GB2477395A

GB2477395A - Chimney cowl comprising a closure means

Info

Publication number: GB2477395A
Application number: GB1101037A
Authority: GB
Inventors: John Hortop; Daniel Gosbee
Original assignee: BREWER METALCRAFT Ltd
Current assignee: BREWER METALCRAFT Ltd
Priority date: 2010-01-21
Filing date: 2011-01-21
Publication date: 2011-08-03
Also published as: GB201101037D0

Abstract

A chimney cowl includes a substantially annular base plate 9, a top cover or lid 1 of substantially circular form, a substantially cylindrical mesh 4 interconnecting the base plate and the top cover or lid, closure means 12 for closing the centre of the substantially annular base plate and operating means 13 for moving the closure means between open and closed positions. Preferably, the closure means comprises a pair of substantially semi-circular flap members pivotally connected to the base plate. The flap members may be urged resiliently into their open positions and may also engage movement stops attached to the underside of the top cover when in their fully open positions. Alternatively, the closure means may comprise a single pivotally mounted plate movable between open and closed positions. The mounting for the pivotally mounted plate preferably comprises a pivot rod that extends across the opening in the base plate, where the pivot rod is offset from the centre of the opening.

Description

CHIMNEY COWLS

Field of the Invention

This invention relates to chimney cowls, i.e. to coverings used for controlling the draught of a chimney. One known form of chimney cowl is disclosed in Irish Patent Specification No. 82894.

It is an object of the present invention to provide an improved form of chimney cowl.

Sum mary of the Invention According to a first aspect of the present invention there is provided a chimney cowl which includes a base plate having an opening, a top cover spaced upwardly from the base plate so that a chamber is defined between the base plate and the top cover, a mesh extending around the sides of the chamber, closure means for closing the opening in the base plate and operating means for moving the closure means between open and closed positions.

According to a second aspect of the present invention there is provided a chimney cowl that includes a substantially annular base plate, a top cover or lid of substantially circular form, a substantially cylindrical mesh interconnecting the base plate and the top cover or lid, closure means for closing the centre of the substantially annular base plate and operating means for moving the closure means between open and closed positions.

The closure means may comprise a pair of substantially semi-circular flap members pivotally connected to the base plate.

The flap members are preferably urged resiliently into their open positions. The flap members preferably engage movement stops attached to the underside of the top cover or lid when in their fully open positions.

The closure means may alternatively comprise a single pivotally mounted plate movable between open and closed positions.

The mounting for the pivotally mounted plate preferably comprises a pivot rod that extends across the opening in the base plate and is offset from the centre of said opening.

Brief Description of the Drawings

Figure 1 is an exploded perspective view of a first embodiment of chimney cowl, Figure 2 is a perspective view of the assembled cowl of Figure 1 showing the flap members in their open positions, Figure 3 is a perspective view of the assembled cowl of Figure 1 showing the flap members in their closed positions, Figure 4 is a perspective view of the cowl of Figure 1 attached to a chimney, Figure 5 is a schematic view illustrating the manner of operation of the flap members, Figure 6 is a schematic perspective view of a second embodiment of chimney cowl with the closure plate in its closed position, Figure 7 is a view corresponding to Figure 6 showing the closure plate of the cowl of Figure 6 in its open position, Figure 8 is a side view showing the means for moving the closure plate of the cowl of Figure 6 between its open and closed positions, Figure 9 is a detail view showing, in more detail, the means for moving the closure plate of the cowl shown in Figures 6 to 8 between its open and closed positions.

Description of the Preferred Embodiments

The cowl shown in Figures 1 to 5 of the drawings includes a generally circular, slightly domed top cover or lid 1, an annular base plate 9 and a bird guard mesh 4 extending between the top cover or lid 1 and the base plate 9. Four equi-angularly spaced fitment legs 3 are provided and each fitment leg 3 includes an upper portion, which is shaped as shown in the drawings and serves to interconnect the base plate 9 and the cover or lid 1, and a lower portion which extends downwardly below the base plate 9 and is engaged by a securing strap 14 for attachment of the cowl on top of a chimney, as shown in Figure 4. The mesh 4 is of cylindrical configuration and thus effectively surrounds a chamber bounded at its lower end by the annular base plate 9 and bounded at its upper end by the top cover or lid 1.

Opening and closing of the central aperture of the annular base plate 9 to permit access to the chamber surrounded by the mesh 4 is controlled by a closure means that comprises a pair of pivotally mounted substantially semi-circular flap members 12.

