Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D13/00—Special arrangements or devices in connection with roof coverings; Protection against birds; Roof drainage ; Sky-lights
  • E04D13/04—Roof drainage; Drainage fittings in flat roofs, balconies or the like
  • E04D13/0404—Drainage on the roof surface
  • E04D13/0409—Drainage outlets, e.g. gullies
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D13/00—Special arrangements or devices in connection with roof coverings; Protection against birds; Roof drainage ; Sky-lights
  • E04D13/04—Roof drainage; Drainage fittings in flat roofs, balconies or the like
  • E04D13/0404—Drainage on the roof surface
  • E04D13/0409—Drainage outlets, e.g. gullies
  • E04D2013/0427—Drainage outlets, e.g. gullies with means for controlling the flow in the outlet

Definitions

• the present invention relates to a roof drain comprising a bowl for building into a roof surface, said bowl having a top, a rim at the top, and a bottom; a central outlet opening in the bowl at the bottom thereof for connection with a drain pipe; a vertical axis extending through the central outlet opening; and a substantially flat cover superimposed on the bowl.
• a roof drain of the above art is known from US-A-3 469 698, which discloses several embodiments of a roof drain in all of which the cover comprises a central opening around which a circumferential, generally cylindrical wall is provided by elements that may be repositioned to provide inlets between.
• the inlets may be symmetric to provide a radial flow into the central opening or asymmetric to provide a vortex inducing action.
• the roof drains disclosed are relatively complicated constructions with many adjustable components. Further the general building height of the roof drain is relatively big with a corresponding large consumption of materials for the construction.
• US-A-5 524 393 discloses a roof drain comprising a vortex chamber placed on top of a flat roof.
• the roof drain including the vortex chamber may be arranged in a sump recessed in the roof surface.
• Roof drains of the above art are generally used to regulate the flow of rain water from flat roofs to utilise the roof surface as a storage for rain water in order to avoid that a downstream drainage system is overloaded in case of a heavy rainfall.
• the provision of a vortex of water in a vortex chamber or bowl of a drain provides a breaking action on the flow to restrict the same while providing for a relatively large cross-sectional area for the flow passage through the drain to avoid blockage by debris in the water.
• a grating such as a slotted dome over the drain.
• a roof drain comprising a bowl for building into a roof surface, said bowl having a top, a rim at the top, and a bottom; a central outlet opening in the bowl at the bottom thereof for connection with a drain pipe; a vertical axis extending through the central outlet opening; and a substantially flat cover superimposed on the bowl, wherein an asymmetric inlet is provided in the cover for directing water present on the roof surface into the bowl such as to provoke a swirling motion of the water inside the bowl around the axis, said asymmetric inlet opening being asymmetric relative to a plane defined by the central axis and a radial line in the cover through the central axis and the asymmetric inlet.
• the bowl has a conical portion extending downwards from the rim
• the cover comprises a sheet material
• the asymmetric inlet being provided by an incision having a first part extending along the rim and a second part extending from the rim towards a centre of the cover allowing a flap of the sheet material to be bent into or out of the bowl to provide the asymmetric inlet.
• the flap When bent out of the bowl, or even removed, the flap will leave an asymmetric inlet opening having a wide end and a narrow end in either circumferential direction that will provoke a swirling mo- tion of the water flowing through the inlet opening, but in an opposite direction compared to the situation when the flap is bent into the bowl.
• the sheet material is perforated along a line extending between distal ends of the incision. This facilitates the bending or re- moval of the flap of sheet material delimited by the incision.
• a number of asymmetric inlets are provided equi- distantly along the rim.
• a number of inlets may be provided to provide a flow characteristic wanted for the instance.
• an orifice member is provided below the cover in- side the bowl to provide a vortex chamber in the bowl between the cover and the orifice member, said orifice member having a central orifice providing an outlet from the vortex chamber.
• the flow characteristic may be further adjusted to provide a flow characteristic wanted for the instance since the size of the orifice influences the flow characteristic, which accordingly may be al- tered by providing an orifice member with an orifice of a different size.
• a pipe is extending downwards from the orifice member coaxially with the central orifice.
