US3722532A - Rain water drain pipe or similar for a building - Google Patents

Abstract

A rain-water outlet for a roof comprising a vertical pipe and a trough fixed to the upper end of said pipe. A cover is fastened in the trough above the inlet end of said pipe. The cover forms a closed surface larger than the inlet opening to cause water to flow radially in the trough to said inlet opening and to prevent axial section of air into the pipe.

Description

ilnited States atent [191 Ebeling et a1.

[ Mar. 27, 1973 [54] RAIN WATER DRAIN PIPE OR SIMILAR FOR A BUILDING [76] Inventors: Olavi Ebeling, Temppelikatu 21; Risto Lunden, Pakilantie 49, both of Helsinki, Finland [22] Filed: Jan. 20, 1971 21 Appl. No.: 108,049

[52] US. Cl ..137/357 [51] Int. Cl. ..E04d 13/04 [58] Field of Search ..210/462, 482, 473, 474, 477, 210/163, 164, 165, 166; 52/94, 95, 96, 302,

[56] References Cited UNITED STATES PATENTS Lewis ..2l0/l63 X OBrien ..285/42 X 2,336,348 12/1943 Demers ..2lO/482 X 2,582,031 l/l952 Harbison ..285/42 X 2,701,644 2/1955 Griffiths ..2l0/477 X FOREIGN PATENTS OR APPLICATIONS France ..2l0/163 France ..285/42 Primary Examiner-Henry T. Klinksiek AtlorneyKurt Kelman [57] ABSTRACT A rain-water outlet for a roof comprising a vertical pipe and a trough fixed to the upper end of said pipe. A cover is fastened in the trough above the inlet end of said pipe. The cover forms a closed surface larger than the inlet opening to cause water to flow radially in the trough to said inlet opening and to prevent axial section of air into the pipe.

2 Claims, 3 Drawing Figures RAIN WATER DRAIN PIPE OR SIMILAR FOR A BUILDING The present invention relates to a rain-water outlet for a building, comprising a substantially vertical pipe leading from a roof or a collecting area, the upper end of said pipe being connected to a trough larger than the inlet opening of said pipe, the upper edge of said trough extending above the inlet opening of said pipe.

In rain water drain pipe arrangements presently used in buildings the water is usually led as well in external as in internal drain pipes directly from a gutter or a corresponding collecting groove formed in the roof into the inlet opening of a vertical drain pipe which inlet opening sometimes may be covered by a perforated screen for protecting dirt and similar to enter the pipe. Owing to this air is allowed to be sucked into the inlet opening of the vertical pipe together with the rain water, whereby a whirl appears in the vertical pipe due to the Coriolis-effect, so that the rain water is flowing downwards in the pipe in a whirling flow solely along the inner periphery of said pipe. Consequently only a part of the cross section of the vertical pipe is utilized for the flow of rain water and therefore the diameter of the vertical pipe must be dimensioned rather large, so that it is able to discharge the desired amount of rain water per time unit.

It is an object of the present invention to eliminate said disadvantage and the rain water drain pipe according to the invention is characterized in that above said inlet opening is fastened a cover forming a closed surface larger than the inlet opening but smaller than the trough, the circumferential edge of the closed surface of said cover being positioned below said upper edge of the trough for directing water to flow in the trough substantially radially into the inlet opening of said pipe to prevent axial suction of air into the pipe and thereby the formation of an air whirl.

According to the invention such conditions are created at the inletopening of the vertical pipe that the flow of water in the pipe occurs as a solid flow, i.e., over the whole cross section of the pipe, whereby the dimension of the vertical pipe may be dimensioned substantially smaller than what has been earlier possible for a certain amount of rain water intended to be discharge per time unit. Consequently the costs of the material for the rain water drain pipe may be considerably reduced. Tests have indicated that one vertical pipe according to the invention having a diameter of 2% inches is able to discharge an equal amount of water per time unit as a rain water drain conduit comprising one 6 inches vertical pipe and one 4 inches vertical pipe.

The cover arranged above the inlet opening of the vertical pipe prevents surrounding air to be sucked into the inlet opening from above and the amount of water present in the trough forms a water layer of sufficient thickness at the inlet opening, so that the trough forms together with the cover a water trap.

It is preferable that the cover is of downwardly open cup like shape, the mantle wall of said cover being perforated and extending to the bottom of said trough.

