CN114554921B

CN114554921B - Vacuum cleaner head for a vacuum cleaner

Info

Publication number: CN114554921B
Application number: CN202080071249.5A
Authority: CN
Inventors: S.科赫
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2019-10-10
Filing date: 2020-09-23
Publication date: 2024-02-23
Anticipated expiration: 2040-09-23
Also published as: GB201914650D0; GB2588155B; CN114554921A; WO2021069862A1; GB2588155A

Abstract

The invention relates to a cleaner head (10) for a vacuum cleaning appliance (2), comprising: a main body (12) defining an agitator chamber (40) in which a rotatable agitator assembly (42) is supported, and a suction opening (28) through which a portion of the agitator assembly (42) protrudes to engage a surface to be cleaned. The body (12) includes a front portion (18) and a rear portion (22). The rear portion (22) defines an outlet (32) of the cleaner head (10), and the front portion (18) includes a deflector plate (47) comprising deflector surfaces (50 a, 50b, 50 c) which in use are impacted by dirt particles excited by rotation of the agitator assembly (42). The deflecting surface (50 a, 50b, 50 c) is configured to deflect the energized dirt particles in an upward direction and across the agitator assembly (42) in a direction away from the suction inlet (28) and toward the discharge outlet (32).

Description

Vacuum cleaner head for a vacuum cleaner

Technical Field

The present invention relates generally to vacuum cleaners and, more particularly, to a cleaner head or floor tool forming part of a vacuum cleaner. The invention relates in particular to a rotationally driven agitator for use in such a cleaner head, whether the cleaner head is permanently or removably secured to a respective vacuum cleaner. The type of vacuum cleaner is not important to the invention and the invention may thus relate to so-called bagless or bagless vacuum cleaners.

Background

Vacuum cleaning appliances or more simply "vacuum cleaners" generally comprise a main body provided with a suction source and a dust separator, wherein the cleaner head is typically connected to the dust separator by a separable coupling. The cleaner head has a suction opening through which the cleaner head engages a surface to be cleaned and through which dirt-laden air is drawn into the vacuum cleaner towards the dust separator. The cleaner head plays a critical role in the effectiveness of a vacuum cleaner in cleaning dirt from a surface, whether it is a hard floor covering such as wood or stone, or a soft floor covering such as carpeting. Accordingly, vacuum cleaner manufacturers have struggled to optimize cleaner head designs to improve pick-up performance.

Some cleaner heads are passive devices that rely on stationary elements such as so-called "active edges" and bristle bars to remove dirt from the floor covering. These types of cleaner heads are relatively simple, but generally they have limited effectiveness in removing dirt from a surface. In general, they are mainly recommended for hard surfaces.

Traditionally, the most effective cleaner heads have included some sort of powered brush bar or agitator. In a known example, the agitator is driven by a turbine, which is actuated by the airflow through the cleaner head. Other known devices include the use of an electric motor arranged to drive an agitator. In these known arrangements, the motor is typically coupled to the agitator by a suitable drive linkage, such as a belt or gear mechanism, although it is also known that the motor is housed within the agitator, which provides a particularly space-saving arrangement.

In either example, the powered agitator is used to wipe and beat a floor surface to enhance the ability of the cleaner head to remove dirt from the surface. A common configuration is for the agitator to have an array of bristles extending radially outwardly from the surface of the agitator. Bristles are typically relatively stiff so that as the agitator rotates, they positively engage the floor surface, thereby acting as a means to scrape and strike the floor surface to loosen embedded particles. Other strips of material such as rubber and carbon fiber filaments may be used to provide additional characteristics to the agitator. For example, US8782851B2 describes an agitator which may be provided with a combination of relatively stiff bristles, carbon filaments and rubber strips.

