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RELATED APPLICATION 
     The present application is a divisional application of U.S. patent application Ser. No. 12/002,750, filed Dec. 18, 2007, now U.S. Pat. No. 8,146,295, which claims the benefit of U.S. Provisional Application No. 60/875,480 filed Dec. 18, 2006, the disclosures of which are incorporated by reference herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to doors. More particularly, the present invention relates to z-bar assemblies for doors. 
     BACKGROUND OF THE INVENTION 
     A door assembly, such as a storm door, often involves the use of what is commonly referred to as a “z-bar.” The z-bars are typically formed to mount the door assembly to the jambs or exterior trim of the entry door. Normally there are two z-bars in such an installation: a hinge-side z-bar and a latch-side z-bar. There may also be a z-bar extending over the top of the door that serves as or facilitates a drip cap. The hinge-side z-bar is so named because it accommodates hinges for pivotal mounting of the door. The latch-side z-bar is so named because it is located adjacent the latch side of the door and may serve as part of a system to latch the door in a closed position. 
     Some manufacturers specify a given door assembly to cover a range of door openings. The door is typically equipped with a door expander or spacer that enables adjustment of the length of the door relative to the opening, as well as the adjustment of the orientation of the lower edge of the door to accommodate door sills and/or door casings that may not be true. 
     It is often desired that the z-bars extend over the entire length of the storm door or entry door jambs for reasons of aesthetics, connectivity and energy conservation. Accordingly, the z-bars are typically sized to operatively match a maximum or fully expanded length of the door. 
     However, the height of door openings will often vary and will often be less than the full length of traditional z-bars, requiring the installer to trim the ends of the z-bars off. Conventional methods and techniques for trimming z-bars are innately inconvenient and time consuming. In addition, many casings feature a sill having an inclined upper surface that sheds water. The trimmed ends of these traditional z-bars are typically cut to accommodate the incline. A trimming cut that either leaves the z-bar too short or at an improper angle relative to the incline is generally detrimental to the aesthetic and energy conservation qualities of the assembly, and increases the installation time of the door assembly. 
     Some manufacturers supply z-bars that are intentionally shorter than the minimum length of the door so that z-bar does not have to be cut to fit the height of the door frame during installation. Such an approach is disclosed in U.S. Patent Application Publication No. 2006/0150524 to Kibbel et al. While this approach negates the need for cutting the z-bar to length, it does not address the aforementioned detriments to aesthetics and energy conservation. 
     A z-bar assembly that avoids the problems that can result from shortened z-bars, and augments a more efficient installation procedure would be welcome. 
     SUMMARY OF THE INVENTION 
     Various embodiments of the invention include a z-bar having an extender for adjusting the length of the overall z-bar assembly. The length of the z-bar is generally undersized, with the extender slidably attached to provide a telescoping adjustment to the overall length of the assembly without need for trimming. The extenders may have substantially the same profile as the z-bar to maintain aesthetic appearance and functionality. The various embodiments may be applicable to both hinge-side and latch-side z-bars. 
     In one embodiment, a door assembly comprises a door casing or frame including a door jamb and a sill, at least one z-bar member mounted to the casing, and a z-bar extension member or extender mounted to the z-bar member and extending beyond the end of the z-bar member. One end of the z-bar assembly may be factory cut or otherwise formed to accommodate sill incline angles standard in the industry. 
     In another embodiment, the z-bar assembly includes an exterior z-bar member with an exterior barrel portion, and an interior z-bar extension member with an interior barrel portion. The interior barrel portion of the extension member is slidably engaged within the exterior barrel portion of the z-bar member, enabling the extender to selectively extend beyond the end of the exterior z-bar member. 
     In another embodiment, the z-bar extension member is made of a resilient material and is mounted on the exterior of the z-bar member by snapping engagement over the barrel portion of the z-bar member. 
     In another embodiment, the z-bar or z-bar extension member may include one or more score lines extending laterally across the z-bar extension member. The z-bar extension member can be snapped off or otherwise truncated at a selected score line to modify the length of the z-bar extension member. The score lines may also serve as a guide for cutting the z-bar or z-bar extension to a unique length between score lines. 
     In other embodiments, the z-bar extension member includes a base portion on one end. The base portion may be formed integrally with the z-bar extension member, and may define an obtuse angle with respect to the z-bar extension member to substantially match the incline angles of sills standard in the industry. 
