GB2120124A

GB2120124A - Filter cowl

Info

Publication number: GB2120124A
Application number: GB08312754A
Authority: GB
Inventors: Maurice Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-05-10
Filing date: 1983-05-10
Publication date: 1983-11-30
Also published as: GB8312754D0; GB2120124B

Abstract

An air intake filter comprises an apertured tubular member 10 enclosing filter elements and an elongate protective cowl 16 which is preferably frusto-conical and is fixed to the tubular member at one end and extends axially towards the other end of the tubular member and is spaced therefrom to permit air to flow into the space between the tubular member and the protective member and hence through the periphery of the tubular member. <IMAGE>

Description

SPECIFICATION Filter cowl The present invention relates to filters and more particularly to air filters.

We have already proposed an air filter construction which is basically cylindrical in form with a coupling member at one end for attaching the filter to air moving apparatus. The arrangement is such that air is drawn radially through holes in the cylindrical surface of an external member, through a filter element and into the interior of the filter and thence axially out of the filter through the coupling member.

Many of these filters are used out of doors and it is necessary to shield the holes in the external member from the weather so as to keep the filter elements dry. This is achieved by fitting a protective member but difficulty arises because the filters in use are disposed in different orientations, e.g. extending vertically up or vertically down, and this means that the protective member has to be fitted to the filter in a different orientation depending on the disposition of the filter.

It is an object of the present invention to provide a protective member for a filter which can be fitted in either one of two positions without requiring alteration of the basic filter constructions.

According to the present invention there is provided a filter device comprising a tubular member having an apertured periphery, an elongate protective member fixed to the tubular member in the region of one end thereof such that the protective member extends axially from one end of the tubular member towards the other end and is spaced therefrom to permit air to flow in the space between the tubular member and the protective member and hence through the periphery of the tubular member.

Features and advantages of the present invention will become apparent from the following description of an embodiment thereof given by way of example with reference to the accompanying drawing which shows diagrammatically a preferred form of filter construction with cowl attached.

As shown in the drawing, the filter comprises a generally cylindrical tubular member 10 of circular cross-section provided with end plates 11 and 12 for retaining one or more annular filter elements within the member 10.

The filter elements are shown in broken lines.

The member 10 is provided with a number of holes in its cylindrical peripheral surface to allow air to pass from the exterior of the filter through the member 10, through the filter elements and into the interior of the filter.

The end plate 12 is generally circular with a depending external flange 1 2a while the end plate 11 is generally annular with an upstanding external flange 1 lea and a depending internal flange 1 1 b. The flanges 1 1 a and 1 2a extend axially in opposite directions to an equal extent. A coupling member 14 in the form of a section of pipe receives the depending flange 11 b of the end plate 11 in its bore so as to locate and centre the end plate 11.

The member 10 is received and located by the recess formed by the external flange 1 1 a of the end plate 11 and the whole assembly is secured together by means of a securing member 15 which passes through the centre of the end plate 12 and is received in a cooperating member 19 fixed to a rigid support which extends from the coupling member 14 through the interior space left by the annular filter elements to the end of the filter.

Thus far, the filter is of conventional con struction. In order to protect the filter from wind and rain, we attach a protective member in the form of a cowl 16 to the member 10.

The cowl 16 is attached to the member 10 at a position spaced from one end of the member 10 so as to leave a portion of the member 10 exposed for receiving the external flange 12a or 1 1 a.

As shown, the cowl 16 is generally frustoconical in shape. However, at the point where it is attached to the member 10 it is provided with a spacer portion 17 extending generally radially of the filter so as to allow air to travel up the whole of the space between the exterior of the member 10 and the interior of the cowl 16. The shape of the junction between the spacer portion 17 and the member 10 depends on the method adopted for attaching the cowl to the filter. In this case, it is preferred to rivet the cowl 16 to the member 10 so the spacer portion 17 is provided with a flange 18 which mates with the exterior of the member 10. The free edge of the flange 18 is arranged to abut the free edge of the flange 1 2a or 1 1 a of the end plate into which the member is fitted.

Alternatively, the spacer portion 17 can be omitted so that the cowl 16 diverges from the point where it is attached to the member 10.

However, with this arrangement the air passing between the cowl 16 and the member 10 as indicated by the arrows in the drawing is restricted in the region of attachment and hence causes a reduction in the effectiveness of the filter.

It will be appreciated that the member 10 fitted with the cowl 16 can be disposed as shown in the drawing or can be inverted as desired, in accordance with the disposition, in use, of the filter.

The cowl 16 as described above may alternatively be of a generally tubular shape instead of being generally frusto-conical. However, with this configuration it is necessary that the spacer portion 17 is present in order to provide the essential space between the cowl 16 and the filter 10.

Preferably, the cowl is made from sheet metal e.g. aluminium, but it can be made of any convenient sheet material and we specifically envisage plastics material to be a particularly suitable alternative in which case the cowl could be transparent and/or flexible.

Claims

1. A filter device comprising a tubular member having an apertured periphery, an elongate protective member fixed to the tubular member in the region of one end thereof such that the protective member extends axially from one end of the tubular member towards the other end and is spaced therefrom to permit air to flow in the space between the tubular member and the protective member and hence through the periphery of the tubular member.

2. A device as claimed in claim 1, wherein the protective member diverges in a direction from said one end to said other end whereby to space the protective member from the tubular member.

3. A device as claimed in claim 1 or 2, wherein the protective member is provided with a laterally stepped portion whereby to space the protective member from the tubular member.

4. A device as claimed in any preceding claim, wherein the fixing of the protective member is axially spaced from said one end of the tubular member.

5. A device as claimed in any preceding claim and comprising two end plates, one for each end thereof, each end plate comprises a flange arranged to abut the periphery of the tubular member, one of said end plates acts as a lid for the tubular member, and the other of said end plates acts as a base for the tubular member.

6. A device as claimed in any preceding claim, wherein the protective member is made from a single sheet of material.

7. A device as claimed in any one of claims 1 to 5, wherein the protective member is made from plastics.

8. A device substantially as hereinbefore described with reference to the accompanying drawing.