CN114554921A

CN114554921A - Vacuum cleaner head for a vacuum cleaning appliance

Info

Publication number: CN114554921A
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: 2022-05-27
Anticipated expiration: 2040-09-23
Also published as: GB2588155B; WO2021069862A1; GB2588155A; CN114554921B; GB201914650D0

Abstract

The invention relates to 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 is supported a rotatable agitator assembly (42), and a suction opening (28) through which a portion of the agitator assembly (42) projects 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 a discharge outlet (32) of the cleaner head (10), and the front portion (18) includes a deflector plate (47) comprising a deflector surface (50a, 50b, 50c) which, in use, is impacted by dirt particles excited by rotation of the agitator assembly (42). The deflecting surfaces (50a, 50b, 50c) are 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 cleaning appliance

Technical Field

The present invention relates generally to vacuum cleaners and in particular to a cleaner head or floor tool forming part of a vacuum cleaner. The invention is particularly concerned with rotary driven agitators for use in such cleaner heads, whether the cleaner head is permanently or removably secured to a corresponding 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" typically comprise a main body equipped with a suction source and a dust separator, with a cleaner head typically connected to the dust separator by a detachable coupling. The cleaner head has a suction inlet through which it engages the surface to be cleaned and through which dirt-laden air is drawn into the vacuum cleaner towards the dust separator. The head plays a crucial role in the effectiveness of the vacuum cleaner in removing dirt from a surface, whether it be a hard floor covering such as wood or stone, or a soft floor covering such as a carpet. Accordingly, vacuum cleaner manufacturers have made great efforts 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 a limited effect in removing dirt from a surface. Generally, they are recommended mainly 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 head of the cleaner. 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 for the motor to be housed within the agitator, which provides a particularly space-saving arrangement.

In either instance, the power agitator is used to wipe and beat a floor surface to enhance the ability of the cleaner head to remove dirt from that surface. A common configuration is an agitator with an array of bristles extending radially outwardly from the agitator surface. The bristles are typically relatively stiff so that as the agitator rotates, they positively engage the floor surface, thereby serving as a means of scraping and striking the floor surface to loosen embedded particles. Other strips of material, such as rubber and carbon fibre filaments, may be used to provide complementary properties 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 manner in which air flows through the head, from where it enters the interior of the head through the suction inlet, to where it is discharged from the outlet towards the dust separator. It is well known that the air flow velocity is an important factor in the pick-up performance, since dirt particles are more efficiently transported when the velocity of the air flowing through the tool is high. This is particularly true for high energy particles such as sand. Because of their small and relative weight, such particles tend to be ejected from the floor surface at high velocity and into the interior of the head where they tend to bounce around the head out of order. High air flow rates are required to carry dirt particles in the air into the cleaner head and transport them away from the cleaner head towards the dust collector. However, at low airflow rates, these heavy particles will be more likely to deposit back onto the floor covering. It will therefore be appreciated that maintaining good pick-up performance is challenging, especially at low airflow speeds of the cleaner head.

Although high airflow rates can be achieved by equipping the vacuum cleaner with a powerful vacuum motor, this is generally undesirable as it means that the machine efficiency is low, 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 that the cleaner head be able to efficiently pick up relatively heavy dirt particles from a floor surface without the need for high air flow velocities.

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 within which is supported a rotatable agitator assembly, and a suction inlet through which a portion of the agitator assembly projects to engage a surface to be cleaned, wherein the main body includes 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 outlet whilst avoiding any accidental impact which could cause the dirt particles to return to the agitator chamber either by inadvertent impact or by failing to be entrained in the airflow through the dust passage. This not only improves the pick-up performance of the head, but also reduces the velocity of air flow through the head, thereby reducing the energy consumption of the vacuum cleaning appliance.

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

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 towards the plurality of deflector plates.

Preferably, the plurality of deflector panels are arranged in an arc-shaped 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 shortest path for dirt particles deflected from the deflecting surface across the agitator assembly toward the discharge outlet.

Preferably, each deflection surface 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 deflecting surfaces are positioned in front of the suction inlet regardless of their orientation relative to the discharge outlet.

Preferably, one or more of the plurality of deflection surfaces that are angularly offset from the outlet opening axis have a substantially perpendicular relationship to an imaginary line extending from the one or more deflection surfaces to intersect the outlet opening 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 energized 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 portion has a concave profile in vertical cross-section.

Preferably, the first and/or second surface portion has 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 deflecting 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 them to the agitator chamber.

Preferably, the deflector plate at least partially defines a dust passage extending rearwardly across the agitator assembly. The dust passage establishes an airflow circuit for dirt particles extending from the agitator chamber to the exhaust outlet.