     In certain embodiments, the interior and exterior z-bar members are formed with mating structures such as, but not limited to, projections and apertures or detents and grooves that cooperate to at least temporarily maintain the mated structures in a generally linear positional relationship with respect to each other to assist in the installation and adjustment of the assembly. In other embodiments, structures or cut-away portions may define slots for slidable engagement that imparts a friction between the interior and exterior z-bar members, thereby aiding in holding the adjustment of the length of the assembly. 
     In some embodiments, the interior z-bar extension member may be sized and configured such that it is under generally constant resistance within the exterior z-bar member, creating friction and restricting, but not prohibiting, movement of the extension member. 
     An embodiment is also disclosed wherein a guard assembly may be mounted on a vertical edge of the door, the guard assembly having a shield portion that extends at least partially over the z-bar or z-bar assembly. The guard assembly may extend the length of the vertical edge or only a portion thereof to cover at least a corresponding portion of the gap that exists between the vertical edge of the door and the z-bar assembly. The guard assembly may also take the form of an end cap that mounts to and covers an end of the door expander, to retain insulation within the door expander and/or to prevent debris such as dirt and salt from entering the door expander. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 through 3  are partial perspective views of a door assembly in an embodiment of the invention; 
         FIG. 4  is a perspective isolation view of the extended z-bar assembly of  FIG. 2 ; 
         FIG. 5  is a partial perspective view of the z-bar of  FIG. 4  in isolation; 
         FIG. 6  is a perspective view of the z-bar extension member of  FIG. 4  in isolation; 
         FIG. 7  is a cross-sectional view of an extended z-bar assembly according to an embodiment of the invention; 
         FIG. 8  is a perspective of the components of an extended z-bar assembly according to an embodiment of the invention; 
         FIG. 9  is a side view of a z-bar extension member having ends with oblique angles in an embodiment of the invention; 
         FIG. 10  is a cross-sectional view of the z-bar extension member of  FIG. 9 ; 
         FIG. 11  is a perspective view of an extended z-bar assembly with weather stripping in an embodiment of the invention; 
         FIG. 12  is a cross-sectional view of an installed z-bar assembly in an embodiment of the invention; 
         FIG. 13  is a cross-sectional view of an installed z-bar assembly having a spacer rib in an embodiment of the invention; 
         FIG. 14  is a partially exploded cross-sectional view of the extended z-bar assembly of  FIG. 13  in isolation; 
         FIG. 15  is a cross-sectional view of an installed z-bar assembly having engaging slots for holding the extended z-bar assembly together in an embodiment of the invention; 
         FIGS. 15A and 15B  are enlarged inset views of the cross-sectional view of  FIG. 15 ; 
         FIGS. 16 and 17  are perspective views of a tongue overlay configuration in an embodiment of the invention; 
         FIG. 18  is a cross-section of  FIG. 17 ; 
         FIG. 19  is a perspective view of a projection and aperture mating system having paired structures in an embodiment of the invention; 
         FIG. 20  is a perspective view of a projection and aperture mating system having elongate structures in an embodiment of the invention; 
         FIG. 21  is a cross section representative of both the  FIG. 19  and the  FIG. 20  embodiments; 
         FIG. 22  is a cross-section of a detent and groove mating system in an embodiment of the invention; 
         FIG. 23  is a perspective view of a z-bar extension member with score lines in an embodiment of the invention; 
         FIG. 24  is a perspective view of a z-bar assembly in an embodiment of the invention; 
         FIGS. 24A and 24B  are perspective views of the z-bar extension member of  FIG. 24  in isolation; 
         FIG. 24C  is an elevation view of the z-bar extension member of  FIG. 24  in isolation; 
         FIG. 24D  is a section view of the z-bar extension member of  FIG. 24C ; 
         FIG. 25  is a side view of a dual base z-bar extension member having a base on each end with and with oblique angles in an embodiment of the invention; 
         FIG. 26A  is a partial cut away view of a guard assembly in an embodiment of the invention; 
         FIG. 26B  is a partial perspective view of a guard assembly for capping an expander in an embodiment of the invention; 
         FIG. 26C  is a top view of the guard assembly of  FIG. 26B ; and 
         FIG. 27  is an end view of a guard assembly mounted to a door in an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 3 , a door assembly  30  including an exterior door  32 , a door frame or casing  34  and an extended z-bar assembly  36  having a z-bar  38  and a z-bar extension member  40  is depicted in one embodiment of the invention. The exterior door  32 , which may be a storm door or a screen door, may include a door expander  44  and a hinge member  46 . The door frame or casing  34  may include an exterior trim or door jamb  52 , a sill  54  and a header (not depicted). The sill  54  may have an inclined upper surface  56 . The z-bar  38  may be dimensioned so that a gap  57  exists between an end of the z-bar  38  and the sill  54 . The gap  57  is bridged by the z-bar extension member  40 . 
