WO1997035151A1

WO1997035151A1 - Evacuation device

Info

Publication number: WO1997035151A1
Application number: PCT/SE1997/000419
Authority: WO
Inventors: Jenny Larsson
Original assignee: Jenny Larsson
Priority date: 1996-03-18
Filing date: 1997-03-12
Publication date: 1997-09-25
Also published as: AU2184297A; SE506381C2; SE9601023L; SE9601023D0

Abstract

An extraction ventilator, particularly for a kitchen stove, comprising a ventilation duct (1) whose suction end is connected to the interior of a generally conical fume-collecting hood (2) whose open base faces downwards. The hood wall (21) can be deformed peripherally around the hood, and means (3, 4, 37, 38, 22, 23, 25) are provided for varying the hood periphery at the rim of the bottom opening of the hood.

Description

EVACUATION DEVICE

The present invention relates to an extraction ventilator, particularly for use with a kitchen stove, of the kind defined in the preamble of Claim 1.

The extraction ventilator is thus of the kind that includes a ventilating duct which is connected at its suction end to the interior of a generally conical fume collecting hood whose open base faces downwards. The ventilation duct connected to the hood may have a variable length.

The known technology is represented by U.S. 4,612,909 and EP- A-0 521 810.

The size of the hood opening normally corresponds to the size of the stove. Extraction of smoke and fumes from a cooking vessel on the stove can be enhanced by increasing the suction flow through the hood and/or by moving the hood closer to the stove and to the cooking vessel thereon.

However, one problem is that the majority of the air that is evacuated through the hood is comprised of room air, while only a small part of the flow is comprised of fumes and steam from a cooking vessel on the stove.

The object of the invention is therefore to provide an extraction ventilator whose hood can be adapted to the smoke and steam generating cooking vessel or vessels on the stove.

This object is achieved with an extraction ventilator according to Claim 1. Further developments of the extraction ventilator are defined in the independent Claims.

The invention is based on an extraction ventilator which includes a generally conical fume-collecting hood whose open base faces downwards, wherein the hood wall can be deformed in a peripheral direction, and wherein means are provided for varying the periphery of the hood wall at the lower opening rim of the hood. Thus, at a given extraction flow, the rate of air flow can be varied at the hood inlet orifice by adjusting the area of the orifice. The hood is preferably supported so that it can be moved both horizontally and vertically, and so as to enable the rim of the hood orifice to be centred relative to an individual cooking vessel on the stove and placed in the proximity of the upper rim of said vessel, wherein the size of the hood orifice rim can be adapted to the size of the upper rim of the cooking vessel.

In one embodiment, the hood wall is comprised of a plurality of laminae which overlap partially in the peripheral direction of the hood. The hood wall will preferably have the shape of a truncated cone, and the laminae are hung on a bearing ring at the upper end of the wall, wherein the laminae are suspended for pivotal movement in an axial plane relative to the hood. A ventilation duct connects with the upper orifice defined by the hood wall. The laminae may advantageously have a general trapezium shape to provide a wide area of variation in the apex angle of the hood. The devices that operate to vary the hood apex angle include means for simultaneously setting the pivot angle of the laminae around their pivot bearing. According to another embodiment of the invention, the hood wall may comprise a longitudinal section of a tube made of flexible sheet material that has been folded or pleated peripherally to form mutually sequential laminae around its periphery, wherein the fold bending lines form a bending joint between adjacent laminae, and wherein the laminae are rotatable about their longitudinal axes so as to enable the hood wall to be journaled to provide a constant cross-section in an upper region while, at the same time, enabling the apex angle of the hood wall to be varied by swinging the laminae in the axial plane of the hood.

The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings.

Fig. 1 is a schematic side view of an inventive extraction ventilator.

Fig. 2 is a partial view taken on the line II-II in Fig. 1.

Fig. 3 is a partial axial view through the stove hood shown in Fig. 1.

Fig. 4 illustrates an alternative embodiment of the hood, in a reproduction corresponding to Fig. 2.

Fig. 1 shows a stove fan which includes a flexible and axially deformable ventilation hose 1 which carries a hood 2 at its bottom end. The upper end of the hose 1 may be attached to a fixed point in the ceiling or wall. The illustrated hose 1 is shown to include a fan 7. The hose 1 communicates with a ventilation duct. The hose 1 may be of concertina-like construction that will maintain its set length and curvature even when subjected to the load represented by the hood 2.

The hood 2 has a generally conical shape. The wall of the hood 2 thus has the form of a truncated conical shell. The term conical as used here also includes a generally pyramidal shape.

