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BACKGROUND 
     The present invention relates to a method and a device for insulating adjacent to a roof or other flat building structure while maintaining a ventilation gap between the insulation material and the flat building structure to allow for air to flow. This ventilation gap, in conjunction with vents, such as ridge vents, improves airflow as well as insulation efficiency (thermal and sound). 
     It is known to mount rigid insulation sheets below a roof while maintaining a ventilation gap by using brackets, as disclosed in U.S. Pat. No. 7,017,315 “Corwin”. Corwin says in column 4, lines 22-28 that for any of the roof structures shown in  FIGS. 1-4  the brackets could be mounted on the rafters first and then the insulating panels  16  installed later, or the brackets could first be secured to the insulating panels and then secured to the rafters. However, it does not appear that all those structures really could be installed in either order as stated. 
     It appears that the embodiments shown in  FIGS. 3-10  would require assembling the panel  16  onto the brackets before installing the brackets onto the rafters, because there would be no way to assemble the insulating panel  16  onto those brackets after the brackets are installed. 
     The embodiments of  FIGS. 1 and 2 , which do not have an upper stop above the insulating panel to prevent the insulating panel from moving into the ventilation gap, would permit the brackets to be installed first, before assembling the panel  16  onto the brackets, because, in those embodiments, the insulating panel  16  could be dropped in from the open top before installing the roof. However, since there is no upper stop in those embodiments, if the insulating panel is not later secured to the brackets, only the force of gravity is holding the rigid panel  16  in place to maintain the ventilation gap. 
     Thus, the various embodiments of Corwin do not provide the convenience of being able to install the brackets onto the rafters first and then installing the rigid panels onto the brackets while also providing a positive upper stop between the insulating panel and the roof or other flat building structure in order to ensure that the desired ventilation gap is maintained. 
     SUMMARY 
     The present invention solves that problem. It provides a bracket which may be secured to the rafters before installing the rigid panel, and then allows for simple installation of the rigid panels onto the brackets while also providing a positive upper stop between the rigid panel and the roof or other flat building structure in order to ensure that the desired ventilation gap is maintained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a broken-away, section view of a roof structure including brackets mounted to rafters, rigid panels mounted to the brackets, and insulating batts mounted below the rigid panels; 
         FIG. 1A  is a broken away plan view of the structure of  FIG. 1 , with part of the roof and sheathing removed; 
         FIG. 2  is a section view along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view of the bracket of  FIG. 2 ; 
         FIG. 4  is a side view of the bracket of  FIG. 3 ; 
         FIG. 4A  is a side view, similar to that of  FIG. 4 , but showing the position of the spring clip as the rigid panel is being installed; 
         FIG. 5  is a perspective view of an alternative bracket; and 
         FIG. 6  is a side view of the bracket of  FIG. 5 . 
     
    
    
     DESCRIPTION 
       FIGS. 1 ,  1 A and  2  show a roof structure on a building  10 . The building  10  includes a roof sheathing  12  (in this case made of plywood) covered with shingles  13 , supported on a plurality of parallel wooden rafters  14  which extend from the peak  16  to the eave  18 . The peak  16  includes a ridge vent  20 , and the eave  18  includes an eave vent  22 . Above the ceiling  24  and below the roof sheathing  12  is the attic space  26 . Insulation batts  28  are placed between the rafters  14  to insulate between the attic space  26  and the roof sheathing  12 . A ventilation gap  30  is provided between the roof sheathing  12  and the insulation  28 , which provides a natural circulation of air in the direction of the arrows of  FIG. 1 , with cooler air being drawn up through the eave vents  22 , along the flow path created by the ventilation gap  30 , and out through the ridge vent  20  at the peak  16 . The ventilation gap and air flow remove moisture and improve the efficiency of the insulation  28 . (While a ridge vent  20  is shown here, an alternative arrangement could use a roof vent instead.) 
