Abstract:
A locking window that is selectively movable between a first closed position and a second open position and a window latch adapted to be attached to the window is disclosed. The window latch includes a cam latch, a housing including a support wall, a pivot fastener for attaching the cam latch to the housing, and a detent for retaining the cam latch in one of the open and the locked positions.

Description:
This application is a continuation of application Ser. No. 09/922,577 filed Aug. 3, 2001, now abandoned. 

   BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   The present invention relates generally to a locking window and, more particularly, to a window latch for such a window. 
   (2) Description of the Prior Art 
   Up to the end of World War II, most windows were constructed of wood. However, following the War, aluminum windows were initially constructed for low-end housing. Over time, the clear superiority of metal windows led to their use in many different types of housing. Similarly, vinyl windows were introduced in low-end housing in the beginning of the last decade. The use of vinyl windows has grown much more quickly than metal windows. In fact, the majority of windows are now constructed of vinyl. 
   During this time, locking windows have generally used metal latches similar to those that were initially used on wooden windows. Now, although vinyl windows are the predominant construction, there has still been a hesitancy to use plastic hardware. However, metal is much heavier than its corresponding plastic counterpart. Also, plastic retains its appearance when mishandled or otherwise misused that would cause unacceptable chips to form on painted metal hardware. Also, in today&#39;s modern economy, window hardware may be made in another country. Accordingly, advantages of substantial weight savings and lower shipping costs have become even more important. 
   However, making a locking window having a plastic latch is more than a mere substitution of materials. Because plastic is generally more flexible than metal, attempts at constructing a window latch having a center mounted sweep latch have failed since there&#39;s not a sufficient amount of support across the center of the sweep to prevent bowing. The importance of bowing is primarily due to the requirement by most manufacturers that the cam latch be able to maintain a static load of about 160 pounds. When a conventional center mounted window latch is formed from plastic materials, the bowing of the cam latch is so substantial that the static load will actually slide off the locking arm. Because of this problem, such window latches have not been able to pass the static load test. 
   Thus, there remains a need for a new and improved locking window having a window latch which may be completely formed from chip resistant plastics while, at the same time, still provides sufficient strength due to its housing arrangement to resist normal wear and tear during assembly and use. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a locking window having a window frame including at least one window sash that is selectively movable between a first closed position and a second open position and a window latch adapted to be attached to the window. The window latch is selectively movable between a first open position and a second locked position to secure the window sash in the closed position. The window latch includes a cam latch, a housing including a support wall, a pivot fastener for attaching the cam latch to the housing, and a detent for retaining the cam latch in one of the open and the locked positions. 
   In a preferred embodiment, the detent provides an audible indication of the cam latch being in one of the open and the locked positions. This may be accomplished by one of several configurations. For example, the detent may include at least one protrusion on one of the housing and the cam latch and a receiving groove on the other of the housing and the cam latch. Preferably, the protrusion and the groove are substantially parallel to the axis of the pivot fastener. 
   Alternatively, the detent may include at least one protrusion on one of the housing and the cam latch and a semi-circular receiving groove on the other of the housing and the cam latch. Preferably, the semi-circular receiving groove includes at least one barbell shaped portion for receiving the protrusion. More preferably, the protrusion is substantially parallel to the axis of the pivot fastener and the groove is substantially perpendicular to the axis of the pivot fastener. 
   In a preferred alternative, the detent may further include a bushing adapted for use with the pivot fastener. In such an arrangement, the detent includes at least one protrusion on one of the housing and the bushing and a receiving groove on the other of the housing and the bushing. The receiving is grooved for receiving the protrusion. Preferably, the protrusion and the groove are substantially parallel to the axis of the pivot fastener. In an even more preferred aspect of the present embodiment, the detent may include at least one resilient portion on one of the housing and the bushing. The resilient portion accommodates the protrusion when the cam latch is moved from one of the open and the locked positions to the other of the open and the locked positions. 