An important design challenge is to optimise the way air flows through the cleaner head, from where it enters the interior of the cleaner head through the suction inlet, to where it exits from the outlet towards the dust separator. It is well known that air flow velocity is an important factor in pick-up performance, as dirt particles are transported more efficiently when the velocity of the air flowing through the tool is high. This is especially true for energetic particles such as sand. Because of the small and relatively heavy nature, such particles tend to spray at high speed from the floor surface and into the interior of the cleaner head where they tend to bounce out of order around the cleaner head. High airflow rates are required to carry dirt particles in the air into the cleaner head and to transport these particles out of the cleaner head towards the dust collector. However, at low air flow rates, these heavy particles will be more likely to deposit back onto the floor covering. It will thus be appreciated that maintaining good pick-up performance is challenging, especially at lower cleaner head airflow speeds.

Although high airflow rates can be achieved by equipping the vacuum cleaner with a high power vacuum motor, this is generally undesirable because it means that the machine is less efficient, which is a significant disadvantage of battery powered vacuum cleaners, where energy efficiency has a direct impact on the available run time. It is therefore desirable for the cleaner head to be able to efficiently pick up relatively heavy dirt particles from a floor surface without the need for high airflow rates.

It is against this background that the present invention has been devised.

Disclosure of Invention

According to an aspect of the present invention there is provided a cleaner head for a vacuum cleaning appliance, the cleaner head comprising: a main body defining an agitator chamber in which a rotatable agitator assembly is supported, and a suction inlet through which a portion of the agitator assembly protrudes to engage a surface to be cleaned, wherein the main body comprises a front portion and a rear portion, the rear portion defining a discharge outlet of the cleaner head; and wherein the front portion comprises a deflector plate comprising a deflector surface which in use is impacted by dirt particles excited by rotation of the agitator assembly, and wherein the deflector surface is configured to deflect the excited dirt particles in an upward direction and across the agitator assembly in a direction away from the suction inlet and towards the discharge outlet of the cleaner head. In this way, the initial energy of the dirt particles is used to direct them towards the discharge opening while avoiding any accidental collisions which could result in the dirt particles returning to the agitator chamber due to unintentional collisions or due to being not entrained in the air flow through the dust channel. This not only improves the pick-up performance of the cleaner head, but also reduces the air flow rate through the cleaner head, thereby reducing the energy consumption of the vacuum cleaning appliance.

Preferably, the deflector plate comprises a plurality of deflector surfaces which are arranged together to define the fresnel reflector in cross section. By having a plurality of series of deflection surfaces, a series of sequential and directional collisions can be used to reduce the energy of the dirt particles. By arranging the plurality of deflector surfaces to define a fresnel reflector in cross-section, dirt particles can be directed to a common point, possibly where the airflow is greatest in the cleaner head.

Preferably, the deflection plate comprises a plurality of deflection panels, each deflection panel comprising a respective deflection surface of the plurality of deflection surfaces.

Preferably, the plurality of deflector plates are arranged side by side in a direction substantially aligned with the longitudinal axis of the agitator assembly. This ensures that all dirt particles excited by the agitator assembly are directed to the plurality of deflector plates.

Preferably, the plurality of deflection panels are arranged in an arcuate manner.

Preferably, the discharge outlet defines a discharge outlet axis, and one or more of the plurality of deflection surfaces are angularly offset from the discharge outlet axis by a respective offset angle. This arrangement establishes a minimal path for dirt particles deflected from the deflecting surface across the agitator assembly towards the discharge outlet.

Preferably, each of the plurality of deflection surfaces is located at a respective panel distance from a point on the discharge outlet axis, and wherein for the respective deflection surface, the panel distance is proportional to its deflection angle. This arrangement ensures that the deflector surfaces are positioned in front of the suction opening regardless of their orientation relative to the discharge opening.

Preferably, one or more of the plurality of deflection surfaces that are angularly offset from the discharge outlet axis have a substantially perpendicular relationship with an imaginary line extending from the one or more deflection surfaces to intersect the discharge outlet axis.

Preferably, one or more of the plurality of deflection surfaces comprises a first surface portion and a second surface portion, the surface portions being separated by a substantially horizontal dividing line.

Preferably, the first surface portion is configured to deflect the excited dirt particles in a direction towards the second surface portion.

Preferably, the second surface portion is configured to deflect the excited dirt particles in a direction across the agitator assembly. More preferably, the second surface portion is configured to deflect the excited dirt particles deflected by the first surface portion in a direction across the agitator assembly.

