WO2002011596A1

WO2002011596A1 - Head for a dust vacuum cleaner

Info

Publication number: WO2002011596A1
Application number: PCT/ES2001/000311
Authority: WO
Inventors: Jorge Garcia Virgili; Lliuis Trench Roca; Francisco Lopez Vizcaino
Original assignee: Electrodomesticos Taurus, Sl
Priority date: 2000-08-01
Filing date: 2001-08-01
Publication date: 2002-02-14
Also published as: ATE343955T1; AU2001284063A1; EP1314388A1; DE60124266D1; WO2002011595A1; PT1314388E; EP1314388B1; BR0113082A; ES2275715T3; US20040025289A1; DE60124266T2; AU2000264440A1; MXPA03000932A

Abstract

Said head comprises a hollow central body (12c) which includes a central open chamber part (10c) that is connected to a vacuum source and at least two lateral bodies (12a, 12b) that are joined together on both sides of the central hollow body (12c) by an articulation (13) enabling turns in relation to a substantially normal common axis relative to the surface to be treated. The central open chamber part (10c) has an opening (14) in the area of the articulation (13) and the lateral hollow bodies (12a, 12b) comprise corresponding lateral open chamber parts (10a, 10b) communicating with said opening (14) in the central open chamber part (10c) by means of said articulation (13). Thus, the vacuum front has variable geometry and covers the two sides and the central articulation (13) of the head by means of said three lateral and central open chamber parts (10a, 10b, 10c).

Description

HEAD FOR DUST VACUUM APPARATUS

Field of the invention

The present invention concerns a head for dust suction apparatus, and more specifically a head for dust suction apparatus provided with a suction front capable of adopting a variable geometry, suitable both for treating relatively large and clear surfaces and for reaching corners and / or corners.

Technical background

Heads have been known for a long time in the market for dust suction appliances, especially for domestic or semi-industrial use, consisting of a first structural, central element, which integrates a hollow body connected to a source of depression through an appropriate conduction , which generally includes a section of rigid tube articulated connected to said central structural element also serving to handle the head without bending down. A second, elongated structural element is connected by its midpoint transversely to the first and comprises an open chamber pneumatically connected with said hollow body, whose open chamber is partially closed when the head is applied on the surface to be treated, delimiting at least one straight suction front, transverse to the central head body. The width of this suction front, according to the power of the machine of the depression source, defines the capacity of the vacuum cleaner, since the wider it is said, the less consecutive parallel passes will have to be given to cover the same surface.

However, although a head with a wide suction front is useful on relatively wide and clear surfaces, it presents serious inconveniences when the surface to be treated includes corners and / or corners, such as the corners formed by two walls in a corner of a room , or hidden corners under furniture.

Attempts have been made to alleviate these inconveniences by providing a set of interchangeable heads for a vacuum cleaner, so that in addition of the aforementioned head with a wide suction front, other heads with narrower fronts or configured according to different shapes adapted to different corners or corners are available. However, this entails the inconvenience of continually changing the heads, apart from the inconvenience of having to store a multitude of small separate elements together with the vacuum cleaner.

An approach to the solution of the said problem is also known in the market, consisting of providing a single head vacuum cleaner provided with a relatively long suction front configured at the tip, forming an approximately right angle, so that such head is apt to reach to corners and corners of the type described. However, this head has the disadvantage that, even having the aforementioned relatively long suction front, it always has a real width of the suction front much smaller because it is bent at right angles. Thus, to cover a certain surface to be treated, a greater number of passes are necessary with a suction front folded at a point than with a front of equal length but of a straight configuration, transverse to the direction of the passes.

Another approach to solving the problem is to provide a suction head equipped with a suction front with a variable configuration.

US-A-3085267 describes a vacuum cleaner head provided with a single open suction chamber, transverse to the direction of the passes, provided with a surrounding flexible lip mounted on an elongated hollow body formed by various articulated sections that confer on the Open chamber mouth a slight ability to adapt to concave or convex surfaces. The connection with the source of depression is made through the central section.