     To ensure that the ventilation gap  30  is maintained, rigid panels  32  are mounted between the rafters  14  by means of brackets  34 , which maintain the spacing between the rigid panels  32  and the roof sheathing  12 . The rigid panels  32  preferably are made of an insulating material, such as polystyrene or polyurethane foam board. (If the rigid panels  32  provide sufficient insulation themselves, or if the goal is just to provide a flow path for venting hot air, the additional layer of insulation  28  may not be needed.) In addition to being supported by the brackets  34 , the ventilation gap is maintained by spacers  36  mounted onto the top of the panels  32  midway between the brackets  34  to prevent any unwanted upward bending of the panels  32  into the ventilation gap  30  between the brackets  34 . While this embodiment uses just a single spacer  36  in the center of each rigid panel  32 , the number and location of the spacers  36  may be arranged as needed to provide sufficient support. In some cases, no spacers would be needed. After the rigid insulating panels  32  are installed, the additional insulation  28  may then be installed below the panels  32 , as needed, as shown in  FIG. 2 . In this embodiment, the insulation batts  28  are made of a fiberglass blanket and include a facing  29  that is stapled to the rafters  14  to secure the insulation batts  28  to the rafters  14 . 
     In  FIG. 2 , a left bracket  34 L is mounted on a left rafter  14 L, and a right bracket  34 R is mounted on a right rafter  14 R directly opposite the left bracket  34 L. (The arrangement of the brackets  34  on the rafters  14  in this embodiment can be seen best in  FIG. 1A . It is understood that the number and arrangement of brackets  34  may be selected as needed to support the rigid panels  32 . For example, if the brackets  34  are wide enough, a single pair of left and right brackets  34 L,  34 R could be used to support the ends of two adjacent rigid panels  32 , thus reducing the number of brackets needed.) The rear of the left bracket  34 L abuts the left rafter  14 L, and the rear of the right bracket  34 R abuts the right rafter  14 R. In this embodiment, the left and right brackets  34 L and  34 R are identical to each other and are described below, generically, as bracket  34 . 
       FIGS. 3 ,  4 , and  4 A show the bracket  34  in more detail. The bracket  34  includes a flat, vertical plate  48 , the rear surface of which mounts against the flat face of the respective rafter  14 . A flat, horizontal projection  42  projects forwardly from the vertical plate  48  and serves as an upper stop for the rigid panel  32 . Two spacer legs  38 ,  40  on the vertical plate  48  project upwardly to a higher elevation than the horizontal projection  42  and terminate at free ends  44 , which abut the bottom surface of the roof sheathing  12 , as shown in  FIG. 2 . The free ends  44  lie at a first elevation, and the horizontal projection  42  lies at a second elevation, lower than the first elevation. The vertical distance between the first and second elevations defines the ventilation gap  30 . 
     First and second spikes  50  project rearwardly from the vertical plate  48  and are used to mount the brackets  34  onto the rafters  14 . In this embodiment, both the upper stop  42  and the spikes  50  are stamped out of the plate  48  and are bent in their respective directions, with the upper stop  42  projecting forwardly and the spikes  50  projecting rearwardly. The spikes  50  have a triangular profile, ending in a sharp point  52 , so they may be easily driven into the rafter  14 , as by hammering, to secure the bracket  34  to the rafter  14 , as shown in  FIG. 2 . The spacer legs  38 ,  40  also define small through openings  62  so nails may be driven through the openings  62  to secure the bracket  34  to a rafter  14  in addition to using the spikes  50 , if desired. 
     The bracket  34  further includes a spring clip  54  extending upwardly and forwardly from the bottom edge of the bracket  34  and having a free end  56  that lies at a third elevation, below the elevation of the upper stop  42 . In this embodiment, the spring clip  54  lies directly below the upper stop  42  and has an arcuate profile. Once the rigid panel  32  is installed on the brackets  34 , the spring clip  54  defines a lower stop for the rigid panel  32 , as shown in  FIG. 2 . In this particular embodiment, the spring clip  54  is stamped and formed from a sheet metal material at the same time as the upper stop  42  and spikes  50  also are being stamped and formed from the same sheet metal material. Alternatively, any of the spring clip  54 , spikes  50 , and upper stop  42  may be a separate piece that is secured to the plate  48  by means such as crimping, welding, or riveting. 
     The spring clip  54  is biased toward the extended position shown in  FIG. 4  (which is also shown in phantom lines in  FIG. 4A ). It is movable to a retracted position (shown in solid lines in  FIG. 4A ) to allow the rigid panel  32  to be pushed upwardly, past the spring clip  54 . 
