Patent Publication Number: US-6216416-B1

Title: Metal roof installation system

Description:
TECHNICAL FIELD 
     This invention relates to the field of metal roofs. More specifically, the present invention relates to a system for safely installing a metal roof on a structure by providing a continuous walking support for workers performing the installation. 
     BACKGROUND ART 
     In the field of roofing, and especially in the field of installing metal roofing, it is well known that safety issues are of great concern. Metal roof systems are well known in the art, as are their methods of installation. Each different roof system requires particular steps in connecting individual roofing panels to each other and to roof trusses. However, all metal roof systems have many basic similarities. For example, it is well known that a metal roof construction includes a number of roof trusses disposed in parallel fashion, and at progressively increasing elevations to define a slope. The slope may be defined either from one side of the roof to the other, or from both sides of the roof toward the center, depending upon the particular structure. Roof trusses in conventional roofs may be any conventional material and configuration. 
     Roof panels are then laid across the roof trusses in the direction of the slope, and at a right angle with respect to the direction of the roof trusses. The individual roof panels are placed from the bottom of the slope to the top, with each successive panel overlapping the last in order to prevent moisture from seeping between. A sealant may be used to further effect a moisture-tight seal. Adjacent roof panels are typically provided with an engagement mechanism to secure the panels together in a sealed disposition After the roof panels are positioned as desired, they are fastened to the roof trusses. However, it is common to position a layer of insulation on top of the roof trusses prior to placing and securing the roof panels. Thus, after the insulation is in place, and before the roof panels are positioned, the insulation is merely laying on the roof trusses. Because there is typically no decking between the insulation and the roof trusses, the insulation provides no support for carrying a load. 
     Due to the placement of the insulation, there have been roof installers who have had a false sense of security in the insulation and, without thinking, have placed all of their weight on the insulation and have thus fallen through to the ground. If there is nothing between the insulation and the ground to break their fall, they will fall on what is typically a concrete floor, thus causing extensive physical damage, and in some cases, death. Accordingly, in an environment such as the installation of a metal roof in the manner described, safety precautions are required. 
     Other systems have been developed to assist in the installation of a metal roof as described. Typical of the art are those described in U.S. Pat. Nos. 5,551,203 and 5,561,959, both issued to R. J. Alderman, et al. As described by the assignee of these patents, Owens Corning, the system described in the &#39;203 and &#39;959 patents, marketed by Owens Corning as at the “Elaminator System”, is designed to provide safety solutions for laminators and builders, as well as cost- and time-effective methods to improve thermal performance. The &#39;203/&#39;959 system includes a carriage which is urged along the purlins of the roof structure. A roll of insulation is mounted to the carriage and dispenses a substantially continuous sheet of blanket insulation material over the purlins as the carriage is progressively moved along the length of the purlins. A radiant barrier dispenser dispenses a layer of radiant barrier material over the dispensed blanket insulation material and a cross-wise layer of insulation is applied across the length of the purlins in a direction normal to the direction of application of the blanket insulation material. Thereafter, sheets of hard metal roofing material are attached to the purlins over the cross insulation to form the insulated roof structure. The radiant barrier material is configured to be received between the purlins, and cannot provide a load bearing surface. Specifically, the &#39;203/&#39;959 system does not provide for the safety of a roofer who may place his weight on the insulation layer, whether intentionally or by accident. 
     An improvement to the &#39;203/&#39;959 system is the “PERFECT R system marketed by CGI/Silvercote, Inc. The PERFECT R insulation system is provided for applying metal building insulation to pre-engineered buildings using a vapor retarder machine which attaches the facing to the top of the roof purlins, trusses or joists. The PERFECT R insulation system, as described by CGI/Silvercote, is designed to provide a cleaner appearance on the interior of metal buildings and to fiicilitate speed and ease during the installation of insulation, as compared to the &#39;203/&#39;959 system described above. The PERFECT R insulation system includes two tape dispensers that apply two-sided tape to the facing as the machines are manually advanced down the length of the building by a push rod. The machines simultaneously dispense and position the facing to a preset depth as they are moved. However, the PERFECT R insulation system does not include a means for supporting the weight of a worker on the insulation. Specifically, the system is described as providing a finished roof area from which to work, once the first roof panels are installed. Further, the PERFECT R insulation system, while claiming to provide a safer work environment, specifically disclaims the use thereof as a fall protection device. One device that is provided as a fall protection device is that disclosed by R. H. Van Auken, et. al., in U.S. Pat. No. 5,251,415. The &#39;415 device is a nonmetallic mesh that is stretched across the entire area of the roof and secured at the periphery of the roof The mesh is placed loosely over the purlins in order to accommodate the placement of insulation. The mesh has sufficient strength to protect workers installing the roof in the event of an accident. However, the &#39;415 device does not provide a surface on which the workers may walk during installation of the roof Further, due to the nature of the mesh material, while workers may be prevented from falling as a result of an accident, it does not prevent items such as tools, nails, and the like from falling through the openings in the mesh. Further, because the mesh is placed permanently as a component of the roof system, it may not be removed and reused, thus elevating the cost of installing the roof system. 
