CN114615915A

CN114615915A - Vacuum cleaner head for a vacuum cleaning appliance

Info

Publication number: CN114615915A
Application number: CN202080071618.0A
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: 2022-06-10
Anticipated expiration: 2040-09-23
Also published as: CN114615915B; GB2588156B; WO2021069863A1; GB2588156A; GB201914651D0

Abstract

The invention relates to a cleaner head 10 for a vacuum cleaning appliance (2) comprising a rotatable agitator assembly (42) and a main body (12) defining an agitator chamber (40) within which the agitator assembly (42) is supported. The agitator chamber (40) includes a suction opening (28) through which a portion of the agitator assembly (42) projects to engage the surface to be cleaned, and an outlet (54) through which, in use, excited dirt particles leave the agitator chamber (40) to enter the rear portion (22) of the main body (12) when the agitator assembly (42) sweeps them rearwardly from the surface. The rear portion (22) comprises a plurality of deflector panels (50) defining a dust channel (52) extending between an outlet (54) of the agitator chamber (40) and a discharge outlet (32) of the cleaner head (10) through which the excited dirt particles are drawn from the dust channel (52), and the plurality of deflector panels (50) comprise respective concave surfaces (74, 80, 86) configured to deflect the excited dirt particles from the outlet (54) of the agitator chamber (40) towards the discharge outlet (32) by a series of successive collisions.

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 exhausted 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 head and transport them away from the head towards the 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 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 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 a first aspect of the present invention there is provided a cleaner head for a vacuum cleaning appliance, the cleaner head comprising: a rotatable agitator assembly; a main body defining an agitator chamber within which the agitator assembly is supported, the agitator chamber including a suction inlet through which a portion of the agitator assembly projects to engage a surface to be cleaned and an outlet through which, in use, excited dirt particles leave the agitator chamber into a rear portion of the main body when the agitator assembly is sweeping the excited dirt particles rearwardly from the surface, wherein the rear portion includes a plurality of deflector panels defining a dust channel extending between the outlet of the agitator chamber and a discharge outlet of the cleaner head through which the excited dirt particles are drawn from the dust channel, and wherein the plurality of deflector panels include respective concave surfaces configured to deflect the excited dirt particles from the outlet of the agitator chamber towards the discharge outlet by a series of successive collisions. In this way, the initial energy of the excited dirt particles entering the dust channel through the outlet of the agitator chamber serves to direct them towards the discharge outlet by a series of successive purposeful collisions with the deflector panel, while avoiding any accidental collisions that could result in their being inadvertently retained within the dust channel, even returning to the floor surface. The collision with the deflector panel dissipates the energy of the dirt particles and in so doing directs them to the discharge outlet where suction is greatest and they are more easily entrained by the airflow in the dust channel. Thus, the present invention not only improves the pick-up performance of the head, but also reduces the flow rate of air through the dust channel, thereby reducing the energy consumption of the vacuum cleaning appliance.

Preferably, the plurality of deflector panels comprises a first deflector panel, and wherein the outlet of the agitator chamber is defined by a lower edge of the first deflector panel.

Preferably, the first deflector panel comprises a first concave surface configured to deflect, in use, excited dirt particles from the outlet of the agitator chamber towards a second deflector panel of the plurality of deflector panels.

Preferably, the first concave surface curves rearwardly and upwardly from a lower end of the first deflector panel adjacent the outlet of the agitator chamber to an upper end of the first deflector panel.

Preferably, the second deflector panel comprises a second concave surface configured to deflect, in use, the excited dirt particles deflected from the first concave surface towards a third deflector panel of the plurality of deflector panels.

Preferably, the second concave surface is curved forward from a rear end of the second deflection panel adjacent to an upper end of the first deflection panel to a front end of the second deflection panel.

Preferably, the third deflector panel comprises a third concave surface configured to deflect, in use, excited dirt particles deflected from the second concave surface towards the discharge outlet of the cleaner head.

Preferably, the third concave surface is configured to deflect, in use, excited dirt particles deflected from the second concave surface towards a focal point located on the longitudinal axis of the discharge outlet. This arrangement avoids any intentional interaction between the deflected dirt particles and the rear sidewall, which could retain the dirt particles in the rear or even return to the agitator chamber.

Preferably, the third concave surface curves downward from an upper end of the third deflector panel adjacent to a front end of the second concave surface to a lower end of the third deflector panel.

Preferably, the rear portion of the main body further comprises a semi-circular cylindrical panel defining the agitator chamber, and wherein a lower end of the semi-circular cylindrical panel defines a plane above which the first concave surface terminates. This arrangement provides sufficient clearance for dirt particles excited by the agitator assembly to enter the dust channel through the outlet of the agitator chamber to avoid or at least minimize inadvertent collisions with the semi-circular cylindrical panel which could retain the dirt particles within the agitator chamber and ultimately return to the floor surface.

Preferably, the plane extends through at least a portion of the discharge opening. This arrangement ensures that any dirt particles that enter the dust channel but do not strike the first concave surface are directed directly to the discharge outlet.

Preferably, the concave surfaces are inclined towards the discharge opening such that the axially outer edge of each concave surface is located forwardly of the axially inner edge thereof relative to the longitudinal axis of the discharge opening. This arrangement adds an axial component to the trajectory of the excited dirt particles to direct them axially inwardly within the head.

