Patent Publication Number: US-2004055233-A1

Title: Anchor attachment for a roof panel rib

Description:
BACKGROUND  
       [0001] 1. Field of the Invention  
       [0002] This invention relates to attachments for roof panels, and more specifically, to an anchor mountable to a roof panel rib, to which roof paraphernalia may be attached.  
       [0003] 2. Prior Art  
       [0004] Metal roof panels are in common usage. With such usage, it is often an advantage to attach equipment to the roof panel. For example, snow guards that control snow and ice sliding on the roof, cable guy wires, walking platforms, piping, signage, brackets, etc. It is important that such attachments not penetrate the roof panel so leaks are not introduced.  
       [0005] Metal roof panels are commonly joined with a raised portion on a first side overlapping a raised portion of an adjacent panel, together forming a roof panel rib raised above the general roof panels. In addition, some metal roof panels have an intermediate rib between the overlapping adjacent panel ribs. The panels are installed with the roof panel ribs running with the roof pitch, so an attachment anchor clamped on the rib can be positioned essentially anywhere on the roof, either laterally by choosing an appropriate rib and vertically along the pitch.  
       [0006] Because the attached paraphernalia may constitute a significant load on the anchor, such as a large sign or a snowfall collection, the anchor attachment must be able to sustain such loads without sliding on or disengaging from the roof panel rib. To prevent sliding and still not penetrate the roof panel, the anchor should have a friction or clamping attachment to the roof panel rib to allow the anchor to support the required loads. To achieve an attachment that can sustain loads of many hundreds of pounds, the anchor is clamped to the rib with a comparable force. To prevent disengagement from the roof panel rib, preferably the anchor should have structural features interconnecting with panel rib structural features that prevent lift-off regardless of friction.  
       [0007] A thin-walled roof panel rib is typically unable to sustain the clamping force required to keep the anchor from sliding on the roof panel rib without permanently deforming the roof panel rib. Once deformed, the roof panel rib is unable to readily come apart or go back together for roof panel replacement. The deformation disrupts the mechanism of the panel rib and is aesthetically displeasing. It is therefore also an advantage to have an anchor securable to a thin-walled metal roof panel at a roof panel rib without significantly deforming the roof panel rib or disrupting the panel interlock with the adjacent metal panel.  
       SUMMARY OF THE INVENTION  
       [0008] These objects are achieved in a roof anchor comprising a two opposing sides depending from an anchor top forming a channel adapted to fit over a roof panel rib. At least one attachment bolt is threaded into a hole in the anchor top for attaching roof paraphernalia to the anchor after the anchor is secured to the roof panel rib. Clearly, any similar attachment device may substitute for the attachment bolt and is deemed included in the anchor. Opposing bolts on each anchor side thread through matching threaded holes in anchor sides and into the channel, sandwiching a roof panel rib therebetween when it is received into the channel. In an equivalent alternative, bolts on a single anchor side may sandwich the roof panel rib between the bolts and the other anchor side with clamping force that prevents the anchor from sliding on the roof panel rib, even under load.  
       [0009] To prevent a roof panel rib from collapsing or suffering severe deformation under clamping force of the bolts, a rib bar typically shaped to functionally match the roof panel rib is inserted within the roof panel rib as a brace. When the anchor bolts tighten against the roof panel rib, the panel rib sides are sandwiched between the rib bar and the bolts, the bar then sustaining the clamping force and thereby maintaining the shape of the roof panel rib.  
       [0010] Typically, a roof panel rib comprises a head supported on a thinner neck. To prevent the anchor from lifting off the roof panel rib, the bolts are located on the anchor sides low in the anchor channel, sufficiently apart from the anchor top so that the roof panel rib head can be received between the bolts and the anchor top. The bolts then tighten into the roof panel rib at the roof panel rib neck. When the bolts are threaded into the channel under the head, the anchor is prevented from lifting off the roof panel rib, independent of the frictional clamping force that might be applied by the bolts against the neck. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011]FIG. 1 is a perspective cut-away view of the anchor mounted over a roof panel rib with a support bar within the rib sustaining the rib from collapse as bolts in the anchor tighten against the rib.  
     [0012]FIG. 2 is an end view of an anchor of the prior art shown with a tightening bolt high in the anchor channel collapsing a roof panel rib within the channel.  
     [0013]FIG. 3 is end view of another anchor of the prior art as in FIG. 2 collapsing a roof panel rib at the joinder of two roof panels.  
     [0014]FIG. 4 is an end view of the anchor of the present invention showing bolts low in the anchor channel and a support bar within a first rib shape functionally matching the rib shape to support the rib as the bolts tighten against the rib.  
     [0015]FIG. 5 is an end view of an anchor of the present invention showing a single bolt low in the channel intersecting a roof panel rib at a rib neck below a rib head at a joinder of two adjacent roof panels.  
     [0016]FIG. 6 is an end view of the anchor of FIG. 5 with a support bar within the rib as the anchor bolt tightens.  
     [0017]FIG. 7 is an end view of the anchor of FIG. 5 without a support bar within the rib with a bolt engaging the rib at the rib neck low in the channel, successfully sandwiching the neck between the bolt and an anchor side as the bolt tightens, flexure in the rib head allowing it to bend without permanent deformation.  
     [0018]FIG. 8 is a perspective view of the anchor of FIG. 5.  