US-A-5502870 discloses an aspirator nozzle in which a central body connected to the source of depression is extended in two suction arms mounted so that they are capable of pivoting up to 90 ° in a plane substantially perpendicular to the surface to be treated, so that its suction channels can face each other forming a tube. In an intermediate position the head is useful for aspirate convex dihedral surfaces, such as steps. However, neither this model nor the previous one is suitable for vacuuming corners such as corners between walls on flat surfaces.

US-A-3739421, EP-A-276396 and EP-A-0894468 have respective heads provided with variable suction fronts that have in common being supported on three articulated parts in a plane substantially parallel to the surface to be treated. . In all three models, a central hollow body is connected to the suction source and comprises an open suction chamber that communicates with the respective open suction chambers of the articulated side bodies. Each lateral body comprises an articulation with respect to the central body, and is elastically loaded to stay aligned with it, whereby the suction front has a straight central portion, transverse to the direction of advance of the passes, and two lateral portions susceptible to pivot and fold to find an obstacle in its advance. However, none of the previous three heads has a suction front that can be folded into a tip that can reach, for example, corners of the surface to be treated flanked by walls.

Document DE-A-4413071, in one of its embodiments, discloses a vacuum head comprising two arms articulated with respect to an axis substantially perpendicular to the surface to be treated. Both arms include respective open suction chambers and are elastically loaded so that they tend to keep each other aligned to form a straight suction front transverse to the direction of the passes, although said arms are able to fold in both directions by effect of any interposed obstacle on their way. The connection of both open chambers with the source of depression is carried out by means of two flexible tubes that join in a manifold from which a single conduction towards said source starts. Thus, the area of the articulation between the arms does not have an open suction chamber and the suction front has a considerable interruption in its central part. Although the arms are able to fold into a point to reach narrow corners, the apex of the suction front is not able to suck dirt from that corner. In view of the state of the art, an objective of the present invention is to provide a head for dust suction apparatus having a suction front of variable geometry, capable of adopting a range of configurations between a straight, transverse front to the central body of the head and relatively wide, suitable for treating wide and clear surfaces, and a pointed front, forming an angle slightly lower than a straight, suitable for reaching corners and corners and capable of sucking dirt from said corners.

Brief exposition of the invention

The foregoing objective is achieved, in accordance with the present invention, by providing a head for dust suction apparatus of the type comprising open chamber suction means connected to a source of depression through at least an appropriate conduction, whose means of The open chamber is partially closed when the head is applied on the surface to be treated, defining at least one suction front. The essential feature is that said suction front, which is at least one, comprises three portions formed by as many open chamber portions integrated into respective structural elements articulated with respect to a common axis, pneumatic communication being effected between the three open chambers through the joint area so that said suction front is continuous and capable of adopting a variable geometry between a straight, transverse front, and a bent tipped front with suction capacity both on the sides and in the vertex. This is achieved, in essence, by integrating the lateral open chamber parts into hollow bodies mechanically connected in a mobile manner to a central hollow body which incorporates the central open chamber, which is maintained communicated with the lateral open chamber parts in a range of relative positions desired. The central open chamber part is connected to said source of depression through the corresponding hollow body and an appropriate conduction coupled by a ball joint.

According to a preferred embodiment of the invention, the two lateral structural elements are symmetrically arranged side and side. of the central hollow body, and said mechanical connection of said lateral structural elements with said central structural element is carried out by means of an articulation with respect to a common axis which, with the head in working position, is substantially normal to said surface to be treated. The area of the joint comprises an opening communicated with the central hollow body, maintaining said mutual communication of the open chamber parts as well as their communication with the source of depression through said joint.

