Patent Publication Number: US-6334283-B1

Title: Water resistant window frame

Description:
FIELD OF THE INVENTION 
     This invention relates to a window frame construction for receiving and supporting a sliding window sash,, the frame to be mounted in a window opening in a wall of a structure, the window frame incorporating a J-rail return member to overlie siding applied to the exterior of the structure. 
     More particularly, the invention is directed to such a window frame that provides increased water resistance for a minimized exposed interior sill frame height and hence increased egress opening, the frame also providing increased stiffness or strength, resistance to impact, and reduced costs of material. 
     BACKGROUND OF THE INVENTION 
     In the prior art there are many window frames which include a window retaining body portion for insertion into an opening in the wall of a building structure to circumscribe the interior of the opening and a nailing flange or fin circumscribing the exterior of the opening. 
     Many such window frames also include a J-rail return member or which comprises a nailing fin member, a member projecting outwardly from the nailing fin and a return member connected at the end of the outwardly projecting member. This J-rail return member defines a J-channel to receive the ends of siding or the like with the return portion of the J-rail return member overlying the siding. Such prior art window frames are disclosed in U.S. Pat. No. 2,983,001, issued May 9th, 1961, U.S. Pat. No. 4,694,612, issued Sep. 22nd, 1987, and U.S. Pat. No. 5,392,574, issued Feb. 28th, 1995. 
     When rain strikes the sliding sash or window unit, particularly when driven against the window unit by a strong wind, the water can penetrate between the sash and frame even with the sash tightly closed to collect under the sash where it drains off through openings at the bottom of the frame. Where the frame includes a J-return rail, the water flows out over the projecting portion of the J-return rail to spill over the end thereof. 
     The water resistance rating of the window, that is the amount of water forced against the window unit that can accumulate before it spills out over the inside of the sill of the window frame is determined by the height of the inside of the window frame at the window sill above the surface of the bottom of the frame or, in the case where the frame has a J-rail return, above the surface of the projecting portion of the J-rail return. The depth to which the water can accumulate before it spills over the inner edge of the frame is hereinafter referred to as the dam height. 
     If the inside height of the sill of the frame is increased, the dam height and hence water resistance of the window unit is increased. However, such increase in window frame height reduces the egress opening, that is the size of the opening through which a person can escape in the event of an emergency. In addition, increasing the height of the frame inner sill for increased dam height either by the frame profile itself or increasing the height of the sash retaining snap-in stop increases the amount of material required for the frame and hence the cost of the frame. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to increasing the dam height without increasing the interior height of the sill thus providing for increased water resistance for the window unit without reducing the size of the egress opening. Further the invention provides such increased water resistance with minimal increase in material costs while affording increased frame stiffness or strength and resistance to impact. 
     This increased water resistance or dam height is achieved according to the invention by forming a section of the return portion of the J-rail return member with a double wall to provide a trough at the sill of the frame to receive water spilling over the projecting portion of the J-rail return member, the trough being provided with a discharge opening at the bottom thereof. With this arrangement, the dam height is the distance between the bottom of the trough of the J-rail return member and the inside height of the sill of the frame. 
     With this arrangement, the dam height increase is obtained without any reduction in the size of the egress opening presented by the frame, with the sash fully open. 
     Further by providing this double walled section of the return portion of the J-rail return member, the strength of the frame and its resistance to impact is significantly increased. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a broken away vertical sectional view through the sill of a prior art window frame having an integral J-rail return member and supporting a slideable window sash and showing the exposed interior height of the frame for a water resisting dam height X. 
     FIG. 2 is a view similar to FIG.  1  through the sill of the window frame embodying the invention showing the reduced exposed interior height of the frame at the sill to obtain the same water resisting dam height X. 
    