Preferably, the first and/or second surface portions have a concave profile in vertical cross section.

Preferably, the first and/or second surface portions have a concave profile in horizontal cross section. The path of deflection of the dirt particles is thus narrowed towards a point due to the concavity of the deflection surface. This arrangement avoids any intentional interaction between the deflected dirt particles and the side walls of the front portion, which would dissipate the energy of the deflected dirt particles and retain them in the front portion, or even return to the agitator chamber.

Preferably, the deflector plate at least partially defines a dust passage extending rearwardly beyond the agitator assembly. The dust channel establishes an air flow circuit for dirt particles extending from the agitator chamber to the discharge opening.

Preferably, the dust channel comprises an inlet for receiving the excited dirt particles from the agitator chamber and an outlet in communication with the discharge outlet.

Preferably, the inlet of the dust channel extends substantially over the longitudinal width of the agitator assembly. This ensures that all dirt particles excited by the agitator assembly are directed into the dust channel.

Preferably, the width of the dust passage is tapered between the inlet and the outlet. This increases the airflow velocity towards the dust channel outlet.

Preferably, the main body further comprises a middle portion partially defining the dust passage.

Preferably, the front portion is removable from the body. The fact that the front part is removable from the main body enables it to be cleaned separately from the other components of the cleaner head.

Preferably, the deflecting surface is pivotally attached to the body.

According to another aspect of the present invention there is provided a vacuum cleaning appliance comprising a cleaner head according to the preceding aspect.

Within the scope of the present application, it is evident that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and/or in the following description and drawings, particularly the individual features thereof, may be employed independently or in any combination. That is, features of all embodiments and/or any embodiments may be combined in any manner and/or combination unless such features are incompatible. Applicant reserves the right to alter any initially filed claim or correspondingly filed any new claim, including modifying any initially filed claim to depend on and/or incorporate any feature of any other claim, even though not initially claimed in this manner.

Drawings

The above and other aspects of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

figure 1 is a front perspective view of a vacuum cleaner comprising a cleaner head according to an embodiment of the invention;

figure 2 is a front perspective view of the cleaner head of figure 1;

figure 3 is a bottom view of the cleaner head of figure 1;

figure 4a is a rear perspective view of the front of the cleaner head of figure 1;

FIG. 4b is a horizontal cross-sectional view of the front portion of FIG. 4 a; and

figure 5 is a schematic vertical section through the centre of the cleaner head of figure 1.

In the drawings, like features are denoted by like reference numerals.

Detailed Description

Specific embodiments of the invention will now be described in which several features will be discussed in detail in order to provide a thorough understanding of the inventive concepts defined in the claims. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details, and in some cases, with the aim of avoiding unnecessary obscuring the present invention, that well-known methods, techniques, and structures are not described in detail. Furthermore, references to "left", "right" and any other terminology with implicit orientation in the following description are not intended to be limiting, but merely refer to the orientation of features as shown in the accompanying drawings.

Figure 1 shows a vacuum cleaning appliance or vacuum cleaner 2 according to an embodiment of the invention comprising a dirt and dust separating unit 4, a motor-driven fan unit 6 and a cleaner head 10. The vacuum cleaner 2 further comprises a wand 8 which connects the dirt and dust separating unit 4 with the cleaner head 10. The motor-driven fan unit 6 sucks dirt-laden air from a surface to be cleaned, such as a floor surface, through the cleaner head 10 to the dirt and dust separation unit 4, where dirt and dust particles are separated from the dirt-laden air and relatively clean air is discharged from the vacuum cleaner 2. The dirt and dust separating unit 4 shown in this example is a cyclonic separating unit, but it will be appreciated by those skilled in the art that the separating unit 4 is not critical to the invention and that the cyclonic separating unit may be replaced with alternative separating units or a combination of different separating units. Similarly, the nature of the vacuum cleaner 2 is not important to the present invention. The vacuum cleaner 2 shown in figure 1 is a stick vacuum cleaner, but it will be appreciated that the cleaner head 10 disclosed herein may be used with other types of vacuum cleaners, such as upright or cylinder vacuum cleaners.