     Referring to  FIGS. 4 through 8 , various embodiments of the extended z-bar assembly are depicted. In one embodiment, the z-bar  38  includes a flange portion  60 , a barrel portion  62 , a web portion  64  and a projecting portion  66 . The z-bar  38  may also be characterized as having an inward-facing surface  67  (e.g. the surface that generally faces the door jamb  52 ) and an outward-facing surface  68  (i.e. the surface opposite the inward-facing surface  67  that generally faces away from the door jamb  54  to which the z-bar  38  is mounted). 
     An embodiment of the z-bar extension member  40  may include an extender flange portion  70 , an extender barrel portion  72 , an extender web portion  74  and an extender projecting portion  76 . Not all of these portions are necessary in the construction of a z-bar extension member; some portions may be omitted and still provide effective extension of the z-bar assembly for functional or aesthetic purposes. Like the z-bar  38 , the z-bar extension member  40  may also be characterized as having an inward-facing surface  77   a  and an outward-facing surface  77   b . The z-bar extension member  40  may be slidably engaged with the z-bar  38 . Note that some embodiments depicted in  FIGS. 4 through 8  do not include the extender flange portion  70  (e.g.  FIGS. 6 through 8 ). Also, the ends  79  of the z-bar extension member  40  may be substantially square with respect to a longitudinal axis  82  of the z-bar extension member  40  ( FIG. 8 ). 
     Referring to  FIGS. 9 and 10 , an embodiment of the z-bar extension member  40  having ends  79  that define an oblique angle  80  relative to the axis  82  of the z-bar extension member  40  is depicted. The oblique angle  80  may be provided at just one end of the z-bar extension member, thereby defining a component that accommodates either the hinge side or the latch side of the door assembly  30  (but not both) without need for cutting an angle. The oblique angle  80  may also be provided on both ends, as depicted in  FIG. 9 , in which case the same z-bar extension member  40  may be used on the hinge side or the latch side of the door assembly  30 . The z-bar extension member  40  may also include an extender flange projection  78  that projects outward from the extender flange portion  70 . 
     The embodiment depicted in  FIGS. 1 through 3  illustrate the z-bar extension member  40  as being located inside the z-bar  38 . The extended z-bar assembly  36  may also be configured so that at least a portion of the z-bar extension member  40  is positioned over the z-bar  38 . Also, if the z-bar extension member  40  is formed of a resilient material, the z-bar extension member  40  can be flexed and snapped into or over the z-bar  38 , depending on the configuration. 
     Also, the embodiment depicted in  FIGS. 1 through 3  illustrate the gap  57  as existing between the z-bar  38  and the sill  54 . In another embodiment, a gap may exist between the z-bar  38  and the header (not depicted), and the z-bar extension member  40  installed to bridge therebetween. 
     Functionally, the z-bar extension member enables the z-bar  38  to be fabricated with a length that is intentionally shorter than the length of the door jamb  52 . The barrel portion  62  of the z-bar  38  and the extender barrel portion  72  of the z-bar extension member  40  cooperate to guide the z-bar extension member  40  in an in-line or telescoping manner along the longitudinal axis  82  to bridge the gap between the z-bar  38  and the sill  54 . The extender flange projection  78  projects normal to the mounting surface of the door jamb  52  along the outside edge of the flange portion  60  and provides an externally accessible means for gripping the z-bar extension member  40  for positioning during installation of the extended z-bar assembly  36 . 
     The use of a resilient material for the z-bar extension member  40  that is mounted over the z-bar  38  (not depicted) enables installation of the z-bar extension member  40  after the z-bar  38  has been mounted to the door jamb  52 . The z-bar extension member  40  may then be secured in place by means known in the art such as with additional fasteners or with an adhesive. 
     Referring to  FIGS. 11 through 15 , a variety of other embodiments of the invention are depicted in assembly. The extended z-bar assembly  36  is attached to the door jamb  52  of the casing  34  with fasteners  84  such as wood screws. The fasteners  84  may pass through the flange portion  60  and the web portion  64  of the extended z-bar assembly  36  to cover a corner  85  of the door jamb  52  that in part defines the exterior opening of the casing  34 . 
