EP1967742A2

EP1967742A2 - A scroll type manifold, particularly for fans for use in extractor hoods

Info

Publication number: EP1967742A2
Application number: EP20080151134
Authority: EP
Inventors: Antonio Ranalli
Original assignee: LN 2 Srl a socio unico
Current assignee: LN 2 Srl a socio unico
Priority date: 2007-03-06
Filing date: 2008-02-06
Publication date: 2008-09-10
Also published as: RU2008108718A; ITPD20070075A1; RU2459121C2

Abstract

There is described a scroll type manifold (1) for fans, comprising a casing which is intended to constitute a housing for a fan impeller (2), the casing including a nozzle (6) which defines the delivery cross-section (3) of the manifold, engagement type connection means which are provided on the delivery nozzle (6) and which are arranged so as to cooperate with respective connection counter-means which are provided on a hood structure (8) which is intended to draw off the air-like gases drawn in by the fan, and axial retention means between the engagement type connection means and connection counter-means in order to retain the manifold (1) relative to the hood structure (8) at least in the mutual axial connection direction, in which the axial retention means comprise at least one retention element (10) which is provided at the delivery cross-section (3) of the manifold (1), the at least one retention element (10) being resiliently deformable between a first position, in which the manifold (1) is free to be engagingly connected with respect to the corresponding hood structure (8), and a second position, in which the element abuts the hood structure (8), preventing disengagement of the manifold (1) from the hood structure (8) at least in the axial direction opposite that for mutual engagement.

Description

The present invention relates to a manifold, in particular a scroll type manifold which is intended to constitute the housing of the impeller of a fan, particularly for extractor hoods, having the features set out in the preamble of the main claim.
The invention is used particularly, though not exclusively, in the construction of ventilation units for hoods for extracting air-like gases from domestic environments.
In this context, it is known to construct the casing of the scroll type manifold as two separate half-shells which can be connected to each other so as to construct the volute of the manifold, inside which the impeller is rotatably supported and is operated by the relevant motor unit.
The manifold is further generally fixed to the frame of the extractor hood so that the intake pipe from the hood is connected to the delivery cross-section of the manifold. Typically, that delivery cross-section is constructed in the form of a substantially cylindrical nozzle which can be fitted, preferably in a fluid-tight manner, in the intake pipe from the extractor hood. The manifold is normally rigidly fixed to the frame of the extractor hood with screw type means or other similar fixing means of the removable type, in order to facilitate the assembly/disassembly phases of the ventilation unit in installation locations and the subsequent maintenance operations.
Those applications normally involve limited accessibility to the members which need to be secured, owing primarily to the small amount of space provided inside the extractor hoods in the manifold assembly zone, which circumstance makes the operations for assembling/disassembling the ventilation unit complex and quite difficult, and in particular those necessary for assembling/disassembling the manifold on/from the frame of the extractor hood.
A main object of the invention is to overcome the above-mentioned limitations by means of a manifold which is configured in such a manner as to enable an operator readily and quickly to connect the manifold to the relevant structure of the extractor hood, with overall greater simplification of the operations for assembling the manifold on the extractor hood.
This object and other objects which will be clearly appreciated below are achieved by a manifold, in particular a scroll type manifold which is constructed in accordance with the appended claims.
Further features and advantages of the invention will be appreciated more clearly from the following detailed description of one preferred embodiment thereof which is illustrated, purely by way of non-limiting example, with reference to the appended drawings, in which:

Figure 1 is a perspective view of a scroll type manifold which is constructed in accordance with the present invention,
Figure 2 is a perspective view, drawn to an enlarged scale, of a component of the manifold of the preceding Figure,
Figure 3 is a side elevation view of the component of Figure 2,
Figure 4 is a partially sectioned view of another component of the manifold of Figure 1,
Figures 5, 6 and 7 are partial schematic views of a component of the manifold of the invention in respective different operating positions which are reached in the phase for connection to a structure of the extractor hood which is only schematically illustrated.