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

Preferably, the inlet of the dust channel extends substantially across 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 channel tapers between the inlet and the outlet. This increases the airflow velocity towards the outlet of the dust channel.

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

Preferably, the front portion is removable from the main body. The fact that the front portion 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 pivotably attached to the main body.

According to a further 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 clear 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, in particular individual features thereof, may be employed independently or in any combination. That is, features of all embodiments and/or any embodiment may be combined in any manner and/or combination unless such features are incompatible. The applicant reserves the right to alter any originally filed claim or to file any new claim accordingly, including the right to modify any originally filed claim to depend on and/or incorporate any feature of any other claim, even if the claim was not originally claimed in such a way.

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 head of figure 1;

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

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

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

Detailed Description

Reference will now be made in detail to the present embodiments of the present invention, in which various features will be discussed 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 these specific details, and in some instances, well known methods, techniques, and structures have not been described in detail in order to avoid unnecessarily obscuring the present invention. Furthermore, in the following description, references to "left", "right", and any other terms having an implied orientation are not intended to be limiting, but rather refer only to the orientation of the feature as shown in the figure.

Figure 1 shows a vacuum cleaning appliance or vacuum cleaner 2 according to an embodiment of the present invention, comprising a dirt and dust separation unit 4, a motor-driven fan unit 6 and a cleaner head 10. The vacuum cleaner 2 further comprises a wand 8 connecting the dirt and dust separation unit 4 with the cleaner head 10. The motor-driven fan unit 6 draws 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 exhausted 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 essential to the invention and that the cyclonic separating unit may be replaced by an alternative separating unit 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 type vacuum cleaner, but it will be appreciated that the cleaner head 10 disclosed herein may be used with other types of vacuum cleaners, for example upright or cylinder vacuum cleaners.

Referring to figure 2, the cleaner head 10 comprises a main body 12 rotatably attached to a coupling 14, the coupling 14 being removably connected to the wand 8. However, it will be apparent to the skilled reader that the present invention is also intended to cover cleaner heads configured for permanent attachment to their respective vacuum cleaner.

The main body 12 includes a housing 16 including front, middle and

rear portions

18, 20, 22 and a lower body panel or floor 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 a releasable fastener (not shown) which is insertable through a recess formed in the base plate 24 so that the front portion 18 is removable from the main 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 head 10 on a floor surface. The duct includes a front portion connected to the exhaust 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 conduit comprises fixing means 36 for connecting a free end 38 of the coupling 14 to the rod 8. A rigid flex hose device 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 located thereon, and are configured to sink into the pile of a carpet when the cleaner head 10 is located 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, allowing it to float smoothly over a carpeted floor surface during cleaning.

The internal volume of the main body 12 includes an agitator chamber 40 that is defined in part by the middle portion 20 of the housing 16 and the sole plate 24. The cleaner head 10 also includes 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 connecting the agitator assembly 42 to the electric motor for driving the cylindrical body 44 about its longitudinal axis. Such agitator drive means are known and will therefore 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 filaments having tips that can bend relative to the cylindrical body 44 when in contact with a floor surface, stiff bristles or a continuous strip of material, and may be made of carbon fiber or nylon, to name two common examples of materials. The agitator assembly 42 is arranged such that the agitator 46 projects through the suction opening 28 as it rotates to sweep dirt and dust particles and other debris (hereinafter "dirt particles") from the hard floor surface and the carpeted 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 across the floor surface rearwardly toward the rear 22 of the housing 16. In this condition, 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 passage 52, the dust passage 52 being defined by the inner side 49 of the front portion 18 of the housing 16 for receiving dirt particles thrown forwardly by the agitator assembly 42 toward 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 in front of the suction opening 28 in the floor 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 the dust channel 52. The top panel 66 and the two

side walls

76, 78, which are generally fan-shaped, converge to define an 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, typically arranged side-by-side in a direction substantially aligned with the longitudinal axis of the agitator assembly 42. In this example, the deflector plate 47 comprises five discrete deflector panels 48, the inner surfaces of which define respective deflector surfaces, generally designated 50a, 50b, 50 c. The deflector 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 parting line 63. Similarly, the deflecting

surfaces

50a, 50b, 50c each include a first surface portion 64 located on an inner side of the first panel portion 61 and a second surface portion 65 located on an inner side of the second panel portion 62. Generally speaking, the deflecting

surfaces

50a, 50b, 50c are configured to deflect, in use, dirt particles thrown forwardly by the agitator assembly 42 through the dust channel 52 in an upward direction and over the agitator assembly 42 towards the outlet 56.

