Base plate for a vacuum cleaner suction head for the suction of fine dust and large debris

Abstract

A base plate for a vacuum cleaner suction head is described, said base plate comprising a lower face, an upper face and a base plate channel open towards the surface to be vacuumed. The channel extends across the whole width of the base plate. The base plate channel comprises a front edge and a rear edge. The lower face comprises: a first surface which extends along the whole front edge of the channel and a second surface which extends along the whole rear edge of the channel, the first and second surfaces lying in a same horizontal plane. The lower face also comprises a front inclined surface extending from said first surface towards the front side. According to the invention, the front inclined surface is inclined upwards so that the front side is raised with respect to the surface to be vacuumed.

Claims

1. A base plate for a suction head for a vacuum cleaner, the base plate comprising: a lower face configured so as to be directed towards a surface to be vacuumed, an opposite upper face, and a base plate channel open towards the surface to be vacuumed, wherein said lower face comprises a front side, a rear side and two lateral sides, wherein said base plate channel extends across a width of said base plate, wherein the base plate channel comprises a front edge and a rear edge, wherein the lower face comprises: a first surface extending along the entire front edge of the base plate channel and extending towards the front side of the base plate over a first length; a second surface extending along the entire rear edge of the base plate channel and extending towards the front side of the base plate over a second length, wherein the first and second surfaces lie in a common horizontal plane; and a front inclined surface extending from said first surface towards the front side; wherein said front inclined surface is inclined upwards so that the front side is raised with respect to the surface to be vacuumed; wherein said front inclined surface is inclined at a front angle of attack of between 10° and 20°; and wherein the first length is shorter than the second length.

2. The base plate of claim 1, wherein said front inclined surface is inclined at an angle of attack of between 11° and 14°.

3. The base plate of claim 1, wherein said front inclined surface extends directly from a most forward edge of the first surface, without any curved surface between said front inclined surface and said first surface.

4. The base plate of claim 1, wherein the front side is raised by 2.0-5.0 mm from the surface to be vacuumed.

5. The base plate of claim 1, wherein said first surface extends by 1.0 to 10.0 mm towards said front side.

6. The base plate of claim 1, wherein said second surface extends by 2.0 to 10.0 mm towards said rear side.

7. The base plate of claim 1, comprising also a rear inclined surface which extends from said second flat surface to the rear side.

8. The base plate according to claim 7, wherein said rear inclined surface is inclined at rear angle of attack smaller than the front angle of attack.

9. The base plate of claim 7, wherein said rear inclined surface extends directly from a rearmost edge of the second flat surface, without any curved surface between said rear inclined surface and said second flat surface.

10. The base plate of claim 1, wherein the base plate channel has a front surface inclined at an angle relative to the surface connecting the front edge and the rear edge and wherein the base plate channel has a rear surface inclined at the same angle with respect to a surface connecting the front edge and the rear edge.

11. The base plate of claim 10, wherein the front edge is shaped with a nose facing the rear edge.

12. The base plate of claim 1, wherein said channel has closed ends at the lateral sides of said base plate and wherein said base plate comprises also a third and a fourth horizontal flat surface extending from end edges of the base plate channel to respective short sides of the base plate so that a single flat surface formed by the first flat surface, the second flat surface, the third flat surface and the fourth flat surface is formed around a whole perimeter of the base plate channel.

13. The base plate of claim 1, wherein at least one end of said channel comprises a hole or an aperture.

14. The base plate of claim 1, further comprising a first strip of velvet or the like on said front inclined surface and a second strip of velvet on said flat rear surface.

15. A suction head comprising: a base plate comprising a base plate channel which is open towards a surface to be vacuumed; a suction channel in fluid communication with the channel of the base plate; and a covering body connected to at least one of said base plate and said suction channel; wherein the base plate comprises a lower face configured to be directed towards the surface to be vacuumed and an opposite upper face, the base plate channel comprising a front edge and a rear edge, wherein said lower face a front side, a rear side and two lateral sides; wherein said base plate channel extends across a width of said base plate; wherein the lower face comprises: a first surface extending along the entire front edge of the base plate channel and extending towards the front side of the base plate over a first length; a second surface extending along the entire rear edge of the base plate channel and extending towards the front side of the base plate over a second length, wherein the first and second surfaces lie in a common horizontal plane; and a front inclined surface extending from said first surface towards the front side; wherein said front inclined surface is inclined upwardly so that the front side is raised with respect to the surface to be vacuumed, wherein said front inclined surface is inclined by a front angle of attack comprised between 10° and 20°; and wherein the first length is shorter than the second length.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The present invention will become completely clear from the following detailed description, provided purely by way of a non-limiting example, to be read with reference to the accompanying drawings, in which:

(2) FIG. 1 is a view of a suction head with base plate according to a first embodiment of the invention;

(3) FIG. 1.1 is an enlarged view of a portion of the suction head of FIG. 1;

(4) FIG. 1.2 is an enlarged view of a variant of the suction head of FIG. 1;

(5) FIG. 2 is a bottom plan view of the base plate of the suction head according to FIG. 1;

(6) FIG. 3 is an axonometric view of the base plate of the suction head according to FIG. 1;

(7) FIG. 4 is a cross-sectional view of the base plate of the suction head according to FIG. 1;

(8) FIGS. 5 and 6 are an axonometric views of a second embodiment of the invention; and

(9) FIGS. 7 and 8 are axonometric views of a third embodiment of the invention.