Thus, the aforementioned range of relative positions of the open chamber parts is obtained by rotating the lateral structural elements relative to the central structural element, around said common axis, between a first position in which said open chamber parts are substantially aligned, delimiting a straight suction front, and a second position in which the lateral open chamber parts are forming an angle slightly lower than a straight one with the central open chamber part located at the vertex, delimiting a front of point aspiration, suitable to reach corners and / or corners and perform the aspiration of the vertex thereof. It should be noted that the suction front is continuous regardless of the configuration adopted between said first and second positions.

The head thus arranged is also provided with elastic means, such as one or more springs connected respectively between the lateral structural elements and the central structural element, which tend to maintain the assembly in said first defining position of a straight suction front. In order to avoid unwanted folding of said straight front, especially when very rough surfaces are treated and / or when the suction force is very strong, means for blocking the rotation of the lateral structural elements with respect to the central structural element are provided while maintaining the set a fixed position, preferably in said first position. The said locking means are automatically released, and independently, when any of the lateral structural elements collides with an obstacle. This is so by virtue of elastically loaded levers that protrude frontally over the entire length of each lateral structural element and which are associated with triggered hooks is respective nails that are released by the displacement of said levers allowing the rotation of the hollow lateral bodies. However, the blocking means could also be capable of being released or fixed manually through an external control.

According to a preferred embodiment, the central hollow body incorporates an additional suction mouth in its lower rear part, whose additional suction mouth includes a shutter linked to externally accessible pedals that allow it to open or close it optionally depending on the type of surface to be treated.

Brief description of the drawings

These and other features will be better understood from the following detailed description of a preferred embodiment of the invention with references to the accompanying drawings, in which: Fig. 1A is a bottom plan view of the head for suction apparatus of powder of the present invention, with the lateral structural elements arranged according to a first position in which the open chamber means are aligned, delimiting a straight suction front, transverse to the central structural element, suitable for treating a relatively wide and clear surface; Fig. 1 B is a bottom plan view of the head for vacuum cleaner of Fig. 1A, with the side structural elements folded according to a second position in which the open chamber means delimit a suction front at a point suitable for reaching to corners and corners; Figs. 2A and 2B are enlarged detail views showing the joint area of Figs. 1A and 1 B, respectively; Fig. 3 is a top plan view of the head of the invention with the lateral bodies shown in dashed lines in said first position and in continuous lines in the second position; Fig. 4 is a partial, enlarged, cross-sectional view, taken along the line IV-IV of Fig. 1A; Fig. 5 is a top plan view of the head of the invention, from which an upper housing has been removed to show the operation of elastic means that tend to maintain the assembly in the first position shown in Fig. 1A; Fig. 6 is an enlarged partial bottom plan view of the head with the side bodies in the first position, from which some parts have been removed to show the assembly and operation of locking means for fixing the assembly in said first position; and Fig. 7 is an exploded perspective view of an articulation ball of a connecting sleeve for a conduction of connected fluid from the source of depression.

Detailed description of the preferred embodiments

Referring first to Figs. 1A and 1 B, the head for dust aspiration apparatus of the present invention is, in general, of the type comprising open-chamber suction means connected to a source of depression (not shown) through at least one appropriate conduction , such as a rigid tube 23 (partially shown in Fig. 3) which is generally extended by a flexible sleeve. The open chamber means are partially closed when the head is applied on the surface to be treated, defining at least one suction front, as is conventional in the art of the sector.

The essential feature of the head according to the present invention is that said open chamber means comprise lateral open chamber parts 10a, 10b integrated in lateral structural elements 12a, 12b and a central open chamber part 10c integrated in a central structural element 12c. Said structural elements 12a, 12b, 12c are hollow bodies, preferably of plastic material and obtained by injection molding, and are mechanically connected to each other in a mobile manner by means of a joint 13 that allows a rotation with respect to a common axis. The aforementioned axis of the articulation 13 is, when the head is in a working situation, substantially perpendicular to the surface to be treated, so that the hollow bodies laterals 12a, 12b pivot with respect to the central hollow body 12c in a plane substantially parallel to said surface.

