Patent Publication Number: US-8528281-B2

Title: Window and door assembly structures

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to clad windows and clad personnel entry doors. This invention relates especially to clad door frames which are used in buildings as avenues for people entering and exiting the building, including door assemblies wherein windows are joined to such door frames either as side lites or as overhead transom windows. This invention also relates to overlying clad transom windows used in clad door assemblies. The invention further relates to joining clad window frames to each other, to joining clad door frames to each other, and to joining clad window frames and clad door frames to each other. 
     Arcuate windows, overlying e.g. a rectangular window, or overlying a door, have achieved an established position in the market for windows and doors. Arcuate windows can provide a desired aesthetic/artistic characteristic to the overall appearance of a building. 
     Penetration of water into window frames is known as a significant source of deterioration/damage in window frames which use wood as a structural and/or decorative material. 
     Advances have been made in the fabrication of the arcuate portions of window framing from wood, and in the fabrication of glazing units from glass or other sheet material, for such windows. The nosing portion of the cladding which attaches to the structural window framing is desirably made of a material which is more weather-resistant than wood in order to avoid frequent maintenance to the outside surface of the window structure and to reduce the amount of water which penetrates the window, thereby reaching the wood substrate and causing deterioration of the wood substrate. 
     Doors and windows are generally assembled by an assembler. The assembler incorporates the respective door slab in a door frame and the respective window glazing in a window frame. As desired, window clusters may be assembled in a single window frame which extends about the outer perimeter of the cluster, and side light windows may be assembled to a door frame. 
     A window which is located directly over a door or door/sidelight combination is commonly referred to as a transom window. Transom windows are desirably assembled into a common unit with the respective underlying door frame so that the combined structure can be inserted, as a single unit, into the rough opening in the building. 
     However, the industry has not to date provided adequate interface structure which facilitates easily joining the transom window frame to an underlying door frame during assembly of the transom window to the underlying door frame. 
     Ongoing advances in development of window and door frames have moved toward extruded aluminum and extruded plastics as materials of choice to face the ambient environment on the outside surface of the building. Extruded aluminum and extruded plastics require only limited maintenance. 
     Transom windows, and windows in general, are conventionally fabricated in a wide variety of shapes. In some windows, all of the sides are straight. In other windows, some of the sides are arcuate or otherwise curvilinear as in conventional half-round and eyebrow windows. So, while it would be desirable to provide similarly-configured nosings and drip caps, extruded aluminum and extruded plastics, from which nosings and drip caps are commonly made, are typically fabricated in extended production runs as straight-line extrusions, whereby arcuate extrusions of such structures are not available as mass produced articles of commerce. 
     In some instances, it is desirable to attach an arcuate drip cap to an arcuate nosing, or to an arcuate portion of a nosing. In response to the desire for arcuate nosing material for arcuate windows, the industry has developed the technical capability to bend conventionally-fabricated straight-line rectangular nosing extrusions, without drip caps. 
     Thus, the industry offers an aluminum nosing which is extruded as a straight nosing. After being extruded as an elongate straight profile nosing, the aluminum nosing is bent to the desired arcuate configuration. In order to have an arcuate drip cap which can be used with such bent/arcuate nosing, a straight, extruded drip cap is separately bent into the desired arcuate shape. The lower surface of the platform of the so-bent drip cap is then positioned over the outer surface of the outer flange of the so-bent nosing, with the inner end of the drip cap in general alignment with the inner-facing web of the nosing. In conventional assemblies, there is no alignment structure in the drip cap or in the nosing which assists in holding the drip cap in alignment over the nosing, or which assists in mounting the drip cap to the nosing. Rather, the assembler places the drip cap on the nosing, and holds the drip cap in “X” and “Y” alignment with the nosing, while attaching the arcuately-formed drip cap to the arcuately-formed nosing, using screws spaced generally uniformly along the full length of the drip cap. 
     The first function of the screws is to attach the drip cap to the nosing. The second function of the screws is to maintain the alignment between the drip cap and the nosing. In addition, as the screws are tightened, the tightening of the screws acts to force the arcuate configuration of the drip cap and the arcuate configuration of the nosing to conform to each other whereby any variations in the angle or consistency of the arc radii of the drip cap and the nosing are desirably nullified as the drip cap and the nosing are drawn together by the tightening of the screws. In the event of a substantial misalignment of nosing and drip cap, or substantially different subtended arcs, extra tightening force may be used on the screws, along with corrective lateral alignment forces between the nosing and the drip cap, within the limits allowed by the screw holes, to attempt to conform the drip cap and nosing to each other. If too much force is used tightening a screw, the threads may be stripped, either on the screw or on the drip cap or on the nosing. If a user encounters excessive difficulty in assembling an assembly, including potential damage to the nosing or the drip cap, the drip cap or the nosing may be discarded in favor of a different piece, drip cap or nosing, which will, hopefully, be better suited for the desired assembly configuration, or will not be damaged during the assembly process. Even where the nosing and the drip cap are properly configured in terms of cooperative arcuate radii, and where the assembler does not strip any threads, the assembly of the two elements together, and their alignment, are completely dependent on use of acceptable gripping power, and structural integrity, relative to the assembly screws, which are maintained under constant stress. The stress on the screws in the assembly represents a combination of the tension normally needed to hold assembled parts in surface-to-surface contact with each other where both parts are in fact formed to the same arcuate configuration, as well as the tension needed to bend either the nosing or the drip cap, potentially along the full lengths of those parts, in order to correct inconsistencies in the arcuate configurations of the parts being assembled. 
     Further, the screws present a less-than-desirable appearance to the window framing. The screws tend to catch dirt; and the screws provide potential avenues for water to leak into the window structure. Further, the screws incur a certain labor cost while assembling the assembly. Overall, the screws are attended by a number of negative factors whereby it is desirable to reduce the number of screws which need to be used at locations where the screws are exposed to casual visual observation or where the screws are exposed to ambient weather. 
     In addition, the assembly process bears a certain risk of misalignment of the drip cap on the nosing. Namely, the worker who is assembling the drip cap to the nosing must ensure that the drip cap remains aligned with the nosing throughout the assembly process, until all of the screws are in place. 
     For conventional joining of clad window frames to clad door frames, or clad window frames to clad window frames, or clad door frames to clad door frames, the respective frames are typically aligned with each other with the assistance of a jig or other fixture which is not part of either frame. The frames are then secured to each other using fasteners such as screws or nails. A mullion cap or the like is then driven into the molding/nosing kerf receptacles thereby to cover the joint between the frames. Such mullion cap is employed for aesthetic/appearance purposes, and does not contribute significantly to the function of holding the frames secured together. Rather, the securement function is performed by the e.g. screws or nails or other fasteners external of the nosings. 
     SUMMARY 
     Thus, it is desirable to provide a nosing assembly which has minimum maintenance requirements and which is less susceptible to penetration by air-borne water from the ambient environment. 
     It is still further desirable to provide a nosing assembly wherein relatively lower levels of attention can be exerted toward holding the respective elements in the desired alignment during the assembly process. 
     It is yet further desirable to provide such nosing assembly wherein at least a portion of the nosing assembly has been fabricated into an arcuate configuration. 
     It is yet further desirable to provide an arcuate nosing assembly wherein the elements being assembled generally fit together in such a way that, in the loose assemblage of the nosing and drip cap to each other, the nosing and the drip cap assist in self-aligning themselves with respect to each other. 
     It is also desirable to provide a method of fabricating an arcuate nosing assembly wherein the assembly method so re-forms the nosing and the drip cap that the re-formed nosing and drip cap, themselves, provide the primary structures which hold the respective elements in fixed relationship with respect to each other. 
     It is yet further desirable to provide a method of fabricating an arcuate nosing assembly wherein the assembly method comprises positioning the nosing and the drip cap generally in the desired assembly configuration, and then bending the combination of the nosing and the drip cap, with the drip cap to the outside of the bent configuration, the bending of the drip cap and the nosing operating to bind the nosing and the drip cap to each other. 
     It is further desirable to provide a combination of first and second nosings wherein the nosings are adapted to being at least temporarily assembled to each other using only elements of the nosings to hold the elements of the nosings in such joinder. 
     It is yet further desirable to provide a combination of first and second nosings wherein structure on the nosings causes the sliding assembling of the nosings into each other to stop when the assembly process reaches the point where the outer-facing webs on the respective nosings define a generally common surface. 
     It is also desirable that the insert on each of the first and second nosings be assembled into a receptacle on the corresponding other nosing. 
     It is further desirable to employ clad door frames using nosings of the invention. 
     It is yet further desirable to provide clad window frames, or clad door/window combinations, using nosings of the invention. 
     It is still further desirable to provide clad door frames which employ the invention in combination with clad window frames in a single assembly unit. 
     It is still further desirable to provide clad door frame combinations which employ the invention. 
     In some embodiments, the invention relates to clad arcuate windows, especially clad arcuate windows which are used in transom configurations overlying a clad window frame or overlying a clad door frame. The invention relates to improved nosing structure for use about the arcuate portion of a clad arcuate transom window, and to improved nosing structure for joining respective window units to each other, for joining respective door units to each other, and for joining clad window units to clad door units. 
     The invention relates to the interface between a first clad window frame and a second clad window frame, or to the interface between a clad window frame and a clad door frame, or to the interface between a first clad door frame and a second clad door frame. 
     In general, a clad window includes a glazing unit, held in a structural clad window frame and a clad door includes a door slab held in a structural clad door frame. 
