VENT PIPE CAP FOR METAL ROOF

Abstract

A roofing vent cap that is configured for use on a metal roof. The inventive vent cap includes a rib receiver designed to fit closely under a metal roof panel rib. Two lateral shoulders are provided to increase the footprint and internal volume of the hollow vent cap. These lateral shoulders allow the vent pipe to be laterally displaced from the roofing panel rib while the vent cap remains centered on the rib.

Claims

1. A vent cap for covering an opening in a metal roof panel having a first flat, a second flat, and an upstanding rib therebetween, comprising: (a) a hollow central portion including an opening; (b) a hollow first shoulder extending laterally from a first side of said central portion; (c) a hollow second shoulder extending laterally from a second side of said central portion; (d) a flange running around a lower portion of said central portion, said first shoulder, and said second shoulder; and (e) said flange including a rib receiver sized to fit over said upstanding rib of said metal roof panel.

2. The vent cap as recited in claim 1, further comprising an overhang above said opening.

3. The vent cap as recited in claim 1, wherein said rib receiver runs along a centerline of said vent cap.

4. The vent cap as recited in claim 1, wherein each of said first and second shoulders include a vertical portion and an angled portion.

5. The vent cap as recited in claim 1, wherein said central portion, said first shoulder, said second shoulder, said flange, and said rib receiver are made as an integral piece of molded polymer.

6. The vent cap as recited in claim 1, wherein said central portion, said first shoulder, said second shoulder, said flange, and said rib receiver are made as an assembly of multiple sheet metal pieces.

7. The vent cap as recited in claim 1, wherein: (a) said metal roof panel has multiple ribs and a standard distance between each of said ribs; (b) said vent cap has a centerline; and (c) said first shoulder extends a lateral distance from said rib receiver that is at least one-half said standard distance between each of said ribs.

8. A vent cap for covering an opening in a metal roof panel having a plurality of upstanding ribs with a standard distance therebetween, comprising: (a) a hollow central portion including an opening; (b) a hollow first shoulder extending laterally from a first side of said central portion; (c) a hollow second shoulder extending laterally from a second side of said central portion; (d) a flange running around a lower portion of said central portion, said first shoulder, and said second shoulder; and (e) said flange including a rib receiver sized to fit over one of said upstanding ribs of said metal roof panel.

9. The vent cap as recited in claim 8, further comprising an overhang above said opening.

10. The vent cap as recited in claim 8, wherein said rib receiver runs along a centerline of said vent cap.

11. The vent cap as recited in claim 8, wherein each of said first and second shoulders include a vertical portion and an angled portion.

12. The vent cap as recited in claim 8, wherein said central portion, said first shoulder, said second shoulder, said flange, and said rib receiver are made as an integral piece of molded polymer.

13. The vent cap as recited in claim 8, wherein said central portion, said first shoulder, said second shoulder, said flange, and said rib receiver are made as an assembly of multiple sheet metal pieces.

14. The vent cap as recited in claim 1, wherein said first shoulder extends a lateral distance from said rib receiver that is at least one-half said standard distance between each of said ribs.

15. A vent cap for covering an opening in a metal roof panel having a plurality of upstanding ribs with a standard distance therebetween, comprising: (a) a hollow body including a first lateral extreme, a second lateral extreme, and an opening; (b) a flange running around a lower portion of said hollow body; and (e) said flange including a rib receiver sized to fit over one of said upstanding ribs of said metal roof panel.

16. The vent cap as recited in claim 15, further comprising an overhang above said opening.

17. The vent cap as recited in claim 15, wherein said rib receiver runs along a centerline of said vent cap.

18. The vent cap as recited in claim 15, wherein each of said first and second lateral extremes include a vertical portion and an angled portion.

19. The vent cap as recited in claim 15, wherein said central portion, said first lateral extreme, said second lateral extreme, said flange, and said rib receiver are made as an integral piece of molded polymer.

20. The vent cap as recited in claim 15, wherein said central portion, said first lateral extreme, said second lateral extreme, said flange, and said rib receiver are made as an assembly of multiple sheet metal pieces.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0008] FIG. 1 is a perspective view, showing a prior art metal roof panel.