     [0019]FIG. 9 is a perspective view of a support bar having a first shape to functionally match a first rib shape.  
     [0020]FIG. 10 is a perspective view of a support bar having a second shape to functionally match a second rib shape, shown with dimples for receiving bolt ends.  
     [0021]FIG. 11 is a perspective view of the support bar of FIG. 10 further comprising a side channel for receiving bolt ends.  
     [0022]FIG. 12 is an end view of an anchor with bolts low in the anchor channel, shown having opposing bolts sandwiching a roof panel rib at its rib neck centered below a cylindrical rib head with rib left and right members in face-to-face contact under pressure of the opposing bolts, the cylindrical rib head providing flexure allowing the rib members to come together without damage to the rib.  
     [0023]FIG. 13 is an end view of the anchor over a joinder of adjacent rib panels with a bolt from one anchor side sandwiching the rib neck against the opposing anchor side. With the neck comprising a left neck member from one roof panel in parallel alongside a right neck member from the other roof panel, the neck is not damaged as the anchor bolt tightens against the rib neck.  
     [0024]FIG. 14 is a perspective view of a building having roof panels with roof panel ribs to which a plurality of anchors are attached to secure a snow guard.  
     [0025]FIG. 15 is an end view of two roof panels joined at a center rib with anchors over roof panel ridges. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0026] A roof panel rib anchor  10  for attachment to a roof panel rib  100  of a roof panel  102  or panels comprises first and second opposing anchor sides  12  and  14  depending from an anchor top  16  forming a channel  18  within and sized to receive a roof panel rib in the channel. A fastener spaced apart from the anchor top  16  on a first anchor side  12  extends into the channel  18  directed toward the other anchor side  14  at least partially closes the channel  18 . Typically, the fastener comprises a threaded bolt  20  and more typically a plurality of threaded bolts penetrating at least a first anchor side  12  through matching threaded holes  22 . When tightened into the channel  18 , the bolts  20  releasably clamp the roof panel rib  100  securely between the bolt  20  and the second anchor side  14  with clamping force sufficient to prevent the anchor from sliding on the roof panel rib. When the bolts are on both anchor sides, they may be arranged in opposing pairs, with a bolt  20 ′ from the first side  12  directed to a bolt  20 ″ from the second side  14 .  
     [0027] Commonly, the anchor  10  includes an attachment mechanism to which other roof paraphernalia, such as a snow guard, may be attached. In the figures, an attachment bolt  5  is shown threaded into a hole  7  in the anchor top  16 . The attachment bolt  5  is then useful for connecting the anchor to such roof paraphernalia, for example, by passing the bolt through a paraphernalia bolt hole and then into the anchor threaded hole.  
     [0028] Typically, the roof panel rib  100  has a cavity, or channel,  104  between two rib walls  106 . To prevent collapse of the cavity  104  when clamping force is applied, a rib bar  24  suitably sized fits within the roof panel rib cavity  104  opposite the bolts  20 . The bar comprises an elongated body  25  with cross section shaped to approximately or at least functionally match said roof panel rib cavity or channel  104 , maintaining the shape and structural integrity of the roof panel rib  100  against forces of attachment of an anchor to the roof panel rib. The roof panel rib wall  106  is then sandwiched between the bolt  20  on its outside and the bar  24  on its inside and the roof panel rib is thus braced from collapse or substantial deformation. Clearly, the bar inserted in the roof panel rib is generally applicable to preventing roof panel rib collapse or deformation as a device is secured to it.  
     [0029] When the bolts  20  are applied to the roof panel rib  100  at a roof panel rib location  108  without a cavity opposite the bolts, or at a location allowing the roof panel rib at that location to close together without deformation, a bar  24  may not be necessary. This might occur where the roof panel rib comprises a roof panel rib neck  110  supporting a roof panel rib head  112  where the neck  110  with two opposing sides  114  and  116  is configured with those sides in face to face contact in which case the bolt  20  simply sandwiches the sides between another opposing bolt or an anchor side. If the neck  110  is configured with opposing neck sides  114  and  116  separated but supporting a head with flexure, the neck sides move together into face to face contact under action of the tightening bolt or bolts  20  as the head  112  flexes, still without collapse or deformation of the roof panel rib. If there is no flexure in the roof panel rib, a bar  24  is inserted between neck sides  114  and  116  to brace them to prevent damage to the roof panel rib head or neck.  
     [0030] When the neck  110  is smaller in cross section than the head  112 , the bolts  20  typically are located in the anchor sides  12  and  14  sufficiently apart from the anchor top  16  such that when a roof panel rib is received in the anchor  10 , the bolts  20  present opposite the roof panel rib neck  110  and undercut the roof panel rib head  112  when tightened into the channel at the roof panel rib neck  110  at least partially closing the channel  18  therein preventing it from passing out of the channel  18  .  
     [0031] Where the bar  24  is made of soft metal, tightening a bolt  20  into the bar  24  can create a dimple or depression  28  in the bar  24  or the bar may be constructed to include a depression to receive the bolt. In the alternative, a bar channel  29  may be provided longitudinal in at least one bar side to receive bolt ends. In either case, as the bolt  20  tightens the neck engages the rib bar depression  28  or shallow channel  29  under said clamping force of the bolt  20  to further securely engage the roof top.