  36 , the top surface  19  of the header  17  engages the bottom surface or arresting edge  47  of the pawl  40 , thereby effectively limiting or preventing further movement of the sash  16 . This is the general function of the securing device  36 . 
     FIG. 2 illustrates the securing device  36  in a retracted, unsecured position. The user&#39;s finger  70  disengages the securing device  36  as described hereinbelow. The pawl  40  is removed from the pathway of the sash as the pawl  40  retracts into the housing  38  (see FIG. 3) securing device  36 . In this position, the lower sash  16  is free to move vertically upward beyond the securing device  36  in the stile  15 . 
     As shown in FIG.3, the securing device  36  includes a housing  38  which is configured to be securely retained in an installation opening (not shown) on the front surface  18  of the stile  15 . The housing has a top end  80 , a bottom end  81 , a front portion  82 , and a rear portion  83 . The housing  38  possesses a unitary construction and may be produced from a range of rigid materials such as extruded or molded plastic polymers, metal, wood, and the like as recognized by one of ordinary skill in the art. One of ordinary skill in the art would certainly recognize that various other forms including different shapes and sizes of housings may be utilized within the spirit and scope of the invention. 
     The front portion  82  of the housing  38  includes a front wall or faceplate  42  which is designed to overlap the surrounding edge of the installation opening (not shown) in the stile  15  to support the housing  38  therein. The housing  38  further includes opposing side walls  34  and a back wall  33 . The top and bottom ends  80  and  81  are open and unbounded. 
     The faceplate  42  is integral with the housing  38  and projected ever slightly forward of the front surface  18  of the stile  15  so as to not interfere with the relative sliding movement of the sashes  14  and  16 . To this end, the faceplate  42  may be provided with a curved outer peripheral edge  48  to improve the outward exterior appearance and aesthetics. 
     The faceplate  42  includes a centrally located elongate vertical opening  51  which is continuous with an interior cavity  50  of the housing  38 . The cavity  50  defined by the opposing side walls  34 , faceplate  42 , and the back wall  33 , is configured to house the pawl  40  therein. The opening  50  of the faceplate  42  includes upper and lower ends  52  and  53 . The upper end  52  is adapted to be engageable with the pawl  40  during the securing operation as described hereinbelow. The lower end  53  includes an inner flange  54  on the inside surface of the faceplate  42 . The flange  54  is adapted to be engageable with the pawl  40  in the retracted and securing positions as described hereinbelow. 
     As shown in FIGS. 3,  4  and  5 , flexible anchor tabs  39  extend from the side walls  34  at both ends  80  and  81  of the housing  38  and positioned proximate to the faceplate  42 . Each anchor tab  39  is integral at one end  68  with the side wall  34  and includes a free end  67 . With use in hollow stiles  15 , the anchor tabs  39  are arranged so that they engage edges of the stile surface  18 , defining the installation opening (not shown) and exert a slight biasing force thereagainst to secure the housing  38  within the installation opening (not shown). In effect the edges are sandwiched between the tabs  39  and the flange  56  behind the faceplate  42 . If the stile  15  is not hollow, the tabs  39  can still retain the housing  38  through frictional contact between the tab  39  and the walls defining the recess in the stile  15 . 
     As best shown in FIG. 5, the housing includes retaining studs  66  extending from the inner opposing side walls  34  within the cavity  50  proximate the top end  80 . The studs  66 , in combination with mounting recesses  65  (described hereinbelow) of the pawl  40 , ensure that the pawl  40  is seated properly within the cavity  50  as it movably transitions between securing and retracted positions as described hereinbelow. 
     FIGS. 6 and 7 illustrate the pawl  40  in the preferred form. However, one of ordinary skill in the art would certainly recognize that various other forms including different shapes and sizes of pawls may be utilized within the spirit and scope of the invention. The pawl  40  is a single unitary piece of material that is operatively connected to the housing  38  and reversibly resides within the cavity  50 . The pawl  40  includes an upper end  74 , a lower end  75 , a front face  76 , and a back portion  77 . The pawl  40  in the extended position (shown in FIG. 1) is configured to withstand the large vertical force associated with the lifting of the lower sash  16 . The pawl  40  like the housing  38  may be formed from a range of rigid materials such as extruded or molded plastic polymer, metal, wood, and the like as recognized by one of ordinary skill in the art. 
     As shown in FIGS. 6 and 7, the pawl  40  includes stud mounting recesses  65  on the opposing sides thereof and proximate to the upper end  74  of the pawl  40 . The recesses  65  are configured to receive the retaining studs  66  extending from the inner side walls  34  of the housing  38 . A ridge  64  bounds the top of each recess  65 . The ridge  64  is configured to keep the stud  66  within the recess  65 , thereby ensuring the proper positioning of the pawl  40  within the cavity  50 . 