     As shown in  FIG. 2 , when the brackets  34  are mounted on the rafters  14 , the left bracket  34 L defines a rightwardly-extending upper stop  42 , and the right bracket  34 R defines a leftwardly-extending upper stop  42 . The left-to-right distance between the right-most edge of the left upper stop  42  and the left-most edge of the right upper stop  42  is designated X. This left-to-right distance X between the upper stops  42  is less than the left-to-right width W of the rectangular rigid panel  32 . The left-to-right distance between the spring clips  54  in the extended position also is less than the left-to-right width W of the rigid panel  32 . Since the width W of the rigid panel  32  is greater than the left-to-right space between the upper stops  42  and greater than the left-to-right space between the lower stops  54 , once the rigid panel  32  is installed on the brackets  34 , the rigid panel  32  is trapped between the upper stops  42  and the lower stops  54 . 
       FIG. 2  also shows an intermediate spacer  36  which includes a short nail or pin  58  which is pressed into the top surface of the rigid panel  32 . 
     Installation: 
     First, the left and right brackets  34 L,  34 R are installed on the left and right rafters  14 L,  14 R, respectively, by aligning the back of the flat plate  48  with the surface of the rafter onto which it is to be installed and abutting the top edges  44  of the spacer legs  38 ,  40  with the underside of the roof sheathing  12  and then hammering against the front of the plate  48  to drive the spikes  50  into the respective rafter  14 . If desired, nails also may be driven through the openings  62  to further secure the brackets to the rafters. In this embodiment, the left and right brackets  34 L,  34 R are installed directly opposite each other as shown in  FIGS. 1A and 2 , and at intervals along the rafters, so that each rigid panel  32  is supported by at least two left brackets  34 L and two right brackets  34 R. In this embodiment, all the brackets  34  are identical to each other. 
     Once the brackets  34 L,  34 R are installed on the rafters  14 L,  14 R, respectively, the intermediate spacers  36  are installed onto the rigid panels  32  by pressing the pin  58  of each spacer  36  downwardly into the top surface of the rigid panel  32 . 
     The rigid panels  32  then are installed onto the brackets  34  by orienting the rigid panel  32  so that it lies parallel to the roof sheathing  12  and pushing each rigid panel  32  upwardly toward the roof sheathing  12 , as shown in  FIG. 4 , until the rigid panel  32  contacts the spring clips  54  of the respective brackets  34 . The rigid panel  32  is then pushed further upwardly, causing the spring clips  54  to retract against their spring bias to the position shown in  FIG. 4A , until the rigid panel  32  clears the spring clips  54 , and the spring clips  54  then spring back to their extended position (shown in phantom in  FIG. 4A ). The rigid panel  32  is then released, and then is supported on top of the spring clips  54 , which also serve as bottom stops. The rigid panel  32  then is trapped between the respective upper stops  42  and lower stops  54  of the left and right brackets  34 L,  34 R, as shown in  FIG. 2 . The upper stops  42  (and the intermediate spacers  36 ) ensure that the ventilation gap  30  is maintained between the roof sheathing  12  and the rigid panel  32 . 
     Once the rigid panel  32  has been mounted between the rafters  14 , insulation  28  (such as batts of insulation) may be installed between the rafters  14  below the rigid panel  32 , as shown in  FIG. 2 . Even if the installer pushes the insulation  28  up against the rigid panel  32  enough to displace the rigid panel  32  upwardly, he knows the rigid panel  32  will be stopped by the upper stops  42  (and by the intermediate spacers  36 ), so the ventilation gap  30  will be preserved. 
       FIGS. 5 and 6  show an alternative embodiment of a bracket  34 * that may be used instead of the bracket  34 . This alternative bracket  34 * is similar to the first bracket  34  described above in that it includes an upper stop  42 *, spacer legs  38 *,  40 * and bendable tabs  54 *, which serve as lower stops. The spacer legs  38 *,  40 * also define spikes  50 * which the user may drive with a hammer to secure the bracket  34 * to the rafters  14 . 
     The bendable tabs  54 * are initially in a retracted position, coplanar with the flat, vertical plate  48 * of the bracket  34 *, as shown in solid lines in  FIGS. 5 and 6 , and they are bent forward to the position shown in phantom in  FIG. 5 , in order to serve as lower stops for the rigid panel  32 . 