     A decorative nosing is commonly included at, or added to, the exterior face of the respective clad door frame or clad window frame, which exterior face will face away from the building, generally to provide both exterior aesthetics and to protect the main body of the frame from direct exposure to the weathering/deterioration affects caused by the ambient environment. 
     In some embodiments of the invention, a combination of an arcuate nosing, and an arcuate drip cap overlying the nosing, are secured together by collective interaction of elements of the nosing and the drip cap. An elongate hook receptacle extends along the length of the nosing, proximate or at an outer flange. An elongate stud receptacle extends along the length of the nosing, also proximate or at the outer flange. Both an elongate hook and an elongate stud extend downwardly from the overlying elongate drip cap. Securement of the drip cap to the nosing is obtained by inter-engaging the elongate hook in the hook receptacle and aligning the stud with the stud receptacle, in a loose engagement combination of straight extruded-aluminum elongate profiles of the respective precursor nosing and precursor drip cap. While the drip cap and nosing are so engaged with each other, the temporary assemblage of the nosing and the drip cap is bent into the desired arcuate configuration, with the inner flange of the nosing being to the inside of the bend, thereby re-forming the combination of the nosing and the drip cap. In the process of bending, reforming the nosing/drip cap combination, to create the desired arcuate nosing assembly configuration, the inter-engaged hook and hook receptacle are re-formed, optionally referred to as “cold-forming”, creating a tightened locking-type engagement between the hook and the hook receptacle. The result is that the nosing and the drip cap are substantially permanently locked to each other as a consequence of the process of bending the assembled nosing/drip cap combination. 
     In other embodiments of the invention, a nosing, and a drip cap overlying the nosing, are positioned relative to each other by collective interaction of elements of the nosing and the drip cap. An elongate stud receptacle extends along the length of the nosing, proximate or in an outer flange. An elongate stud extends downwardly from the overlying elongate drip cap. Positioning of the drip cap relative to the nosing is obtained by aligning the stud with the stud receptacle, in a loose engagement combination of straight extruded-aluminum elongate profiles of the respective precursor nosing and precursor drip cap. While the drip cap and nosing are so engaged with each other, screw holes are fabricated through the drip cap, and through an outer panel of the nosing. The drip cap is then secured to the nosing using screws extending through the respective holes. The result is that the nosing and the drip cap are substantially permanently secured to each other by the so-employed screws, where the nosing and drip cap are oriented in a straight-line configuration. 
     In a first family of embodiments, the invention comprehends a combination of an elongate nosing and an elongate drip cap. The elongate nosing has a nosing length, and comprises an elongate inner flange having a first outer end and a second inner end, an elongate outer flange having an outer surface, an outer flange length, a third outer end, and a fourth inner end, the outer flange being spaced from the inner flange, an elongate outer-facing web having an outer-facing web length, the outer-facing web connecting to the first end of the inner flange and the third end of the outer flange, an elongate inner-facing web, the inner-facing web connecting to the second end of the inner flange and to the fourth end of the outer flange, an elongate front facia flange, the front facia flange extending away from the outer flange, and being displaced from the outer-facing web, and at least one of a stud receptacle having an opening extending from the outer surface of the outer flange toward the inner flange, and a hook receptacle having an opening and extending from the opening at one of the outer flange, the outer-facing web, and the inner-facing web, into the nosing and toward one of the outer-facing web and the inner-facing web; and the elongate drip cap being adapted to being mounted to the nosing, the drip cap having opposing ends and a drip cap length, and comprising an elongate drip cap platform, having a first inner side and a second outer side, a platform upper surface, and a platform lower surface, and at least one of a stud and a hook extending downwardly from the platform and being adapted to cooperate with a respective one of the stud receptacle and the hook receptacle in assembling the drip cap and the nosing to each other. 
     In some embodiments, the inner side of the platform is in alignment with the inner-facing web when the drip cap is assembled to the nosing. 
     In some embodiments, the nosing comprises a hook receptacle, and the drip cap further comprises a hook extending downwardly from the platform, and toward one of the first inner side of the platform and the second outer side of the platform. 
     In some embodiments, the drip cap further comprises a stud located, from the hook, toward the first inner side of the platform. 
     In some embodiments, the elongate drip cap further comprises an elongate drip flange extending from the platform, at the second outer side of the platform, in a direction away from the first inner side of the platform. 
     In some embodiments, the nosing and the drip cap are extruded aluminum profiles, and at least portions of the lengths of the nosing and the drip cap are arranged in arcuate configurations and the front facia flange is disposed to the inside of the arc in the nosing. 
     In some embodiments, the invention comprehends an arcuate nosing assembly wherein the drip cap and the nosing are assembled to each other with the hook in the hook receptacle, the nosing assembly having been bent about a radius of at least 6 inches, into the arcuate configuration, and the hook and the hook receptacle have been brought into a locking-type engagement with each other. 
     In some embodiments, the nosing assembly further comprises an elongate intermediate web extending between intermediate parts of the inner flange and the outer flange and extending along the length of the inner-facing web. 
     In some embodiments, the hook receptacle comprises an upper wall, the hook and the upper wall of the hook receptacle having been brought into locking-type engagement with each other as a result of the bending of the nosing assembly. 
     In some embodiments, each of the outer-facing web, the inner-facing web, and the intermediate web has a web thickness of about 0.05 inch to about 0.09 inch, and the front facia flange has a web thickness greater than the thicknesses, taken individually, of the inner-facing web, the outer-facing web, and the intermediate web, the front facia flange having an average web thickness of about 0.08 inch to about 0.10 inch, and optionally, the nosing assembly has been bent about a radius of at least 12 inches. 
     In some embodiments, the invention comprehends a window frame having a straight side and an arcuate side, with an arcuate nosing assembly of the invention mounted to the arcuate side of the window frame, the drip cap and the nosing optionally being secured to each other by a locking engagement of the hook and the hook receptacle, the drip cap being devoid of fasteners driven therethrough and into the nosing at locations away from end portions of the drip cap. 
     In some embodiments, the window frame further comprises a fastener extending through the drip cap, and into the nosing, at each of the end portions. 
     In some embodiments, the invention comprehends a window comprising a window frame of the invention, and a glazing in the window frame. 
     In some embodiments, the window frame has at least first, second, and third sides joined to each other in end-to-end relationship, a first side comprising a nosing assembly of the invention, arranged in an arcuate configuration, with the inner flange disposed to the inside of the arc. 
     In some embodiments, the invention comprehends a nosing assembly made with a combination of nosing and drip cap of the invention where the drip cap and the nosing are assembled to each other with the stud in the stud receptacle, the stud and the stud receptacle so cooperating with each other as to inhibit movement of the drip cap toward or away from the third end of the outer flange, and a plurality of fasteners spaced along the length of the drip cap, including away from end regions of the drip cap, the plurality of fasteners holding the drip cap and the nosing in fixed longitudinal relationship to each other. 
     In some embodiments, fasteners extend through the drip cap and into the nosing through a plurality of mounting holes, and a flexible sealing compound is disposed between the drip cap and the nosing at the holes. 
     In some embodiments, the window frame has at least first, second, and third sides joined to each other in end-to-end relationship, at least one of the sides comprising a nosing assembly of the invention. 
     In a second family of embodiments, the invention comprehends a nosing assembly, comprising an elongate nosing having a nosing length, and comprising inner and outer flanges, and a plurality of webs connecting the inner and outer flanges to each other, an outer surface being defined on the outer flange, and a hook receptacle on one of the plurality of webs connecting the inner and outer flanges to each other, or on the outer flange, the hook receptacle being defined, at least in part, by one or more walls, including an upper wall; and an elongate drip cap, the drip cap comprising an elongate drip cap platform, having a platform upper surface and a platform lower surface, a first inner side and a second outer side, and a hook extending downwardly from the platform and toward one of the first inner side and the second outer side, the drip cap being assembled to the nosing with the hook in the hook receptacle. 
     In some embodiments, the nosing assembly has been bent about a radius of 12 inches or more, the hook and the hook receptacle being in locking-type engagement with each other so as to hold the drip cap and the nosing to each other at an interface between the outer surface of the outer flange and the lower platform surface of the drip cap. 
     In some embodiments, a flexible sealing compound extends along the interface between the nosing and the drip cap, from the first end of the nosing assembly to the second end of the nosing assembly. 
     In some embodiments, the hook and the hook receptacle cooperate with each other to inhibit movement of the drip cap toward or away from the third end of the outer flange and wherein the hook so engages the hook receptacle at an upper wall of the receptacle as to prevent movement of the drip cap perpendicularly away from the outer flange of the nosing. 
     In some embodiments, a first framed window comprises an arcuate window frame, having a straight side comprising a first insert and a first insert receptacle, a second framed window comprises a second insert and a second insert receptacle. The first insert is received in the second insert receptacle and the second insert is received in the first insert receptacle, thereby to mount the first and second windows to each other. 
     In some embodiments, the invention comprehends a door assembly comprising a framed door, and an attached arcuate window frame of the invention. 
     In a third family of embodiments, the invention comprehends a method of making an arcuate nosing assembly for use in a window having an arcuate side. The method comprises assembling together an elongate nosing and an elongate drip cap. The nosing has inner and outer flanges, and a plurality of webs connecting the inner and outer flanges to each other, an outer surface being defined on the outer flange, and a hook receptacle defined on one of the plurality of webs connecting the inner and outer flanges to each other, or on the outer flange. The drip cap comprises an elongate drip cap platform, having a platform upper surface and a platform lower surface, a first inner side and a second outer side, and a hook extending downwardly from the platform and toward one of the first inner side and the second outer side. The nosing and the drip cap are assembled with the hook engaged in the hook receptacle. The method further comprises bending the assembly of the nosing and the drip cap, with the inner flange to the inside of the bend and thereby re-forming the combination of the hook and the hook receptacle so as to bring the hook and the hook receptacle into a tightened locking-type engagement with each other. 