    
     PRIOR ART FRAME 
     With respect to the prior art frame, generally designated at F 1 , FIG. 1, of which only the sill is shown, it will be seen that the body portion  1  is provided with an integral J-rail return member generally designated at  2  which comprises a nailing fin  3  projecting perpendicular to the body portion  1 , an outwardly projecting portion  4  and a return portion  5  extending in the same direction as and generally parallel to the nailing fin  3 . The purpose of the J-rail return member  3  is to receive and overlap the ends of siding  6 . 
     Although only the sill is shown, it will be understood that the frame F 1  will have a rectangular configuration capable of receiving and supporting a slideable window sash with the body portion  1  being adapted to be received in and circumscribe the interior of an opening  7  in the wall  8  of a structure while the nailing fin  3  is adapted to circumscribe the outer face  9  of the wall  8  around the opening  7 . 
     The body portion  1  of the frame as shown at the sill is provided with an outer sash or window stop formation  11  and a support seat  12  for a screen  13  and forms with the projecting portion  4  of the J-rail return member a chamber  14 . As mentioned, the frame F 1  is adapted to support a sliding window unit or sash  15  for opening and closing the lower half of the window opening, the top half being fixed glazed (not shown). 
     The body portion  1  of the frame F 1  is formed to provide a channel  16  with sash engaging or stop ledges  17  and  18  at the entrance to the channel which at the sill form sash closing stops. At the inner side, the body portion of the frame is provided with a latching section  19  which extends to a point flush with the stop ledges  17  and  18  and this latching section is adapted to receive a snap-in stop  20  to retain the window unit or sash  15 . Suitable brush type weather stripping  21  is provided on opposite sides of the window unit to prevent free air flow around the edge of the window unit. However, in heavy rain, particularly when driven against the window unit, the rain water will be forced in the direction of the arrows  22  between the frame stop  11  and the closed sash  15  to accumulate in the channel  16 . Channel  16  is provided with an opening  23  to allow for outflow into the chamber  14  over the projecting portion  4  of the J-rail return member  2  and out the chamber outlet  24 . 
     Under sufficiently heavy rain as, for example, represented by tests of turning a hose on the window, the water will accumulate in the channel  16  and chamber  14  until it backs up between the closed sash  15  and the inner stop  20  until it spills over into the interior of the building structure. 
     The resistance to this spilling over of the water is measured in terms of “dam height”. As the dam height is increased, the water resistance of the window is increased. 
     In FIG. 1, the dam height X of the frame F 1  is the distance between the top of the snap-in window stop  20  to the bottom of the chamber  14  where the water is released through the outlet  24 . In FIG. 1, this dam height, in effect, is the height of the body portion  1  at the interior of the wall opening  7  plus the height of the stop  20 . Thus, the dam height or water resistance of the window is increased as the height of the stop  20  is increased. However, this increases the exposed interior height of the window sill detracting from its appearance and reducing the egress opening, that is the space available for exiting the window in the case of an emergency when the window is fully open. In other words, to increase the water resistance of the window, the egress opening is correspondingly reduced and may require an overall increase in window size, window frame and wall opening to obtain the allowable window egress opening in order to meet the required water resistance. 
     DETAILED DESCRIPTION ACCORDING TO THE PREFERRED EMBODIMENTS OF THE PRESENT INVENTION 
     FIG. 2 illustrates a window frame unit designated as F 2  which achieves the desired water resistance represented by the dam height X while reducing the exposed interior height at the sill of the window frame thus increasing the size of the egress opening and increasing the aesthetic appearance of the window interior. 
     FIG. 2 is a view similar to FIG. 1 but showing a section through the sill of the frame F 2  which has been modified to incorporate the invention. Frame F 2  has a body portion  25  corresponding to the body portion  1  of the frame F 1 . The body portion  25  carries an integral J-rail return member designated at  26  which is modified from the J-rail return  2  of FIG. 1 but does provide a J-channel  27  for receiving siding  28 . 
     The J-rail return  26  comprises a nailing fin or flange  29  portion corresponding to the nailing fin  3  in FIG. 1, an outwardly projecting arm or portion  30  and a return portion generally designated at  31 . This return portion  31  comprises a double walled section  32  forming a channel or trough  33  and a single leg  34  projecting from the bottom of the trough  33  and ending in an inturned bead  35 . 
     The remainder of the frame F 2  has essentially the same construction as the frame F 1  with the body  25  being adapted to be inserted into an opening  7 ′ in a wall  8 ′ to circumscribe the wall opening with the nailing fin  29  abutting the outer face  9 ′ of the wall  8 ′ and circumscribing the perimeter of the wall opening  7 ′. 
     The body portion  25  of the frame F 2  has a window stop formation  36  corresponding to the window stop  11 , a screen support seating section  37  corresponding to the screen support section  12  supporting a screen  38  and defining with the outwardly projecting portion  30  and the return portion  31  a chamber  39  which includes the trough  33 . 
     As in the case of frame F 1 , the body portion  25  of frame F 2  includes a channel  40  beneath stop ledges  41  and  42 , a latch section  43  for receiving a snap-in inner stop  44  for retaining a window unit or sash  45  between the outer window stop formation  36  and the snap-in inner stop  44 . 
     It will be noted that the snap-in stop  44  of the frame F 2  has significantly less height than the snap-in stop  20  of the frame F 1 , FIG.  1 . That is, the interior height of the sill of the frame F 2  including the snap-in stop  44  at the sill is substantially less than the interior height of the frame F 1  with its snap-in stop  20 . This results not only in improving the interior appearance of the window but importantly increases the egress opening available on opening of the sash  45  of frame F 2  over the egress opening available on opening the sash  15  of the frame F 1 . 
     As with frame F 1 , as viewed at the sill of the frame, the channel  40  beneath the closed sash  45  of frame F 2  has an outlet opening  46  so that water forced against the sash in heavy rain storms will penetrate in the direction of the arrows  47  beneath the sash and into the chamber  39 . However, in the case of the chamber  39 , the water will drop into the trough  33  which, in turn, is provided with an outlet opening  48  at the bottom thereof. 
     In the example given, the depth of the trough  33  has been chosen to equal the reduction in height of the snap-in stop  44  of frame F 2  from the height of the snap-in stop  20  of frame F 1 . As a result, frame F 2  provides the same water resistance or dam height X as frame F 1  while at the same time reducing the interior sill height of the frame and increasing the egress opening available on opening of the window. 
     It will be understood that the depth of the trough  33  and height of the snap-in stop  44  may be varied as desired depending upon the desired water resistance and other details of the frame may be changed without departing from the scope of the appended claims. 
     Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the scope of the appended claims.