     Installation: 
     First, the brackets  34 * are secured to the rafters  14 R,  14 L, with the free ends  44 * of the spacer legs  38 *  40 * abutting the bottom surface of the roof sheathing  12 , by using a hammer to drive the bent back projections  50 * into the rafters  14 . Nails may be driven through the openings  62 * and into the rafters  14  instead of or in addition to using the projections  50 *, as desired. The rigid panel  32  then is pushed upwardly against the upper stop  42 * of the brackets  34 *. As the rigid panel  32  is held in that position by the installer, he bends one or both of the tabs  54 * on each bracket  34 * to the extended position shown in phantom in  FIGS. 5 and 6 , and then releases the rigid panel  32  which will be trapped between the upper stops  42 * and the tabs  54 *, which serve as lower stops.  FIG. 5  shows the tabs  54 * bent forward until each tab  54 * is substantially perpendicular to the flat plate  48 *. However, the tabs  54 * may be bent any desired amount by the installer, from a few degrees to the full 90 degrees shown in  FIG. 5 , or even more, as long as at least one of the tabs  54 * on each bracket  34 * projects far enough forward that it will support the rigid panel  32 . 
     It may be appreciated that the distance d* (see  FIG. 6 ) between the bottom surface of the upper stop  42 * and the top edge of the tab  54 * is slightly greater than the thickness of the rigid panel  32 , although it could be substantially greater, if desired. In the first embodiment, the distance d between the top of the bottom stop  54  and the bottom of the upper stop  42  is substantially greater than the thickness of the rigid panel  32 , as shown in  FIG. 4 , in order to provide enough room for the lower stop  54  to deform to its retracted position and for the rigid panel  32  to move upwardly beyond the lower stop  54  until the lower stop  54  springs back to its extended position. 
     With either embodiment of the bracket  34 ,  34 *, the installation of the rigid panel  32  involves moving the lower stops  54  or  54 * from a retracted position (which allows the rigid panel  32  to get past the lower stop) to an extended position which will then support the rigid panel  32  once the rigid panel  32  is released by the installer. 
     This second embodiment also may use the intermediate spacers  36  discussed earlier to provide additional support, preferably at locations midway between the brackets  34 *. The rigid panel  32  may be made of an insulating material. As discussed with respect to the first embodiment of the bracket  34 , once the rigid panel  32  installation is complete, insulation  28  may be added between the rafters  14  below the rigid panel  32 . 
     While the embodiments described above show brackets  34 ,  34 *, which are intended to be stamped out of sheet metal, it is understood that various other designs, materials, and manufacturing methods could be used. For instance, the brackets may have one or more spacer legs, one or more upper stops, and one or more lower stops. They may be stamped out of metal, injection molded, or made using other known methods. 
     While these embodiments use the same bracket design throughout a given installation, it would be possible to use different bracket designs within a given installation, and it would be possible for only the lower stops on one side of the rigid panel  32  to be movable between an extended position and a retracted position and for the lower stop on the other side of the rigid panel  32  to be non-movable. In that case, one edge of the rigid panel  32  would first be inserted between the upper and lower stops on the side with the non-movable brackets, and then the opposite edge of the rigid panel  32  would be tilted upwardly to move past the movable lower stops on that side, and then the movable lower stops on that side would be moved to the extended position to hold the rigid panel  32  in place. 
     Also, while the rigid panels  32  shown here were installed between rafters and with a ventilation gap between the rigid panels  32  and a roof, they could be installed between other parallel boards, which for the purposes of the claims, will also be considered to be rafters, so that pushing the rigid panel  32  upwardly means pushing in the direction from the lower stop toward the upper stop regardless of the orientation of the bracket, and with a ventilation gap between the rigid panels  32  and another flat structure of the building that lies parallel to the rigid panels  32 . It will be obvious to those skilled in the art that various other modifications may be made to the embodiments described above without departing from the scope of the present invention as claimed.

Summary:
A method and a device for installing a rigid panel parallel to a flat building structure and between rafters while providing a ventilation gap between the rigid panel and the flat building structure.