US3509811A - Cowls for air vent pipes - Google Patents

Description

May 5, 1970 Filed July 15, 1968 2 Sheets-Sheet l May 5, 1970 w. TOPP 3,509,811

COWLS FOR AIR VENT PIPES Filed July 15, 1968 2 Sheets-Sheet 2 United States Patent O 3,509,811 COWLS FOR AIR VENT PIPES Wilhelm Topp, deceased, late of Empelde, Germany, by

Rudi Kaulfuss, executor, Eschwege, Germany, assignor to Bernd Kretzschmer, Hinter den Hofen, Germany Filed July 15, 1968, Ser. No. 746,705 Int. Cl. F231 17/02 US. CI. 98-78 14 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION In one existing method of drying-out, keeping dry and ventilating roofs consisting of a number of layers, with or without an air gap between them, small ventilation pipes are incorporated into the roofs, and pass through the outer-most covering to the open air. These small tubes or pipes may be provided with a swan neck, to give a chimney action and enable air to be vented from the roof space below the pipes or from the space between two of the roof coverings, while preventing the entry of moisture such as rainwater, for instance. Alternatively, the upper end of the pipe just projects above the surface and is ice sages between the lenticular body and the closure member.

The vent apertures are formed in the flat end wall of a bucket-shaped member or tubular body, the said end wall of which extends as a skirt portion beyond the periphery of the bucket-shaped member itself and is curved downwards.

The lenticular body is spaced above the vent apertures and the curvature of its faces is approximately the same as that of the skirt portion.

The connection between the lenticular body and the skirt portion is in the form of radial, streamlined, vertical walls or partition members which extend axially and run inwards from the outer periphery of the skirt portion and the periphery of the lenticular body and terminate outside the area containing the vent apertures, thus producing a number of radial flow passages between the lenticular body and the skirt portion.

The vent apertures should preferably be surrounded by annular flanges, so that they open above the general plane of the flat end-wall of the bucket-shaped member.

The slightly tapered bucket-shaped member can be fitted over an air vent tube or pipe.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a ventilator cowl constructed according to one embodiment of the present provided with one or more nozzle openings in the end SUMMARY OF THE INVENTION The present invention provides a cowl for a vent pipe comprising a closure member for the vent pipe, a plurality of apertures in the closure member opening in a substantially common plane, the closure member being at least partly curved downwardly from said plane towards the vent pipe, a lenticular body spaced upwardly from the closure member and a number of inwardly tapering radially extending flow passages formed between the lenticular body and the closure member.

The present invention further provides a cowl for a vent pipe comprising a cylindrical body adapted to fit over the open end of the vent pipe, a closure member for the cylindrical body having a centrally disposed substantially flat circular portion and an outwardly extending skirt portion curved downwardly from the general plane of the central portion towards the cylindrical body, a plurality of bosses formed on the central portion on the face remote from the cylindrical body, a plurality of apertures formed through the central portion and the bosses to open above the general plane of the central portion, a lenticular body part spaced from the closure member and having that face opposed to the closure member oppositely curved to the skirt portion but of substantially the same curvature as the skirt portion and a plurality of inwardly tapering radially extending fiow pasinvention, and

FIG. 2 is a section taken along the line II-II of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT This example of the present invention, as can be seen from FIGS. 1 and 2 comprises a slightly tapered tubular body or bucket-shaped member 1 which is closed at the top by a closure member comprising a centrally disposed substantially flat circular portion 2 surrounded by a skirt portion 5.

Vent apertures 3 are provided in concentric rings in the circular portion 2 as is more clearly shown in FIGURE 2. The vent apertures 3 extend through locally thickened portions of the central portion 2 on the face thereof remote from the body 1 so that they are each surrounded by an annular boss 4 and open above the general plane of the central portion by a distance corresponding to the depth of the annular bosses 4. The skirt portion 5 curves downwardly away from the general plane of the central portion 2 towards the tubular body 1. Supported on the annular skirt portion 5 are a number of partition members 6, which run from the periphery 7 of the skirt portion 5 and terminate with their inner edges 13 on the periphery of circular portion 2. The partition members 6 which extend radially inwardly are streamlined in section, as can be seen from FIGURE 2, being thicker in cross-section in the vicinity of the periphery 7 of the skirt portion 5 than at their inner ends.

Fixed to the top edges of the partition members 6 is a lenticular body 8, the curvature of the opposed faces of which correspond approximately to that of the skirt portion 5, so that the cross-section of the passages 12 between the curved underside 9 of the lenticular body 8 and the upper face of the skirt portion 5 is reduced continuously from the outside to the centre. Hence, because of the reduction in cross-section, there is a corresponding increase in velocity as the air flows through. The lenticular body 8 should preferably be hollow and consist of two separate curved members 9 and 10 joined together.