The area of the joint 13 includes an opening 14 that communicates the central open chamber part 10c with said source of depression through the central hollow body 12c and said tube 23. The lateral open chamber parts 10a, 10b communicate with the central open chamber part 10c, and consequently with the opening 14, in a range of relative positions between a first position (Fig. 1A), wherein said open chamber parts 10a, 10b, 10c are substantially aligned delimiting a straight suction front, and a second position (Fig. 1 B), in which the lateral open chamber parts 10a, 10b are forming at each other an angle slightly lower than a right angle, with the central open chamber part 10c substantially at the vertex, delimiting a pointed angular suction front, suitable for vacuuming corners and / or corners, as expressly shown in Fig. 2.

It is described below, with reference to Figs. 2A and 2B, the special configuration of the articulation 13 which enables this continuous communication of the lateral open chamber parts 10a, 10b with the central open chamber 10c. The opening 14 occupies the central area of the joint 13, and around this opening 14 a cylindrical wall 17 is arranged coaxial to the common axis of the joint 13. Said cylindrical wall 17 is integral with the central hollow body 12c and has interruptions, openings or recesses 18 through which said communication of the lateral open chamber parts 10a, 10b is made with the central open chamber part 10c. As can be seen from Figs. 2A and 2B, this arrangement allows the flow between the open chamber parts 10a, 10b and 10c in the entire range of desired relative positions, while the portions of the cylindrical wall 17 substantially close the flow in other directions. In the area of the vertex there is a recess 19 in the form of a channel that allows a direct aspiration from said vertex towards the opening 14. The cylindrical wall 17 can also include other interruptions, openings or recesses that allow a flow between the opening 14 and the area of said vertex of the suction front, at least when the hollow bodies 12a, 12b, 12c are in said second position or close to the same. In an alternative embodiment not shown, each hollow body could have a corresponding cylindrical wall arranged coaxially around the opening 14 and provided with suitable interruptions. The relative rotation of the said coaxial cylindrical walls would place the interruptions in communication with one another depending on the angular position so that at all times the lateral open chamber parts would be communicated with the central open chamber part while the flow in Other addresses would be prevented. However, the exemplary embodiment illustrated in the figures has the advantage of providing a single cylindrical wall 17 incorporated in the periphery of a circular piece 37 provided with a flat annular portion 38, and a cavity in part of whose bottom and side is the opening is found 14. The circular piece 37 is screwed in its central part to the central hollow body 12c once the hollow lateral bodies 12a and 12b are mounted, so that it keeps the pieces in position and collaborates in guiding the rotation thereof to the time that said annular flat portion 38 covers the interfaces between said parts avoiding the flow of air and the penetration of dust therein.

Going back to Figs. 1A and 1 B, each of said lateral open chamber parts 10a, 10b, corresponding to each of said lateral structural elements 12a, 12b, is formed by a longitudinal groove 16 having a first end 16a communicating, in any of said desired relative positions, through said articulation 13, said opening 14 of the central open chamber part 10c being connected to the source of depression through the central structural element 12c. Optionally, said longitudinal groove 16 of each of said lateral structural elements 12a, 12b has a second end 16b that ends at a lateral end, distal of the joint 13, of the corresponding lateral structural element 12a, 12b. The said first ends 16a of the grooves 16 have their bottoms flush with the flat portion 38 of said circular piece 37, which facilitates the fluid communication between the lateral open chamber parts 10a, 10b with the central open chamber 10c.

Conveniently, and as is conventional in the art of the sector, the grooves 16 decrease in width and depth as they move away from the joint 13 and are flanked, on the side opposite the suction front, by a section of protruding lip 15 (see also Fig. 4), of flexible and elastic material, such as rubber, which prevents a flow towards the open chamber parts 10a, 10b, 10c from said opposite side in front of aspiration. Optionally, the central open chamber part 10c may also be partially flanked by said lip. Also, on the part corresponding to the suction front, means, possibly elastic, such as groups of bristles, can be arranged to partially restrict the incoming air flow. In the example illustrated in Figures 1A and 1 B there are also a plurality of small recesses in the form of channels 19a distributed between the grooves 16 and the front part of the hollow bodies 12a, 12b in order to provide a certain suction capacity by said frontal zone.