• Such pipe may under certain circumstances run full and provide a suction or siphon effect.
• the flow characteristic may be further adjusted to provide a flow characteristic wanted for the instance.
• the cover has an additional opening and an overflow pipe is extending upwards from said additional opening thereby providing an overflow inlet to the bowl at a higher level compared to the asymmetric inlet(s).
• the overall flow characteristic is further adjusted to provide a flow characteristic wanted for the instance due to the fact that a significantly larger flow is provided for when the level of water on the roof has reached the higher level.
• the additional opening and the overflow pipe will provide an emergency overflow to avoid an excess amount of water on the roof.
• the additional opening has a smaller diameter than the orifice.
• first and the second vertical axes are coincident.
• a perforated shielding member is provided above the cover. Hereby entry of large debris into the roof drain is avoided.
• the cover and, if present, the orifice member are exchangeable.
• a bowl of one embodiment and size a number of roof drains having different flow characteristics may be pro- vided.
• Fig. 1 shows a side view of a roof drain according to the present in- vention
• Fig. 2 shows a top plan view of the roof drain of Fig. 1 ;
• Fig. 3 shows a top plan view of the roof drain of Fig. 1 omitting a grating
• Fig. 4 shows an exploded sectional side view of the roof drain shown in Figs. 1 and 2 sectioned along line IV-IV indicated in Figs. 2 and 3;
• Fig. 4a shows part of Fig. 4 in a not in scale view showing more clearly details:
• Fig. 5 shows a top plan view of a bowl of the roof drain shown in Fig.
• Fig. 6 shows an orifice member
• Fig. 7 shows a sectional side view of a part of the roof drain of Fig. 1 with different insides, sectioned along line VII-VII in Fig. 8;
• Fig. 8 shows a top view of the roof drain of Fig. 7 omitting a grating.
• the drawings show an embodiment of a roof drain according to the invention comprising a bowl 1 and a cover member 3.
• the bowl is shaped as an inverted, stepped, truncated cone with an upper rim 5, a first conical portion 7 extending downwards from the rim 5 to a step 9, the function of which will be described below, and a lower, second conical portion 1 1 .
• the second conical portion 1 1 is truncated to provide a central outlet opening 13 at a bottom of the bowl, of a size appropriate to fit a drain pipe or a drain hose with which to roof drain is to be connected when installed at a given site.
• a cylindrical spout 15 for connection with such drain pipe or drain hose is attached to the second conical portion 1 1 around the central outlet opening 13.
• the rim 5 is provided with holes 17 for fasteners such as screws.
• the cover member 3 comprises as central cover portion 19 for covering the conical portions 7, 1 1 of the bowl 1 , and a flashing portion 21 surrounding the central cover portion 19 to seal between the bowl 1 and the roof covering of a roof in which the roof drain is installed.
• the central cover portion 19 provides a cover superimposed on the bowl 1 , when the cover member 3 and the bowl are assembled.
• the flashing portion 21 comprises holes 23 for insertion of fasteners, when installing the roof drain in a roof, and holes 25 for fasteners such as screws for fastening the cover member 3 to the bowl 1 .
• the cover member is in an embodiment made from a single piece of sheet material and in another embodiment the cover member is made from two different pieces of sheet material whereby the central cover portion 19 is made from one sheet material and the flashing portion 21 is made from another sheet material, which facilitates selecting respective materials suitable for the two portions.
• the central cover portion 19 comprises several openings for letting water into the drain.
• the central cover portion 19 has in the embodiment shown six incisions 29 each comprising a first part 31 extending along the rim 5 of the bowl, when the bowl and cover member are assembled, and a second part 33 extending towards the centre of cover member.
• the second parts of the incisions extend along radial lines extending from a vertical central axis 35 of the roof drain.
• Perforations 37 extend between distal ends 31 a, 33a of the re- spective first and second parts 31 , 33.
• the respective first and second parts 31 , 33 and the perforations 37 circumscribe flaps 39 of the sheet material.
• the flaps 39 can selectively be bent around their respective perforation 37 either down into the bowl 1 or up and away from the bowl. In the latter case the flaps 39 may be detached from the sheet material by cutting or breaking the perforations 37.
• a flap 39 Bending or removing a flap 39 will provide an asymmetric inlet 27 with an asymmetric inlet opening 27a in the central cover portion 19.
• the asymmetry of the inlet 27 is in relation to a plane defined by, i.e. comprising, the central axis 35 and a radial line 41 through the inlet proper and the central axis 35.