     Therefore, it is an object of this invention to provide a system for installing a metal roof system including an insulation layer placed over a series of purlins and under a metal deck while also providing a means for preventing workers from falling through the insulation. Another object of the present invention is to provide such a system whereby a working deck is provided for supporting insulation prior to securement of a section of metal decking. 
     Still another object of the present invention is to provide such a system whereby the working deck is moved along the purlins as the roof is being installed. 
     Yet another object of the present invention is to provide such a system whereby a material handling device is provided proximate the working deck such that time and energy dedicated to moving metal roofing materials is greatly reduced when compared to conventional alternatives. 
     DISCLOSURE OF THE INVENTION 
     Other objects and advantages will be accomplished by the present invention which is provided for installing a metal roof system including an insulation layer placed over a series of purlins and under a metal deck while also providing a means for preventing workers from falling through the insulation. The system is primarily comprised of a material handling assembly and a working deck. The working deck is mounted along one side to the material handling assembly. Each of the material handling assembly and the working deck of the preferred embodiment is configured to extend the entire length of the roof. 
     The material handling assembly includes at least one conveyor segment positioned across the purlins. Each conveyor segment is comprised of a rectangular flame in which is disposed a series of rollers. The rollers are disposed in parallel fashion relative to each other and in a lateral direction with respect to the frame. A roller assembly is secured to the conveyor segments at each purlin in order to accomplish lateral movement of the system as the roof installation process progresses. At least one winch is mounted to the material handling assembly. A winch cable is extended from each winch and secured to the far end of the building. When it is desired to move the system toward the far end of the building in order to secure a roof panel, each winch is actuated to retract the winch cable. 
     The working deck is secured along a leading edge to each roller assembly using conventional bolts. The working deck is fabricated from a corrugated metal such as to withstand the weight of several roofers, as well as materials and other equipment necessary to the installation of a metal roof system. 
     A safety cable or hand rail is provided on the leading edge of the material handling assembly to serve as a fall barrier. The safety cable is tautly stretched between each of two end frames, and supported by at least one intermediate support. After a sufficient number of roof panels have been secured to the purlins, a retractable handrail and skid assembly is employed on each end of the trailing edge of the roof A first portion of the retractable handrail is mounted to each end of the trailing edge of the material handling assembly and a skid—on which a second portion of the retractable handrail is mounted—is positioned at each end of the trailing edge of the roof. A restraint is positioned between the first portion of the retractable handrail and the end frame in order to allow passage of workers, while also providing a fall restraint when in place. 
     The roller assembly includes a frame having opposing end members mounted on the terminal ends of two side walls. A plurality of rollers is journalled in parallel fashion between the side walls such that the roller assembly is free to roll along its longitudinal axis. Each end member defines an extended portion extending upwardly above the side walls. The side walls define a length greater than the width of the conveyor segment such that a conveyor segment is receivable between the end wall extended portions. The end wall extended portions define threaded openings for receiving cooperating bolts therein, the bolts being tightened to engage the opposing side walls of the conveyor segment. Once tightened, the relative positions of the conveyor segment and the roller assembly are fixed. 
     The side walls of the roller assembly in one embodiment terminate at an elevation above the bottom extent of the rollers. In an alternate embodiment, the side walls terminate below the bottom extent of the rollers in order to limit lateral movement of the roller assembly relative to the purlins, thereby preventing the conveyor segment mounted thereon from moving along its longitudinal axis. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: 
     FIG. 1 is a perspective view of the metal roof installation system constructed in accordance with several features of the present invention showing an initial step in the installation of a metal roof system; 
     FIG. 2 is a perspective view of the metal roof installation system of FIG. 1 showing two roof panels in place for securement to the roof; 
     FIG. 3 is a perspective view of the metal roof installation system of FIG. 2 showing the two roof panels secured to the roof and the roof installation system having been moved to repeat the roof installation process; 
     FIG. 4 is an end elevation view of the metal roof installation system illustrating the various components of the present invention; 
     FIG. 5 is a perspective view of the roller assembly used in association with the present invention; 
     FIG. 6 is a top plan view of a portion of the present invention illustrating the fastening of two conveyor segments thereof; 
     FIG. 7 illustrates, in section, a side elevation view of the roller assembly and conveyor segment of the present invention; 
     FIG. 7A illustrates, in section, a side elevation view of an alternate embodiment of the roller assembly and conveyor segment of the present invention; and 
     FIG. 8 illustrates a top plan view of the metal roof installation system of the present invention showing more clearly the handrail and warning line system used in association therewith. 