[0009] FIG. 2 is a perspective view, showing the prior art roof panel of FIG. 1 with a vent pipe installed.

[0010] FIG. 3 is a perspective view, showing a prior art sealing device placed around the vent pipe of FIG. 2.

[0011] FIG. 4 is a perspective view, showing an exemplary embodiment of the present invention installed on a roof panel.

[0012] FIG. 5 is a perspective view with a cutaway, showing interior details of the installation of FIG. 4.

[0013] FIG. 6 is an elevation view, showing interior details of the installation of FIG. 4.

[0014] FIG. 7 is an elevation view, showing interior details of the installation of FIG. 4.

[0015] FIG. 8 is an elevation view, showing interior details of the installation of FIG. 4.

[0016] FIG. 9 is a plan view, showing how the inventive vent cap sits on the roof panel.

[0017] FIG. 10 is a perspective view, showing an alternate embodiment of the inventive vent cap.

[0018] FIG. 11 is an elevation view, showing the embodiment of FIG. 10 with the addition of some explanatory dimensions.

[0019] FIG. 12 is a perspective view, showing an embodiment incorporating a flow directing feature on the up slope side.

[0020] FIG. 13 is a sectional elevation view, showing a variation for the rib receiver.

[0021] FIG. 14 is a sectional elevation view, showing another variation for the rib receiver.

[0022] FIG. 15 is a sectional elevation view, showing an alternate location for the vent opening.

[0023] FIG. 16 is a perspective view, showing how an embodiment of the present invention that is configured to be stacked for more efficient shipping and storage.

REFERENCE NUMERALS IN THE DRAWINGS

[0024] 10 metal roof panel [0025] 12 rib [0026] 14 rib [0027] 16 rib [0028] 18 flat [0029] 20 flat [0030] 22 opening [0031] 24 vent pipe [0032] 26 tapered boot [0033] 28 metal flange [0034] 29 vent cap [0035] 30 fastener [0036] 32 flange [0037] 34 rib receiver [0038] 36 opening [0039] 38 overhang [0040] 40 central portion [0041] 42 shoulder [0042] 44 shoulder [0043] 46 shoulder [0044] 48 shoulder [0045] 50 centerline [0046] 52 cricket [0047] 54 convoluted rib [0048] 56 rib receiver [0049] 58 butyl tape [0050] 60 standing seam rib [0051] 62 rib receiver [0052] 64 setback [0053] 66 drip rail [0054] 68 opening

DETAILED DESCRIPTION OF THE INVENTION

[0055] FIG. 2 depicts the problem to be addressed-a vent pipe 24 protruding through an opening 22 in a metal roof panel. FIG. 4 depicts an embodiment of the present invention installed over the vent pipe and opening. Vent cap 29 is a hollow structure configured to secure to the metal roof panel-including lying over one of the upstanding ribs.

[0056] The roof panel has a slope, though the slope is not great for the example shown. Downslope is the direction water travels under the influence of gravity as it travels off the roof panel. Upslope is the opposite direction. First and second lateral direction are orthogonal to the upslope/downslope directions.

[0057] Central portion 40 in this example is a hollow box structure with an open bottom that fits over the roof panel. Opening 36 is providedin this case on the downslope side of the vent. Overhang 38 is preferably provided to shield the opening and prevent the ingress of rain. Shoulder 42 extends laterally from a first side of central portion 40 and shoulder 44 extends from the opposite side. The two shoulders expand the interior volume of the hollow structure and provide additional room for possible misalignment of the vent pipeas will be explained.

[0058] Flange 32 extends outward from the lower portion of the hollow structure. Most of the flange is flat so that it can lay against the flats of the roof panel. However, rib receiver 34 is provided in the flange and adjacent structures in order to accommodate rib 14 of the roofing panel. The ribs on the roofing panel have standard dimensions. Rib receiver 34 is sized to fit snugly over the ribs of the roofing panel. The rib receiver runs all the way from the downslope to the upslope side of the vent cap-though not of course in the hollow central portion where no relief for the upstanding rib is needed. Only the downslope portion of the rib receiver is visible in FIG. 4.