• a side 43 of the flap 39 adjacent the first part 31 of the incision may be brought into engagement with the first conical portion 7 of the bowl 1 thereby providing as a part of the asymmetric inlet 27 a circumferential channel for guiding water from the roof surface down into the bowl 1 in a swirling motion in a clockwise direction as indicated in Fig. 3 by arrow 45.
• the flap 39 functions as a guide plate.
• the orifice member 47 is a circular piece of sheet material and it has a central coaxial orifice 49 having a diameter. Below the orifice 49 a pipe 51 is extending from the orifice member 47.
• the pipe 51 has an internal diameter that may be equal to the diameter of the orifice 49, but in the embodiment shown is slightly larger.
• the orifice 49 provides an outlet of the vortex chamber. Due to swirling motion of water running through the orifice 49 a centrifugal force may pull the water to the inner surface of the pipe 51 even if the internal diameter of the pipe 51 is slightly larger than the diameter of the orifice 49.
• an additional opening 53 is provided.
• the additional opening 53 is surrounded by an overflow pipe 55 extending to an overflow level 57 higher than the level of the inlet opening(s) 27a.
• the additional opening 53 and the overflow pipe 55 are coaxial with the vertical central axis 35.
• the overflow pipe 55 is shown to be cylindrical. It might however e.g. be wider at its top, i.e. funnel-shaped, to provide for a lar- ger flow.
• a perforated shielding member in the form of a grating 59 is provided above the central cover portion 19 to avoid that debris on the roof, such as leaves, twigs, bits of paper, etc. get into the inlet openings 27a and risk blocking the drain.
• the grating 59 may e.g. be made from a sheeting material provided with slots (not shown in Figs. 1 and 4, but indicated in Fig. 7).
• the grating may have any appropriate shape: cylindrical (as shown), domed, conical, etc.
• the roof drain works as follows.
• a roof drain having a certain flow characteristic to provide for retaining water on the roof for some time at an event of rain, especially heavy rain, to avoid overload of a downstream piping system such as a sewer system.
• a breaking effect is obtained by providing for the formation of a vortex in the bowl 1 possibly in a vortex chamber above the orifice member 47. Also the combined area of the inlet openings 27a is used to control the breaking effect of the roof drain.
• flaps 39 are bent down into the bowl 1 for abutment on the inside wall of the first conical portion 7 as described above. It is preferred provide inlet openings 27a symmetrically relative to the central axis 35 to provide for a vortex swirling coaxially with the central axis 35. Thus preferably at least two diametrically opposite flaps 39 are bent down.
• flaps 39 should be bent up or removed instead of bending down flaps.
• the removed flaps will leave asymmetric inlet openings 27a having in a circumferential direction a wide end at the second part 33 of the incision and an opposite narrow part at the distal end 31 a of the first part of the incision.
• This asymmetry will provide for a deflection of the flow of water in to the inlet opening 27a thereby providing for a swirling flow in the bowl 1 .
• the swirl will be in the opposite direction compared to the situation when the flaps are bend down and the swirl will be less pronounced or vigorous.
• a smaller breaking effect will be provided, and a larger flow will occur.
• the orifice member may be dispensed with.
• the overflow pipe 55 will enter centrally into the orifice 49 and the combined flow of water through the overflow pipe 55 and the inlet opening(s) 27a may fill the cross sectional area of the pipe 51 below the orifice member which will thereby provide a suction or siphon effect providing for a larger flow through the orifice member.
• Figs. 7 and 8 illustrate further the versatility of a roof drain according to the invention.
• a central tube 61 with three supporting fins 63 resting on the step 9 has been inserted.
• the central tube 61 extends through the cylindrical spout 15 and possibly into a drain pipe 65 connected to the cylindrical spout 15 thereby providing an annular channel 67 that may run full of water being drained from the roof thereby providing a suction or siphon effect enhancing the flow through the drain.
• the central tube 61 will provide for venting the drain pipe 65 to avoid trapped air blocking the flow of water through the drain pipe.
• a much larger flow through the bowl 1 described above is provided for.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Building Environments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=47750378

Family Applications (1)

Country Status (2)

Citations (2)

Family Cites Families (4)

• 2013
  • 2013-02-15 WO PCT/DK2013/050040 patent/WO2014124645A1/en active Application Filing
  • 2013-02-15 EP EP13706163.6A patent/EP2956597A1/de not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (1)

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