   Those skilled in the art will appreciate that any of the above-described detent configurations may be used separately or in various combinations with each other and other detent configurations to accomplish the creation of the audible indication of the cam latch being in one of the open and the locked positions. 
   The cam latch may include an actuator arm, a locking arm and a pivot point location between the actuator arm and the locking arm. A finger tab may be included on the actuator arm. Further, the locking arm may include a cam wall. To provide a mechanical advantage when the window latch is operated, a ratio of a length of the actuator arm to a length of the locking arm is greater than about 2. 
   One of the actuator arm and the locking arm may include a key lock receptor and the other of the actuator arms and the locking arms then includes a complementary key lock extending into the key lock receptor for attaching the cam latch to the housing. A fastener may extend into the key lock and key lock receptor. Preferably, such fastener is a self-tapping threaded fastener. Further, one of the key lock and the key lock receptor may include an alignment feature  82  and then the other of the key lock and the key lock receptor includes a mating alignment feature. 
   The housing may extend beyond the pivot fastener parallel to the window frame and include an aperture for receiving a fastener for attaching the housing to the window. The aperture may include a retainer for receiving a fastener. The base of the aperture for receiving a fastener may include a cavity for receiving shavings formed by attaching the window latch to the window. The support wall may be between the aperture and cam latch, preferably, being substantially perpendicular to the window frame. The housing may extend beyond the pivot fastener parallel to the window frame to include a finger shoulder for providing access to the cam latch. 
   Also, the window latch may include a locking arm catch. Preferably, the locking arm includes a cam detent for engaging the locking arm. Further, the locking arm catch may include an aperture for receiving a fastener for attaching the locking arm catch to the window. Preferably, the aperture of the locking arm catch may include a retainer for receiving a fastener. 
   In a preferred embodiment, the pivot fastener is substantially non-compressible so as to facilitate the selective movement of the cam latch between the first open position and the second locked position. 
   Accordingly, one aspect of the present invention is to provide a locking window having a window frame including at least one window sash that is selectively movable between a first closed position and a second open position. A window latch is adapted to be attached to the window. The window latch is selectively movable between a first open position and a second locked position to secure the window sash in the closed position. The window latch includes a cam latch, a housing and a pivot fastener for attaching the cam latch to the housing. 
   Another aspect of the present invention is to provide a window latch for a locking window having a window frame including at least one window sash that is selectively movable between a first closed position and a second open position. The window latch includes a cam latch, a housing including a support wall, and a pivot fastener for attaching the cam latch to the housing. The cam latch is selectively movable between a first open position and a second locked position to secure the window sash in the closed position. 
   Still another aspect of the present invention is to provide a locking window having a window frame including at least one window sash that is selectively movable between a first closed position and a second open position and a window latch adapted to be attached to the window. The window latch is selectively movable between a first open position and a second locked position to secure the window sash in the closed position. The window latch includes a cam latch, a housing including a support wall, a pivot fastener for attaching the cam latch to the housing, and a detent for retaining the cam latch in one of the open and the locked positions. 
   These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a locking window constructed according to the present intention; 
       FIG. 2A  is an isometric top exploded view of the window latch of the locking window shown in its closed position; 
       FIG. 2B  is an isometric view of the assembled cam latch of the window latch of  FIG. 2A ; 
       FIG. 3A  is an isometric bottom view of the window latch of the locking window shown in its closed position; 
       FIG. 3B  is an isometric bottom exploded view of the housing and the cam latch of the window latch of the locking window shown in its closed position; 
       FIG. 4A  is a top view through section of the window latch of  FIGS. 1 ,  2 A, and  3 A, shown in its closed position; 
