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PRIORITY CLAIM 
     The priority benefit of U.S. provisional patent application Ser. No. 61/243,301 is claimed which was filed Sep. 17, 2009, and which is incorporated herein in its entirety by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     A roof or floor may be constructed by fastening metal deck units together to form a deck system. The deck system may then serve as a roof or a floor, or may be covered with a layer of concrete to form a composite structure. For some applications, such as airports, stadiums, sports arenas, convention centers, schools and other large, open areas, a deck system may include sound-absorbing materials. 
     The ability of a deck system to support its design load is the most critical consideration. The design load for a roof begins with the weight of the roof itself and may vary with local environmental conditions, such as, for example, snow, ice and wind loads. Likewise, the design loads for floor applications vary by the use and location of the building. The strength of a deck system comes from its geometry, the choice of construction materials, and how those materials are formed, are connected and cooperate with each other and with other structural materials in the building. Finally, a deck system must be economical and its components easily manufactured, efficiently transported and simply and quickly installed at the job site. Designing an economical and practical roof or floor deck unit capable of supporting the design load presents a challenge. 
     Thus there is a continuing need for improvements in the design of deck units, particularly those that are designed for greater strength for a given amount of materials while remaining cost-effective. 
     SUMMARY OF THE INVENTION 
     The present invention is a deck unit for use in forming a deck system capable of supporting heavier loads and/or spanning greater distances. The deck unit of the present invention is a profiled metal unit that derives its greater load-bearing strength in part from its greater depth and in part from the way the additional depth is obtained. In particular, the additional depth and strength is accomplished by attaching a full length channel to the top of a hat-shaped profile. Adding a channel to the profiled deck unit to obtain additional strength not only provides greater strength but also increases flexibility in the design and manufacture of deck units. 
     The present deck unit may comprise a hat-shaped profile with a top flange supported by two opposing webs, with a channel bearing on or nested with on the hat-shaped profile. The deck unit may be fluted or, optionally, the deck unit may include a liner panel to define a cellular deck unit. In alternative embodiments, the liner panel may be perforated and a deck unit may include sound absorbing material in the interior of the hat-shaped profile of the deck unit. Alternatively, webs and/or top flange of a fluted deck unit may be perforated and may include acoustical material between the hat sections and/or in the interior of the channel. 
     The present deck unit has advantages in its ability to support considerably greater design loads with relatively little additional material. Its strength and its design flexibility derive from the channel bearing on or nested with the hat-shaped profile rather than in simply forming a deeper hat-shaped profile. The hat-shaped profile can be the same dimensions for many different roof design conditions but the size and gauge of the channel can be varied to adjust the overall deck&#39;s strength and stiffness. 
     Another advantage of the present invention is that, whether in cellular or fluted form, the channel itself can serve as an unobstructed and protected conduit for running cable, wiring or piping. The cellular and fluted deck units can additionally support sound-absorbing materials. 
     The features and advantages of the present invention will be readily apparent to those skilled in the art of steel deck systems for roofs and floors from a careful reading of the Detailed Description of Preferred Embodiments, accompanied by the following drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the figures, 
         FIG. 1  is a perspective view of a portion of a deck, according to the present invention; 
         FIG. 2  is an end view of a cellular deck unit with a channel attached to the hat-shaped profile supporting a layer of concrete, according to the present invention; 
         FIG. 3A  is an end view of a cellular deck unit with channels attached to each hat of a two-hat-shaped profile, according to the present invention; 
         FIG. 3B  is an end view of a cellular deck unit with channels attached to each hat of a two-hat-shaped profile supporting a layer of concrete, according to the present invention; 
         FIG. 4  is a perspective view of a portion of a deck with channels nested on the hat-shaped profiles, according to the present invention; 
         FIG. 5  is an end view of a fluted deck unit with a channel nested with the hat-shaped profile, according to the present invention; 
         FIG. 6  is an end view of a cellular deck unit with a channel nested with the hat-shaped profile, according to the present invention; 
         FIG. 7  is an end view of a cellular deck unit with a channel bearing on the hat-shaped profile with a perforated liner panel and sound-absorbing material carried in the hat-shaped profile, according to the present invention; 
         FIG. 8  is an end view of a fluted deck unit with a channel bearing on the hat-shaped profile with a perforated top flange and sound-absorbing material carried in the channel, according to the present invention; 
         FIG. 9  is an end view of a cellular deck unit with a channel bearing on the hat-shaped profile with perforated webs and sound-absorbing material carried adjacent to the hat-shaped profile, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The present invention is a deck unit suitable for supporting heavy design loads and/or spanning greater distances. The present deck unit is made of sheet metal and has a profile that allows it to be joined to other similar deck units in order to form a deck system that supports a specified design load. The present deck system may be used as a roof or a floor; it may be combined compositely with concrete for added strength, and it may include acoustic features for those applications where noise reduction is desired. Acoustic features are structures and materials that absorb sounds or facilitate the absorption of sounds. 