     The present invention will be further appreciated and understood when considered in combination with the following description and the accompanying drawings. It should be understood, however, that the following description is given by way of illustration and not of limitation. Certain changes and modifications can be made within the scope of the invention without departing from the spirit of the invention, and the invention includes all such changes and modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a front elevation view of an assembly comprising a transom window mounted over a door frame, with the door frame being shown in part. 
         FIG. 2  shows a pictorial view of the assembly of  FIG. 1 . 
         FIG. 3  shows a cross-section of a short length of a straight nosing assembly of the invention, illustrating locations of the window framing, the glass stop, and the glazing assembly. 
         FIG. 4  shows an upwardly-directed end view of the assembly of  FIGS. 1 and 2 , illustrating the cooperative crimping affect of the hook in the hook receptacle when the nosing assembly is bent, thus securing the drip cap on the nosing by means of the bending process. 
         FIG. 5  shows a cross-section taken at  5 - 5  of  FIG. 2  illustrating the horizontal joint between the underlying door frame and the overlying arcuate transom window. 
         FIG. 6  shows a cross-section as in  FIG. 5 , but showing a horizontal joint between upper and lower windows. 
         FIGS. 7(   a )- 7 ( p ) show front elevation views of additional examples of shapes of windows of the invention, including windows which can be joined to each other and windows which can be joined to underlying door frames. 
         FIG. 8  shows a cross-section of a short length of a straight nosing assembly as in  FIG. 3 , except without any stud or stud receptacle, and with the hook receptacle opening into the outer flange of the nosing. 
         FIG. 9  shows a pictorial view as in  FIG. 2 , of a rectangular transom window mounted over a door frame. 
         FIG. 10  is a cross-section view, taken at  10 - 10  in  FIG. 9 , showing the relationships between the screws, the drip cap, the nosing, and the caulk. 
     
    
    
     The invention is not limited in its application to the details of construction, or to the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various other ways. Also, it is to be understood that the terminology and phraseology employed herein is for purpose of description and illustration and should not be regarded as limiting. Like reference numerals are used to indicate like components. 
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
       FIG. 1  illustrates a front view of a cladded arcuate transom window of the invention mounted on the top of a cladded door frame, with only the top portion of the door frame being shown.  FIG. 2  shows the same arcuate transom window mounted at the top of the same door frame, in orthogonal view. As seen in  FIGS. 1 and 2 , the door frame in general is represented by the number  10 . The transom window  12  of the invention is mounted on the door frame by structure described hereinafter. 
     Window  12  includes a window frame  14  illustrated as being made of wood, a glazing unit  16  mounted in the window frame, an elongate arcuate extruded aluminum nosing assembly  18 , and an elongate straight extruded aluminum nosing  20 . Arcuate nosing assembly  18  is mounted to the upper, arcuate portion of the window frame. Straight nosing  20  is mounted to the lower, straight portion of the window frame. 
     Referring now to  FIGS. 3 and 4 ,  FIG. 3  shows a short length of a combination of a nosing  22  and a drip cap  24 , in their as-extruded, straight configurations, with the drip cap and nosing temporarily assembled to each other.  FIG. 4  shows the elongate combination mounted to the window frame after the nosing and drip cap have been bent into the desired arcuate configuration, with corresponding securement of the nosing and drip cap to each other during the bending process. 
     Turning back to  FIG. 3 , nosing  22  has an inner flange  26 , and an outer flange  28  spaced from the inner flange. Inner flange  26  has a first outer end  30  and a second inner end  32 . Outer flange  28  has a third outer end  34 , a fourth inner end  36 , and an outer surface  38 . 
     An elongate outer-facing web  40  connects to the inner and outer flanges at outer ends  30  and  34 . Elongate inner-facing web  42  connects to the inner and outer flanges at inner ends  32  and  36 . Elongate intermediate web  44  connects to intermediate portions of the inner and outer flanges. 
     An elongate stud-receiving receptacle  46 , adjacent inner-facing web  42 , has an opening  47  extending downwardly and toward the inner flange, from outer surface  38  of outer flange  28 . An elongate hook-receiving receptacle  48  has an opening  49  adjacent outer end  34  of outer flange  28 . The hook-receiving receptacle extends from the opening  49  toward inner-facing web  42 . The hook-receiving receptacle includes a remote upper wall  50  defined between the main body of the receptacle and the upper surface  38  of outer flange  28 . Remote upper wall  50  of the hook-receiving receptacle is generally spaced from the remaining portions of nosing  22 . 
     Elongate front facia flange  52  extends downwardly from the inner flange  26 , generally as an extended element of inner-facing web  42 . In the illustrated embodiment, the front facia flange has a substantially thicker cross-section than either the adjacent inner flange  26  or the adjacent inner-facing web  42 . 
     A first elongate mounting finger  54 A extends generally as an extension of the inner flange from the joinder of the inner flange and the inner-facing web. A second elongate mounting finger  54 B is spaced from the first mounting finger, generally parallel to the first mounting finger, and extends from the inner-facing web away from the outer-facing web.  FIG. 3  shows, in dashed outline, a portion of the window frame  14  which fits between mounting fingers  54 A and  54 B, including the recesses cut into the frame member such that the outer surface of the frame member represents a generally continuous surface with the corresponding outer surface of the second mounting finger. 
       FIG. 3  also illustrates in dashed outline the glazing stop  56  which abuts glazing assembly  16 , also shown in dashed outline. Glazing assembly  16  abuts front facia flange  52 . Flange  52 , glazing assembly  16 , the illustrated frame element  14 , and glazing stop  56  thus illustrate the relative positioning of the main body of the window frame, the upper arcuate nosing assembly, and the window glazing assembly. 
     Returning to the nosing assembly, elongate drip cap  24  has a platform  60  and a drip flashing flange  61 . Platform  60  has an inner end  62 , an outer end  64 , an upper surface  66 , and a lower surface  68 . An elongate drip flange  70  extends downwardly from outer end  64  of the platform at an angle “α” of about 30 degrees, more or less in the embodiment illustrated. Angle “α” is required to, and the magnitude of angle “α” is selected to, direct water away from the window frame to a drip edge  71 . Thus, the magnitude of angle “α” can vary depending on the particular implementation. An elongate hook  72  extends down from a locus on the platform lower surface which locus is generally toward outer end  64 ; and the hook extends from there toward inner end  62  of the platform. 
     An elongate stud  74  extends downwardly from the lower surface  68  of the platform, adjacent inner end  62  of the platform. 
     The nosing assembly illustrated in  FIG. 3  is designed to loosely fit together such that, at initial assembly of the straight extruded elements, the drip cap and nosing can readily slide longitudinally with respect to each other with limited, if any, noticeable friction. 
     The straight drip cap and the straight nosing can be initially joined together by longitudinally sliding the drip cap and nosing with respect to each other, with the hook engaged in the hook receptacle. With the hook so engaged, the stud is automatically aligned over the stud receptacle and is readily engaged in the stud receptacle. 
     As a second method of joining the nosing and the drip cap, the nosing and drip cap can be brought together with the lower surface of the drip cap overlying the upper surface of the outer flange, and with the leading edge of the hook at opening  49  of the hook receptacle. With the hook so positioned, the stud is proximate, but displaced from, stud receptacle  46 . The drip cap is then slid toward fourth inner end  36  of outer flange  28 , to a stop location where the structure of the platform or nosing stops the engaging of the hook into the hook receptacle and the stud is in alignment over the stud receptacle. With the hook so-engaged and fully seated in the hook receptacle, the stud is readily seated in the stud receptacle. Full engagement of the hook and the stud, thus brings the drip cap and the nosing into registered alignment with respect to each other relative to the inner and outer webs, e.g. such that the inner end of the drip cap platform is aligned with the inner end of the outer flange of the nosing. 
     The nosing and drip cap are easily disassembled from each other at this stage by simply raising the inner end of the drip cap, thus disengaging the stud from the stud receptacle and then sliding the drip cap relatively toward the outer-facing web. As a second disassembly technique, the drip cap can simply be slid longitudinally with respect to the nosing. 
     With the drip cap so-joined to the nosing, as a temporary assembly that can be readily separated, the temporary assembly can be converted to a permanently-mounted assembly having an arcuate shape. To make such conversion, the temporary assembly is mounted in a bending jig or other suitable machine. The nosing/drip cap assembly combination is then bent into a desired arcuate configuration, typically in a cold-forming process, bending both the drip cap and the nosing together as a single unit. In the illustrated embodiments, the assembly is bent with the inner flange of the nosing disposed toward the interior of the bend and the drip cap platform disposed toward the outside of the bend. 
     As the bending force is applied collectively to both nosing  22  and drip cap  24 , both the nosing and the drip cap, bending together, take on bent configurations generally similar to each other. As the bending force is released, and the normal limited rebound of the cold-formed elements occurs, the now-arcuate upper surface  76  of hook  72  is left in a forceful abutting-type surface-to-surface engagement with the arcuate lower surface  77  of upper wall  50 , as illustrated in  FIG. 4 . The surface-to-surface engagement locks the nosing and drip cap to each other, creating the nosing assembly, and provides a stabilizing frictional relationship between the hook and the remote upper wall of the hook receptacle, holding the drip cap and the nosing firmly engaged with, and locked to, each other such that no additional measures need be taken to retain the now-arcuate nosing and the now-arcuate drip cap in the assembled relationship with each other. 