[0059] FIG. 5 shows the same assembly with half of the vent cap cut away to reveal internal features. The reader will note how the rib receiver fits snugly over the upstanding rib. The reader will also note how central portion 40 easily accommodates the protruding vent pipe 24. The vent cap is preferably a thin-walled hollow structure so that the internal volume is maximized. Its internal dimensions are made large enough in the upslope/downslope directions to provide good clearance for the pipe and accommodate any installation errors. The internal dimensions are made even larger in the lateral directions.

[0060] FIG. 6 illustrates the advantage of providing more lateral internal volume. FIG. 6 is looking along the plane of the roof panel in the upslope direction. Vent pipe 24 is installed vertically, which causes it to appear tilted away from the viewer when looking along the plane of the sloping roof panel. The portion of the vent pipe protruding into the inventive vent cap is shown as a hidden line. Shoulder 42 extends away from central portion 40 in a first lateral direction and shoulder 44 extends away in a second lateral direction.

[0061] The vent cap functions well with the vent pipe located anywhere within the interior volume. No matter the location of the vent pipe, gasses escaping from the vent pipe will exit opening 36. However, extending the coverage of shoulders 42,44 allows a vent pipe that is farther and farther from the rib on which the inventive vent cap is mounted to be accommodated. In the example shown, rib receiver 34 is provided on the centerline of the inventive vent cap. The reader will appreciate that the vent cap can slide easily along the rib in the upslope/downslope direction, but it cannot move laterally because of the interface between rib receiver 34 and the rib on which the vent cap is mounted.

[0062] FIG. 7 shows a vent pipe 24 that is offset a greater distance from rib 14 than was the case in the example of FIG. 6. The presence of shoulder 42 accommodates this greater offset. FIG. 8 shows a lateral view of the same assemblywith the plane of the roof vent panel again being oriented horizontally (though it is of course sloped in the actual installation). Vent pipe 24 is again installed verticallybut appears at an angle because of the view being referenced to the roof panel. The portion of the vent pipe extending into vent cap 29 is again shown in hidden lines. The reader will note how adequate clearance is provided in the upslope/downslope directions. This clearance allows for installation errors.

[0063] FIG. 9 shows a plan view of the same installation-looking down on the plane of the roof panel. The reader will note how flange 32 runs entirely around the lower portion of the hollow structure. Centerline 50 is an axis running through the middle of this example. Rib receiver 34 in this example is provided along centerline 50.

[0064] Looking back at FIG. 7, the reader will note that-even with the presence of shoulders 42,44there is a limit to how much lateral displacement of vent pipe 24 from rib 14 can be accommodated. The inventive vent cap can only be placed upon a rib for lateral positioning. Thus, while one can lift it and move it over to the next ribthis will not always accommodate a large vent pipe such as shown in FIG. 7 that is laterally displaced too far from the rib on which the vent cap is mounted. Thus, it is desirable to provide an embodiment with additional lateral capacity.

[0065] FIG. 10 depicts such an embodiment. Shoulders 46,48 include a vertical portion extending up from flange 32 and a sloping portion that joins central portion 40. This version increases the lateral displacement of the vent pipe that can be accommodated within the interior volume. FIG. 11 illustrates this principle.

[0066] In the example of FIG. 11, vent pipe 24 has a diameter w. It is offset from rib 14 a distance x. The ribs on the roofing panel have a standard fixed pitch y (the distance from the center of one rib to the center of the next rib). The maximum displacement of the center of the vent pipe from any rib is therefore given by the expression:

x.sub.max=y/2

[0067] Shoulders 46,48 are offset from the centerline of the vent cap a distance z. In order to accommodate every possible lateral offset of the vent pipe, it is preferable to make z according to the following equation:

[00001]$z=\frac{y}{2}+\frac{w}{2}+t,$

where t is the thickness of the wall of the vent cap in the vicinity of the vent pipe. Using this expression as a guide for the vent cap dimensions ensures that you can fit the vent pipe within the vent cap at the current rib installation location (or move the vent cap over to the next rib and install it there).

[0068] Some additional explanation as to the installation of the vent cap is helpful. In the view of FIG. 4, the reader will note how flange 32 conforms to the shape of the flats and ribs of the roof panel. Fasteners 30 are installed through flange 32 and the roof panel. Holes can be provided in the flange to receive the fasteners. Alternatively, the flange can be made of a material that allows self-tapping or other fasteners to be driven through without the provision of pre-existing holes through the flange.