     The flange portion  60  may also be formed with a pair of rails  87  that straddle the fasteners  84 . A cap strip  86  may be formed to accommodate the rails  87  for placement over the heads of the fasteners  84 . 
     The embodiment of  FIGS. 13 and 14  depict a rib  92  that projects from the web portion  64  of the z-bar  38  toward the door jamb  52 . The rib  92  may or may not pass through the z-bar extension member  40  in final assembly. 
     A weather stripping  88  or other suitable material may be mounted to the face of the projecting portion  66 . The projecting portion  66  may be formed with a pair of L-brackets  94  that define a track  96  for capturing the base of the weather stripping  88 . 
     Referring to  FIGS. 15A and 15B , details of the configuration of  FIG. 15  are depicted. In  FIG. 15A , the projection portion  66  is limned as having a projection lip  98  that is substantially parallel with the projection portion  66  to define a slot  100 . The end of the extender projecting portion  76  is seated within the slot  100  and captured by the projection lip  98 . Likewise,  FIG. 15B  portrays a flange lip  102  that is substantially parallel with the flange portion  60  and defines a slot  104  that captures the edge of the extender flange portion  70 . The slots  100  and  104  may be dimensioned to provide a frictional resistance between the z-bar  38  and the z-bar extension member  40 . 
     Referring to  FIGS. 16 through 18 , another embodiment of the extended z-bar assembly  36  is illustrated, including a pair of elongate slots  108  formed on the z-bar extension member  40 . In the depicted embodiment, one elongate slot  108  is located near the junction of the extender barrel portion  72  and the extender web portion  74 , the other near the junction of the extender projecting portion  76  and the extender web portion  74 . The elongate slots  108  may extend from a proximal end  109  of the z-bar extension member  40  along a portion of the length of the z-bar extension member  40  to form a tongue portion  110  of the extender web portion  74 . The elongate slots  108  may be substantially parallel to the longitudinal axis  82 . 
     The weather stripping  88  can be attached to both the projecting portion  66  and the extender projecting portion  76 . The weather stripping may be adhesively attached, or captured by a track or channel such as the track  96 , or by other means known in the art. The weather stripping  88  may be pre-installed, running the full length of the z-bar extension member  40 , and trimmed off when the desired length of the extended z-bar assembly  36  is established. Alternatively, the z-bar extension member  40  may be assembled without the weather stripping  88 , and a strip of it provided for trimming and mounting to the z-bar extension member  40  after the extended z-bar assembly  36  has been mounted to the door jamb  52 . 
     In assembly, the extender barrel portion  72  of the z-bar extension member  40  may be inserted into the barrel portion  62  of the z-bar  38 . The z-bar extension member  40  may be formed so that the extender web portion  74 , and therefore the tongue portion  110 , overlays an outer face  112  of the web portion  64  of the z-bar  38 . In this configuration, while the extender barrel portion  72  is engaged with the inward-facing surface  77   a  of the barrel portion  62  of the z-bar  38 , the tab portion  110  is engaged with the outward-facing surface  77   b  of the web portion  64  of the z-bar  38  in an interlacing fashion ( FIG. 18 ). The elongate slots  108  may be dimensioned to provide a frictional fit between the z-bar  38  and the z-bar extension member  40 . 
     The number of elongate slots  108  is arbitrary, as well as their placement. Consider, for example, a single elongate slot extending parallel to the longitudinal axis  82 . Such a configuration would enable the extension member  40  to engage both the inward-facing surface  77   a  and the outward-facing surface  77   b  of the z-bar. Likewise, more than two elongate slots can also be utilized for interlacing contact between the z-bar extension member  40  and the z-bar  38 . 
     Referring to  FIGS. 19 through 22 , various structures for maintaining the lineal relationship between the z-bar  38  and the z-bar extension member  40  are illustrated. The  FIG. 19  embodiment includes a plurality of mating projections  138  that extend outward from the extender web portion  74 . In the embodiment depicted, the mating projections  138  are in pairs at a given longitudinal location along the longitudinal axis  82 . The mating projections  138  of each pair are separated at a lateral spacing  139 . A plurality of mating apertures  140  are formed on the web portion  64  of the z-bar  38 , also in pairs having a lateral spacing  139  at a given longitudinal location. The mating projections  138  are dimensioned to engage with the apertures  140 . The layout (dimensional spacing) of the mating projections  168  and the mating apertures  140  are the same, and the respective pairs can be spaced at equal intervals  145 . 