The perforated mantle wall of the cup like cover forces the rain water in the trough to flow into the inlet opening of the vertical pipe through a number of holes which positively prevents the formation ofa continuous whirl. Consequently it is possible even when the suction action of the pipe is considerable to maintain the height of the trough relatively small without any risk that water whirls are formed and air may enter into the inlet opening. Furthermore the perforated mantle wall ofthe cover acts as a screen which prevents dirt from entering the vertical pipe.

The invention is described more closely in the following with reference to the accompanying drawing in which FIG. 1 is an axial sectional view of a preferred embodiment of a rain water drain pipe according to the invention,

FIG. 2 is a plan view of the drain pipe according to FIG. 1 and FIG. 3 is an axial sectional view of a second embodiment of the invention.

The drawing illustrates an internal rain water drain pipe for a building, comprising a vertical pipe 1. The upper end of the inlet opening of the pipe is fastened by soldering in the middle of the bottom of a rectangular trough 2. The trough 2 is intended to be assembled at the roof of a building in such a way that the upper edge flange 3 is positioned flush with the roof surface 4.

In the middle of the trough there is fastened to the bottom thereof by means of bolts 5 a downwardly opening cup like cover 6. The bottom plate 7 of the cover is unperforated but the mantle wall 8 is provided with a number of holes 9. The upper row of holes is positioned at a distance below the surface of the bottom plate of the cover. As appears from FIG. 1, the diameter of the cover 6 is larger than the diameter of the vertical pipe 1 but smaller than the width of the trough 2. Thus, rain water is allowed to flow from the roof surface to the vertical pipe only through the trough 2 and the holes 9 in the cover.

If the intensity of the rain is smaller than the amount of water per time unit according to which the vertical pipe is dimensioned based upon a solid flow and which amount of water the pipe is capable of discharging from a given roof area as a whirlfree water column, the trough is only partially filled with water whereby air may of course enter through the holes in the cover into the inlet opening of the vertical pipe. The inflowing amount of water is however, in this case smaller than the maximum receiving capacity of the pipe and therefore the pipe is capable to discharge this amount of rain water regardless of any whirling action in the pipe. If the intensity of the rain is equal to or greater than the maximum receiving capacity of the pipe, the trough is filled with rain water up to its upper edge whereby the water layer in the trough prevents, in co-operation with the whirl resisting holes of the cover, air to enter into the vertical pipe so that the pipe discharges the amount of water as a continuous water column. Thus the diameter of the vertical pipe may be determined based upon a solid flow in the pipe. The number and size of the holes in the cover are determined in such a way that the holes cause a minimum throttling action upon the flow of water from the trough to the vertical pipe.

The drawing and the corresponding description are only intended to illustrate the invention. The details of the rain water drain pipe or similar according to the invention may. vary considerably within the scope of the claims. Thus the cover may comprise solely a disc-like horisontal plate 10, as shown in FIG. 3, the periphery of which extends radially at a sufficient distance from the inlet opening of the vertical pipe. It is apparent that the idea of the invention may also be applied to other objects than rain water drain pipes, such as waste water pipes and similar drainage devices.

What we claim is:

1. A drain outlet for a building, said outlet comprising in combination, a substantially vertical pipe, the upper end of said pipe being connected to an inlet opening disposed in the bottom surface of a trough having an area larger than the inlet opening of said pipe, trough walls extending above the inlet opening of said pipe, 2 flange member projecting from the trough walls,

a cover forming a continuous surface larger than the inlet opening and smaller than the trough walls, said cover disposed above said inlet, secured to the said bottom of the trough, and having a circumferential edge within the said upper edge of the trough whereby water is directed to flow in the trough substantially radially into the inlet opening of the pipe to prevent axial suction of air into the pipe and thereby prevent the formation of an air whirl.

2. The drain outlet of claim 1 wherein a perforated wall extends from the cover to the bottom surface of the trough.

Claims (2)

1. A drain outlet for a building, said outlet comprising in combination, a substantially vertical pipe, the upper end of said pipe being connected to an inlet opening disposed in the bottom surface of a trough having an area larger than the inlet opening of said pipe, trough walls extending above the inlet opening of said pipe, a flange member projecting from the trough walls, a cover forming a continuous surface larger than the inlet opening and smaller than the trough walls, said cover disposed above said inlet, secured to the said bottom of the trough, and having a circumferential edge within the said upper edge of the trough whereby water is directed to flow in the trough substantially radially into the inlet opening of the pipe to prevent axial suction of air into the pipe and thereby prevent the formation of an air whirl.

2. The drain outlet of claim 1 wherein a perforated wall extends from the cover to the bottom surface of the trough.

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