     In addition to the locking of the nosing and the drip cap to each other, the resulting abutting engagement between the hook and the hook receptacle, and the convoluted path around hook  72 , around wall  50 , and along the interface between outer flange  28  and platform  60 , to inner end  62 , serves as a barrier to air-borne water penetrating to inner end  62  of the nosing assembly where such water can potentially reach water-susceptible wood frame  14 . Applicant contemplates that such barrier is effective to prevent weather-generated water penetration except, perhaps, in dangerously-violent weather conditions. 
     In the arcuate embodiments built to date, of which  FIGS. 1 ,  2 , and  4  are representative, it appears that the rebounded drip cap tends to stabilize after the bending operation, with the ends  78  of the drip cap drawn away from the nosing at inner end  62  of the platform, by up to e.g. about 0.15 inch. Such spacing of the inner ends  78  of the drip cap from the nosing can be readily remedied by driving a single screw (not shown) through platform  60  and into outer flange  28  of the nosing in each end region of the arcuate nosing assembly, e.g. between inner-facing web  42  and intermediate web  44 . Tightening such screws draws the inner end  62  of the platform into intimate relation with outer flange  28 , thus essentially eliminating the open space between the drip cap and the nosing at inner ends  62 , namely holding the elements in the configuration shown in  FIG. 4 . Thus, the invention eliminates all except two of the assembly screws which are used in conventional nosing/drip cap assemblies. 
     And, in order to better insure that the two screws which are used are not entry points for water getting into the window frame, once the screw holes are drilled after the drip cap and nosing are bent, caulk or other flexible sealing compound is forced/injected between the drip cap and the nosing, from the ends of the drip cap and nosing, to and past the screw holes. When a screw is installed, and the drip cap and nosing are drawn together, the space between the drip cap and the nosing, at the ends of the nosing and drip cap, is closed. As the distance between the nosing and drip cap is closed, the caulk is forced to spread in the narrowing space, filling voids between the screw and the side walls of the holes, and occupying the space between the nosing and the drip cap. This application of caulk, including the method of spreading the caulk about the holes which present potential water entry points, essentially eliminates risk of water entering the window frame through the screw holes. 
     The observed abutting surface-to-surface locking-type engagement of the hook and the upper wall of the hook receptacle, with each other, may be at least in part caused by re-forming of the configuration of the hook  72  relative to the hook receptacle  48  as the nosing and the drip cap take on the arcuate configuration, as well as by the collective rebound from the forming/bending operation. Whatever the mechanism, the bending of the nosing and the drip cap, collectively as the nosing assembly, brings the nosing and the drip cap into an essentially inseparable locked engagement at hook  72  and upper wall  50  as illustrated in  FIG. 4 , with the hook and hook receptacle providing a substantial barrier to water penetrating into the frame through the resulting nosing assembly. 
     Both hook receptacle  48  and stud receptacle  46  extend to depths substantially greater than the depths reached by the hook or the stud. The space between the end of the stud and the end of the stud receptacle is greater than the space occupied by the stud in the receptacle. Similarly, the space between the end of the hook and the end of the hook receptacle is greater than the space occupied by the hook in the hook receptacle. Such greater depths allow for flow of material during the bending of the initially-joined nosing/drip cap assembly. 
     While hook receiving opening  48  is illustrated on the outer flange, opening  48  can as well be located on the outer-facing web or the inner-facing web. And while the hook receptacle is shown extending toward the inner-facing web, it could as well extend toward the outer-facing web. 
     What is important for the hook receptacle is that the receptacle extend in such direction that an upper wall of the receptacle, or other structure which is capable of cooperating with a hook to re-form and/or engage the combination, is defined as part of the hook receptacle. In the illustrated embodiment, the combination is re-formed such that the hook and the upper wall of the receptacle are brought into the firm abutting-type locking engagement whereby the drip cap and the nosing are securely bound to each other. 
     The opening for the hook receptacle can be located on the outer flange as shown, or on the inner-facing web, or on the outer-facing web. For example, opening  49  can be located anywhere along the height of the outer-facing web, e.g. between inner and outer flanges  26  and  28 , whereby hook  72  extends down the face of the outer-facing web  40  to the opening. A similar arrangement can, in the alternative, be defined for the inner-facing web  42 . When the assembly is bent and released, both the hook, as part of the drip cap, and the receptacle as part of the nosing, are re-formed, and the resulting abutting-type locking engagement is created. 
     The hook receptacle is illustrated remote from drip flashing flange  61  and the stud receptacle is illustrated proximate the drip flashing flange. The hook receptacle and the stud receptacle can be relocated to generally reversed relative positions, and are typically spaced from each other. The hook and stud are correspondingly relocated also. 
     In the illustrated embodiments, the nosing and drip cap are elongate aluminum extrusion profiles. As such, each element defined in such profiles typically extends, as extruded, for the full length of the respective profile. Thus, the extrusions generally function as cladding, covering/cladding surfaces of the wood substrate elements which generally provide the structural substance of the window frame and which surfaces would otherwise be exposed to the ambient environment. 
     While the description herein addresses primarily wood substrates for window and door frames, the substrates can be any desired material including, without limitation, solid plastic substrates, extruded profile plastic substrates, extruded aluminum profiles, pultruded fiberglass-reinforced profiles, or combinations of any of the above, with or without wood elements. 
     In the illustrated embodiment of  FIGS. 3-4 , the extruded aluminum profile elements in the nosing are generally 0.05 inch thick. Thus, inner and outer flanges  26  and  28 , webs  42 ,  44 , and  46 , drip flashing flange  61 , and mounting fingers  54 A and  54 B are all generally about 0.04 inch to about 0.06 inch thick, allowing for the thicker structure on outer flange  28  which supports upper wall  50  of the hook receptacle, and the illustrated screw boss. Facia flange  52  is about 0.07 inch to about 0.10 inch thick, optionally about 0.08 inch to about 0.10 inch thick, as it has surprisingly been found that a thicker facia flange  52  can better receive the material flow during the bending process, without buckling. Drip cap platform  60  is about 0.09 inch to about 0.12 inch thick proximate inner end  62  and about 0.04 inch to about 0.06 inch thick adjacent outer end  34  and screw boss  80 . 
     EXAMPLE 1 
     Making an Arcuate Nosing Assembly 
     Referring to  FIG. 3 , a straight, loosely-assembled nosing assembly was made having approximately the following material thicknesses. Inner and outer flanges  26  and  28 , webs  42 ,  44 , and  46 , drip flashing flange  61 , and mounting fingers  54 A and  54 B were all generally about 0.05 inch thick, allowing for the thicker structure on outer flange  28  which supports hook finger  50  and the illustrated screw boss. Facia flange  52  was about 0.09 inch thick. Drip cap platform  60  was about 0.09 inch thick proximate inner end  62  and about 0.045 inch thick adjacent outer end  34  and screw boss  80 . 
     The general size of the nosing profile as seen in  FIG. 3  was about 1.25 inches high and about 1 inch wide. Facia flange length was about 0.5 inch. Platform length was, left-to-right, about 1.25 inches. Flashing flange height was about 1.1 inches. Mounting fingers  54 A,  54 B were about 0.5 inch wide. In the loosely-assembled assembly, with stud  74  in stud receptacle  46 , and hook  72  in hook receptacle  48  as illustrated in  FIG. 3 , the drip cap was readily longitudinally slidable relative to the nosing. For disassembly, the drip cap was readily slidable toward the outer-facing web after raising stud  74  out of stud receptacle  46 , thus to release the drip cap from the nosing. 
     The thus loosely-assembled straight assembly was then placed in a bending jig and bent about an approximately 18-inch radius, measured from the inner flange, into a half-circle, and released from the bending operation. Once released, the assembly retained its general half-circle configuration and the resulting bent assembly exhibited a strong securement of the drip cap and nosing to each other along the bent length, such that the drip cap and the nosing were essentially inseparable from each other along the bent length. A strong abutting-type locking engagement was noted between hook  72  and upper wall  50 . Thus, upon completion of the bending process, the drip cap and the nosing were in a locked relationship with each other. 
     Given the 18-inch radius bend in the subject nosing assembly, the inventor contemplates that even shorter radius bends such as 15 inches radius, or 12 inches radius, or 7.5 inches radius, may be achieved with little if any modification to the disclosed profiles and such shorter-radius profiles are thus considered to be part of the invention. The inventor contemplates that, in light of the disclosure herein, substantially any radius equal to half of the width of conventional commercially-available windows and doors, down to e.g. about 6 inches radius, can be accommodated by making obvious modifications to the nosing and drip cap profiles in order to achieve some of the smaller such radii whereby all such radii are considered to be enabled by the disclosure herein. 
     The above portion of the detailed description generally refers to the upper arcuate portion of transom window frame  14 . Turning now to the interface between transom window  12  and door frame  10 , reference is made to  FIGS. 1 and 2 , and especially to  FIG. 5 , where nosing  20  joins the lower portion of the transom window to the upper portion of the underlying clad door frame. 
     Turning now to  FIG. 5 , nosing  76  on header jamb  79  of the clad door frame interfaces with nosing  20  on the window frame. 
     As seen in  FIG. 5 , nosing  76  has an inner flange  81 , and an outer flange  82  spaced from the inner flange. Inner flange  81  has a first outer end  84  and a second inner end  86 . Outer flange  82  has a third outer end  88  and a fourth inner end  90 , and an outer surface  92 . 