As illustrated in Fig. 3, it should be noted that although the length of the suction front remains constant in any of the possible positions, the width A1 of the suction front of the head disposed in said first position is substantially greater ( of the order of 20% greater) than the width A2 of the head of aspiration of the head arranged in said second position. This allows the machine power of the depression source to be optimized to the maximum without changing the head, since, with the head in the first position, shown in Fig. 1A, fewer consecutive parallel passes will be required to cover the same relatively wide and clear surface that if the head had a permanent configuration like that of Fig. 1 B, and on the other hand, with the head in the second position, shown in Fig. 1 B, there is easy access to corners and / or corners, such as the corners formed by two walls in a corner of a room, or hidden corners under furniture, whose access would be forbidden for a head that had a permanent configuration like that of Fig. 1A.

Since, usually, most of the time of use of the head is going to be in the treatment of relatively wide and clear surfaces, the head comprises elastic means that tend to keep the assembly in said first position, and blocking means of the rotation of the hollow lateral bodies 12a, 12b with respect to the hollow body central 12c, keeping the set fixed in said first position. These locking means are releasable by displacement of levers 9 located slightly protruding along the front parts of the lateral hollow bodies 12a, 12b. In Fig. 5 this arrangement of elastic means is shown, which comprise a spiral bending spring 11 with the coils arranged coaxially to the axis of the joint 13 and branches connected respectively to anchor points 34 located in the lateral structural elements 12a, 12b. Similarly, two helical tension springs (not shown) could be used, each disposed between the central hollow body 12c and a corresponding lateral hollow body 12a, 12b.

The said levers 9, as shown in Figs. 4 and 6, are longitudinally arranged in the front part of the hollow lateral bodies 12a, 12b, partially retracted in a slot provided between two parts or shells 35, 36 forming said hollow bodies. Each lever 9 (Fig. 6) is fixed to its corresponding hollow body by means of a screw or pin 31 which in turn constitutes a pivot with respect to which the lever 9 can rotate against the elastic force of a spring 44. Each lever 9 includes, at an end close to the central zone, a trigger 26 capable of engaging in a corresponding nail 27 of the central hollow body 12c. Thus, when the lever 9 is displaced, for example by contact with an obstacle, it releases the trigger 26 of the nail 27 then allowing the corresponding lateral hollow body 12a or 12b to rotate towards the second position. A reinforcing partition 55 of the upper shell 35 serves as support for said spring 44 and as an internal support of the flexible elastic lip 15 (Fig. 4), which is passed through a slit of the lower shell 36.

Thanks to this, the lateral structural elements 12a, 12b are capable of being plagued independently towards the second position under the influence of an external force. For example, when a relatively wide and clear surface is being treated, such as the central area of a room, the head is held in the first position, while, when pressed against a corner, the levers 9 are displaced by the effect of contact with the walls and release the locking means, bringing the head it adopts by itself only the required folded position, recovering again the first position when being removed from the corner due to the elastic force of the spring 11. Similarly, it can occur when the path of a single lateral structural element is interfered, for example, by a leg of a piece of furniture, in which case only this lateral structural element will fold momentarily towards its second position to then recover its first position. When the surface to be treated is very rough, for example, a carpet or carpet, and if the power of the machine is considerable, the blocking means will prevent the tendency of the head to fold towards its second position, overcoming the force of the spring 11, in the forward movements of the head. Instead of the levers 9, a mechanical locking element (not shown) that could be manually activated or deactivated at will be incorporated through a button or slide accessible from the outside. Referring now to Fig. 4 in conjunction with the other figures, the structural elements 12a, 12b, 12c comprise respective bottom surfaces, mutually coplanar, in which the corresponding longitudinal grooves 16 and the opening 14 are opened, being provided, said wheels 20, 20a protruding from said lower surfaces that maintain said mutually coplanar lower surfaces substantially parallel to said surface to be treated and at a predetermined height thereof, so that the head is easily movable on the surface to be treated when applied in operation. about it. In the illustrated embodiment, the central hollow body 12c has a pair of large and separate wheels 20 mounted on its back that provide stability to the assembly, while each of the lateral hollow bodies 12a, 12b has a small wheel 20a mounted in the shape of a kite.