       FIG. 4B  is a magnified detail of a portion of the top view through section of  FIG. 4A ; 
       FIG. 5A  is a top view through the same section as  FIG. 4  of the window latch shown in its opened position; 
       FIG. 5B  is a magnified detail of a portion of the top view through section of  FIG. 5A   
       FIG. 6A  is an exploded isometric top view of a window latch including a bushing; 
       FIG. 6B  is an exploded isometric bottom view of the window latch of  FIG. 6A ; and 
       FIG. 6C  is a magnified detail of the bushing of  FIGS. 6A and 6B . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In the following description, like reference characters designate like or corresponding parts throughout the several views. Also in the following description, it is to be understood that such terms as “forward,” “rearward,” “front,” “back,” “right,” “left,” “upwardly,” “downwardly,” and the like are words of convenience and are not to be construed as limiting terms. 
   Referring now to the drawings in general and  FIG. 1  in particular, it will be understood that the illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto. A perspective partial view of the locking window  10  is shown in  FIG. 1 . The window latch  12  includes a housing  22  fastened to one sash of the frame  14  and a locking arm catch  20  having a cam detent  21  fastened to another corresponding sash of the frame  14  and opposite to the housing  22 . As seen in  FIGS. 2A and 2B , a cam latch  16  includes an actuator arm  26  and locking arm  30  pivotally mounted through an aperture in the housing  22 . 
   The window  10  is locked by pivotally moving the actuator arm  26  inward toward the housing  22 , causing the locking arm  30  to pivotally move away from the housing  22  and engage the cam detent  21  of the locking arm catch  20 . The locking arm  30  disengages the cam detent  21  of the locking arm catch  20  and unlocks the window  10  when the actuator arm  26  pivotally moves away from the housing. 
   As best seen in  FIGS. 2A ,  3 A,  4 A, and  4 B, in the locked position, the locking arm  30  protrudes beyond the face of the housing  22 . By extending into the locking arm catch  20  on the corresponding sash of the frame of the window  10 , a cam wall  36  of the locking arm  30  engages the cam detent  21 . At the same time, the actuator arm  26  is to one side of the housing  22  of the window latch  12  so as to be substantially aligned with the face of the housing  22 . At the advance end of the cam wall  36 , the locking arm  30  may include an incline  38 , seen in  FIGS. 2A ,  2 B,  4 A,  4 B,  5 A,  5 B and  6 A, to better facilitate insertion of the locking arm  30  into the locking arm catch  20  to engage cam detent  21 . 
   As best seen  FIGS. 5A and 5B , in the open position, the locking arm  30  is withdrawn from the locking arm catch  20  and concealed within the housing  22  of the window latch  12 . At the same time, the actuator arm  26  of the cam latch  16  is at another side of the housing  22  of the window latch  12  so as to be substantially aligned with the face of the housing  22  at the other side of the window latch  12 . 
   As previously mentioned, the cam latch  16  includes an actuator arm  26  and a locking arm  30 . The cam latch  16  pivots about a pivot point  32 . The housing  22  has an aperture at the pivot point  32  to accommodate a pivot fastener  28 ,  28 ′. The length of the actuator arm  26  is approximately twice the length of the locking arm  30 , thereby providing a mechanical advantage in opening and locking the window  10 . 
   As seen in  FIGS. 3A ,  3 B,  4 A,  5 A,  6 A and  6 B, the housing  22  is strengthened by support walls  46 ,  50  located between an aperture  40  or  70  for attachment and the pivot point location  32 . 
   The pivot fastener  28 ,  28 ′ is shown in  FIGS. 2A and 6A  in a top exploded view; in  FIGS. 4 and 5  in through sectional views; and in  FIG. 6B  in a bottom exploded view of the window latch  12 . The pivot fastener  28 ,  28 ′ allows the cam latch  16  to pivot freely about the pivot point  32  while the window latch  12  is affixed to the window frame  14 . The pivot fastener  28 ,  28 ′ includes a male key lock portion  28  and a female key lock portion  28 ′, both having a central aperture that allows a fastener  48  to pass therethrough. In the preferred embodiment, the fastener  48  may be any threaded fastener, such as a screw. The female key lock portion  28 ′ is part of the locking arm  30  of the cam latch  16 . It will be understood by those skilled in the art that the female key portion  28 ′ may instead be part of the actuator arm  26  and the male portion  28  may be part of the locking arm  30 . Further, each of the male key lock potion  28  and the female key portion  28 ′ may include a complementary alignment feature  82  that facilitates the rapid assembly of pivot fastener  28 ,  28 ′ so that actuator arm  26  and locking arm  30  align properly with the face of housing  22 . 