     As shown in FIG. 7, the pawl  40  includes a recessed area  43  on its back portion  77 , and is configured to receive a torsional spring  32  (shown in FIGS.  8  and  9 ). A truncated pin  41  serves as the mounting structure for the torsional spring  32  within the recessed area  43  in the pawl  40 . The torsional spring  32  functions to normally bias the pawl  40  forward into the securing position. Variations of the spring  32  shown may also be suitable, including a leaf spring, coil spring, integral flexing member or other device for biasing the pawl  40 . As shown best in FIG. 10, an alternative embodiment of the pawl  40  utilizes an integral spring element  70 . The integral spring element  70  is fabricated together with the pawl  40  during the plastic polymer extrusion or molding process. 
     As the torsional spring  32  biases the pawl  40  into the securing position, a retaining lip  44  on the lower end of the front face  76  is configured to retain the pawl  40  in the retracted position within the cavity  50 . The lip  44  is adapted to be engageable with the inner flange  54  proximate the lower end  53  of the opening  51  as described hereinbelow. 
     Along the lower end  75  (see FIG. 6) of the pawl  40 , an arresting edge  47  provides a surface engageable with the top surface  19  of the header  17  of the lower sash  16 . In the securing position, the edge  47  lies parallel to the surface  19  of the header  17  (as shown in FIG.  1 ). The pawl  40  further includes a contact edge  46  proximate the upper end  74  on the front face  76 . In the securing position, the contact edge  46  abuts flat against the upper end  52  of the opening  51  in the housing  38 . The contact edge  46  in conjunction with the upper end  52  serves to transfer the vertical force originating from the arresting surface  47  in engagement with the lower sash  16  into the stile wall  20  above the device  36 . 
     A dust tab  45  extends from the back portion  77  of the pawl  40  proximate the lower end  75 , and is configured to engage with the inner flange  54  proximate the lower end  53  of the opening  51 . The tab  45  engages the flange  54  when the pawl  40  is in the securing position and serves to keep dirt or debris out of the cavity  50  that could enter the spacing between the lower end  75  of the pawl  40  and the lower end  53  of the opening  51 . 
     A gripping surface  49  is included along the front face  76  of the pawl  40  and is configured to be engageable with a user&#39;s finger  70 . The gripping surface  49  may include a plurality of spaced apart ridges  55  along the face  76  which is adapted to be readily gripped by the user&#39;s finger  70  (shown in FIG. 2) so that the necessary force can be applied to urge the securing device  36  into the securing or retracted positions. One or more ridges  55  may be provided, with four ridges  55  to engage the user&#39;s finger  70  being a preferred design. 
     Referring to FIGS. 8 and 9, the securing device  36  is shown in greater detail. For ease of assembly, the housing  38  is formed of a unitary body. The pawl  40  with the torsional spring  32  mounted on the truncated pin  41 , is placed in the cavity  50  through the opening  58  at the bottom end  81  of the housing  38 . The upper end  74  of the pawl  40  enters first and continues on until the studs  66  become seated within the recess  65  on each side. The retaining ridge  64  is configured so that the top edge has a slight downward slope to allow the studs  66  to slip by with ease, but the undersurface thereof is flat to prevent the studs  66  from reversibly sliding out the recess  65 . Utilizing the above simple and minimal number of steps, the assembly of the securing device  36  is complete. With the simple design of the present invention, the advantages in manufacturing become apparent. 
     In operation, the pawl  40  of the securing device  36  is normally in the retracted position shown in FIG.  8 . The torsional spring  32  biases the retaining lip  44  against the inner flange  54  to retain the pawl  40  inside the housing  38 . The retaining studs  66  are seated in the associated stud mounting recesses  65  and in combination allow for swiveling action as the pawl  40  goes from a retracted to securing position. To limit the upward movement of the lower sash  16 , the user slides the pawl  40  vertically upward  5  along the front face  76 , with the aid of the ridges  55  on the gripping surface  49 , until the retaining lip  44  clears the inner flange  54 . 
     Referring specifically to FIG. 9, once the lip  44  clears the inner flange  54 , the torsional spring  32  then moves the lower end  75  of the pawl  40  in the direction  6 . The arresting edge  47  is then positioned above and parallel to the top surface  19  of the header  17  of the lower sash  16  (as shown in FIG.  1 ). The contact edge  46  abuts with the upper end  52  of the opening  51 . The dust tab  45  engages with the inner flange  54  to cover the gap forming between the arresting surface  47  and the lower end  53  of the opening  51 . The tab  45  effectively prevents dust or debris from entering the cavity  50 . 
     When the arresting surface  47  engages the surface  19  of the header  17  of the lower sash  16  (i.e. when the lower sash is lifted), the contact edge  46  and the upper end  52  of the opening  51 , prevents over-rotation of the pawl  40  to limit movement of the lower sash  16 . The associated vertical force is absorbed into the stile wall  20  above the securing device  36 . Little or no force is exerted on the retaining studs  66 . No surface of the pawl  40  is adapted to engage housing  38  for resisting over-rotation except for the contact edge  46 . 
     The securing device  36  is returned to the retracted position by disengaging the lower sash  16  from the arresting edge  47  and pushing the pawl  40  into the housing  38  until the face  76  is flush with the faceplate  42 . Next the pawl  40  is slid downward with the aid of the gripping surface  49  until the retaining lip  44  engages behind the inner flange  54 . 
     While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention and the scope of protection is only limited by the scope of the accompanying Claims.