    
    
     BEST MODE FOR CARRRYING OUT THE INVENTION 
     A metal roof installation system incorporating various features of the present invention is illustrated generally at  10  in the figures. The metal roof installation system, or system  10 , is designed for installing a metal roof system  70  including an insulation layer  72  placed over a series of purlins  76  and under a metal deck  74  while also providing a means for preventing workers from falling through the insulation  72 . The system provides a working deck  42  for supporting the insulation  72  prior to the securement of a section of metal decking  74 , the working deck  42  being moved along the purlins  76  as the roof  70  is being installed, and particularly, the working deck  42  remaining under the insulation  72  until a roof panel  74  is in place and ready for securement to the purlins  76 . Moreover, the system  10  of the present invention is provided with a material handling assembly  12  proximate the working deck  42  for quickly and efficiently moving roofing materials. 
     Referring to FIG. 1, the system  10  of the present invention is primarily comprised of a material handling assembly  12  and a working deck  42 . The working deck  42  is mounted along its leading edge  44  to the material handling assembly  12 . Each of the material handling assembly  12  and the working deck  42  of the preferred embodiment is configured to extend the entire length of the roof. Although not shown, for a roof defining two sloped portions, with a peak disposed at a point between two sides, each sloped portion is roofed independently of the other. Accordingly, in that situation, the system  10  of the present invention is configured to extend between an edge of the roof and the peak. Illustrated for use in association with the system  10  of the present invention is a handrail and warning line system  56  for placement generally around the periphery of the roof It will be understood that such safety precautions, as set forth in standard safety codes, such as OSHA, are used in association with the present invention for the protection of workers on the roof. 
     FIGS. 1-3 illustrate briefly the process of installing a metal roof system  70  using the system  10  of the present invention. In FIG. 1, insulation  72  is being rolled along the entire length of the working deck  42 . As will be disclosed below, the working deck  42  is designed to support the weight of any roofers that may be standing thereon. Because the insulation  72  that is exposed is being supported by the working deck  42 , any roofer who steps on the insulation  72  is supported by the working deck  42 . Also illustrated in FIG. 1 is at least one roof panel  74  disposed on the material handling assembly  12 . FIG. 2 illustrates the next step of placing the roof panels  74  in place for securement to the roof In order to secure the roof panels  74 , however, the working deck  42  must be moved out from under the insulation  72 . Therefore, as illustrated in FIG. 3, the material handling assembly  12  and working deck  42  have been moved until the trailing edge  46  of the working deck  42  is positioned to allow the securement of the last roof panel  74  to the underlying purlins  76 . After the first roof panel  74  is secured to the roof, each subsequent roof panel  74  in a conventional roof system  70  is secured to the previous roof panel  74  such that when the system  10  of the present invention is moved, the unsecured roof panel  74  will remain substantially in place while preparations are made for the securement thereof to the roof Thus, while the roof panel  74  is briefly unsecured to the roof and unsupported by the system  10  of the present invention, risk of accidental falls through the insulation  72  is minimal. 
     Referring now to FIG. 4, which is an end elevation view of the system  10 , the individual components of the present invention are more clearly illustrated and understood. The material handling assembly  12  includes at least one conveyor segment  14  positioned across the purlins  76 . As better illustrated in FIG. 6, each conveyor segment  14  is comprised of a rectangular frame  16  in which is disposed a series of rollers  22 . The rollers  22  are disposed in parallel fashion relative to each other and in a lateral direction with respect to the frame  16 , such that as particular roofing materials or equipment are needed, they are fed onto the first conveyor segment  14 , disposed at the edge of the roof, and then rolled up to a desired location on the roof. For example, as roof panels  74  are needed, they are loaded onto the material handling assembly  12 , rolled to the desired location, and then simply pulled off of the material handling assembly  12  and placed over the insulation  72  that has been positioned. 