It is evident that said wheels 20, 20a can be replaced by other members of contact with the surface to be treated, such as self-orientating wheels, skates, or sliding hemispherical stops, provided they perform the same function. Optionally, the head of the invention comprises means (not shown) for regulating the distance of the portion protruding from said wheels 20, 20a, or other contact members, from said lower surfaces, thereby regulating said predetermined height at least between two different levels, suitable for surfaces to be treated with different characteristics. In general, a hard and smooth floor requires a lower height of the open chamber means than a fluffy surface, such as a carpet or carpet.

As can be seen in Figs. 1A and 1 B, said central hollow body 12c comprises, in its lower rear part, an additional suction mouth 28 communicated with the central open chamber part 10c through an opening provided with a shutter 29 that can be optionally opened or closed. by the user depending on the type of surface to be treated. To this end, said shutter 29 is associated with a mechanism 43 of levers and cams connected to two pedals 30a, 30b, accessible from the outside, by means of an alternate actuation of which said shutter can be placed in open and closed positions, respectively. Said additional suction mouth 28 is flanked by longitudinal bars 39, slightly protruding and pivoting, which serve to restrict the flow of aspiration to the area immediately below the mouth 28.

The hollow bodies 12a, 12b, 12c, according to a preferred embodiment, are each formed by a pair of pieces, such as the shells 35, 36 of the lateral hollow bodies illustrated in Fig. 4, which are obtained by Injection molding of a plastic material and are fitted and fixed together by screws. Associated with the central structural element 12c, an upper housing 21 is provided to cover at least the joint 13, said elastic means, such as the spring 11, a large part of the lateral structural elements 12a, 12b when they are in said second position and the most of the large rear wheels 20. In the illustrated example, the central structural element 12c, in addition to said hollow portion constituting the central open chamber part 10c, has lateral extensions 40 intended to completely close the upper housing 21 by the bottom. Thus, in said central structural element 12c, cavities are formed below said extensions 40 laterals intended to partially receive the lateral structural elements 12a, 12b when they adopt said second folded position.

The pedals 30a and 30b emerge at their rear through openings of the upper housing 21. An articulated coupling 22 also emerges from an opening between said pedals to connect the central open chamber part 10c with said connection conduit 23 connecting to the source of depression. Said articulated coupling 22, the configuration of which is shown in detail in Fig. 7, comprises a hollow body in the form of a cylinder or barrel mounted so that it can rotate a certain angle around the axis of said cylinder or barrel in a suitable housing of the central hollow body 12c. This hollow body comprises a lateral opening 24 that communicates, whatever its angular position, with the open chamber 10c and a transverse coupling sleeve 25 protruding from a lateral area of the cylinder or barrel opposite to said opening 24. As is shown in Fig. 7, the hollow body 22 is formed by two identical halves 22a, 22b, coupled by the tongue and groove of fins 41 and grooves 42 formed in their edges. Each half piece 22a, 22b comprises one half of the cylinder or barrel, one half of the opening 24 and one half of the sleeve 25. The fact that the two halves 22a, 22b are identical allows them to be obtained from a plastic material by injection molding by a single set of relatively simple molds despite the complexity of the entire hollow body 22.

The described embodiment is merely illustrative, so that in no case should it be taken as limiting the object of the present invention, the scope of which is defined by the appended claims.