Referring to figure 2, the cleaner head 10 comprises a main body 12 rotatably attached to a coupler 14, the coupler 14 being removably connected to the wand 8. However, it will be apparent to the skilled reader that the invention is also intended to encompass cleaner heads which are configured to be permanently secured to their respective vacuum cleaners.

The body 12 includes a housing 16 that includes front, middle and rear portions 18, 20, 22 and a lower body panel or base 24. The front portion 18 extends rearwardly over a central portion of the central portion 20 and is connected to the base plate 24 by releasable fasteners (not shown) that are insertable through recesses formed in the base plate 24 so that the front portion 18 is removable from the body 12. The sole plate 24 defines a generally rectangular suction opening 28 through which, in use, dirt-laden air is drawn into the cleaner head 10 from a surface to be cleaned, such as a floor surface. The coupling 14 comprises a conduit supported by the rolling assembly 34 for supporting the cleaner head 10 on a floor surface. The conduit includes a front portion connected to a discharge port 32 formed in the rear portion 22 of the housing 16, and a rear portion pivotally connected to the front portion. The portion of the coupling 14 defining the rear portion of the catheter comprises fixing means 36 for connecting the free end 38 of the coupling 14 to the rod 8. A rigid curved hose means is retained within the conduit and extends between the front and rear portions of the conduit.

Referring to figure 3, two wheels 27 are mounted in recesses in the bottom surface of the sole plate 24 for supporting the cleaner head 10 on a floor surface. The wheels 27 are configured to support the sole plate 24 above a hard floor surface when the cleaner head 10 is positioned on the floor surface and are configured to sink into the pile of a carpet when the cleaner head 10 is positioned on a carpeted floor surface so that the bottom surface of the sole plate 24 can engage the fibres of the carpet. The sole plate 24 is movable relative to the housing 16 to allow it to float smoothly on a carpeted floor surface during cleaning.

The interior volume of the body 12 includes an agitator chamber 40 defined in part by the central portion 20 of the housing 16 and the floor 24. The cleaner head 10 further comprises an agitator assembly 42 comprising a generally cylindrical body 44 mounted within the agitator chamber 40, the body 44 being rotatable about its longitudinal axis. The cylindrical body 44 houses an electric motor and a drive mechanism that connects the agitator assembly 42 to the electric motor for driving the cylindrical body 44 about its longitudinal axis. Such agitator drives are known and will not be explained in detail. The agitator assembly 42 also includes a plurality of agitators 46 extending outwardly from the outer radial surface of the cylindrical body 44. The agitator 46 may comprise one or more of a plurality of soft wires, have tips, bristles or a continuous strip of material that can flex relative to the cylindrical body 44 when in contact with a floor surface, and may be made of carbon fiber or nylon, just to name two common materials. The agitator assembly 42 is arranged such that the agitator 46 protrudes through the suction inlet 28 as it rotates to sweep dirt and dust particles and other debris (hereinafter referred to as "dirt particles") from the hard floor surface and carpet surface into the agitator chamber 40. In this example, the electric motor and drive mechanism are arranged to rotate the agitator assembly 42 in a direction such that the agitator 46 sweeps the floor surface rearwardly toward the rear 22 of the housing 16. In this case, most of the dirt particles excited by the rotation of the agitator assembly 42 are swept toward the rear of the agitator chamber 40, and a small but still significant proportion of the dirt particles are thrown forward toward the front of the agitator chamber 40.

The agitator chamber 40 is in fluid communication with a dust channel 52, the dust channel 52 being defined by the inner side 49 of the front portion 18 of the housing 16 for receiving dirt particles thrown forward by the agitator assembly 42 towards the front of the agitator chamber 40. Referring to fig. 4a, in this example, the front portion 18 of the housing 16 includes a deflector plate 47, a top panel 66 and two side walls 76, 78, the deflector plate 47 being arranged to be located forward of the suction inlet 28 in the base plate 24, the top panel 66 extending substantially horizontally from an upper end of the deflector plate 47. The deflector plate 47 at least partially defines a dust channel 52. The top panel 66, which is generally fan shaped, and the two side walls 76, 78 converge to define the outlet 56, which outlet 56 is in fluid communication with the discharge outlet 32 formed in the rear portion 22 of the housing 16 when the cleaner head 10 is assembled, thereby establishing an air flow circuit through the dust channel 52 from the agitator chamber 40 to the discharge outlet 32.