     A roller assembly  24  is secured to the conveyor segments  14  at each purlin  76  in order to accomplish lateral movement of the system  10  as the roof installation process progresses. In order to accomplish such lateral movement, at least one winch  52  is mounted to the material handling assembly  12  in a conventional manner. A winch cable  54  is extended and secured to the far end of the building. When it is desired to move the system  10  toward the far end of the building in order to secure a roof panel  74 , each winch  52  is actuated to retract a length of the winch cable  54  equal to the width of the roof panel  74 . 
     The working deck  42  is secured along a leading edge  44  to the trailing edge  18  of the material handling assembly  12  in a conventional manner. In the preferred embodiment, the working deck  42  is releasably secured to each roller assembly  24  using conventional bolts (not shown), as will be described in greater detail below. However, to this end, the leading edge  44  of the working deck  42  defines a series of through openings  48  provided for receiving a conventional bolt  50  also received by a through opening  34  defined in each roller assembly  24 . In the preferred embodiment, the working deck  42  is fabricated from a corrugated metal such as to withstand the weight of several roofers, as well as materials and other equipment necessary to the installation of a metal roof system  70 . 
     The handrail and warning line system  56  is mounted to the material handling assembly  12 . Referring to FIGS. 1 and 2, in the illustrated embodiment, end frames  58  are mounted to the leading edge  19  of the material handling assembly  12 . Intermediate supports  59  are likewise mounted to the leading edge  19  of the material handling assembly  12  at appropriate distances between the end frames  58 . A safety cable  60  is tautly stretched between each of the end frames  58 , and supported by each intermediate support  59 . In the preferred embodiment, two such safety cables  60  are employed, with one at the top of the end frames  58  and intermediate supports  59 , and one disposed at an intermediate height. It will be understood that, although not shown, the safety cables  60  illustrated may be replaced with handrail as well. 
     Referring now to FIG. 3, after a sufficient number of roof panels  74  have been secured to the purlins  76 , a retractable handrail  62  and skid  65  assembly is employed on each end of the trailing edge of the roof  70 . Specifically, a first portion  63  of the retractable handrail  62  is mounted to each end of the trailing edge  18  of the material handling assembly  12  and a skid  65 —on which a second portion  64  of the retractable handrail  62  is mounted—is positioned at each end of the trailing edge of the roof  70 . Once the retractable handrails  62  are positioned, a restraint  61 , commonly referred to as a cattle gate, is positioned between the first portion  63  of the retractable handrail  62  and the end frame  58  in order to allow passage of workers, while also providing a fall restraint when in place. In the preferred embodiment the restraint  61  is a chain. 
     The first and second retractable handrail portions  63 , 64  are telescopically received one within the other, such that as the system  10  is moved along the roof by actuation of the winches  52 , the retractable handrail  62  is lengthened. The skid  65  is releasably secured to the roof such as by clamping the skid  65  to a seam formed by two roof panels  74  in a conventional manner. When the retractable handrail  62  is fully extended, prior to movement of the system  10 , the skids  65  are released from the roof  70  and moved until the retractable handrail  62  is fully retracted. The skids  65  are then secured to the roof  70  at their new position. Each skid  65  includes a handrail portion  71  disposed parallel to the trailing edge of the roof  70  and defining a length at least equal to the minimum set forth by OSHA for the distance from the edge of a roof  70  at which a warning cable  67  must be disposed. Currently, such length is six feet (6′). To this extent, as best illustrated in FIG. 8, a warning cable  67  is tied to the terminal end of the skid handrail  71 . The warning cable  67  is maintained on a spool  69  in the preferred embodiment and released as the skid  65  is moved along the roof  70 . In the illustrated embodiment, a warning cable  67  is provided for each side of the handrail and warning line system  56 . However, it will be understood that the warning cable  67  can be devised to employ a single warning cable  67 . Intermediate supports  68  are provided for holding the warning cable  67  at a prescribed height above the roof  70 . However, because the warning cable  67  is not to serve as a fall restraint, it is not maintained in a taut fashion. As the skids  65  are moved along the roof  70 , additional intermediate supports  68  may be required. 