     An elongate outer-facing web  94  connects to the inner and outer flanges at outer ends  84  and  88 . Elongate inner-facing web  96  connects to the outer flange at inner end  90  and extends toward inner end  86 . 
     A first lock  98  on the inner-facing web and a second lock  100  at the inner end  86 , of the inner flange define an opening  102  which extends from outside the nosing, between the first and second locks, and into the interior space  104  inside the nosing. 
     An elongate receptacle  106  has an opening  108  where third outer end  88  of outer flange  82  and the upper end of outer-facing web  94  come together. Thus, opening  108  can be considered either as part of outer flange  82  or as part of web  94 . Receptacle  106  extends from opening  108  toward inner-facing web  96 . Receptacle  106  includes a remote upper wall  110  defined between the main body of the receptacle and the outer surface  92  of outer flange  82 . Remote upper wall  110  is generally spaced from the remaining portions of nosing  76 . 
     Nosing  76  is mounted to jamb cover  112 . Jamb cover  112  covers the surfaces of an e.g. wood jamb substrate  114  of the header jamb  79  of the door frame, thus, generally functioning as cladding and thereby covering surfaces of the wood substrate elements which generally provide the structural substance of the door frame and which surfaces are otherwise exposed to ambient environmental conditions. Jamb cover  112  has a main side panel  118  which covers that side of the e.g. wood substrate which faces into the doorway opening. Outer panel  120  of the jamb cover is joined to main side panel  118  at a common corner, and covers the side of the substrate which faces away from the building. Lock structure extends from the outer panel in the physical expression of two lock studs  122 A,  122 B. Lock studs  122 A,  122 B interface with first and second locks  98  and  100  on the nosing  76 . 
     Jamb cover  112  can be mounted to the substrate by e.g. screws or other fasteners, not shown, at screw apertures, not shown, between lock studs  122 A and  122 B, such apertures being spaced along the length of the jamb cover. 
     Given the relative flexibility in the respective locks on the extruded aluminum nosing  76  and jamb cover  112 , nosing  76  can be secured/mounted to the jamb cover, and thus to the illustrated header jamb, by snap-locking the first and second locks  98  and  100  on nosing  76  to studs  122 A and  122 B on the jamb cover. 
     Nosing  20  has an inner flange  124 , and an outer flange  126  spaced from the inner flange. Inner flange  124  has a fifth outer end  128 , a sixth inner end  130 , and an inner surface  132 . Outer flange  126  has a seventh outer end  134  and an eighth inner end  136 . 
     An elongate outer-facing web  138  connects to the inner and outer flanges at outer ends  128  and  134 . Elongate inner-facing web  140  connects to the inner and outer flanges at inner ends  130  and  136 . An elongate spacing stud  141  extends down from inner surface  132  of inner flange  124 . Spacing stud  141  thus spaces the inner flange of nosing  20  from the outer flange of nosing  76  by a distance which maintains the inner flange of nosing  20  in a generally parallel relationship with the outer flange of nosing  76  for the full depth, between the inner-facing webs and the outer-facing webs, of nosings  76  and  20 , whereby outer-facing webs  94  and  138  define a generally common and flat surface. 
     An elongate receptacle  142  proximate fifth outer end  128  of nosing  20  has an opening  144  spaced, from outer end  128 , toward the sixth inner end  130  of inner flange  124 . Receptacle  142  extends from opening  144  toward outer-facing web  138 . Receptacle  142  includes a remote lower wall  146  defined between the main body of the receptacle and inner surface  132  of inner flange  124 . Remote lower wall  146  is generally spaced from the remaining portions of nosing  20 . 
     A first elongate mounting finger  148 A extends generally as an extension of outer flange  126  from the joinder of outer flange  126  and inner-facing web  140 . A second elongate mounting finger  148 B is spaced from the first mounting finger and extends from the inner-facing web away from the outer-facing web, generally parallel to mounting finger  148 A.  FIG. 5  shows a portion of the window frame  14  which fits between mounting fingers  148 A and  148 B, including a recess cut into the upper surface of the frame member such that the upper surface of the frame member represents a generally continuous surface with the corresponding outer surface of the first mounting finger. 
     Elongate front drip flange  150  extends upwardly from the outer flange, generally as an extended element of inner-facing web  140 . 
       FIG. 5  also illustrates glazing stop  56  which abuts glazing assembly  16 . Glazing assembly  16  abuts front drip flange  150 . Flange  150 , glazing assembly  16 , glazing stop  56 , and mounting fingers  148 A and  148 B, along with frame elements  14 , thus illustrate the relationships of the main elements of the window frame with the nosing and the glazing assembly. 
       FIG. 5  further shows a side view of an elongate window support  152  which is mounted to the bottom of window frame  14  and which extends from a location proximate mounting finger  148 B toward the interior of the building to which the door frame is mounted, generally to the inner end of the door frame. A plurality of supports  152  are spread along the left-to-right width of the header jamb and support the window from the underlying door frame at header jamb  79 . Spacing between supports is such as to adequately support the weight of the overlying window assembly. For e.g. a 36-inch wide half-circle transom window, three supports, each about 1 inch wide and extending the full depth of the frame behind the mounting fingers, are adequate for such support function. 
     In assembling the door frame, left and right side jambs are joined to a header jamb, and optionally to a threshold. In assembling the window frame, the arcuate upper frame section is assembled to the lower straight frame section. 
     The items illustrated in  FIG. 5  are typically assembled first as a door frame and a window frame. The top of the door frame is at header jamb  79 . Jamb cover  112  is assembled to jamb substrate  114 . Nosing  76  is snap-locked, to the jamb cover, thus to join the nosing  76  to the door frame. 
     The bottom of the window assembly is at the bottom of supports  152 . Nosing  20  is mounted to the window frame as illustrated in  FIG. 5 , with e.g. staples or other fasteners (not shown) driven through mounting fingers  148 A,  148 B into the wood of the window frame  14 . 
     EXAMPLE 2 
     Mounting Transom Window to Door Frame 
     The window frame and door frame can be assembled to each other as follows. With the door frame held stationary, the window frame is positioned generally as illustrated in  FIG. 5 , but with the window frame juxtaposed slightly ahead of the door frame such that remote upper wall  110  is at opening  144  and remote lower wall  146  is at opening  108 . Upper wall  110  is parallel with, and aligned with, opening  144 . Lower wall  146  is parallel with, and aligned with, opening  108 . Supports  152  are generally positioned at the upper surface of the header jamb as shown. 
     An e.g. manual pushing force is then engaged at the bottom of the window frame, pushing rearwardly, e.g. on nosing  20 , toward fourth inner end  90  of the outer flange of nosing  76 . The force required to push the window rearwardly is typically, though not necessarily, within the capability of an average adult. As the window is pushed rearwardly, remote upper wall  110  of nosing  76  becomes at least temporarily engaged in receptacle  142  of nosing  20  and remote lower wall  146  of nosing  20  becomes at least temporarily engaged in receptacle  106  of nosing  76 , thus locking nosings  76  and  20  to each other as shown in  FIG. 5 , with the lower surface of the upper nosing  20  generally in surface-to-surface relationship with the upper surface of the lower nosing  76 . 
     In the assembly process, the window frame is moved rearwardly until the outer-facing web  138  on nosing  20  comes into alignment with outer-facing web  94  on nosing  76 , such that the two outer-facing webs form a generally common surface as illustrated. 
     With the nosings so joined, and with the window frame located at its desired final juxtaposition relative to the door frame, the assembly is being held together at the outwardly-facing surface of the assembly, which will face outwardly of a building to which the assembly will be joined, by the interaction of upper wall  110  and lower wall  146  in the respective receptacles. Given the restraints provided by the interactions of the upper and lower walls  110 ,  146 , no mull cap is needed or used to hold the two nosings in the desired nearer/further e.g. vertical relationship with respect to each other. While receptacle slots could be designed into the outer webs of nosings  20  and  76 , such that a mull cap could be used, no such receptacles or mull caps are needed, and normally none are employed. 
     By avoiding the need to use a mull cap, the cost of the mull cap element is avoided, as is the labor cost of installing the mull cap. Also, the dirt and water penetration associated with the two conventional mull cap recesses is avoided. Further, the collective design of walls  110  and  146 , along with the respective receptacles, provides ease of assembly, and ease of alignment of the underlying and overlying nosings with respect to each other so as to provide a generally common surface at the front face of the assembly, namely that face which is directed outwardly from the building. 
     The window is further secured to the door frame header at or adjacent the inwardly-facing surfaces of the assembly. For example, a corrugated sheet fastener  147 , illustrated to the right of the header jamb and the supports in  FIG. 5 , can be driven into the inner faces of the header  79  and supports  152  as suggested by the illustration in  FIG. 5 . A conventional such fastener is a corrugated metal sheet, sharpened on one corrugated end, and driven into the wood elements of header  79  and a support  152  thereby to bridge the joint between the header and the support. With a plurality of fasteners so driven while outer-facing webs  94 ,  138  are held in a common surface, and with the nosings joined at receptacles  106  and  142 , the door frame and the window frame are securely joined to each other in permanent assembly and outer-facing webs exhibit a common surface. 
     Other methods of securing the window and door to each other are contemplated, such as nails and/or screws toe-nailed through the joint at the inner faces. Or screws or nails can be driven through the wood surface  154  of that portion of the jamb which faces the doorway opening, especially adjacent or under weather seal kerf  156  where such fasteners will be hidden by the weather seal. 