The deflector plate 47 includes a plurality of deflector panels 48 arranged side-by-side, generally in a direction substantially aligned with the longitudinal axis of the agitator assembly 42. In this example, the deflector plate 47 includes five discrete deflector panels 48, the inner surfaces of which define respective deflector surfaces, generally indicated at 50a, 50b, 50 c. The deflection panels 48 each include a first panel portion 61 and a second panel portion 62 above the first panel portion 61, the second panel portion being separated from the first panel portion 61 by a generally horizontal dividing line 63. Similarly, the deflection surfaces 50a, 50b, 50c each include a first surface portion 64 located inboard of the first panel portion 61 and a second surface portion 65 located inboard of the second panel portion 62. Generally, the deflector surfaces 50a, 50b, 50c are configured to deflect, in use, dirt particles thrown forward by the agitator assembly 42 through the dust channel 52 in an upward direction and across the agitator assembly 42 toward the outlet 56.

Referring to fig. 4b, the deflector panels 48 are arranged such that the deflector surfaces 50a, 50b, 50c together define a fresnel reflector in cross section. That is, the deflector surfaces 50a, 50b, 50c (which in this example have a slightly concave profile in horizontal cross section) are arranged in an arcuate manner so as to deflect dirt particles through the dust channel 52 directly towards the outlet 56. In this example, because the outlet 56 of the dust channel 52 is centrally located, it is aligned with a longitudinal axis 68 of the discharge outlet 32 (hereinafter referred to as the "discharge outlet axis 68"). This arrangement ensures a direct fluid connection between the outlet 56 of the dust channel 52 and the region of the cleaner head 10 which, in use, experiences the greatest pressure drop, and so does the suction force. However, the skilled reader will recognize that it is not necessary to align the outlet 56 of the dust channel 52 with the discharge outlet axis 68, and that the outlet 56 may alternatively be positioned such that it is not aligned with respect to the discharge outlet axis 68 while still maintaining a fluid connection with the discharge outlet 32.

In cross-section, the central deflector surface 50a is oriented substantially perpendicular to the discharge outlet axis 68 so as to deflect dirt particles toward the outlet 56 over the agitator assembly 42 along a path narrowing from the deflector surface 50a to the outlet 56, with the remaining deflector surfaces 50b, 50c being angularly offset from the discharge outlet axis 68 by respective offset angles. Specifically, the deflection surface 50b adjacent the central deflection surface 50a is offset relative to the discharge port axis 68 by a first offset angle α, while the outermost deflection surface 50c is offset relative to the discharge port axis 68 by a second offset angle β that is greater than the first offset angle α. In this example of the cleaner head 10, the offset angles α, β are selected such that an imaginary line 72, 74 extending between the deflector surfaces 50b, 50c and the point at which they intersect the discharge outlet axis 68 has a substantially perpendicular relationship with the deflector surfaces 50b, 50 c. This arrangement establishes a minimal path for dirt particles deflected from the deflecting surfaces 50b, 50c across the agitator assembly 42 towards the outlet 56. Due to the concavity of the deflecting surfaces 50b, 50c, the path of dirt particle deflection therefore narrows towards a point 71 where the imaginary lines 72, 74 intersect the discharge port axis 68. This arrangement avoids any intentional interaction between the deflected dirt particles and the side walls 76, 78 of the front portion 18, which would dissipate the energy of the deflected dirt particles.