Claims

1.- Head for dust suction apparatus, of the type comprising open chamber suction means connected to a source of depression through at least one appropriate conduction, whose open chamber means are partially closed when the head is applied to a surface to be treated delimiting at least one suction front, the head comprising at least two hollow lateral bodies (12a, 12b) arranged on the side and side of a joint (13) that admits turns relative to a common axis which, with the head in working position, it is substantially normal to said surface to be treated, the lateral hollow bodies (12a, 12b) incorporating respective lateral open chamber parts (10a, 10b) pneumatically communicated with said source of depression such that said front of suction is of variable geometry, characterized in that said joint (13) is integrated in a central hollow body (12c) that includes a chamber part a central open (10c) connected to said source of depression through an opening (14) located in the area of the joint (13), pneumatic communication being made of the lateral open chamber parts (10a, 10b) with said part of central open chamber (10c) and opening (14) through said articulation (13) in a desired range of relative positions, and because said variable geometry suction front is continuous in any of said positions and encompasses, by means of said three lateral and central open chamber parts (10a, 10b, 10c), the two sides and the central articulation zone (13) of the head.

2. Head according to claim 1, characterized in that said desired range of relative positions between the lateral and central open chamber parts (10a, 10b, 10c) is obtained by independent rotation of the hollow lateral bodies (12a, 12b) with respect to the central hollow body (12c) between a first position in which said open chamber parts (10a, 10b, 10c) are substantially aligned, delimiting a straight transverse suction front, and a second position in which the parts Open-side camera (10a, 10b) are forming each other at an angle slightly lower than a right angle, with said opening (14) substantially at the vertex, delimiting a pointed angular suction front, suitable for corners and / or corners.

3. Head according to claim 2, characterized in that it comprises elastic means, such as one or more springs (11) connected between the hollow lateral bodies (12a, 12b) and the central hollow body (12c), which tend to keep the set in the said first position.

4. Head according to claim 3, characterized in that it comprises means for blocking the rotation of the lateral hollow bodies (12a, 12b) with respect to the central hollow body (12c), whose blocking means are releasable and in an active situation they keep the set fixed in the first position.

5. Head according to claim 4, characterized in that the release of said locking means is effected by displacement of levers (9) that protrude slightly along the front parts of the hollow side bodies (12a, 12b ), said displacement of at least one of said levers (9) being capable of being caused by any obstacle that comes into contact frontally with the corresponding lateral hollow body (12a, 12b) in its advance.

6. Head, according to claim 5, characterized in that each of said levers (9) is articulated by a pivot and elastically loaded, including a trigger (26) on a mobile end that engages by effect of said elastic load in a nail (27) of the central hollow body (12c), whose lever (9), when displaced against said elastic load, releases the trigger (26) from the nail (27) allowing then the rotation of the corresponding hollow lateral body (12a, 12b) towards the second position.

7. Head, according to claim 2, characterized in that each of said lateral open chamber parts (10a, 10b), corresponding to each of said lateral hollow bodies (12a, 12b), comprises at least one slot longitudinal (16) having a first end (16a) that communicates, at least in said desired relative positions, through said articulation (13), with said opening (14) of the central open chamber part (10c) connected to the source of depression through the central hollow body (12c), the bottoms of said first ends remaining (16a) of the grooves (16) flush with the bottom of the central open chamber part (10c).

8. Head, according to claim 7, characterized in that said joint (13) comprises a cylindrical wall (17) arranged around the opening (14) coaxially to the axis of the joint (13), whose cylindrical wall (17) It has some interruptions, openings or recesses (18) through which said communication of the lateral open chamber parts (10a, 10b) is made with the central open chamber part (10c) allowing the flow between the two in the range of desired relative positions while the portions of the cylindrical wall (17) substantially close the flow in other directions.