There are up-standing lugs on the base plate 9 and the flap members 12 are pivotally connected to the base plate 9 by hinge pins 10 that pass through apertures in the up-standing lugs. The hinge pins 10 are held in engagement with the lugs by means of retaining rings 11 fitted onto the ends of the hinge pins 10 and the flap members 12 are urged into their open positions by stainless steel springs 5. The extent of opening movement of the flap members 12 is limited by engagement of the end portions of the flap members 12 with movement stops 2 attached to the underside of the cover or lid 1.

The two ends of a flap link wire 8 are attached to the undersides of the flap members 12 and the midpoint of the flap link wire 8 is attached to the upper end of a pre-loading spring 7, the lower end of which is attached to a cable securing crimp 6. The upper end of an actuating wire 13 is attached to the crimp 6 and the lower end of the wire 13 is attached to an operating handle 15 located at fireplace level (see Figure 5).

The cowl of Figures 1 to 5 thus provides protection to the chimney from birds and debris and reduced rain entry whether open or closed. In the closed position of the flap members 12, heat loss up the chimney is reduced as compared with what would be the case in respect of an unprotected chimney or flue when no heating appliance is being used.

An important advantage of the cowl of Figures 1 to 5 is that it can be cleaned at the same time as the rest of the chimney/flue system without any need for removal of the cowl.

When the operating handle 15 located at fireplace level at the end of the stainless steel actuating wire 13 is in the open position, the two flap members 12 located within the cowl are open allowing free passage to atmosphere of the smoke and fumes. The flap members 12 are held open by the strong stainless steel springs 5 to the maximum allowed by engagement with the movement stops located adjacent the bird guard mesh 4 in this position, so that cleaning by a sweep is possible. It is recommended that cleaning of the chimney and cowl should be effected twice a year.

To move the flap members 12 into their closed positions, the user operates the handle 15 to pull the wire 13 downwardly and then secures the handle 15 in its closed position. With the handle in its closed position, the system is closed to the outside preventing the ingress of rain, hail and snow and also preventing heat loss up the chimney.

The cowl shown in Figures 6 to 8 of the drawings is similar to that shown in Figures 1 to 5 and includes a generally circular, slightly domed top cover or lid IA, an annular base plate 2A and a bird guard mesh 3A extending between the top cover or lid 1A and the base plate 2A. The mesh 3A is again of cylindrical configuration and thus effectively surrounds a chamber bounded at its lower end by the annular base plate 2A and bounded at its upper end by the top cover or lid IA.

Opening and closing of the central aperture of the annular base plate 2A to permit access to the chamber surrounded by the mesh 3A is controlled by a pivotally mounted substantially circular plate 4A. The mounting for the plate 4A comprises a rod 5A which extends across the central aperture of the base plate 2A and is offset from the centre of this aperture. Fixings 6A are provided at the two ends of the rod 5A so as to permit rotation of the rod 5A and thus movement of the plate 4A between its open and closed positions, as shown in Figure 7 and Figure 6.

Two wires 7A and 8A are provided for moving the closure plate 4A between its open and its closed positions. An operating handle (not shown) is located to the side of the fireplace wall and the wires 7A and 8A are attached to the closure plate 4A, one on each side of the rod 5A, and to the two ends of the operating handle. The operating handle can be rotated about a horizontal axis so as to pull down one of the wires 7A, 8A and effect the required movement of the closure plate 4A, which is normally disposed in its open position.

In the alternative arrangement shown in Figure 9, the two wires 7A and 8A extending downwardly from the closure plate 4A are connected to an operating mechanism 9A.

Claims

Claims:- 1. A chimney cowl which includes a base plate having an opening, a top cover spaced upwardly from the base plate so that a chamber is defined between the base plate and the top cover, a mesh extending around the sides of the chamber, closure means for closing the opening in the base plate and operating means for moving the closure means between open and closed positions.
2. A chimney cowl that includes a substantially annular base plate, a top cover or lid of substantially circular form, a substantially cylindrical mesh interconnecting the base plate and the top cover or lid, closure means for closing the centre of the substantially annular base plate and operating means for moving the closure means between open and closed positions.
3. A cowl as claimed in Claim 1 or Claim 2, in which the closure means comprises a pair of substantially semi-circular flap members pivotally connected to the base plate.
4. A cowl as claimed in Claim 3, in which the flap members are urged resiliently into their open positions.
5. A cowl as claimed in Claim 4, in which the flap members engage movement stops attached to the underside of the top cover or lid when in their fully open positions.

*
6. A cowl as claimed in Claim I or Claim 2, in which the closure means comprises a single pivotally mounted plate movable between open and closed positions.
7. A cowl as Claimed in Claim 6, in which the mounting for the pivotally mounted plate comprises a pivot rod that extends across the opening in the base plate and is offset from the centre of said opening.
8. A chimney cowl substantially as hereinbefore described with reference to and as shown in the accompanying drawings.