     The spacings and tolerances of the remote upper and lower walls of the nosings, and the corresponding receptacles are such that the engagements of the upper and lower walls of the respective nosings in the receptacles are substantial frictionally-restrained engagements, such that, even before the frames are further secured to each other at e.g. the inwardly-facing surfaces of the assembly, the nosings tend to remain engaged with each other under modest handling and are not generally released from each other by the action of gravity, even if the temporarily-engaged assembly is re-oriented with limited support for one or more of the door frame and/or the window frame in the assembly. 
     Within the same context, disengagement of the window frame and the door frame from each other is accomplished by e.g. manually pulling the base of the window frontward toward nosing  76 , and tilting the window so spacing stud  141  will clear top surface  92  of nosing  76 . 
     While the process of joining, and disengaging, the nosing and drip cap to the door frame has been described in terms of the window frame being moved relative to the door frame, the joining and disengaging of the nosing and drip cap can as well be accomplished by holding the window frame stationary and moving the door frame, or both the window frame and the door frame can be moved as part of the process of joining and/or disengaging the nosing and the drip cap. 
     While  FIG. 5  illustrates the interface between a cladded door frame and an overlying transom window frame, the same interface, and the same assembly process, can be used to join a side-light window frame to a side jamb of a cladded door frame, including side-light frames on both side jambs of the door frame. 
       FIG. 6  illustrates the interface between first and second window frames  14 A and  14 B using interface structure similar to the interface structure shown in  FIG. 5 , but adapted to the joining of two window frames. In general, instead of using a door interface nosing  76  in combination with a window interface nosing  20  as in  FIG. 5 , window nosing  22  is used without bending the nosing, in combination with window nosing  20 . 
     Thus, nosing  22  in  FIG. 6  has inner flange  26 , and outer flange  28  spaced from the inner flange. Inner flange  26  has first outer end  30  and second inner end  32 . Outer flange  28  has third outer end  34 , fourth inner end  36 , and outer surface  38 . 
     Elongate outer-facing web  40  connects to the inner and outer flanges at outer ends  30  and  34 . Elongate inner-facing web  42  connects to the inner and outer flanges at inner ends  32  and  36 . Elongate intermediate web  44  connects to intermediate portions of the inner and outer flanges. 
     Elongate stud-receiving receptacle  46 , adjacent inner-facing web  42 , extends downwardly and toward the inner flange, from outer surface  38  of outer flange  28 . 
     Elongate hook-receiving receptacle  48  has an opening  49  adjacent outer end  34  of outer flange  28 . The hook-receiving receptacle extends from the opening  49  toward inner-facing web  42 . The hook-receiving receptacle includes a remote upper wall  50  defined between the main body of the receptacle and the upper surface  38  of the outer flange. Remote upper wall  50  of the hook receptacle is generally spaced from the remaining portions of nosing  22 . 
     Elongate front facia flange  52  extends downwardly from inner flange  26 , generally as an extended element of inner-facing web  42 . In the illustrated embodiment, the front facia flange has a substantially thicker cross-section than either adjacent inner flange  26  or adjacent inner-facing web  42 . 
     First elongate mounting finger  54 A extends generally as an extension of inner flange  26  from the joinder of inner flange  26  and inner-facing web  42 . Second elongate mounting finger  54 B is spaced from the first mounting finger and extends from the inner-facing web away from the outer-facing web, generally parallel to first mounting finger  54 A.  FIG. 6  shows a portion of the window frame  14 A which fits between mounting fingers  54 A and  54 B, including the recess cut into the frame such that the lower surface of the frame member represents a generally continuous surface with the corresponding inner-facing surface of the first mounting finger. 
       FIG. 6  also illustrates the glazing stop  56 A which abuts glazing assembly  16 A. Glazing assembly  16 A abuts front facia flange  52 . Flange  52 , glazing assembly  16 A, glazing stop  56 A and frame member  14 A, in combination, thus illustrate the relative positioning of the main body of the window frame, the nosing assembly, and the window glazing assembly. 
     Nosing  20  has inner flange  124 , and outer flange  126  spaced from the inner flange. Inner flange  124  has fifth outer end  128 , sixth inner end  130 , and inner surface  132 . Outer flange  126  has seventh outer end  134  and eighth inner end  136 . 
     Elongate outer-facing web  138  connects to the inner and outer flanges at outer ends  128  and  134 . Elongate inner-facing web  140  connects to the inner and outer flanges at inner ends  130  and  136 . Elongate spacing stud  141  extends down from inner surface  132  of inner flange  124  thus to space the inner flange of nosing  20  from the outer flange of nosing  22  by a distance which maintains the inner flange of nosing  20  in a generally parallel relationship with the outer flange of nosing  22  for the full depths of nosings  20  and  22 , between the inner-facing webs and the outer-facing webs. 
     An elongate receptacle  142  proximate fifth outer end  128  of nosing  20  has an opening  144  spaced, from outer end  128 , toward the sixth inner end  130  of inner flange  124 . Receptacle  142  extends from opening  144  toward outer-facing web  138 . Receptacle  142  includes remote lower wall  146  defined between the main body of the receptacle and inner surface  132  of inner flange  124 . Remote lower wall  146  is generally spaced from the remaining portions of nosing  20 . 
     A first elongate mounting finger  148 A extends generally as an extension of outer flange  126  from the joinder of outer flange  126  and inner-facing web  140 . A second elongate mounting finger  148 B is spaced from the first mounting finger and extends from the inner-facing web away from the outer-facing web.  FIG. 6  shows a portion of the window frame  14 B which fits between mounting fingers  148 A and  148 B, including a recess cut into the upper surface of the frame member such that the upper surface of the frame member represents a generally continuous surface with the corresponding outer surface of first mounting finger  148 A. 
     Elongate front drip flange  150  extends upwardly from the outer flange, generally as an extended element of inner-facing web  140 . 
       FIG. 6  also illustrates glazing stop  56 B which abuts glazing assembly  16 B. Glazing assembly  16 B abuts front drip flange  150 . Flange  150 , glazing assembly  16 B, glazing stop  56 B and frame member  14 B, in combination, thus illustrate the relationships of the main elements of window frame  14 B with nosing  20  and glazing assembly  16 B. 
       FIG. 6  further shows a side view of a window support  152  which is mounted to the bottom of window frame  14 B, or which may, in the alternative, be mounted to a corresponding surface, e.g. top surface, of window frame  14 A. A plurality of supports  152 , spaced along the side-to-side widths of the windows, space window frames  14 A and  14 B from each other, e.g. support overlying window frame  14 B from window frame  14 A. Spacing between the supports  152  is such as to adequately support the weight of the overlying window assembly. Where the joint between the window frames represents other than a horizontal orientation, supports  152  may be better described as spacers, tasked with maintaining a desired spacing between respective window frames. In such case, spacers  152  are spaced along the length of the respective side of the window frame on a given side of glazing  16 A. 
     The items illustrated in  FIG. 6  are typically assembled, first, as first and second window frames  14 A and  14 B, or as first and second window assemblies including glazings. Referring to the illustration in  FIG. 6 , the top of window frame  14 A is that frame element which extends from mounting fingers  54 A and  54 B. The bottom of window frame  14 B is the bottom surfaces of supports  152 . Nosing  22  is mounted to window frame  14 A as illustrated in  FIG. 6 . Nosing  20  is mounted to window frame  14 B, also as illustrated in  FIG. 6 . 
     EXAMPLE 3 
     Mounting Two Window Frames to Each Other 
     The two window frames  14 A and  14 B, with nosings attached, can be assembled to each other as follows. With the lower window frame  14 A held stationary, upper window frame  14 B is positioned generally as illustrated in  FIG. 6 , but with upper window frame  14 B juxtaposed slightly ahead of lower window frame  14 A such that remote upper wall  50  is at opening  144  and remote lower wall  146  is at opening  49 . Upper wall  50  is parallel with, and aligned with, opening  144 . Lower wall  146  is parallel with, and aligned with, opening  49 . Supports  152  are generally positioned at the upper surface of lower window frame  14 A. 
     A pushing force is then engaged at the bottom of upper window frame  14 B, such as at nosing  20 , pushing rearwardly toward fourth inner end  36  of the outer flange of nosing  22 . As the window frame is pushed rearwardly, remote upper wall  50  of nosing  22  becomes engaged in receptacle  142  of nosing  20  and remote lower wall  146  of nosing  20  becomes engaged in receptacle  48  of nosing  22 , thus locking nosings  22  and  20  to each other as shown in  FIG. 6 . 
     In the assembly process, the upper window frame is moved rearwardly until one of the inserts reaches the inner end of the corresponding receptacle, which serves as a stop, terminating the rearward movement of the upper window frame, whereupon the outer-facing web  138  on nosing  20  is in alignment with outer-facing web  40  on nosing  22 , such that the two outer-facing webs form a generally common surface as illustrated. 
     The spacings and tolerances of the remote upper and lower walls and the respective receptacles are such that the engagements of the remote upper and lower walls of the respective nosings in the receptacles are substantial frictional engagements, such that the nosings tend to remain engaged with each other with modest handling and are not generally released from each other by the action of gravity, even if the temporarily-engaged assembly is re-oriented with limited support for one or more of the window frames. Within the same context, disengagement of the window frames from each other is accomplished with substantial e.g. manually-applied force urging the respective frames in a disengaging direction. Restated, while the nosings are not so loosely engaged as to easily disengage with normal handling, neither do the nosings need to be so forcefully held together that disengagement requires more than the force which can be applied manually by an average adult. 