     A similar concept is illustrated in  FIG. 20 . Instead of paired projections and apertures, the web portions  64  and  74  can include elongate mating projections  142  and elongate mating apertures  144  spaced at uniform intervals  145 . 
     The cross-sectional depiction of  FIG. 21  depicts how the embodiments of  FIGS. 19 and 20  can appear after assembly. 
     An embodiment of similar concept is portrayed in  FIG. 22 . In this embodiment, the extender web portion  74  is formed with a plurality of detents  146 , and the web portion  64  is formed with a plurality of grooves  148 . The detents  146  and grooves  148  can have a uniform spacing  150  and can be formed to mate or interlock with each other. 
     It is noted that the various projections, apertures, detents and notches are not limited to being formed on the components specified in  FIGS. 19 through 22 . For example, in the  FIG. 19  embodiment, mating projections may be formed on the interior of the web portion  64  to cooperate with mating apertures formed on the extender web portion  74 . Also, the detents of  FIG. 22  may be utilized in the embodiments of  FIGS. 19 and 20 . Furthermore, the positive locking concepts illustrated in  FIGS. 19 through 22  may be incorporated with the sliding tab configuration of  FIGS. 13 through 16 . 
     In operation, the z-bar extension member  40  may be slid inside the z-bar  38  until the extended z-bar assembly  36  is at or near a desired length. Depending on the embodiment utilized, at least a portion of the mating projections  138 ,  142  or the detents  146  are then aligned with the nearest corresponding mating apertures  140 ,  144  or the grooves  148  and snapped into place. The resolution of the adjustment can be minor fractions of an inch, depending on the spacing of the intervals  145 ,  150  and the dimension of the mating apertures  140 ,  144  or grooves  148 . 
     For the embodiment that includes the rib  92 , the rib  92  serves as a spacer to accommodate the thickness of the z-bar extension member  40 , thereby augmenting adjustment of the z-bar extension member  40  after the extended z-bar assembly  36  has been mounted to the door jamb  52 . 
     The slots  100  and  104  can serve to secure the z-bar extension member  40  in slidable engagement with the z-bar  38  during installation. The slots  100  and  104 , if properly dimensioned, also provide a frictional resistance between the z-bar  38  and z-bar extension member  40  that temporarily holds the z-bar extension member  40  in a fixed relationship in line with the z-bar  38  during the installation process. 
     The various components of the extended z-bar assembly  36  may be made of any suitable material such as extruded metal, forged metal, ferrous or non-ferrous metals, or a resilient material such as high density plastic. Extrudable materials include, but are not limited to, aluminum, aluminum alloy and composite resin materials. The z-bar assembly or components thereof may be of a roll formable material, such as aluminum, aluminum alloy or steel. 
     Referring to  FIG. 23 , another embodiment of the z-bar extension member  40  is depicted wherein the z-bar extension member  40  further includes a plurality of score lines  200 . The score lines  200  may extend laterally across the z-bar extension member  40  (i.e. across the width of the z-bar extension member  40 ). In some embodiments, score lines  200  extend across one or more of the flange portion  70 , the barrel portion  72 , the web portion  74 , and the projecting portion  76  of z-bar extension member  40 . The score lines  200  can be formed on one side of z-bar extension member  40  (e.g. on the inward-facing surface  77   a , as depicted), or alternatively on both sides of z-bar extension member  40 . 
     The score lines  200  on the z-bar extension member  40  may comprise grooves that extend into the thickness of the z-bar extension member  40 . In this configuration, the z-bar extension member  40  may be rendered frangible or additionally scored at one of the score lines  200  for frangible separation. Alternatively, the score lines  200  may comprise printed guidelines to guide the installer in scoring the z-bar extension member  40 . 
     In operation, the frangible score lines  200  may enable the length of the z-bar extension member  40  to be modified by snapping off z-bar extension member  40  at the desired score line  200 . In one embodiment, the z-bar extension member  40  may be snapped off by application of a manual force. In another embodiment, additional tools such as clamps or wrenches may be used to assist an installer to snap z-bar extension member to a desired length. 
     For z-bar extension members  40  having the score lines  200  located only on the inward-facing surface  77   a , the outward-facing surface  77   b  may have a smooth finish, which may have desirable aesthetic and maintenance qualities. 