With reference to the Figures mentioned, a scroll type manifold which is generally designated 1 is constructed in accordance with the invention and provided so as to constitute a housing for a radial impeller 2 of a fan, which is only schematically illustrated and which is able to be caused to rotate by a motor unit 2a about an axis of rotation which is designated X.
There is defined in the manifold 1 a delivery cross-section 3, in which the delivery flow direction which is represented by the direction of the axis Y in the Figures, is substantially directed perpendicularly relative to the axis of rotation.
The volute of the manifold 1 is defined by a casing which is constructed as two half-shells, which are designated 4 and 5, respectively, and which can be connected to each other in a connection plane. Preferably, the half- shells 4, 5 are substantially formed in a practically specularly symmetrical manner with respect to the connection plane, the plane therefore defining a median plane of substantial symmetry.
Each half- shell 4, 5 comprises a respective portion 4a, 5a of a delivery nozzle 6, the portions 4a, 5a together defining the delivery cross-section 3. The nozzle portions are further advantageously formed so as to have a semi-cylindrical profile so as to define a delivery nozzle having a circular cross-section. Alternatively, there is provision for the nozzle to be formed integrally on one of the half-shells (in the half-shell 4 in the example described). The nozzle is able to be connected in an engaging manner in a structure of the extractor hood 8, which is only partially illustrated in the appended Figures. In the connection zone with respect to the hood, the hood is provided with an intake pipe (in fluid connection with the delivery of the fan), through which the conveying of the flow drawn in by the ventilation unit is brought about in the direction of the discharge of the hood. An opening in the hood 8 is designated 9 and is formed in a portion 9a of the frame of the hood, that opening being able to be engaged, with axial engagement connection, with the nozzle 6 of the manifold.
In order to connect the manifold to the hood structure, there are provided axial retention means which include a plurality of retention elements which are all designated 10 and which are provided on the nozzle 6 at the delivery cross-section 3. In greater detail, each retention element 10 comprises a respective tab 11 which is resiliently deformable between a first position, in which the manifold is free to be connected by means of axial engagement in the opening 9 of the hood, and a second position, in which each tab moves into abutment against the structure 8 of the hood, preventing the disengagement of the manifold from the opening 9 in the opposite axial direction to that of mutual engagement, thereby bringing about unidirectional retention, as will be appreciated more clearly below.
The tabs 11 have structural and functional identity relative to each other and therefore only one of them will be described in detail below. The tab is preferably formed in one piece with the manifold and is formed in the cylindrical wall portion of the nozzle 6. There are formed in the tab 11 one end 11a for attachment to the nozzle and an opposite free end 11b which is provided so as to constitute abutment surfaces with respect to the hood structure. The tab 11 is resiliently deformable primarily in a radial direction (transversely relative to the delivery direction Y). Preferably, the tab has, when viewed from above, a quadrilateral configuration in which the attachment end 11a extends along one of the sides, the tab being spaced apart from the wall of the manifold at the remaining sides. The tab can, for example, advantageously be constructed by interrupting the wall of the nozzle 6 along the three above-mentioned sides, with a portion projecting from the wall being formed in the non-deformed state. In this configuration, the attachment end 11a is directed away from the portion of the free end of the delivery nozzle 6.
At the opposite end 11b, the tab has an abutment surface 12 which can meet the portion of the frame 9a of the hood, that surface 12 having a curved profile, in cross-section, as illustrated in Figure 4. Alternatively, the profile of the surface 12 can be rectilinear.
In a preferred configuration, the connection system provides for a plurality of tabs 11 which are arranged with regular angular spacing along the cylindrical wall of the delivery nozzle 6, as illustrated in Figure 1.
An annular collar which is designated 15 projects radially from the nozzle 6 of the manifold and is arranged so as to be axially spaced-apart relative to the tabs 11, in such a position as to face the free ends 11b of the tabs. There is defined in the collar 15 a shoulder surface 15a, at the side directed towards the tabs 11, whose function is to cooperate with the tabs in order to meet the frame 9a of the hood structure, in the position for mutual axial retention, so as to bring about a bidirectional retention action of the manifold with respect to the hood structure along the axial connection axis Y.
The connection system provides that, starting from the position of Figure 5, with portions being disengaged and being moved apart from each other axially, the nozzle 6 of the manifold is axially inserted (direction Y) in the opening 9 of the hood. That axial engagement movement defines the flexion in a radial direction (in the direction of the arrow A of Figure 6) of the tabs 11 (by means of interference with the opening 9 of the frame 9a) which causes the hood frame to pass the nozzle zone having the tabs. Once the above-mentioned interference action has been completed, the tabs 11, owing to the resilient return action caused by the flexion deformation, are again moved into the non-deformed position, in which the frame of the hood is retained axially (in a bi-directional manner) because one side is in abutment with the tabs (abutment surfaces 12) and the other side is in abutment against the shoulder surface 15a (Figure 7). It will be noted that the tabs 11, by means of the resilient return brought about automatically during the relative axial engagement movement, bring about a releasable snap-fit connection.
In the mutual axial retention state, therefore, relative angular rotation is allowed between the connected portions (manifold/hood) in the direction Y which can, for example, be used for small adjustments or for precise control of the relative positioning between the connected portions.
In order to disconnect the manifold from the hood structure, it is necessary to act simultaneously on the tabs, with radial compression (in the direction of the arrow A), for example, by means of a suitable tool, so as to permit the axial movement for disengaging the frame of the hood (in the direction away from the shoulder 15) with respect to the manifold in the opposite direction to the engagement direction. Therefore, disengagement is possible only by means of a deliberate action by the operator, thereby preventing any possible undesirable occurrences of disconnection of an inadvertent nature.
The invention thereby achieves the objects set out and provides a number of advantages over known solutions.
A main advantage consists in that the manifold of the invention is able to be connected in an engaging manner in the hood extremely quickly, with movements which are simple and easy for the operator without the use of specific equipment or fixing means independent of the connected portions, thereby ensuring an effective and reliable axial retention action of the manifold with respect to the hood structure.