[0069] A seal between the flange and the roof panel is important, particularly on the upslope side. An adhesive or sealant can be applied to the underside of the flange before the vent cap it pressed down into position. The adhesive/sealant can even be applied as part of the manufacturing process and covered by a removable strip. The strip would be removed just prior to installation.

[0070] Compressible butyl tape is a particularly effective sealant. This substance has been used in the roofing industry for many years and its performance and endurance is well established. Double-sided butyl tape is preferably adhered to the downward-facing surfaces of the flange. The downward-facing surface of the butyl tape is then covered by a removable strip. The strip is left in place while the vent pipe cap is test fitted. When it is time to permanently install the cap, the strip is removed and the tape is pressed against the roofing panel. Securing screws can then be driven through the flange, the butyl tape, and the roofing panel. The screws are tightened to compress the tape and secure a good seal.

[0071] Alternatively, the vent cap can be screwed in place and the adhesive/sealant can be added after the mechanical installation is complete. The invention is not limited to any particular method of installation. Many other methods will occur to those skilled in the art.

[0072] The invention can assume many other forms incorporating desirable features in different combinations. FIG. 12 provides an alternate embodiment of the inventive vent cap. The vantage point is from the up slope side of the installation. In this embodiment, a flow-directing feature is provided to the up slope side of the vent cap. Cricket 52 divides the water flow coming down the roof and helps it split and flow around the vent cap without pooling against the uphill side of the vent cap. The vee shape is commonly called a cricket in the field of roofing. Many other shapes can be employed for the cricket, so long as they direct the water around the vent cap. The reader will note how flange 32 and rib receiver 24 conform to the shape of the cricket used.

[0073] The rib receiver provided in a particular embodiment is preferably shaped to fit closely over a particular type of rib. As those skilled in the art will know, many different rib types are used in roofing panels. FIGS. 13 and 14 provide sectional elevation views through two very different types of ribs. FIG. 13 shows convoluted rib 54. A corresponding rib receiver 56 is provided to approximate the shape of the convoluted rib. Butyl tape 58 is compressed between the rib receiver and the convoluted rib. The butyl tape is quite compressible-allowing it to accommodate some mismatch between the shape of the rib receiver and the shape of the convoluted rib.

[0074] FIG. 14 shows a rib created by a junction in a standing seam metal roof-designated as standing seam rib 60. Rib receiver 62 is provided to conform to the shape of the standing seam rib. Butyl tape is again provided. The reader will note how a very different shape of the rib receiver is provided in FIG. 14 as compared to the example of FIG. 13. Many different shapes for the rib receiver can be provided and the invention is not limited to any particular shape.

[0075] FIG. 15 shows a section view through another embodiment of the inventive vent cap. This embodiment features a more horizontally-oriented opening 68 (covered by screen or mesh), contained within setback 64. Drip rail 66 is provided so that even a hard rain will not tend to drip into the opening. Many other shapes and locations for these features are possible.

[0076] Most embodiments of the inventive vent cap will include thin walls surrounding a hollow interior. This results in the vent cap having a low overall density. Such bulky but light items are inefficient for shipping and storage. It is beneficial to provide an alternate design that can be nested and stacked-thereby increasing storage and shipping efficiency. FIG. 16 shows such an embodiment. The inventive vent caps 29 shown include thin walls surrounding a hollow interior. All of the side walls are given a suitable draft angle so that they tilt inward when proceeding from bottom to top. Suitable fillet radii are preferably also provided on the corners. These features allow multiple instances of the vent cap 29 to be stacked as shown. The instances can be urged together until central portion 40 of the lower instance bears against setback 64 of the upper instance. Even deeper nesting can be provided by eliminating the use of setback 64.

[0077] Many other variations are possible for the inventive embodiments. As an example, the inventive vent pipe cap can be made with tapering sidewalls so that multiple instances of the invention can be stacked for storage and shipping. Metal versions can be provided using galvanized steel. Injection-molded plastic versions can be provided. Still other versions can be pressed from sheet molding compound.

[0078] The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Thus, the scope of the invention should be fixed by the claims ultimately drafted, rather than by the examples given.