     In the present specification, the word deck refers to a small group of deck units, such as one, two or three deck units, that can be manufactured, handled and delivered as an assembly, and thus deck systems can be made by combining a sufficient number of individual deck units or multi-deck-unit decks or combinations thereof. The deck units may be cellular or fluted; that is, when the deck units include a liner panel, the liner panel defines a cell with the deck unit above it. If there is no liner panel, the deck units are said to be fluted. 
     Referring now to a first preferred embodiment of the present invention, illustrated in  FIG. 1 , there is shown a deck  10  according to the present invention, made of three cellular deck units  20 . Deck  10  may be joined to other decks  10  or deck units  20 , or combinations of decks  10  and deck units  20  to form a deck system. Plural decks  10  are joined by any convenient means including welding, crimping, riveting or using self-drilling fasteners, or a combination of these, to form a deck system of the desired dimensions and shape. A framework, not shown, may support a deck system. 
     After deck units  20 , or decks  10 , are joined to form a deck system, the system may be covered with a layer of concrete to form a composite structure. Additional material layers may also be applied. 
     Each deck unit  20  has a hat-shaped profile  30  comprising two opposing webs  32 ,  34  that are integrally joined to a top flange  36  to define a shape that is roughly an upside-down U, when viewed from the end. Lengthwise, webs  32 ,  34 , and top flange  36  extend the full length of a span which defines the major dimension of deck unit  20 . Laterally, webs  32 ,  34 , terminate in integrally-formed, opposing, bottom flanges identified by reference numbers  44  and  42 , respectively. A box-like channel  46  is attached to hat-shaped profile to increase the height of deck unit  20 . Channel  46  is characterized by a generally flat top with or without stiffeners, straight sides may or may not be bent at 90 degrees with respect to the flat top and terminal portions of the sides that may or may not be bent inwardly. The top and two sides at angles to the top define the box-like shape. Channel  46  is attached to top flange  36  or to webs  32 ,  34 , preferably by weldments  38 . 
     One measure of the load-bearing capability of a deck unit  20  is its depth: generally, the greater the depth, the greater the load-bearing capability of the deck. Depth is measured from the top of channel  46  to the bottom of bottom flanges  42 ,  44 . To increase further the overall depth of deck unit  20 , hat-shaped profile  30  and/or channel  46  may be made deeper. 
     Channel  46  is not integrally formed with hat-shaped profile  30  but formed from a separate sheet of metal and attached to hat-shaped profile  30 , preferably by weldments  38 . This is an important feature of the present invention as channel  46  not only increases the depth of deck unit  20  without increasing the height of first and second webs  32 ,  34 , and thus its load-bearing capability, but does so in a way that provides flexibility in designing deck unit  20 . For example, the thickness of channel  46  can be selected to provide sufficient strength for deck unit  20 , a little thicker for a stronger deck unit  20 , a little thinner for a deck unit  20  that is a little less strong. For another example, the gauge of metal of which channel  46  is made does not have to be the same gauge as hat-shaped profile  30  is made, thus allowing, for example, the use of a thicker gauge for channel  46  when additional strength is needed for deck system  10  or for a particular portion of deck system  10 . Therefore, the same hat-shaped profile  30  can be used with different gauges of metal for channels  46  when deck units  20  of different strengths are needed rather than having to produce entirely different deck units  20 , as only channel  46  needs to be different. 
     Channel  46  in  FIG. 1  is shown being carried on hat-shaped profile  30 . In this configuration, channel  46  is bent in the form of an open box-like shape with at least two rounded corners and terminal portions  52 ,  54  that are attached, spaced-apart, to top flange  36 . Terminal portions  52 ,  54 , of channel  46  are fastened to top flange  36  preferably by weldments  38  at intervals along the length of deck unit  20 . Self-drilling fasteners and rivets can also be used. 
     Topographic or structural features may be added to the components of deck  10  to improve stiffness. Top flange  36  (or channel  46 ), for example, may be formed to have a trough  48  parallel to the major axis of deck unit  20  for increased stiffness. Webs  32 ,  34  are canted so as to be closer together at top flange  36  than at bottom flanges  42 ,  44 . Bottom flanges  42 ,  44 , may have stiffeners  60 ,  62  such as beads. Stiffeners may be added not only for strength but also for preventing misalignment and shape distortion during manufacturing. Stiffness can also be added by incorporating struts at intervals within and along hat-shaped profile, The dimensions of these features are determined by sound engineering principles and a modest amount of experimentation, along with considerations of cost. 