Claims

A scroll type manifold (1) for fans, comprising:
- a casing which is intended to constitute a housing for a fan impeller (2), the casing including a nozzle (6) which defines the delivery cross-section (3) of the manifold,

- engagement type connection means which are provided on the delivery nozzle (6) and which are arranged so as to cooperate with respective connection counter-means which are provided on a hood structure (8) which is intended to draw off the air-like gases drawn in by the fan,

- axial retention means between the engagement type connection means and connection counter-means in order to retain the manifold (1) relative to the hood structure (8) at least in the mutual axial connection direction,
characterized in that the axial retention means comprise at least one retention element (10) which is provided at the delivery cross-section (3) of the manifold (1), the at least one retention element (10) being resiliently deformable between a first position, in which the manifold (1) is free to be engagingly connected with respect to the corresponding hood structure (8), and a second position, in which the element (10) abuts the hood structure, preventing disengagement of the manifold (1) from the hood structure at least in the axial direction opposite that for mutual engagement.
A manifold according to claim 1, comprising at least one shoulder surface (15a) which is provided at the delivery cross-section (3), in a position which is axially spaced-apart from the at least one retention element (10), and which is intended to cooperate with that element in order to abut the hood structure (8), in the second position, so as to allow bi-directional retention of the manifold (1) with respect to the hood structure (8) in the axial connection direction.
A manifold according to claim 1 or 2, wherein the at least one retention element (10) brings about a disengageable snap-fit connection of the manifold (1) with respect to the hood structure (8).
A manifold according to claim 3, wherein the at least one retention element (10) is selected to have such a form as to be resiliently deformed, in the first position, following interference with the hood structure (8) in the mutual engagement phase between the manifold and the hood, in order to return, owing to the resilient return action, to the second position, once the axial engagement of the manifold (1) has been completed with respect to the hood.
A manifold according to one or more of the preceding claims, wherein there are provided a plurality of retention elements (10) which are angularly spaced apart from each other along the circumferential development of the delivery cross-section (3).
A manifold according to claim 5, wherein the retention elements (10) constituting the plurality are mutually spaced apart with regular spacing.
A manifold according to any one of the preceding claims, wherein the at least one retention element (10) is formed in one piece with the manifold.
A manifold according to claim 7, wherein the at least one retention element (10) is formed in the nozzle portion (6) of the manifold.
A manifold according to claim 8, wherein the at least one retention element (10) comprises a tab (11) having an end (11a) for attachment to the nozzle (6) and an opposite end (11b) which is free and which is able to abut the hood structure (8) in the second position, the tab (11) being resiliently deformable mainly in the radial direction between the first position and the second position.
A manifold according to claim 9, wherein the second end (11b) comprises a surface (12) for abutment against the hood (8) having a curved or rectilinear profile.
A manifold according to any one of claims 2 to 10, wherein the shoulder surface (15a) is defined on an annular collar (15) which projects radially from the nozzle (6) of the manifold and which extends in an axially spaced-apart position from the retention elements (10).
A manifold according to claim 11, wherein the collar (15) is arranged in a position facing the respective second end (11b) of each tab (11) of the plurality of tabs which are provided on the nozzle, the tabs (11) being arranged with regular spacing on the nozzle and being arranged at the same axial distance from the shoulder collar (15).