9. - Head, according to claim 8, characterized in that said cylindrical wall also includes at least one other interruption, opening or recess (19) that allows the flow through it between the opening (14) and the area of said vertex of the suction front, at least when the hollow bodies (12a, 12b, 12c) are in said second position or next to it.

10. Head, according to claim 9, characterized in that said cylindrical wall (17) is incorporated protruding from the periphery of a circular piece (37) provided with a flat annular portion (38), and a cavity in part of whose bottom and side is the opening (14), whose circular piece (37) is fixed to the central hollow body (12c) keeping the lateral hollow bodies (12a and 12b) in position and collaborating in guiding their rotation to the time that said annular flat portion (38) covers the interfaces between said pieces avoiding the flow of air and the penetration of dust therein.

11. - Head according to claim 1, characterized in that said central hollow body (12c) comprises, in its lower rear part, an additional suction mouth (28) communicated with the central open chamber part (10c) through of an opening provided with a shutter (29) that can be optionally opened or closed by the user depending on the type of surface to be treated.

12. - Head, according to claim 11, characterized in that said shutter (29) is associated with a lever and cam mechanism connected to two pedals (30a, 30b) accessible from the outside to place said shutter in open positions and closed respectively.

13. Head, according to claim 7, characterized in that said longitudinal groove (16), which is at least one, of each of said lateral hollow bodies (12a, 12b) has a second end (16b) that flows into a lateral end, distal of the joint (13), of the corresponding hollow lateral body (12a, 12b).

14. - Head, according to claim 7, characterized in that the hollow bodies (12a, 12b, 12c) comprise respective lower surfaces, mutually coplanar, in which the corresponding longitudinal grooves (16) and the opening (14) are opened. ), being provided, protruding from said lower surfaces, contact members with the surface to be treated, such as wheels (20, 20a), skates, or sliding hemispherical stops, which keep said mutually coplanar bottom surfaces substantially parallel to said surface to be treated and at a predetermined height thereof, so that the head is easily movable on the surface to be treated when it is applied in operation thereon.

15. - Head, according to claim 14, characterized in that it comprises means for regulating the distance that said contact members protrude from said lower surfaces, thereby regulating said predetermined height at least between two different levels, suitable for surfaces To try different characteristics.

16. Head, according to claim 7, characterized in that said grooves (16) decrease in width and depth as they move away from the joint (13).

17. Head according to claim 7, characterized in that said grooves (16) and / or opening (14) are flanked, on the opposite side to the suction front, by an protruding lip (15), of flexible material and elastic, such as rubber, which prevents a flow to the respective parts of open chamber (10a, 10b, 10c) coming from said side opposite the suction front.

18. Head, according to claim 1, characterized in that the hollow bodies (12a, 12b, 12c) are each formed by at least two pieces that can be fixed and fixed together, obtained by injection molding of a plastic material, being provided an upper housing (21) associated with the central hollow body (12c) to cover at least the joint (13), said elastic means (11), and part of the lateral hollow bodies (12a, 12b) when they are in said second position, through whose upper housing (21) emerges an articulated coupling (22) of the central open chamber part (10c) with said conduction connection to said depression source, also protruding through said upper housing (21) pedals (30a, 30b) connected through a lever and cam mechanism to a shutter (29) for opening and closing an additional suction mouth (28) located in the lower rear part of the central hollow body ( 12c ) and communicated with the central open chamber part (10c).

19. - Head according to claim 18, characterized in that said articulated coupling (22) comprises a hollow body in the form of a cylinder or barrel mounted so that it can rotate a certain angle around the axis of said cylinder or barrel in a housing suitable of the central hollow body (12c), said hollow body comprising a lateral opening (24) communicated in any of its positions with the open chamber (10c) and a transverse coupling sleeve (25) protruding from an opposite lateral area, being said hollow body (22) formed by two identical halves (22a, 22b), coupled, each of which comprises a half of the cylinder or barrel, a half of the opening (24) and a half of the sleeve (25).