     Deck  10  may also include a liner panel  70  that encloses the interior  72  of hat-shaped profile  30  of deck unit  20 . Liner panel  70  may have a bead  74  running parallel to the long dimension of deck unit  20 , for strength but also, in particular, so that liner panel  70  remains flat across interior  72  for a more uniform appearance across a deck system when it is used as a ceiling or roof. 
     Liner panel  70  has a first bottom flange  80  and an opposing second bottom flange  82 . First bottom flange  80  and second bottom flange  82  nest, that is, each bottom flange is formed to have one or more faces at angles with respect to each other, so that, when first bottom flange  80  of a liner panel  70  of a deck  10  is brought into engagement with a second bottom flange  82  of a panel  70  of an adjacent deck unit, a first bottom flange  80  receives second bottom flange  82  within it (or vice versa) thereby to allow the corresponding faces of first bottom flange  80  to be brought into parallel and close relationship with the faces of second bottom flange  82  so that first and second bottom flanges  80 ,  82  may be joined by convenient means, such as clinching, welding, riveting, using self-drilling fasteners, or combinations thereof. Bottom flanges  42 ,  44  of each deck unit  20  are fastened to liner panel  70  preferably by welding. 
       FIGS. 2 and 3A  and  3 B illustrate other embodiments of the present invention. The use of the same reference numbers in  FIGS. 2 and 3A  and  3 B indicates the structures are the same and serve the same function. 
       FIG. 2  shows a deck  10 ′ made of a single cellular deck unit  20  with a hat-shaped portion  30  with webs  32 ,  34  and a top flange  36 . A channel  46  is carried on top flange  36  and a panel liner  70  encloses the space  72  inside hat-shaped portion  30 . Webs  32 ,  34  terminate in bottom flanges  42 ′,  44 ′, and panel liner  70 ′ is flat except for a bead  84 . A layer of concrete  86  lies over deck  10 ′. 
       FIG. 3A  illustrates a deck  10 ″ made with two cellular deck units  20 , each with a hat-shaped portion  30  with webs  32 ,  34  and a top flange  36 . A channel  46  is carried on top flange  36  and a panel liner  70  encloses the space  72  inside hat-shaped portion  30 . Webs  32 ,  34  terminate in bottom flanges  42 ,  44 , and liner panel  70  includes a bead  74  as well as two bottom flanges  80 ,  82 . 
       FIG. 3B  illustrates a deck  10 ″ made with two cellular deck units  20 , each with a hat-shaped portion  30  with webs  32 ,  34  and a top flange  36 . A channel  46  is carried on top flange  36  and a panel liner  70  encloses the space  72  inside hat-shaped portion  30 . Webs  32 ,  34  terminate in bottom flanges  42 ,  42 ′,  44 ,  44 ′, and liner panel  70  includes a bead  74  as well as beads  60 ,  62  on two bottom flanges  80 ,  82 . A layer of concrete  86  lies over deck  10 ″. Bottom flanges  42 ′,  44 ′ extend vertically and then bend to terminate in horizontal flanges  88 ,  90  so that bottom flanges  42 ′,  44 ′ nest with each other to act compositely with concrete  85   
       FIGS. 4-6  illustrate an alternative preferred embodiment of the present invention similar to that shown in  FIGS. 1-3 .  FIG. 4  illustrates a deck  110  made of three deck units  120 . As with deck  10 , plural decks  110  can be joined to form a deck system to serve as a floor or roof. Each deck unit  120  has a hat-shaped profile  130  with webs  132 ,  134  integrally formed with a top flange  136  and terminating laterally in opposing bottom flanges  142 ,  144 . 
     Each deck  120  also has a channel  146  similar to channel  46  of  FIGS. 1-3 , in that channel  146  is a separate but integral component, and is attached to hat-shaped profile  130  and channel  146  is also shaped like an open box. However, channel  146  rather than terminating in inwardly folded terminal portions  52 ,  54  to allow channel  46  to bear on top flange  36  of hat-shaped profile  30  as shown in  FIG. 1 , channel  146  has terminal portions  152 ,  154  that are not folded but are attached to webs  132 ,  134  of hat-shaped profile  130  preferably by weldments  138  in an overlapping and nested arrangement. 
     Deck  110  is shown in  FIG. 4  and deck unit  120  is shown in  FIG. 6  as having a liner panel  170  to enclose an interior  172  of hat-shaped profile  130 . Liner panel  170  has a first bottom flange  180  and an opposing second bottom flange  182  (and bead  174 ) that, as with first and second bottom flanges  80 ,  82  of  FIG. 1 , are formed to have faces that nest, that is, the faces of first bottom flange  180  are formed and dimensioned to receive the corresponding faces of second bottom flange  182  in parallel and close proximity so that two decks  110  can be placed side by side and fastened together. Any convenient means of fastening, including welding, clinching, riveting and using self-drilling fasteners, and combinations thereof may be used. 