Referring to fig. 4b, the deflection panels 48 are arranged such that the deflection surfaces 50a, 50b, 50c collectively define a fresnel reflector in cross-section. That is, the deflecting

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 head 10 which, in use, experiences the greatest pressure drop and so does the suction force. However, the skilled reader will appreciate that it is not necessary to align the outlet 56 of the dust channel 52 with the discharge outlet axis 68, and the outlet 56 may alternatively be positioned such that it is misaligned relative to the discharge outlet axis 68 while still maintaining a fluid connection with the discharge outlet 32.

In cross-section, the central deflecting surface 50a is oriented substantially perpendicular to the discharge outlet axis 68 so as to deflect dirt particles over the agitator assembly 42 toward the outlet 56 along a path that narrows from the deflecting surface 50a to the outlet 56, while the remaining deflecting

surfaces

50b, 50c are angularly offset from the discharge outlet axis 68 by a corresponding offset angle. Specifically, the deflection surface 50b adjacent the central deflection surface 50a is offset relative to the discharge outlet axis 68 by a first offset angle α, while the outermost deflection surface 50c is offset relative to the discharge outlet axis 68 by a second offset angle β, which 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

imaginary lines

72, 74 extending between the deflecting

surfaces

50b, 50c and the point at which they intersect the discharge outlet axis 68 have a substantially perpendicular relationship to the deflecting surfaces 50b, 50 c. This arrangement establishes the shortest path for dirt particles deflected from the deflecting

surfaces

50b, 50c across the agitator assembly 42 toward the outlet 56. Due to the concavity of the deflecting

surfaces

50b, 50c, the path of deflection of the dirt particles is thus narrowed towards the point 71 where the

imaginary lines

72, 74 intersect the discharge outlet 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 opening axis 68, as measured relative to the discharge opening axis 68 and

imaginary lines

72, 74. In this example, point 71 is located on discharge port axis 68 near outlet 56. The panel distance of each deflecting

surface

50a, 50b, 50c is proportional to its offset angle. That is, the panel distance of the deflecting

surfaces

50a, 50b, 50c increases with increasing offset angle. Thus, in this example, the centrally located deflection surface 50a has the smallest panel distance because its offset angle with respect to the discharge outlet axis 68 is zero, but the panel distance increases with respect to the deflection surface 50b, with the deflection surface 50b being at the first offset angle α with respect to the discharge outlet axis 68. For the outermost deflection surfaces 50c, the panel distances are further increased because they are at a second offset angle β relative to the discharge outlet axis 68 that is greater than the first offset angle α. This arrangement ensures that the deflecting

surfaces

50a, 50b, 50c are positioned in front of the suction inlet 28 regardless of their orientation relative to the discharge outlet 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 including an inlet 54 and an outlet 56, the inlet 54 for receiving excited 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 channel 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 central 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 deflecting

surfaces

50a, 50b, 50 c.

The first surface portion 64 of the deflecting surface 50a has a concave profile in vertical section and generally faces the inlet 54 of the dust channel 52 and extends from its lower edge forward and upward to the horizontal dividing line 63. The second surface portion 65 also has a concave profile in vertical cross-section and faces generally rearwardly across an upper side 67 of the central 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, horizontal parting line 63 defines an intersection between first and

second surface portions

64, 65, although the skilled reader will appreciate that first and

second surface portions

64, 65 do not necessarily need to intersect. Furthermore, although fig. 5 shows only 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 energized dirt particles, generally indicated by arrow 80 in FIG. 5, that are thrown forward from the agitator chamber 40 by rotation of the agitator assembly 42. Upon entering the dust channel 52, the initial energy of the dirt particles is generally too high for the dirt particles to be immediately entrained within the airflow passing through the dust channel 52. Previously, this problem has been addressed by configuring the walls defining the dust channel to retain the dirt particles within the dust channel through a series of accidental collisions until the energy of the dirt particles is dissipated sufficiently by the collisions with the walls to enable them to be entrained within the airflow through the dust channel. However, this may cause dirt particles to return to the agitator chamber by inadvertent impact or by failing to be entrained by the airflow of the dust channel. The present invention differs in that by using a series of successive purposeful collisions with the deflecting

surfaces

50a, 50b, 50c, the initial energy of the dirt particles is used to direct them through the dust channel 52 towards the discharge opening 32, while avoiding any accidental collision. In particular, each deflecting

surface

50a, 50b, 50c is configured such that the excited dirt particles are guided through the dust channel 52 to the discharge opening 32 by a first collision with the first surface portion 64 and a second collision with the second surface portion 65.