The deflection surfaces 50a, 50b, 50c are located at respective panel distances from a point 71 on the discharge outlet axis 68, as measured with respect to the discharge outlet axis 68 and the imaginary lines 72, 74. In this example, point 71 is located on the discharge outlet axis 68 near the outlet 56. The panel distance of each deflection surface 50a, 50b, 50c is proportional to its deflection angle. That is, the panel distance of the deflection surfaces 50a, 50b, 50c increases with increasing deflection angle. Thus, in this example, the panel distance of the centrally located deflection surface 50a is minimal because its offset angle relative to the discharge port axis 68 is zero, but the panel distance increases relative to the deflection surface 50b, the deflection surface 50b being at a first offset angle α relative to the discharge port axis 68. For the outermost deflection surfaces 50c, the panel distances further increase because they are at a second deflection angle β relative to the discharge port axis 68 that is greater than the first deflection angle α. This arrangement ensures that the deflector surfaces 50a, 50b, 50c are positioned forward of the intake 28 regardless of their orientation relative to the discharge axis 68.

Referring to fig. 5, which shows a vertical cross-section of the deflector surface 50a, the inner side 49 of the front portion 18 and the outermost side 51 of the middle portion 20 of the housing 16 define a dust channel 52 comprising an inlet 54 and an outlet 56, the inlet 54 for receiving the energized dirt particles from the agitator chamber 40. As described above, the outlet 56 is in fluid communication with the discharge outlet 32 formed in the rear portion 22 of the housing 16 to establish an air flow circuit through the dust passage 52 from the agitator chamber 40 to the discharge outlet 32. The inlet 54 of the dust channel 52 extends substantially horizontally across the longitudinal width of the agitator assembly 42 and, in this example, is defined in part between a lower end 58 of the deflector panel 48 and a lower end 60 of the middle portion 20 of the housing 16. In other examples, the inlet 54 of the dust channel 52 may be at least partially defined by the lower edges of the deflector surfaces 50a, 50b, 50 c.

The first surface portion 64 of the deflector surface 50a has a concave profile in vertical section and generally faces the inlet 54 of the dust channel 52 and extends forward and upward from its lower edge to a horizontal parting line 63. The second surface portion 65 also has a concave profile in vertical cross-section and generally faces rearwardly across the upper side 67 of the middle portion 20, which in part defines the dust channel 52. The second surface portion 65 extends upwardly and rearwardly from the horizontal parting line 63 to connect with a top panel 66 of the front portion 18 of the housing 16. In this embodiment, the horizontal parting line 63 defines an intersection between the first and second surface portions 64, 65, although the skilled reader will appreciate that the first and second surface portions 64, 65 need not necessarily intersect. Furthermore, although fig. 5 only shows a cross section of the deflection surface 50a, the skilled reader will appreciate that the deflection surfaces 50b, 50c are similarly arranged.

As described above, the inlet 54 receives the energized dirt particles thrown forward from the agitator chamber 40 by rotation of the agitator assembly 42, generally indicated by arrow 80 in FIG. 5. Upon entering the dust channel 52, the initial energy of the dirt particles is typically too high for the dirt particles to be immediately entrained in the air flow through the dust channel 52. Previously, this problem has been solved by constructing the walls defining the dust channel to retain dirt particles within the dust channel by a series of occasional collisions until the energy of the dirt particles is sufficiently dissipated by collisions with the walls to enable them to be entrained within the airflow passing through the dust channel. However, this may cause dirt particles to return to the agitator chamber due to inadvertent collisions or due to failure to be carried away by the airflow of the dust channel. The present invention differs in that by using a series of consecutive purposeful collisions with the deflector surfaces 50a, 50b, 50c, the initial energy of the dirt particles is used to guide them through the dust channel 52 towards the discharge opening 32, while avoiding any accidental collisions. Specifically, each deflecting surface 50a, 50b, 50c is configured such that, by a first collision with the first surface portion 64 and a second collision with the second surface portion 65, the excited dirt particles are guided through the dust channel 52 to the discharge opening 32.