     With the nosings so joined, and with the upper window frame located at its desired final juxtaposition relative to the lower window frame, the assembly is being held together at the outwardly-facing surface of the assembly, which will face outwardly of a building to which the assembly will be joined. The upper window is further secured to the lower window at or adjacent the inwardly-facing surface of the assembly by e.g. a corrugated sheet fastener  147 , or by nails, or screws, all as discussed with respect to  FIG. 5 . 
     While the process of joining and disengaging the nosings has been described in terms of the upper window frame being moved relative to the lower window frame, the joining and disengaging of the nosings can as well be accomplished by holding the upper window frame stationary and moving the lower window frame, or both members can be moved as part of the joining and/or disengaging of the nosings. 
     Still referring to  FIG. 6 , the nosing  22  profile is used as the nosing on the lower window frame simply for convenience of using the same extrusion profile as was used in the arcuate nosing assembly  18  at the top of the transom window discussed with respect to  FIG. 3 , with exception that the nosing  22  in  FIG. 6  is not bent into an arcuate configuration. Neither is the nosing in  FIG. 6  assembled to an arcuate drip cap  24 . Accordingly, the nosing used with the lower window frame need not have certain of the features of the arcuate nosing used at the top of the arcuate transom window frame  14 . The features which can be eliminated at will are, without limitation, as follows: 
     Since the nosing on lower window frame  14 A is not bent into an arcuate configuration, the support of intermediate web  44  is not needed, whereby intermediate web  44  becomes optional and can, as desired, be eliminated. 
     Also because the nosing is not bent into an arcuate configuration in the embodiments illustrated in  FIG. 6 , the thickness of facia flange  52  can be the same as the thicknesses of the remaining major elements of the nosing, thus about the same thickness as the thicknesses of the inner and outer flanges and/or the inner-facing web and the outer-facing web. 
     Since the nosing on lower window frame  14 A is not joined to an arcuate drip flashing flange,  FIG. 6  shows that stud receptacle  46  is not being used and can optionally, as desired, be eliminated so long as the specifications for receptacle  48 ,  142  and walls  50 ,  146  provide suitable alignment of outer facing webs  40 ,  138 . 
     While window frames  14 A and  14 B have been illustrated as being in overlying, underlying relationship, the same elements and assembly procedures can be used in mounting window frames in a wide variety of collective configurations, thus to mount together multiple window frames/windows in an “X-Y” window matrix having essentially any number of window units in each of the “X” and “Y” directions. Thus, window assemblies can be fabricated in any desired size using a wide variety of assembly configurations, and using a wide variety of window shapes for the designs of the respective windows. Such assemblies can be fabricated in any desired configuration which can subsequently be handled safely for installation. 
     Any time a straight nosing is being joined to either another straight nosing or a straight drip cap, a flexible sealing compound such as caulk can optionally be spread along the interface before the nosings, or the nosing and the drip cap, are joined to each other. For example and without limitation, in the embodiments of  FIG. 5  or  FIG. 6 , caulk can be applied in receptacle  142  of nosing  20 , or on inner flange  124  of nosing  20 , or on outer flange  28  of nosing  22 , or outer flange  82  of nosing  76 . 
       FIGS. 7(   a )- 7 ( p ) illustrate a wide variety of shapes of windows which can be built using the nosings and drip caps, and collective assemblies of such nosings and drip caps.  FIGS. 7(   a )- 7 ( p ) are illustrative only, and are not exhaustive of the windows designs which can benefit from the nosing structures of the invention. 
     Any such window having a straight bottom side can be so-mounted to a door header jamb as a transom window. Where the bottom of the window is not straight, the lower edge of the window can be set in an adapter which adapts the lower end of the window to a straight configuration, with the nosing  20  mounted to the lower portion of the adapter. 
     In the alternative the upper edge of the door frame can be mounted into an adapter which adapts the upper edge of the door frame to the lower edge of the window frame. Either way, the adapter can provide the interface between window and door. 
     Returning now to the drawings,  FIG. 7(   a ) shows a horizontally-elongate rectangular window  158 ( a ) which can be used alone, in a cluster, or as a transom window  12  over a door frame. Window  158 ( a ), as illustrated, includes an outer frame  14 ( a ), and a glazing unit  16 ( a ). Window  158 ( a ) has four nosing sections which meet at four nosing joints  162 ( a ) at respective corners of the window. Window  158 ( a ) can be used alone or in clusters, or can be used as a transom window above a door. 
     A straight drip cap  24  is used with the nosing which extends the top of the window. Drip cap  24  uses e.g. a stud  74  to engage e.g. stud receptacle  46 , both of which are illustrated in  FIG. 3 , thus to fix the inner-to-outer positioning of the drip cap relative to the nosing. Since this nosing/drip cap combination is not bent, any hook/hook receptacle combination does not provide the permanent securement of the nosing and drip cap to each other, although a hook/hook receptacle combination can provide a degree of water resistance by means of the corresponding arduous path the water would have to travel to reach wood substrate. 
     Since the hook/hook receptacle combination does not secure the drip cap to the nosing like in the arcuate configuration, the drip cap must be otherwise secured to the nosing. In the illustrated embodiment of e.g.  FIG. 7(   a ), the drip cap is temporarily positioned at its mounting location over nosing  22 . Screw holes are then drilled, at regularly-spaced intervals along the length of the drip cap, through the drip cap and into the nosing outer flange. The drip cap is then removed from the nosing and caulk is applied to the lower surface of the drip cap, at each hole. The drip cap is then re-located to its mounting location on the nosing and the screws are driven through the drip cap and into the nosing, drawing the drip cap into intimate relationship with the nosing. As the drip cap is thus drawn toward the nosing, the movement of the lower surface of the drip cap toward the upper surface of the nosing compresses the caulk whereby the caulk is spread between the lower surface of the drip cap and the upper surface of the outer flange of the nosing, including into and around the screw holes. This spreading of the caulk provides an effective weather seal around the screw holes which, along with the shielding affect of drip flange  70 , prevents routine entry of air-borne/weather-borne water into the window frame at the interface of the drip cap and the nosing. 
     The above description illustrates that the stud and stud receptacle, in the nosing/drip cap combination, serve a positioning function when the stud is seated in the stud receptacle. Namely, the stud will seat in the stud receptacle only when the drip flashing and the nosing are properly aligned with each other. Thus, the stud/stud receptacle combination always provides certainty that the nosing and drip cap are properly aligned with each other. Thus, even where the nosing and drip cap do not need to be bent, the stud/stud receptacle combination provides a desired benefit of certainty of alignment. 
     In the straight assembly of e.g.  FIG. 3 , as described earlier herein, the hook and hook receptacle serve as no more than a temporary assembly, which can be readily disengaged. Thus, the need for screws or other fasteners spaced along the length of the drip cap in providing the permanent assembly where the nosing assembly is not arcuate/bent. 
     In other embodiments, illustrated in  FIG. 9 , the stud-in-stud receptacle combination is used along with regularly-spaced screws  164  holding a straight drip cap to a straight nosing. In such embodiments, the screws hold the upper-to-lower spatial relationship while the stud holds the inner-to-outer relationship whereby the combination of a hook and a hook receptacle is optional. 
       FIG. 7(   b ) shows a rectangular window  158 ( b ), similar to window  158 ( a ) of  FIG. 7(   a ), except that window  158 ( b ) has been re-oriented vertically. Window  158 ( b ), as illustrated, includes an outer frame  14 ( b ), a glazing unit  16 ( b ), and an optional decorative grid  160 ( b ). In the vertical/upright orientation, window  158 ( b ) can be used alone or in clusters, or can be used as a transom window above a door where the ceiling height at the doorway inside the building so allows. Window  158 ( b ) has four nosing sections which meet at four nosing joints  162 ( b ) at respective corners of the window. A straight drip cap  24  is assembled to the nosing which extends across the top of the window. 
       FIG. 7(   c ) shows a trapezoidally-shaped window  158 ( c ). Window  158 ( c ), as illustrated, includes an outer frame  14 ( c ), a glazing unit  16 ( c ), and an optional decorative grid  160 ( c ). Window  158 ( c ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( c ) has four nosing sections which meet at four nosing joints  162 ( c ) at respective corners of the window. A straight drip cap  24  is assembled to the nosing which extends across the top of the window. 
       FIG. 7(   d ) shows a parallelogram-shaped window  158 ( d ). Window  158 ( d ), as illustrated, includes an outer frame  14 ( d ), a glazing unit  16 ( d ), and an optional decorative grid  160 ( d ). Window  158 ( d ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( d ) has four nosing sections which meet at four nosing joints  162 ( d ) at respective corners of the window. A straight drip cap  24  is assembled to the nosing which extends across the top of the window. 
       FIG. 7(   e ) shows a triangularly-shaped window  158 ( e ). Window  158 ( e ), as illustrated, includes an outer frame  14 ( e ), a glazing unit  16 ( e ), and an optional decorative grid  160 ( e ). Window  158 ( e ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( e ) has three nosing sections which meet at three nosing joints  162 ( e ) at respective corners of the window. Straight drip caps  24  are assembled to the nosings which extend from the top nosing joint to the lower left and right side nosing joints. 
       FIG. 7(   f ) shows a half round-shaped window  158 ( f ). Window  158 ( f ), as illustrated, includes an outer frame  14 ( f ), a glazing unit  16 ( f ), and an optional decorative grid  160 ( f ). Window  158 ( f ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( f ) has two nosing sections which meet at two nosing joints  162 ( f ) at respective corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends, from the two nosing joints along the arcuate top of the window. 