DETAILED DESCRIPTION

(10) FIG. 1 shows by way of example a first embodiment of a suction head 1 of a vacuum cleaner or the like with a base plate 2 mounted in accordance with an embodiment of the present invention.

(11) The suction head 1 according to the invention is particularly suitable for vacuuming surfaces such as carpets, rugs, doormats, matting or the like. However, it is also effective for smooth and compact surfaces such as floors made of stone (marble or the like), terracotta, clinker, cement, resin, tiles, parquet or the like, in particular when used together with bristles and/or extruded (or co-moulded) profiles which may vary their configuration according to needs.

(12) As shown in the various figures, the base plate has a lower face 2A directed towards the surface to be vacuumed and an opposite upper face 2B which is connected to the brush body 8 or to other components of the suction head.

(13) The suction head 1 has a suction channel 4 which, during use, is joined to the base plate 2 and is fluid communication with a base plate channel 3 and optionally a covering body which can be connected to the base plate and/or to the suction channel. The other end of the suction channel 3 communicates with a suction tube usually via a joint 7 which may be rotatable or non-rotatable.

(14) The base plate 2 may have any form, but typically has a roughly rectangular shape with a front side 21, a rear side 22 and two shorter lateral sides 23, 24.

(15) According to the first embodiment, the base plate channel 3 has a front edge 31, a rear edge 32 and two end edges 33 and 34.

(16) As shown in FIG. 1 and in FIGS. 1.1 and 1.2, the base plate channel 3 has a front surface 311 inclined at an angle β (beta) relative to the surface connecting the front edge 31 and the rear edge 32.

(17) The base plate channel 3 has a rear surface 321 inclined substantially of the same angle β (beta) with respect to the surface connecting the front edge 31 and the rear edge 32. The inclination of the two front and back surfaces is such that the two surfaces converge upwards. The value of the angle β is less than 90° and is preferably greater than 80°. More preferably, the angle β is between 82° and 86°. Even more preferably it is between 83° and 85°.

(18) As shown in FIG. 1 and, even more clearly in FIG. 1.1, to increase the forward scraping effect, the front edge 311 is shaped with a nose 31′ facing the rear edge 31.

(19) According to the present invention, the lower face of the base plate comprises a first front flat surface H1 and a second rear flat surface H2. The first and second flat surfaces H1, H2 lie in the same plane. This common plane of lying substantially coincides with the plane of the surface to be vacuumed or is substantially parallel thereto and at a minimum distance therefrom.

(20) According to the alternative embodiment of FIG. 1.2, the front surface 311 form substantially a sharp edge with the front flat surface H1, i.e. with a minimum radius of curvature, necessary for production reasons. For example, the radius of curvature is 1 mm or less. Such a sharp edge increases the scraping effect over the known embodiments having curved edges, as for instance EP 1964501. As shown in FIG. 1 and in FIGS. 1.1 and 1.2, the rear surface 321 form a sharp edge with the rear flat surface H2. Also this rear sharp edge increases scraping effect when the nozzle is moved backwardly.

(21) The first flat surface H1 is delimited by the front edge 31 of the base plate channel 3 and extends towards the front side 21 of the base plate 2 over a first length L1. The first length L1 may be between 1.0 mm and 10.0 mm. However, according to embodiments, L1 is less than 5.0 mm. According to other embodiments, L1 is less than 4.0 mm. Preferably it is greater than 2.0 mm. According to a preferred embodiment, L1 is between 2.5 and 3.0 mm. In any case, the first flat surface extends over an area such as to ensure suitable sealing of the mouth of the base plate channel when the suction head is in contact with the surface to be vacuumed (which may be for example a carpet, a rug or a surface of this type). Therefore, the first flat surface is a substantially thin surface.

(22) The second flat surface H2 is delimited by the rear edge 32 of the base plate channel 3 and extends towards the rear side 22 of the base plate 2 over a second distance L2. The second distance L2 may be a few mm, for example 2.0-10.0 mm or more.

(23) According to variants of the first embodiment, the lower face of the base plate also comprises a third lateral flat surface H3 and a fourth lateral flat surface H4.

(24) The third and fourth flat surfaces extend from the end edges 33 and 34 of the base plate channel 3 to the respective short sides 23, 24 of the base plate. In this way, a single flat surface formed by the surfaces H1, H2, H3 and H4 extends around the entire perimeter of the base plate channel. This surface (or also only the surface formed by the first and second flat surfaces H1 and H2) forms a seal with respect to the surface to be vacuumed and limits the losses, increasing consequently the suction efficiency.

(25) According to the present invention, an inclined front surface I1 is provided in front of the first horizontal flat surface H1. The inclined front surface I1 extends from the first flat surface towards the front side 21, namely the inclined front surface I1 starts directly where the first horizontal flat surface H1 ends, substantially without a curved surface between them. Preferably, the inclined front surface I1 extends as far as the front side 21 of the base plate 2.