When entering the dust channel 52 from the agitator chamber 40 through the inlet 54, the excited dirt particles will first tend to hit the first panel portion 61. The concavity of the first surface portion 64 causes the first panel portion 61 to deflect substantially all of the energized dirt particles that collide therewith substantially upwardly toward the second panel portion 62. The concavity of the second surface portion 65 is such that the second panel portion 62 will deflect substantially all of the energized dirt particles impinging thereon substantially horizontally toward the outlet 56 and hence the discharge opening 32, regardless of the angle of incidence of the energized dirt particles deflected by the first surface portion 64. 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 that hit the first point 82 on the first surface portion 64 will be directed to the 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 angle θ of the point of impact of the

dirt particles

82, 84 with respect to a respective line 86 perpendicular to the

points

82, 84 is such that the dirt particles impact at the

point

82, 84₁Equal to the angle theta of deflection of the dirt particles₂. This arrangement is analogous to the law of reflection, where the angle of an incident ray is equal to the angle of a reflected ray. Behind the second panel part 62, by means of collisions with the first and

second panel parts

61, 62, dirt particles are formedThe energy of the particles has been dissipated so that they are more likely to be entrained in the airflow through the dust channel 52. Thus, the deflecting

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 inadvertent impact or by not being entrained in the airflow through the dust channel 52), but rather to direct the dirt particles towards the region of the cleaner head 10 where the airflow is greatest and therefore they are more likely to be entrained therein.

Many modifications may be made to the examples described above without departing from the scope of the present invention, which is defined by the following 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 impacting 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 on their way through the dust channel 52, and it may be desirable to prevent the path from narrowing by using deflecting

surfaces

50a, 50b, 50c having a straight or planar profile in horizontal cross-section, so as to minimize the collisions between these particles. Alternatively, some of the deflecting

surfaces

50a, 50b, 50c may have a concave profile, while the remaining

deflecting surfaces

50a, 50b, 50c may have a straight profile.

Furthermore, in the present example of the cleaner head 10, a proportion of the particles which are excited are directed through the dust channel 52 by initial impact with the first surface portion 64 and subsequent impact with the second surface portion 65. These successive collisions direct the dirt particles through the dust channel 52 to the outlet 56, where the energy of the dirt particles is sufficiently dissipated to be entrained by the airflow 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 is supported a rotatable agitator assembly (42), and a suction inlet (28) through which a portion of the agitator assembly (42) projects to engage a surface to be cleaned, wherein the main body (12) includes 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 (50a, 50b, 50c) which, in use, is impacted by dirt particles excited by rotation of the agitator assembly (42), and wherein the deflector surface (50a, 50b, 50c) 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).

2. The cleaner head (10) of claim 1, wherein the deflector plate (47) comprises a plurality of deflecting surfaces (50a, 50b, 50c) which are collectively arranged 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 (50a, 50b, 50c) of the plurality of deflector surfaces (50a, 50b, 50 c).

4. The cleaner head (10) of claim 3, wherein the plurality of deflector panels (48) are arranged side-by-side in a direction substantially aligned with a 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 claims 2 to 5, wherein the discharge outlet (32) defines a discharge outlet axis (68), and wherein one or more of the plurality of deflecting surfaces (50a, 50b, 50c) is angularly offset from the discharge outlet axis (68) by a respective offset angle (α, β).

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

8. The cleaner head (10) of claim 6 or 7, wherein one or more of the plurality of deflecting surfaces (50a, 50b, 50c) that are angularly offset from the discharge outlet axis (68) have a substantially perpendicular relationship with respective imaginary lines (72, 74) extending from the one or more deflecting surfaces (50a, 50b, 50c) to intersect the discharge outlet axis (68).

9. The cleaner head (10) of any one of claims 2 to 8, wherein one or more of the plurality of deflecting surfaces (50a, 50b, 50c) comprises a first surface portion (64) and a second surface portion (65), the surface portions (64, 65) being separated by a substantially horizontal dividing line (63).

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

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

13. The cleaner head (10) of any one of claims 9 to 12, wherein the first and/or second surface portions (64, 65) have a concave profile in vertical cross-section.

14. The cleaner head (10) of any one of claims 9 or 13, wherein the first and/or second surface portion (64, 65) has a concave profile in horizontal cross-section.

15. The cleaner head (10) of any one of the preceding claims, wherein the deflector plate (47) at least partially defines a dust channel (52) extending rearwardly across the agitator assembly (42).

16. The cleaner head (10) of claim 15, wherein the dust channel (52) includes an inlet (54) for receiving excited 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 the longitudinal width of the agitator assembly (42).

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

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

20. The cleaner head (10) of any one of the preceding claims, wherein the front portion (18) is removable from the main body (12).

21. The cleaner head (10) of any one of the preceding claims, wherein the deflecting surface (50a, 50b, 50c) is pivotably attached to the main body (12).

22. A vacuum cleaning appliance (2) comprising a cleaner head (10) according to any one of the preceding claims.