When entering the dust passage from the agitator chamber 40 through the inlet 54Upon passage 52, the energized dirt particles will first tend to strike the first panel portion 61. The concavity of the first surface portion 64 deflects the first panel portion 61 substantially upward toward the second panel portion 62, deflecting substantially all of the energized dirt particles impinging therewith. The concavity of the second surface portion 65 is such that, regardless of the angle of incidence of the energized dirt particles deflected by the first surface portion 64, the second panel portion 62 will deflect substantially all of the energized dirt particles impinging thereon substantially horizontally toward the outlet 56 and, thus, the discharge outlet 32. This trajectory of the excited dirt particles is achieved by pairing points on the first surface portion 64 with corresponding points on the second surface portion 65, such that most of the excited dirt particles striking the first points 82 on the first surface portion 64 will be directed to corresponding second points 84 on the second surface portion 65. The local curvature of the first and second surface portions 64, 65 at their respective points 82, 84 is such that the dirt particle impact points 82, 84 are at an angle θ relative to a respective line 86 perpendicular to the points 82, 84 ₁ Equal to the angle theta of deflection of the dirt particles ₂ . This arrangement is similar to the law of reflection, where the angle of the incident light is equal to the angle of the reflected light. After the second panel portion 62, the energy of the dirt particles has been dissipated by collision with the first and second panel portions 61, 62, making them more likely to be entrained in the air flow through the dust channel 52. Thus, the deflector surfaces 50a, 50b, 50c are not configured to retain dirt particles within the dust channel 52 (which may cause the dirt particles to return to the agitator chamber 40 by inadvertently colliding with or by not being entrained in the airflow through the dust channel 52), but rather to direct the dirt particles towards the region of greatest airflow of the cleaner head 10, so that they are more likely to be entrained therein.

Numerous modifications may be made to the examples described above without departing from the scope of the invention, as defined by the accompanying claims.

For example, the deflection surfaces 50a, 50b, 50c are shown in fig. 4b as having a concave profile in horizontal cross section. This arrangement has the effect of narrowing the path of the dirt particles after impinging on the first and second surface portions 64, 65. This narrowing of the path may cause most of the deflected dirt particles to collide with each other en route through the dust channel 52, and it may be desirable to prevent the path narrowing by using deflecting surfaces 50a, 50b, 50c having straight or planar profiles in horizontal cross-section, thereby minimizing collisions between these particles. Alternatively, some of the deflection surfaces 50a, 50b, 50c may have a concave profile, while the remaining deflection surfaces 50a, 50b, 50c may have a straight profile.

Furthermore, in the present example of the cleaner head 10, the excited part of the particles is guided through the dust channel 52 by an initial collision with the first surface part 64 and a subsequent collision with the second surface part 65. These successive collisions direct dirt particles through the dust channel 52 to the outlet 56, wherein the energy of the dirt particles is sufficiently dissipated to be entrained by the air flow in the dust channel 52. However, it may be desirable to dissipate the energy of the dirt particles in a greater amount, in which case each deflecting surface 50a, 50b, 50c may comprise three or more surface portions configured to dissipate the energy of the dirt particles through a series of three or more collisions.

Claims

1. A cleaner head (10) for a vacuum cleaning appliance (2), the cleaner head comprising:

a main body (12) defining an agitator chamber (40) within which a rotatable agitator assembly (42) is supported, and a suction inlet (28) through which a portion of the agitator assembly (42) protrudes to engage a surface to be cleaned, wherein the main body (12) comprises a front portion (18) and a rear portion (22), the rear portion (22) defining a discharge outlet (32) of the cleaner head (10); and wherein the front portion (18) comprises a deflector plate (47) comprising a deflector surface (50 a, 50b, 50 c) which in use is impacted by dirt particles excited by rotation of the agitator assembly (42), and wherein the deflector surface (50 a, 50b, 50 c) is configured to deflect the excited dirt particles in an upward direction and across the agitator assembly (42) in a direction away from the suction inlet (28) and towards the discharge outlet (32),

wherein the deflecting surface comprises a first surface portion and a second surface portion, the local curvature of the first surface portion at a first point thereof and the local curvature of the second surface portion at a second point thereof being arranged such that the angle at which the dirt particles strike the first point and the second point relative to a respective line perpendicular to the first point and the second point is equal to the angle at which the dirt particles are deflected, whereby the trajectory of the excited dirt particles is achieved by pairing the first point on the first surface portion with the second point on the second surface portion such that a majority of the excited dirt particles striking the first point on the first surface portion will be directed to the respective second point on the second surface portion.