   A housing  22  having at least a single aperture  40  partially encloses both the locking arm  30  of the cam latch  16  and pivot fastener  28 ,  28 ′, protecting them from debris that may be generated during construction or installation of the window frame  14  or window  10 . The aperture  40  serves as a first attachment point and, in the preferred embodiment, the housing  22  includes a second aperture  70  which serves as a second attachment point for the window latch  12 . 
   Apertures  40  and  70  may each further include an internal retainer  44 . An internal retainer  44  may be a small piece of plastic molded into the aperture  40  or aperture  70  that allows a fastener  72  to be temporarily secured in apertures  40  and  70  for packaging or shipping purposes and to prevent loss. Expediting the rapid assembly of window frames in a manufacturing environment is a further advantage of an internal retainer  44 . 
   Each aperture  40  and  70  further may include a cavity  62  in its bottom surface to accommodate shavings generated when the window latch  12  is affixed to the window frame  14 . Cavity  62  also may accommodate any pull-up of the window frame  14  during attachment of the window latch  12  to the window frame  14 . 
   The window latch  12  may include structural features such as a detent  6  that limits the range of movement of the cam latch  16  relative to the housing  22 . The limited of movement of the cam latch  16  may be accomplished through the cooperation of structural features of the housing  22  and the cam latch  16 . Likewise these structural features may cooperate in manner that provide a user of the window latch  12  a feel or sound or both that allow the user to know whether the cam latch  16  is fully engaged or fully disengaged position. In this manner, a user may see, feel and hear that the window latch  12  fully engaged or fully disengaged position. 
   As may be best seen in  FIGS. 3B ,  4 A,  4 B  5 A,  5 B and  6 B, the detent may be a protrusion  60  extending from the housing  22  that cooperates with a groove  68  defined by the cam wall  36  and collar  58  of the locking arm  30 .  FIGS. 4A ,  4 B  5 A, and  5 B are through sections of the window latch  12  just below the bottom of the upper most inner surface and above the top of the lower most outer surface of housing  22 . As seen in  FIGS. 3B ,  4 A,  4 B  5 A,  5 B and  6 B the housing may include a pair of protrusions  60 . As seen in  FIGS. 4A ,  4 B  5 A, and  5 B the locking arm  30  may include a pair of grooves  68 . The longer of the grooves  68  has a slightly enlarged diameter  64  at blind end. The presence of the enlarged diameter  64 , which may resemble a barbell shaped region, reduces a diameter of the collar  58  creating a recess for seating one protrusion  60  when the locking arm  30  is moved to the position for engaging the cam detent  21  as shown in  FIGS. 4A and 4B . In this manner, a user window latch experiences the sensations of the one protrusion  60  seating in the recess at the blind end created by the enlarged diameter  64 . In addition to seeing, the sensation may include the feel and audible snap of the cam latch  16  fully engaging. The shorter of the grooves  68  cooperates with the other of the protrusions  60  when the locking arm  30  is moved to the position for fully disengaging the window latch  21  as shown in  FIGS. 5A and 5B . 
   Each protrusion  60  cooperates with a corresponding groove  68  and the collar  58 . The protrusions  60  are located proximate to the pivot point  32  of the cam latch  16 . In addition to the recess at the barbell shaped region  64  of the longer groove  68 , the collar  58  includes regions having different diameters. As seen in  FIGS. 4B and 5B , a smaller diameter region extends from the end of the shorter groove  68  to the start of the longer groove  68 . Also as seen in  FIGS. 4B and 5B , a larger diameter region extends from the transition from the smaller diameter region to the larger diameter region to the end of the longer groove  68 . The transition from the smaller diameter region to the larger diameter region is opposite the barbell shaped region  64  of the longer groove  68 . In addition, the collar  58  includes a grove  80  that is opposite to the end of the shorter groove  68 . The pair of protrusions  60  mate with the grooves  68  and collar  58  of the locking arm  30 . 
   In operation, as the cam latch  16  moves along its range of motion, protrusions  60  travel along the different diameter regions of collar  58 , a portion of which may be within grooves  68 . As seen in  FIGS. 4A and 4B , when moving cam latch  16  to the fully engaged position, one protrusion  60  reaches the barbell shaped regions  64  while the other reaches groove  80 . At this point, the one protrusion  60  enters a barbell shaped region  64  of groove  68 , producing an audible snap. As seen in  FIGS. 5A and 5B , when moving cam latch  16  to the fully disengaged position, one protrusion  60  reaches transition from the larger diameter region to the smaller diameter region of collar  58  while the other reaches the end of the shorter groove  68 . At this point, the one protrusion  60  drops from the larger diameter region to the smaller diameter region of collar  58 , producing an audible snap. The audible snap assists the user in determining whether the window latch  12  is in a fully engaged or fully disengaged position. 