(26) The inclined front surface I1 is inclined with respect to the horizontal at an angle of attack α (alpha), as shown in FIG. 4 and also in FIGS. 1.1 and 1.2. The value of the angle of inclination is preferably greater than 10°. Preferably it is less than 20°. Preferably, the value of the angle of inclination is between 10° and 15°. The Applicant has carried out various tests varying the angle of inclination and has concluded that an optimum value is between 11° and 14°, for example 12° or 13°.

(27) Owing to this inclined front surface I1, the front side 21 of the base plate 2, during use, is raised with respect to the surface to be vacuumed. This raised configuration favours capturing of large-size debris which is not pushed forwards or downwards in the event of surfaces with bristles (such as rugs or carpets). In addition, the inclined front surface I1 provides a “surf effect” on carpets or the like. Namely, it increases the capability to surf and slide on carpets, rugs, doormats, matting or the like.

(28) The Applicant has in particular established that the inclination of the inclined front surface I1 must be such as to raise the front side 21 of a height P1 equal to some millimetres, for example 2-5 mm. Raising by more than 5 mm was considered to be excessive. Raising by less than 1 mm was unable to ensure the efficient suction of large-size debris of the type mentioned above. According to preferred embodiments, the front side 21 is preferably raised by 3-4 mm, for example 3.5 mm.

(29) Preferably, an inclined rear surface I2 is provided at the rear with respect to the second horizontal flat surface H2. The inclined rear surface I2 extends from the second flat surface to the rear side 212, i.e. the inclined rear surface I2 starts directly where the second horizontal flat surface H2 ends, substantially without a curved surface between them. Preferably, the inclined rear surface I2 extends up to the rear side 22 of the base plate 2.

(30) The inclined rear surface I2 is inclined with respect to the horizontal plane of a rear angle of attack γ (gamma) as shown in FIG. 4 and also in FIGS. 1.1 and 1.2 is smaller than the front angle of attack α. The value of the rear angle of attack γ is preferably less than 10°. Preferably, it is greater than 5°. Preferably, the value of the rear angle of attack is between 6° and 8°. Also the inclined back surface I2 provides a “surf effect” on carpets or the like when the nozzle is moved backwardly. The nozzle becomes less attracted to the carpet.

(31) According to embodiments of the present invention, there may be strips of velvet (or other similar material suitable for capturing very fine dust or small-size material) 36F, 36R along (at least) the central part of the base plate channel 3. Preferably there is a front strip of velvet 36F which is inset with respect to the inclined front surface I1 and a rear strip of velvet 36F which is inset with respect to the second (rear) flat surface H2. In the present description and in the claims, the term “velvet” is used to indicate not only velvet, but also (synthetic or natural) felt or in any case a surface suitable for capturing and trapping particularly small particles (for example fine dust).

(32) Preferably, as shown in FIGS. 2-4, the base plate is provided with two rear wheels 9 for favouring the movement of the suction head over the surface to be vacuumed. During the movement of the suction head, the base plate 2 of the suction head makes sliding contact with the surface to be vacuumed along the first and second flat horizontal surfaces H1, H2 (as well as the fourth and fifth flat surfaces H3 and H4) and rests on the rear wheels 9. The rear wheels 9 project at the bottom only over a small height or in any case such as to keep the horizontal flat surfaces H1 and H2 in contact with the surface to be vacuumed.

(33) FIGS. 5 and 6 show a second embodiment of the present invention. The suction head of the second embodiment is identical to the suction head of the first embodiment and will not be described again in detail. The difference lies in the fact that the base plate channel 3 is not closed at the ends, but has at least one hole 60 formed in at least one of the two ends. The hole may be circular (as shown in FIGS. 5 and 6), oval, square, rectangular or any other shape. The purpose of the hole 60 is to reduce the suction power which tends to cause the suction head “to stick” on the ground with a suction effect. Due to the holes 60, the suction pressure diminishes and reduces correspondingly the force needed to move the suction head forwards and backwards. Preferably, a strip of material not smaller than 2 mm, preferably not smaller than 2.5 mm, is provided underneath the hole 60 so as not to weaken the end zone of the base plate channel. Depending on the surface to be vacuumed, the holes may also be at least partially closed, for example with a small stopper or the like (not shown).

(34) FIGS. 7 and 8 show a third embodiment of the present invention. The suction head of the third embodiment is identical to the suction head of the first embodiment and will not be described again in detail. The difference lies in the fact that the base plate channel 3 is not closed at the ends, but has at least one aperture 61 formed in at least one of the two ends. The aperture 61, differently from the hole 60, does not have a bottom closing side, facing the surface to be vacuumed. The purpose of the aperture 61 is to reduce the suction power which tends to cause the suction head “to stick” on the floor with a suction effect. Due to the apertures 61, the suction pressure diminishes and reduces correspondingly the force needed to move the suction head forwards and backwards. Depending on the surface to be vacuumed, the apertures may be at least partially closed, for example with a small stopper or the like (not shown).

(35) According to other embodiments, not shown, one end of the channel 3 has a hole and the other end has an aperture.