       FIG. 7(   g ) shows a circle-segment/eyebrow shaped window  158 ( g ). Window  158 ( g ), as illustrated, includes an outer frame  14 ( g ), a glazing unit  16 ( g ), and an optional decorative grid  160 ( g ). Window  158 ( g ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( g ) has two nosing sections which meet at two nosing joints  162 ( g ) at lower left and right corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends, from the lower left nosing joint, along the arcuate top of the window, to the lower right joint. 
       FIG. 7(   h ) shows a window known as a springline window  158 ( h ). Window  158 ( h ), as illustrated, includes an outer frame  14 ( h ), a glazing unit  16 ( h ), and an optional decorative grid  160 ( h ). Window  158 ( h ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( h ) has two nosing sections which meet at two nosing joints  162 ( h ) at respective corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends, from the lower left nosing joint, along the arcuate top of the window, to the lower right joint. 
       FIG. 7(   i ) shows a window  158 ( i ) known as an equal leg arch window  158 ( i ). Window  158 ( i ), as illustrated, includes an outer frame  14 ( i ), a glazing unit  16 ( i ), and an optional decorative grid  160 ( i ). Window  158 ( i ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( i ) has four nosing sections which meet at four nosing joints  162 ( i ) at respective corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends from the upper left nosing joint, along the arcuate top of the window, to the upper right nosing joint. 
       FIG. 7(   j ) shows a full round window  158 ( j ). Window  158 ( j ), as illustrated, includes an outer frame  14 ( j ), a glazing unit  16 ( j ), and an optional decorative grid  160 ( j ). Window  158 ( j ) is typically used alone. Window  158 ( j ) can have a single nosing section which encircles the entirety of the window. Optionally, window  158 ( j ) has two nosing sections, a first such nosing section wrapping the top portion of the window and a second such nosing section wrapping the bottom portion of the window, thus defining first and second nosing joints  162 ( j ). Window  158 ( j ) is commonly used alone, but may be used in clusters with suitable adaptation framing and/or in combination with other window shapes/designs. Where upper and lower nosings are used, an arcuate drip cap  24  is assembled to the upper nosing. 
       FIG. 7(   k ) shows a full oval window  158 ( k ). Window  158 ( k ), as illustrated, includes an outer frame  14 ( k ), a glazing unit  16 ( k ), and an optional decorative grid  160 ( k ). Window  158 ( k ) is typically used alone. Window  158 ( k ) can have a single nosing section which encircles the entirety of the window. Optionally, window  158 ( k ) has two nosing sections, a first such nosing section wrapping the top portion of the window and a second such nosing section wrapping the bottom portion of the window, thus defining first and second nosing joints  162 ( j ). Window  158 ( j ) is commonly used alone, but may be used in clusters with suitable adaptation framing and/or in combination with other window shapes/designs. Where upper and lower nosings are used, an arcuate drip cap  24  is assembled to the upper nosing. 
       FIG. 7(   l ) shows an elliptical/oval-shaped window  158 ( l ). Window  158 ( l ), as illustrated, includes an outer frame  14 ( l ), a glazing unit  16 ( l ), and an optional decorative grid  160 ( l ). Window  158 ( l ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( l ) has two nosing sections which meet at two nosing joints  162 ( l ) at respective corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends, from the lower left joint, across the top of the window, to the lower right joint. 
       FIG. 7(   m ) shows a gothic-shaped window  158 ( m ). Window  158 ( m ), as illustrated, includes an outer frame  14 ( m ), a glazing unit  16 ( m ), and an optional decorative grid  160 ( m ). Window  158 ( m ) can be used alone, in clusters, or as a transom window over a door. Window  158 ( m ) has three nosing sections which meet at three nosing joints  162 ( m ) at respective lower left, lower right, and upper, corners of the window. First and second arcuate drip caps  24  are assembled to the nosings which extend, from the upper nosing joint, down the left and right sides of the window. 
       FIG. 7(   n ) shows a regular octagon window  158 ( n ). Window  158 ( n ), as illustrated, includes an outer frame  14 ( n ), a glazing unit  16 ( n ), and an optional decorative grid  160 ( n ). Window  158 ( n ) is typically used alone, but can be used in clusters or as a transom window over a door. Window  158 ( n ) has eight nosing sections which meet at eight nosing joints  162 ( n ) at respective corners of the window. First, second, and third straight drip caps  24  are assembled to the nosings which extend along the top and upper left and right sides of the window. 
       FIG. 7(   o ) shows an elongate octagon window  158 ( o ). Window  158 ( o ), as illustrated, includes an outer frame  14 ( o ), a glazing unit  16 ( o ), and an optional decorative grid  160 ( o ). Window  158 ( o ) is typically used alone, but can be used in clusters or as a transom window over a door. Window  158 ( o ) has eight nosing sections which meet at eight nosing joints  162 ( o ) at respective corners of the window. First, second, and third straight drip caps  24  are assembled to the nosings which extend along the top and upper left and right sides of the window. 
       FIG. 7(   p ) shows a quarter-circle-arc window  158 ( p ). Window  158 ( p ), as illustrated, includes an outer frame  14 ( p ), a glazing unit  16 ( p ), and an optional decorative grid  160 ( p ). Window  158 ( p ) is typically used alone, but can be used in combinations or as a transom window over a door. Window  158 ( p ) has four nosing sections which meet at four nosing joints  162 ( p ) at respective corners of the window. An arcuate drip cap  24  is assembled to the nosing which extends from the upper right nosing joint to the lower left nosing joint. 
     As seen in  FIGS. 5 ,  6 , and  8 , some embodiments of the nosing assembly do not use the stud-in-stud receptacle combination.  FIG. 8  illustrates a nosing assembly where both the stud and the stud receptacle have been eliminated. Hook  72  extends downwardly through a hook opening  49  in outer flange  28 . Below the outer flange, hook  72  extends toward outer-facing web  40 . The horizontally-extending portion  72 A of the hook holds the drip cap in vertical fixation relative to the nosing. The downwardly-extending base portion  72 B of the hook interfaces with the sidewalls of opening  49  thus to hold the drip cap in horizontal fixation relative to the nosing. 
     Drip cap  24  is assembled to nosing  22  in  FIG. 8  by aligning the drip cap with the nosing, with the inner end  62  of platform  60  raised from outer surface  38  of outer flange  28 . With inner end  62  so raised, the leading edge of hook  72  is aligned with opening  49 , and is inserted into opening  49 . As the hook progresses into opening  49 , the curvature on hook  72  urges the lowering of inner end  62 . By the time the hook is fully seated in opening  49  as shown in  FIG. 8 , inner end  62  of the platform is in general surface-to-surface relationship with outer surface  38  of the nosing, allowing for any caulk or other flexible sealing compound between such surfaces. With the drip cap is so assembled to the nosing, the interaction between the base of the hook and the sidewalls of opening  49  control/limit/prevent front-to-rear e.g. horizontal movement of the drip cap relative to the nosing. The e.g. horizontal portion of the hook controls/limits/prevents movement of the front of the drip cap relative to the nosing perpendicular to the outer surface of the nosing, but does not so limit such movement at the rear/inner portion of the drip cap. If such assembly is bent as in the embodiments of  FIGS. 1 ,  2  and  4 , the bending provides the restraint to such perpendicular movement. If the assembly is not bent, then other means such as fasteners, as are disclosed hereinafter with respect to  FIG. 9 , are employed toward the rear of the drip cap, e.g. adjacent inner end  62  of the platform. 
       FIG. 9  illustrates a straight nosing assembly, including a straight drip cap  24 , mounted at the top of a rectangular e.g. transom window. Such straight drip cap can be held in horizontal, front-to-rear position relative to the nosing either by a combination of stud and stud receptacle, or by a hook  72  as illustrated in  FIG. 8 . Either way, in such straight configuration, screws  164  are spaced along the length of the drip cap, extending through the drip cap and into the nosing, thus providing permanent attachment of the drip cap and nosing to each other. 
       FIG. 10  shows a cross-section of the nosing assembly of  FIG. 9 , illustrating a screw  164  extending through the drip cap, and outer flange of the nosing.  FIG. 10  also illustrates caulk  166  between lower surface  68  of the drip cap platform and outer surface  38  of the nosing outer flange. Caulk  166 , where used, can be confined to the areas of the screws, thus to seal around the screws. In the alternative, caulk  166  can extend the full length of the drip cap, as well as being present at the screw holes, thus to provide a continuous barrier between the nosing outer flange and the drip cap lower surface, as well as at the screw holes. Such continuous barrier serves as a back-up barrier, backing up the barrier which is created by the convoluted path about the combination of the hook and the hook receptacle. 
     Joining frames together has been described herein in terms of joining a clad window frame to a clad door frame as in  FIG. 5 , and in terms of joining a clad window frame to a clad window frame as in  FIG. 6 . The same principles can be used, along with selected ones of the nosings, to similarly join a clad door frame to a clad door frame. 
     Those skilled in the art will now see that certain modifications can be made to the apparatus and methods herein disclosed with respect to the illustrated embodiments, without departing from the spirit of the instant invention. And while the invention has been described above with respect to the preferred embodiments, it will be understood that the invention is adapted to numerous rearrangements, modifications, and alterations, and all such arrangements, modifications, and alterations are intended to be within the scope of the appended claims. 
     To the extent the following claims use means plus function language, it is not meant to include there, or in the instant specification, anything not structurally equivalent to what is shown in the embodiments disclosed in the specification.