   In addition to or in place of the structures discussed above, the window latch  12  further may include structural features such as a bushing  92  as a detent that limits the range of movement of the cam latch  16  relative to the housing  22 . 
   As may be best seen in  FIGS. 6A ,  6 B and  6 C, the detent may be a protrusion  94  extending from the bushing  92  that cooperates with a groove  98  in a recess  96  defined by the bottom surface of housing  22 . The bushing  92  may include a resilient portion  90  that in the present example is created by using a gap  88  adjacent to protrusion  94 . The resilient portion  90  acts to compress the bushing  92  to permit the movement of cam latch  16 . The bushing  92  may include a pair of protrusions  94  and corresponding gaps  88 . As seen in  FIGS. 6A , and  6 B the bushing  92  may fit on pivot fastener  28 ,  28 ′ between the actuator arm  26  and the locking arm  30  and below housing  22  in recesses  96 . Each protrusion  94  cooperates with a corresponding groove  98  and the housing  22 . Bushing  92  is seated within recess  96  and protrusions  94  are initially aligned with corresponding grooves  98 . The protrusions  94  may be located on the outer diameter of the bushing  92 . It will be appreciated by those skilled in the art that the protrusion  94  and resilient region  90  may be included as part of the housing  22  and the groove  98  may be in the busing  92 . Any other structural combinations that accomplish at least one of the see, feel, hear and combination thereof functions are part of the present invention. 
   In operation, as the cam latch  16  moves along its range of motion, protrusions  94  travel from grooves  98  and the wall of recess  96  compresses the resilient region  90  of bushing  92 . When moving cam latch  16  to the fully engaged position, the protrusions  94  reach their corresponding grooves  98 . At this point, the resilient region  90  replaces the protrusions  94  to their original extended position so that while the protrusions  94  enter their corresponding grooves  68  an audible snap is produced. When moving cam latch  16  to the fully disengaged position, similar events occur. The audible snap assists the user in determining whether the window latch  12  is in a fully engaged or fully disengaged position. 
   As seen in  FIGS. 4A ,  4 B,  5 A and  5 B, the locking arm catch  20  includes a cam detent  21  that the locking arm  30  engages. The locking arm catch  20  has at least one aperture  74 . The aperture  74  serves as a first attachment point and, the locking arm catch  20  may include a second aperture  76  that serves as a second attachment point for the window latch  12 . 
   Apertures  74  and  76  may each further include an internal retainer  44 . A small piece of plastic molded into the aperture  74  or aperture  76  may act as an internal retainer  44  that allows a fastener  72  to be temporarily secured in apertures  74  and  76  for packaging or shipping purposes, and to prevent loss. Expediting the rapid assembly of window frames in a manufacturing environment is a further advantage of an internal retainer  44 . 
   Each aperture  74  and  76  further may include a cavity  62  in its bottom surface to accommodate shavings generated when the locking arm catch  20  is affixed to the window frame  14 . Cavity  62  also may accommodate any pull-up of the window frame  14  during attachment of the window latch  12  to the window frame  14 . 
   The window latch  12  may be formed from any lightweight durable material, such as a lightweight metal including aluminum, or a polymeric material. Applicants contemplate that suitable materials may be characterized by at least one of high strength, high rigidity, very good impact resistance, good elastic properties, dimensional stability, low tendency to creep, and simple processing. Preferably, suitable materials may be characterized by a plurality of the above. Applicants have found that among polymeric materials, polyamides (also known as nylons) to work well and, in particular, that polyamides including a filler may work well. In the preferred embodiment, the material used to form the window latch  12  was made using commercially available polyamides such as the “ULTRAMID®” polyamide sold by BASF Corporation of Mount Olive, N.J. These ULTRAMID®” polyamide materials, their applications, properties and processing as described in a publication by BASF Plastics entitled “ULTRAMID®” Polyamides, the subject mater of which is incorporated in its entirety herein by reference. 
   Applicants contemplate that a semi-crystalline Nylon 6 (PA6) containing about 30 percent glass fiber may be preferred. One such material is manufactured by Hughes Supply &amp; Manufacturing Company of Thomasville, Inc. of Thomasville, N.C. under the trademark “FIBERTRON™” material and has the properties presented below in Table 1. 
   