     Bottom flanges  142 ,  144 , of each deck unit  120  are fastened to liner panel  170 , preferably by welding. The use of panel  170  creates a cellular structure for deck units  120  that is strong and accommodates sound-absorbing materials within interiors  172 . 
     Channel  146 , in addition to providing increased depth for deck unit  120 , also provides a protected and convenient conduit for cabling, wiring and piping, allowing a way to run cabling, etc., through deck  110 , where it is hidden from view and protected. 
     Channels  46  and  146  do not require uniform cross-sectional area from one end of a deck unit  20 ,  120 , respectively, to the other but can have a depth that varies from one end to the other, assuming the loading varies from one end to the other or other design requirements dictate a varying depth of deck system along its length. Under these circumstances, the present channel-on-hat-profile configuration offers yet additional design flexibility. 
     Deck units  120  may include features that increase stiffness, such as trough  148  in top flange  136  (or a similar trough in channel  146 ), stiffeners  160  and  162  in bottom flanges  142 ,  144 , respectively, and bead  174  in liner panel  170 . 
       FIG. 7  illustrates a deck  210  with sound absorbing materials  212 . Deck  210  comprises two cellular deck units  220 , each with a hat-shaped profile  230  that includes webs  232 ,  234  and a top flange  236 . A channel  246  is attached to hat-shaped profile  230 . Webs  232 ,  234  terminate in bottom flanges  242 ,  244 , respectively. A liner panel  270  defines a space  272  within hat-shaped profile  230 . Liner panel  270  is perforated with an array of holes  284  and beads  274 . Within space  272  is sound-absorbing materials  212 . Sound enters space  272  through holes  284  and is absorbed by sound absorbing materials  212  in space  272 . 
       FIG. 8  illustrates another deck  310  with sound absorbing materials  312 . Deck  310  comprises two fluted deck units  320 , each with a hat-shaped profile  330  that includes webs  332 ,  334  and a top flange  336 . A channel  346  is attached to hat-shaped profile  330 . Webs  332 ,  334  terminate in bottom flanges  342 ,  344 ′,  342 ′,  344 , respectively. Top flange  336  is perforated with an array of holes  374 . Within channel  346  is sound-absorbing materials  312 . Sound enters hat-shaped profiles  330 , passes through holes  374  into channel  346  where it is absorbed by sound absorbing materials  312 . Bottom flanges  342 ′,  344 ′ extend vertically and then bend to terminate in horizontal flanges  388 ,  390  so that bottom flanges  342 ′,  344 ′ nest with each other. 
       FIG. 9  illustrates yet another deck  410  with sound absorbing materials  412 . Deck  410  comprises two fluted deck units  420 , each with a hat-shaped profile  430  that includes webs  432 ,  434  and a top flange  436 . A channel  446  is attached to hat-shaped profile  430 . Webs  432 ,  434  terminate in bottom flanges  442 ,  442 ′,  444 ′  444 , respectively. Webs  432 ,  434 ,  436  are perforated with an array of holes  474 . Between fluted deck units  420  are sound-absorbing materials  412 . Sound enters hat-shaped profiles  430  and proceeds through holes  474  in webs  432 ,  434 , and is absorbed by sound absorbing materials  412  between deck units  420 . Bottom flanges  442 ′,  444 ′ extend vertically and then bend to terminate in horizontal flanges  488 ,  490  so that bottom flanges  442 ′,  444 ′ nest with each other. 
     It will be clear to those familiar with deck systems that the arrangements of sound-absorbing materials shown in  FIGS. 8 and 9  can of course be combined and the arrangements of sound-absorbing materials in  FIGS. 7 and 8  can also include a layer of concrete as illustrated in  FIG. 3B . 
     Those familiar with the use of steel decks in constructing floors and ceilings will appreciate that many modifications and substitutions can be made to the foregoing preferred embodiments of the present invention without departing from the spirit and scope of the present invention, defined by the appended claims.

Summary:
A deck unit is disclosed to form a deck system for a roof or floor that is capable of supporting a heavier load and/or spanning greater distances. The deck unit is a profiled, metal unit, that derives its greater load-bearing strength in part from its greater depth but provides flexibility in achieving the greater strength from the way the additional depth is obtained. In particular, a full length channel is attached to a hat-shaped profile. The channel adds strength both by increasing deck unit depth and by avoiding lengthening the webs on the hat-shaped profile. The channel increases design flexibility by allowing the designer to increase the strength of pre-existing decks by the addition of a channel of suitable metal thickness and size. It also provides a channel for conduit, cabling and wiring. The deck unit may be fluted or, by the addition of a liner panel to close the interior of hat-shaped profile, cellular. Sound absorbing materials can be installed in either a fluted or cellular deck unit.