     Where guide lines or light score lines are utilized instead of frangible score lines, the installer may cut the z-bar extension member  40  to any length whether on the guideline or not. The guidelines may provide the installer with sufficient resolution to create a desired cut between the guidelines. 
     In another embodiment of the invention, the score line concept is applied to the z-bar  38  (not depicted). That is, a plurality of score lines may be located proximate one or both ends of the z-bar  38  to enable an installer to readily shorten the z-bar. In this way, the z-bar  38  may be oversized initially. The scored lines on the z-bar  38  can be configured in any of the variety of ways discussed in relation to the scored lines  200  on the z-bar extension member  40 . 
     During installation, the installer could shorten the scored z-bar  38  for suitable clearance between the z-bar  38  and the sill  54  and /or header. Such clearance, however, may be less than a z-bar manufactured to provide clearance over a variety of door sizes, thus enabling coverage of the clearance gap with a shorter z-bar extension member  40  (or, in some cases, without need for a z-bar extension member at all). Generally shorter z-bar extension members may provide functional advantages to the door assembly, such as an ability to seal the entire inward-facing surface  77   a  with a caulk or sealant to provide a more reliable moisture and/or thermal barrier. The shorter z-bar extension member may also provide aesthetic advantages as well. 
     In various embodiments, the length of z-bar extension member  40  may be modified by additionally scoring and/or cutting the z-bar extension member  40  using the desired score line  200  as a guide. Tools may be used to perform this operation, such as a saw, utility knife, hot wire, or other cutting tool. Also, the score lines  200  may be formed at an obtuse angle relative to the longitudinal axis  82  to conform to a given sill incline angle after being trimmed (not depicted). 
     Referring to  FIGS. 24 and 24A  through  24 D, a z-bar assembly  230  including the z-bar  38  and a molded z-bar extension member  240  comprising a moldable material is depicted in an embodiment of the invention. As in the previous embodiments, the molded z-bar extension member  240  may include an extender flange portion  270 , an extender barrel portion  272 , an extender web portion  274  and an extender projecting portion  276 . The z-bar extension member  240  may also be characterized as having an inward-facing surface  278  and an outward-facing surface  280 . 
     In one embodiment, a base portion  284  may be attached or integrally formed on one end of the molded z-bar extension member  240 . For the molded extender  240 , an integrally formed base  284  may be effected by the shape of the mold. The base portion  284  may be generally perpendicular with a longitudinal axis  286  of the z-bar assembly  230 . Alternatively, the base  284  may define an obtuse angle  288  (i.e. an angle that is greater than 90 degrees), as depicted in  FIG. 24D . 
     The extender projecting portion  276  may include a slot or channel portion  290  and a deflecting portion  292 . The channel portion  290  and the deflecting portion  292  may be connected through a flexure or hinge portion  294  such as a living hinge. The base portion  284  may be formed with an aperture  296  immediately adjacent the deflecting portion  292 . In this way, the deflecting portion  292  is not directly connected to the base portion  284 , thus enabling the deflecting portion  292  to rotate about the hinge portion  294 . 
     The extender flange portion  270  may include a pocket structure  300  sized to accommodate the flange portion  60 , rails  87  and cap strip  86  of an embodiment such as depicted in  FIG. 14 . In cross section, the pocket structure  300  may form a closed loop (not depicted) or a partially closed loop (as depicted). 
     The molded z-bar extension member  240  is generally comprised of a moldable material. Moldable materials include, but are not limited to, polypropylene, polyvinyl chloride (PVC), nylon, polycarbonate, acrylonitrile butadiene styrene (ABS), styrene and delrin. Other moldable materials available to the artisan may be utilized. 
     Functionally, the molded z-bar extension member  240  may be slidably engaged with the z-bar  38 . The channel portion  290  cooperates with the projecting portion  76  of the z-bar  38  to help secure the molded z-bar extension member  240  to the z-bar  38 . When the door is brought into contact with the deflecting portion  292 , the deflecting portion  292  can act as a positive sealing member against the door, thereby serving as a barrier or seal akin to a weatherstrip. Alternatively, the deflecting portion  292  may be excluded from the z-bar extension member  240  and weather stripping mounted to the z-bar  38  left exposed to perform the barrier function. Weatherstrip may also be adhesively attached to the projecting portion  276  to extend weather barrier protection beyond the end of the z-bar  38 . 