In the embodiment illustrated in Figs. 1-3, the hood wall 2 is comprised of laminae 21 whose longitudinal axes lie in an axial plane relative to the hood. The longitudinal edges of the laminae 21 overlap and seal against one another. The laminae 21 are mounted at the upper end of the wall for pivotal movement in the axial plane of the hood. In the illustrated case, the laminae 21 include eyelets 22 which are mounted on a bearing ring 23 at the top of the hood. A ring- shaped draw spring 25 embraces the upper ends of those parts of the laminae 21 that extend up beyond the ring 23. The draw spring 25 thus biases the laminae to effect pivotal movement towards an end position in which the hood has a large apex angle, e.g. an apex angle of 160°. A peripheral edge of a housing 4 that surrounds the upper end-part of the hood may form an abutment that functions to restrict the apex angle of the hood to an upper value, for instance 160°. An outer ring 3 surrounds the hood 2, and may lie against the outside of the hood. The ring 3 can be moved vertically in relation to the bearing ring 23, such that when moved axially downwards the ring 3 will cause the laminae 21 to pivot while reducing the apex angle of the hood 2 at the same time. The ring 3 may be mounted on the housing 4 by means of a screw thread 37 that coacts with a screw thread 38 on the outer wall of the housing, such as to enable the ring 3 to be moved axially by rotation relative to the housing 4.

As will be evident from Figs. 2 and 3, the laminae 21 may conveniently have a generally trapezoidal shape, with the narrower ends of the laminae located at the top of the hood.

As will be evident from Fig. 3, the hose 1 extends centrally through the housing 4 in the upper part of the hood, said hose preferably opening out at a level beneath the bearing ring 23. A sealing membrane may be attached between the rim of the hose orifice and the inside of the hood beneath the pivot journal of the laminae.

Fig. 4 illustrates an alternative embodiment of the invention, in which the hood 2 has the form of a tube comprised of sheet material and folded or pleated alternately around its periphery to form laminae 21 that are tightly connected via the ridges 28 of the folds, these ridges also defining fold joints between adjacent laminae 21. The laminae 21 are also preferably rotatable about their longitudinal axes, to facilitate adjustment to the apex angle of the hood 2. The hood 2 may be provided with eyelets located on the inside of the hood in the proximity of its narrower upper end, e.g. at the inwardly facing fold ridges 21, and mounted on a bearing ring 23. In other respects, the hood shown in Fig. 4 can replace the hood 2 shown in Fig. 3.

An important feature of the invention is that the generally conical hood is constructed to enable it to be deformed to different apex angles, so as to enable the bottom orifice of the hood to be given a chosen diameter. Because the hood 2 rests supported such as to enable it to take a selected position both horizontally and vertically above a stove, fumes and steam can be evacuated selectively from a cooking vessel while maintaining a low flow through the ventilation hose 1.

As will be evident from Figs. 2-4, the bearing ring 23 may be supported from a sleeve connector 10 by means of spokes 27. The sleeve connector 10 forms an end-section of the hose 1 and also supports the housing 4 that surrounds the upper end- parts of the laminae.

Claims

1. An extraction ventilator, particularly for a kitchen stove, comprising a ventilation duct (1) which is connected at its suction end to the interior of a generally conical fume collecting hood (2) having an axis and a downwardly open base that extends generally perpendicularly to said axis, characterized in that the hood wall (21) can be deformed in a peripheral direction that extends in a plane normal to the hood axis; and in that means (3, 4, 37, 38, 22, 23, 25) are provided for varying the hood periphery at the rim of the bottom orifice of the hood.

2. An extraction ventilator according to Claim 1, characterized in that the hood wall is deformable with respect to the slope of the hood wall in an axial plane relative to the hood.

3. An extraction ventilator according to Claim 1 or 2, characterized in that the ventilation duct (1) connects with the hood (2) through a central upper orifice in the hood, such that the hood wall will generally have the shape of a truncated cone.

4. An extraction ventilator according to any one of Claims 1-3, characterized in that the hood (2) is comprised of separate laminae, each of which extends over the wall height of the hood, wherein mutually adjacent laminae partially overlap one another, and wherein the laminae are pivotally mounted at the upper part of the hood in fixed journal positions for pivotal movement in axial planes relative to the hood; and in that the outwardly exposed longitudinal edge region of respective laminae lies substantially sealingiy against the surface of underlying laminae.

5. An extraction ventilator according to any one of Claims 1-3, characterized in that the hood wall is comprised of tubular sheet material that is folded or pleated (28) around the wall periphery, wherein the fold lines (28) of the folds form bending joints between the laminae (21) defined thereby; and in that the laminae are preferably rotatable about their longitudinal axes.

6. An extraction ventilator according to Claim 5, characterized in that the upper end-parts of respective laminae are journalled on a journal ring for pivotal movement in an axial plane relative to the hood.

7. An extraction ventilator according to any one of Claims 4-6, characterized in that the variation means includes means for varying the slope of the laminae (21) in axial planes relative to the hood.

8. An extraction ventilator according to any one of Claims 1-7, characterized in that a ring-shaped housing (4) surrounds the upper rim region of the hood (2); and in that the housing (4) carries an axially movable ring (3) which acts against the hood wall around its periphery.

9. An extraction ventilator according to Claim 8, characterized in that the axially movable ring (3) is carried by the housing (4) via a screw thread which is coaxial with the hood axis.

10. An extraction ventilator according to Claim 8 or 9, characterized in that the ventilator includes spring means (25) that acts against the hood laminae (21) such as to bias the hood wall towards an end position with respect to the apex angle of the hood (2); and in that the axially movable ring (3) is adapted to counteract pivotal movement of the laminae by the spring means in the axial plane of the hood.