     
       
             
           
             
             
             
             
           
             
           
             
             
             
             
           
             
           
             
             
             
             
           
             
           
             
             
             
             
           
             
           
             
             
             
             
           
         
             
               TABLE 1 
             
           
           
             
                 
             
             
               FIBERTRON ™ MATERIAL 
             
             
               Description: Semi-crystalline Nylon 6 (PA6) 
             
             
               Filler System: 33% Glass Fiber 
             
             
               Characteristics: Near Prime 
             
           
        
         
             
                 
                 
               TYPICAL 
                 
             
             
               PROPERTY 
               UNITS 
               VALUES 
               STANDARD 
             
             
                 
             
           
        
         
             
               General 
             
           
        
         
             
               Density 
               g/cm3 
               1.42 
               ASTM D792 
             
             
               Melt Flow Index 
               g/10 min. 
               — 
               ASTM D1238 
             
             
               Water Absorption 
               % 
               — 
               ASTM D570 
             
             
               Mold Shrinkage 
               in/in 
               0.002-0.004 
               ASTM D955 
             
           
        
         
             
               Mechanical 
             
           
        
         
             
               Tensile Strength (break) 
               psi 
               19,500 
               ASTM D638 
             
             
               Elongation (break) 
               % 
               3.2 
               ASTM D638 
             
             
               Flexural Strength (yield) 
               psi 
               29,750 
               ASTM D790 
             
             
               Flexural Modulus 
               psi 
               1,250,000 
               ASTM D790 
             
             
               Impact Strength 
               ft-lb/in 
               3.3 
               ASTM D256 
             
             
               (Izod-notched) 
             
           
        
         
             
               Thermal 
             
           
        
         
             
               Heat Deflection Temperature 
               F 
               — 
               ASTM D648 
             
             
               (264 psi) 
             
             
               Vicat Softening Temperature 
               F 
               — 
               ASTM D1525 
             
           
        
         
             
               Flammability 
             
           
        
         
             
               UL Flammability Rating 
               Class 
               — 
               UL 94 
             
             
                 
             
           
        
       
     
   
   The “FIBERTRON™” material may be made using commercially available polyamides such as the “ULTRAMID®” polyamide sold by BASF Corporation of Mount Olive, N.J. These ULTRAMID®” polyamide materials, their applications, properties and processing as described in a publication by BASF Plastics entitled “ULTRAMID®” Polyamides, the subject mater of which is incorporated in its entirety herein by reference. 
   Applicants contemplate that alternative materials may appropriate for bushing  92 . As with the remainder of the window latch  12 , suitable materials for bushing  92  may be characterized by at least one of high strength, high rigidity, very good impact resistance, good elastic properties, dimensional stability, low tendency to creep, and simple processing. Further, suitable materials for bushing  92  may be characterized by at least one of compatible with the materials used for the remainder of window latch  12 , wear resistance, non-abrasive, and a capability of providing the elastic properties for resilient region  90 . To that end, bushing  92  may be formed from any lightweight durable material, such as a lightweight metal including aluminum, or a polymeric material. Applicants have found that among polymeric materials, polyoxymethylene (also known as POM, polymethyleneoxide, PMO, polyformaldehyde, polyacetal, acetals, acetal resin, and simple acetal) to work well. Polyoxymethylene including a filler may work well. In the preferred embodiment, the material used to form the bushing  92  are made using commercially available polyoxymethylenes such as the “DELRIN®” acetal resin sold by E.I. du Pont de Nemours and Company of Wilmington, Del. These “DELRIN®” acetal resin materials, their applications, properties and processing as described in a publications by E.I. du Pont de Nemours and Company entitled “DELRIN®” acetal resin: Low wear low friction; “DELRIN®” acetal resin: Design Guide-Module III; “DELRIN®” acetal resin: Molding Guide; and “DuPont®” DuPont Engineering Polymers: Products and Properties Guide-“DELRIN®” acetal resin, “DELRIN®” P performance acetal resin, “DELRIN®” “ELEVEN Series” acetal resin, the subject mater of each is incorporated herein by reference in its entirety. 
   As may be appreciated by those skilled in the art, a window and window latch  12  constructed according to the present invention may be substantially completely formed from plastics while at the same time still provide sufficient strength due to their arrangement to resist normal wear and tear during assembly and use. 
   Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.