     FIG. 4 further illustrates the process as described generally above. Illustrated are two roof panels  74 A secured in placed to the purlins  76 . Also illustrated is a two roof panel  74 B laid in place above insulation being supported by the working deck  42 . Further illustrated are several roof panels  74 C disposed upon the material handling assembly  12  and ready to be positioned above the insulation  72 . In the illustrated stage, because the roof panel  74 B is positioned over the insulation  72  and fastened to the roof panels  74 A, the system  10  is ready to be moved to a distance equal to the width of the roof panel  74 B such that it may be secured. The winch  52  is actuated to retract the winch cable  54 , thus drawing the winch  52 , and therefore the entire system  10 , away from the completed portion of the roof When the edge of the insulation  72  is reached by the roof panels  74 A, more insulation  72  is placed on the working deck  42  next to the insulation  72  illustrated, and the roof panels  74 C will be ready to be placed. 
     FIG. 5 illustrates a perspective view of the roller assembly  24  of the present invention. The roller assembly  24  includes a frame having opposing end members  26  mounted on the terminal ends of two side walls  36 . A plurality of rollers  40  is journalled in parallel fashion between the side walls  36  such that the roller assembly  24  is free to roll along its longitudinal axis. Each end member  26  defines an extended portion  28  extending upwardly above the side walls  36 . The side walls  36  define a length greater than the width of the conveyor segment  14  such that a conveyor segment  14  is receivable between the end wall extended portions  28 , the conveyor segment  14  resting on the roller assembly side walls  36  when so received. The end wall extended portions  28  define threaded openings  30  for receiving cooperating bolts  32  therein, the bolts  32  being tightened to engage the opposing side walls of the conveyor segment  14 . Once tightened, the relative positions of the conveyor segment  14  and the roller assembly  24  are fixed. It will be understood that other conventional devices may be used to mount the roller assembly  24  to the material handling assembly  12 . 
     As illustrated in FIG. 7, the side walls  36  of the roller assembly  24  in one embodiment terminate at an elevation above the bottom extent of the rollers  40 . In this embodiment, the length of the rollers  40  relative to the width of the purlins  76  is not critical, and the roller assembly  24  is thus free to move laterally with respect to the purlins  76 . An alternate embodiment as illustrated in FIG. 7A shows the side walls  36 ′ as terminating below the bottom extent of the rollers  40 . In this embodiment, the rollers  40  must define a length greater than the width of the purlin  76  such that the purlin  76  is received between the two side walls  36 ′. In this embodiment, lateral movement of the roller assembly  24  is limited, thereby preventing the conveyor segment  14  mounted thereon from moving along its longitudinal axis. In the preferred embodiment of the present invention, each of the roller assemblies  24 , 24 ′ are used in combination with each other. 
     Illustrated in FIG. 6 is a top plan view of two conveyor segments  14  secured in an end to end fashion. Each conveyor segment  14  defines opposing end walls  20  which, when two conveyor segments  14  are placed in an end to end fashion, are secured in a conventional manner such as by bolting. It will be understood that other conventional devices for releasably securing the conveyor segments  14  may be used as well. 
     In order to use the system  10  of the present invention, a conveyor segment  14  is placed across a plurality of purlins  76 , with a lower end of the conveyor segment  14  disposed at the edge of the roof At each purlin  76 , a roller assembly  24  is positioned under and mounted to the conveyor segment  14 . At least one roller assembly  24 ′ is used in the preferred embodiment to prevent the conveyor segment  14  from sliding across the purlins  76 . A segment of a working deck  42  is then mounted to at least two of the roller assemblies  24 . Subsequent conveyer segments  14  are mounted in an end to end fashion to define a continuous conveyor substantially equal to the length of the roof Also mounted to the conveyor segments  14  are the safety cord  56  and the winches  52 . For each winch  52 , the winch cable  54  is withdrawn and secured at a location proximate the far end of the roof After the system  10  has been installed, the first roll of insulation  72  is placed on the working deck  42 , and upon which is placed the first roof panels  74 . Thereafter, the roofing process continues as heretofore described. 
     From the foregoing description, it will be recognized by those skilled in the art that a metal roof installation system offering advantages over the prior art has been provided. Specifically, the system is provided for installing a metal roof system including an insulation layer placed over a series of purlins and under a metal deck while also providing a means for preventing workers from falling through the insulation. The system provides a working deck for supporting the insulation prior to the securement of a section of metal decking, the working deck being moved along the purlins as the roof is being installed, and particularly, the working deck remaining under the insulation until a roof panel is in place and ready for securement to the purlins. Moreover, the system of the present invention is provided with a material handling device proxinate the working deck for quickly and efficiently moving roofing materials. 
     While a preferred embodiment has been shown and described, it will be understood that it is not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and the scope of the invention as defined in the appended claims.