     The pocket structure  300  may be dimensioned to surround the lower end of the cap strip assembly (as depicted) or to abut with the cap strip  86 . The partial loop depicted in  FIGS. 24  enables any water that enters the pocket from the top to drain out. Alternatively or additionally, slits or holes (not depicted) may be formed at the base of the pocket structure  300  for the drainage function. 
     The obtuse angle  288  between the base potion  284  and the longitudinal axis  286  may be formed to correspond with the incline of a sill (e.g. sill  54  of  FIG. 1 ). The base portion  284  may serve as sealing structure that engages a door expander spline at the base of a door expander (not depicted) for a better seal between the door expander spline and the sill. 
     In other embodiments, the base may be formed separately. In these embodiments, the z-bar extension member and/or separate base may be formed by a process such as molding, extrusion, or roll forming, then glued, fused, fastened or otherwise connected to the molded z-bar extension member. 
     Referring to  FIG. 25 , a dual base z-bar extension member  320  having an extension portion  322 , a first base portion  324  and a second base portion  326  is depicted in an embodiment of the invention. The extension portion  322  may define a longitudinal axis  328 . The ends may form substantially right angles with respect to the longitudinal axis  328  (not depicted) or obtuse angles  330  with respect to the longitudinal axis  328  (as depicted). 
     Functionally, the dual base z-bar extension member may be severed along a line  332  between the first and second base portions  324  and  326  to provide left side and right side z-bar extension members. Severability may be provided by a score line, or the user may cut the dual base z-bar extension member  320  at an arbitrary location between the first and second base portions  324  and  326 . 
     Referring to  FIGS. 26A through 26C , a guard assembly  352  is depicted in another embodiment of the invention. The guard assembly  352  may be comprised of a base portion  354  having a first major surface  356 , a second major surface  358 , a top end  360 , a bottom end  362 , a front edge  364  and a back edge  366 . One or more rail portions  368  may extend in a direction substantially orthogonal to the first major surface  356 . A shield portion  370  may extend from the second major surface  358 . The rail portions  368  and the shield portion  370  may be formed integral to the base portion  354 , and may be flush with the front and back edges  364  and  366 . A spacing  372  may be defined between rail portions  368  so that the guard assembly  352  effectively caps a vertical edge  373  of the door  32 . 
     In one embodiment, the guard assembly  352  may be operatively coupled to the vertical edge  373  of the door  32 . The length of the guard assembly may cover substantially the entire length of the vertical edge  373  of the door  32 , or a portion thereof. 
     The guard assembly may serve as an end cap to the door expander  44 . The spacing  372  between the rail portions  368  may be dimensioned to provide an interference or snap-on fit between the end of the door expander  44  and the guard assembly  352 . The guard assembly  352  may be sized so that the top end  360  extends above the door expander  44  and the bottom end  362  extends below the door expander  44  so as to cover the end of the door expander  44 . 
     Referring to  FIG. 27 , the top end  360  and/or the bottom end  362  of the guard assembly  352  may be formed or cut at an angle  374  relative to the front edge  364 . The angle  374  may correspond to the inclined surface  56  of the sill  54 . 
     In assembly, the guard assembly  352  may be mounted to one or both edges of the door  32  for engagement with either the hinge side or the latch side z-bar or z-bar assembly. Coverage of the guard assembly  352  may be along the entire vertical edge or edges  373  of the door  32  or just a portion thereof such as the expander  44 . In an alternative configuration, the rails may be spaced to fit both inside the door expander  44  while capping the vertical edge  373  of the door  32 . The guard assembly  352  may be placed over the end of the door expander  44  and adjusted to a position appropriate to provide contact or near contact with the top of the sill  54  when the exterior door  32  is closed. The guard assembly  352  may also be mounted to the end of the door expander  44  with glue, or with fasteners (not depicted), or by other means available to the artisan. 
     To accommodate mounting the guard assembly  352  with fasteners, the one or more rail portions  368  may extend over one or more of the faces of the door expander  44  or the door  32  at a distance sufficient to accommodate the head of a fastener (not depicted). The various means of mounting the guard assembly  352  to the door expander  44  herein disclosed or otherwise known to the artisan may be utilized separately or in combination. 
     For embodiments that include the angle  374  on the top and/or the bottom end  360  and  362 , the guard assembly  352  may be installed without need for cutting the guard assembly  352 . When both ends  360  and  362  have inclines  370 , the same guard assembly  352  may be utilized on either the hinge side or the latch side of the exterior door  32 . 