2. The cleaner head (10) of claim 1, wherein the deflector plate (47) comprises a plurality of deflector surfaces (50 a, 50b, 50 c) arranged together to define a fresnel reflector in cross-section.

3. The cleaner head (10) of claim 2, wherein the deflector plate (47) comprises a plurality of deflector panels (48), each deflector panel comprising a respective deflector surface (50 a, 50b, 50 c) of the plurality of deflector surfaces (50 a, 50b, 50 c).

4. A cleaner head (10) according to claim 3, wherein the plurality of deflector panels (48) are arranged side by side in a direction substantially aligned with the longitudinal axis of the agitator assembly (42).

5. The cleaner head (10) of claim 4, wherein the plurality of deflector panels (48) are arranged in an arcuate manner.

6. The cleaner head (10) of any one of claims 2 to 5, wherein the discharge outlet (32) defines a discharge outlet axis (68), and wherein one or more of the plurality of deflection surfaces (50 a, 50b, 50 c) are angularly offset from the discharge outlet axis (68) by a respective offset angle (a, β).

7. The cleaner head (10) of claim 6, wherein each deflection surface (50 a, 50b, 50 c) of the plurality of deflection surfaces (50 a, 50b, 50 c) is located at a respective panel distance from a point (71) on the discharge outlet axis (68), and wherein for the respective deflection surface (50 a, 50b, 50 c), the panel distance is proportional to a deflection angle (α, β) of the deflection surface.

8. The cleaner head (10) of claim 6, wherein one or more of the plurality of deflection surfaces (50 a, 50b, 50 c) that are angularly offset from the discharge outlet axis (68) have a substantially perpendicular relationship with a respective imaginary line (72, 74) extending from the one or more deflection surfaces (50 a, 50b, 50 c) to intersect the discharge outlet axis (68).

9. The cleaner head (10) of any one of claims 2 to 5, wherein one or more of the plurality of deflection surfaces (50 a, 50b, 50 c) comprises a first surface portion (64) and a second surface portion (65) separated by a substantially horizontal parting line (63).

10. The cleaner head (10) of claim 9, wherein the first surface portion (64) is configured to deflect the energized dirt particles in a direction toward the second surface portion (65).

11. The cleaner head (10) of claim 9, wherein the second surface portion (65) is configured to deflect the energized dirt particles in a direction across the agitator assembly (42).

12. The cleaner head (10) of claim 9, wherein the second surface portion (65) is configured to deflect the energized dirt particles deflected by the first surface portion (64) in a direction across the agitator assembly (42).

13. The cleaner head (10) of claim 9, wherein the first and/or second surface portions (64, 65) have a concave profile in vertical cross-section.

14. The cleaner head (10) of claim 9, wherein the first and/or second surface portions (64, 65) have a concave profile in horizontal cross-section.

15. The cleaner head (10) of claim 1, wherein the deflector plate (47) at least partially defines a dust channel (52) extending rearwardly beyond the agitator assembly (42).

16. The cleaner head (10) of claim 15, wherein the dust channel (52) comprises an inlet (54) for receiving energized dirt particles from the agitator chamber (40) and an outlet (56) in communication with the discharge outlet (32).

17. The cleaner head (10) of claim 16, wherein the inlet (54) of the dust channel (52) extends substantially across a longitudinal width of the agitator assembly (42).

18. The cleaner head (10) of claim 17, wherein the dust channel (52) tapers in width between the inlet (54) and the outlet (56).

19. The cleaner head (10) according to any one of claims 15 to 18, wherein the main body (12) further comprises a middle portion (20) partially defining the dust channel (52).

20. The cleaner head (10) of claim 1, wherein the front portion (18) is removable from the main body (12).

21. The cleaner head (10) of claim 1, wherein the deflector surface (50 a, 50b, 50 c) is pivotally attached to the main body (12).

22. A vacuum cleaning appliance (2) comprising a cleaner head (10) according to claim 1.