As indicated in FIGURE 1, the cowl can be fitted by its tapered bucket-shaped tubular body 1 over the vent pipe 11. The example illustrated has 25 vent apertures 3, and 12 partition members 6, which support the lenticular body 8. The number of vent apertures and partition members 6 can naturally be varied, according to the size of the cowl and the use to which it is put.

A plastics such as P.V.C., for example, may well be used for making the cowl.

The cowl here proposed is characterised in particular by highly effective air extraction from below the roof covering of hot and cold roofs, with and without heatbarrier layers. Air venting under the steam brake is also possible. When used as a fit-over cowl, the flow passage 12 formed in accordance with the invention between the skirt portion 5 and the lenticular body 8 results in a particularly marked ejector action in the associated vent pipe, so that the cowl is especially good for ventilating chemical laboratories, kitchens, store-rooms of all kinds, baths, garages, laundries, lavatories and bathrooms, stables, cattle stalls, containers, tanks and other utilitarian spaces, as well as for the draught-free ventilation of rail way carriages, omnibuses, closed troop-carrying vehicles, lorry drivers cabins and the like.

i What is claimed is:

1. A cowl for a vent pipe comprising a closure member for the vent pipe, a plurality of apertures in the closure member opening in a substantially common plane, the closure member being at least partly curved downwardly from said plane towards the vent pipe, a lenticular body spaced upwardly from the closure member and a plurality of substantially radially extending partition members disposed between and fixedly attached to said closure member and said lenticular body to define a number of inwardly tapering radially extending flow passages formed between the lenticular body and the closure member and opening outwardly of the cowl substantially throughout the entire outer periphery thereof.

2. A cowl according to claim 1, in which the closure member has a substantially flat central portion in which the apertures are formed and a skirt portion extending around the fiat portion which skirt portion is downwardly curved.

3. A cowl according to claim 2 in which the lenticular body has one face which is opposed to the closure member and which has substantially the same curvature as the skirt portion.

4. A cowl according to claim 1 in which the partition members are of streamline cross-section.

5. A cowl according to claim 1 in which the partition members are of reducing cross-section in the radially inwardly direction considered in a plane normal to the axis of the vent pipe.

6. A cowl according to claim 1 in which the partition members extend inwardly from the edges of the skirt portion and the lenticular body and terminate short of the area of the closure member in which the apertures are formed.

7. A cowl according to claim 1 in which the closure member provides an end wall for a slightly tapering tubular body adapted to be fitted over the end of the vent pipe.

8. A cowl for a vent pipe comprising a closure member for the vent pipe, a plurality of apertures in the closure member opening in a substantially common plane, the closure member being at least partly curved downwardly from said plane towards the vent pipe, a lenticular body spaced upwardly from the closure member and a number of inwardly tapering radially extending flow passages formed between the lenticular body and the closure member, the closure member being provided with a number of thickened portions through which the apertures extend so that the plane to which said apertures open lies above the general plane of the closure member.

9. A cowl for a vent pipe comprising a closure member for the vent pipe, a plurality of apertures in the closure member opening in a substantially common plane, the closure member being at least partly curved downwardly from said plane towards the vent pipe, a lenticular body spaced upwardly from the closure member and a number of inwardly tapering radially extending flow passages formed between the lenticular body and the closure member, each aperture being surrounded by an annular boss extending above the general surface of the closure member.

10. A cowl for a vent pipe comprising a cylindrical body adapted to fit over the open end of the vent pipe, a closure member for the cylindrical body having a centrally disposed substantially flat circular portion and an outwardly extending skirt portion curved downwardly from the general plane of the central portion towards the cylindrical body, a plurality of bosses formed on the central portion on the face remote from the cylindrical body, a plurality of apertures formed through the central portion and the bosses to open above the general plane of the central portion, a lenticular body part spaced from the closure member and having that face opposed to the closure member oppositely curved to the skirt portion but of substantially the same curvature as the skirt portion and a plurality of inwardly tapering radially extending flow passages between the lenticular body and the closure member.

11. A cowl according to claim 10 in which the flow passages are defined by radially extending partition members between the closure member and the lenticular body.

12. A cowl according to claim 11 in which the partition members extend radially inwardly from the peripheries of the lenticular body and the closure member and terminate at the circumference of the circular portion of the closure member.

13. A cowl according to claim 11 in which the partition members are of inwardly tapering thickness.

14. A cowl according to claim 11 in which the flow passages have an inwardly tapering cross-section considered both in a plane normal to the axis of the tubular body and in a plane containing the axis of the tubular body.

References Cited UNITED STATES PATENTS 697,125 4/ 1902 Anderson 9378 3,302,552 2/1967 Walsh 9878 XR 3,345,931 10/1967 Walsh 98-78 MEYER BERLIN, Primary Examiner US. Cl. X.R. 98-122. 83

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