     Functionally, the shield portion  370  may engage or nearly engage the z-bar  38  when the door  32  is in a closed position. The guard assembly  352  enables the z-bar  38  to be dimensioned shorter than the length of the door jamb  52 , and bridges the gap  57  (e.g.  FIG. 2 ) between the z-bar  38  and the door jamb  52 . The guard assembly  352  provides a barrier at the end of the door expander  44  that inhibits collection of matter such as dirt, sand and salts that may corrode the door expander  44  over time. The guard assembly  352  may also enhance the thermal insulative quality of the exterior door assembly in at least two ways. First, the guard assembly  352  inhibits the flow of air through the door expander  44 , thereby providing a dead air pocket  376  within the door expander  44  and enhancing the thermal resistance of the door assembly  30 ; the dead air pocket  376  may alternatively be filled with an insulation  378  that is contained when guard assemblies  352  are utilized on both ends of the door expander  44 . Second, the guard assembly  352  serves as an additional barrier for impeding air flow and inclement elements such as rain and snow into a gap  380  between the door  32  and the z-bar assembly  36  ( FIG. 26C ), particularly when the guard assembly  352  extends over an appreciable length of the vertical edge  373  of the door  32 . 
     The guard assembly  352  may be utilized without the z-bar extension member  40 , as depicted in  FIGS. 26A through 26C , or in conjunction with the z-bar extension member  40  to provide the additional barrier characteristics outlined above. 
     The guard assembly  352  may be fabricated from a resilient material, such as metal or high density plastic, or from a more compliant material such as a rubber or silicone, or from a combination of resilient and compliant materials. Additionally, the shield portion  370  may be fitted with weather stripping or other suitable material to provide further insulative characteristics to the door assembly  30  and to compensate for dimensional intolerances that may occur in fabrication and installation. 
     In another embodiment, the shield portion  370  may be connected to the base portion  354  of the guard assembly  352  through a hinge portion (not depicted). The hinge portion may be a separate member, such as a spring-loaded pivot pin that connects the base and shield portions  354  and  370 , or a living hinge that is integral to the base and shield portions  354  and  370 , or by other hinging techniques known to the artisan. The hinge concept can provide compliance between the shield portion  370  and the z-bar  38  that compensates for dimensional intolerances that may occur in fabrication and installation, or which develop over time. The hinge concept may find enhanced utility in conjunction with hinge-side z-bars; the tight radius of rotation of the shield portion  370  about the z-bar  38  may cause over extension of the flexing of the shield portion  370  relative to the base portion  354  of the guard assembly  352  whenever the exterior door  32  is partially or fully opened. Repeated over extension may lead to fatigue failure between the shield portion  370  and the base portion  354 . The hinge member or hinge portion could be designed to reduce the fatigue of the components, thereby extending the life of the guard assembly  352 . 
     As previously discussed, a z-bar may be mounted to the header of a door casing, defining an upper gap between the z-bar and the header (not depicted). The guard assembly  352  may be utilized on the top edge of the door  32  to cover the upper gap when so configured. 
     References to relative terms such as upper and lower, front and back, left and right, or the like, are intended for convenience of description and are not contemplated to necessarily limit the present invention, or its components, to any specific orientation. All dimensions and aspect ratios depicted in the figures may vary with a potential design and the intended use of a specific embodiment of this invention without departing from the scope thereof. 
     Each of the additional figures and methods disclosed herein may be used separately, or in conjunction with other features and methods, to provide improved devices and methods for making and using the same. Therefore, combinations of features and methods disclosed herein may not be necessary to practice the invention in its broadest sense and are instead disclosed merely to particularly describe representative and preferred embodiments of the instant invention. Because various modifications, substitutions, and changes of this invention may be made by one of skill in the art without departing from the spirit thereof, the invention is not limited to the embodiments illustrated and described herein. Rather, the scope of the invention is to be determined by the appended claims and their equivalents.

Summary:
A method of assembling a z-bar extension member to a z-bar that negates the need for trimming the z-bar. The apparatus includes an exterior z-bar member having an exterior barrel portion and an interior z-bar member having an interior barrel portion. The interior barrel portion is slidably or snappingly engaged within the exterior barrel portion. Mating structures may be included on the cooperating components to maintain a positional relationship therebetween during assembly. A guard assembly that mounts to the edge of a door or on the end of a door expander to cover the gap between the z-bar and the casing is also disclosed that may be used in conjunction with or as an alternative to the z-bar extension member.