Preferably, the first and second concave surfaces are configured to diverge from the third concave surface toward the discharge opening. This arrangement gradually widens the dust channel to avoid intentional interaction between the deflected dirt particles and the side walls of the dust channel, which could cause the dirt particles to remain behind in the housing or even return to the agitator chamber.

According to a second aspect of the present invention there is provided a vacuum cleaning appliance comprising a cleaner head according to the first 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, all embodiments and/or features of 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 from and/or incorporate any feature of any other claim, even though not originally claimed in such a 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 2a is a front perspective view of the head of figure 1;

figure 2b is a rear perspective view of the head of figure 1;

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

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

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

FIG. 5 is an upper plan view of the rear portion of FIGS. 4a and 4 b;

FIG. 6a is a cross-sectional view of the rear portion of FIG. 5 along section A-A;

FIG. 6B is a cross-sectional view of the rear portion of FIG. 5 along section B-B;

FIG. 6C is a cross-sectional view of the rear portion of FIG. 5 along section C-C; and

figure 7 is a cross-sectional view taken at the level 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, many of which 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 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 any terms having an implied orientation are not intended to be limiting, but rather refer to the orientation of the feature as shown in the drawings.

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 the surface to be cleaned 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 the skilled reader will appreciate that the dirt and dust 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 cordless 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 figures 2a and 2b, the cleaner head 10 comprises a main body 12 rotatably attached to a coupling 14, in this example the coupling 14 is 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 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 30 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 34 for connecting a free end 36 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 26 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 26 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 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 number 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, as well as 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 from the front 18 back 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.

Referring to fig. 4a and 4b, the rear portion 22 of the housing 16 is removable from the main body 12 of the cleaner head 10, except for the discharge outlet 32, and includes a generally semi-circular cylindrical panel 48 which, together with a plurality of deflector panels (generally indicated at 50), defines the rear of the agitator chamber 40. The plurality of deflector panels 50 define a dust channel 52 for receiving dirt particles that have been swept toward the rear of the agitator chamber 40 by the agitator assembly 42. A dust channel 52 extends between an outlet 54 of the agitator chamber 40, defined by the semi-circular cylindrical panel 48 and the plurality of deflector panels 50, and the discharge outlet 32, establishing a fluid connection from the suction inlet 28 to the discharge outlet 32, the discharge outlet 32 being subjected to suction in use. The outlet 54 of the agitator chamber 40 extends substantially horizontally across the longitudinal width of the agitator assembly 42.

Referring to fig. 5, in this example of the rear portion 22 of the housing 16, the plurality of deflector panels 50 includes nine

discrete deflector panels

57, 58, 59, 60, 61, 62, 63, 64, 66 symmetrically arranged in an arcuate manner about the longitudinal axis 56 of the discharge outlet 32 (hereinafter "discharge outlet axis 56") to deflect the energized dirt particles passing through the dust channel 52 from the outlet 54 of the agitator chamber 40 to the discharge outlet 32 through a series of successive directed collisions. 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 in the airflow 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 occasional non-directional collisions until the energy of the dirt particles is sufficiently dissipated by impact with the walls that they can be entrained within the airflow through the dust channel. The present invention differs in that the initial energy of the dirt particles is used to direct them through the dust channel 52 towards the discharge opening 32 using a series of successive purposeful collisions with the deflector panel 50. This not only improves the pick-up performance of the head 10, but also reduces the flow rate of air through the dust channel 52, thereby reducing the power consumption of the motor-driven fan unit 6 of the vacuum cleaner 2. Eight

deflector panels

57, 58, 59, 60, 61, 62, 63, 64 define the peripheral surface of the rear portion 22 of the housing 16 (although only four

deflector panels

58, 60, 62, 64 are visible in fig. 5), while the last deflector panel 66, also not visible in fig. 5, is adjacent to the semicircular cylindrical panel 48, within the internal volume of the rear portion 22, generally opposite the other eight

deflector panels

57, 58, 59, 60, 61, 62, 63, 64. In this example of the rear portion 22 of the housing 16, the exhaust opening 32 is centered in the lateral direction, which facilitates a symmetrical arrangement of the deflector panel 50 about the exhaust opening axis 56. However, the skilled reader will appreciate that such an arrangement is not required, and the deflector panels 50 may be arranged asymmetrically about the discharge outlet axis 56, as long as they still perform the function of deflecting the excited dirt particles from the outlet 54 of the agitator chamber 40 towards the discharge outlet 32 by a series of successive collisions within the dust channel 52. Further, it will also be appreciated that positioning the exhaust port 32 in the center of the rear portion 22 is not a necessary requirement of the present invention.

Fig. 6a is a cross-sectional view through the rear portion 22 of the housing 16 at the section indicated by a-a in fig. 5, including the agitator assembly 42. Due to the symmetrical arrangement of the deflector panel 50 about the discharge opening axis 56, the structure of the rear portion 22 of the housing 16 through the

deflector panels

57, 58, 66 is similar to that shown in fig. 6 a. At this point, the rear portion 22 of the housing 16 includes first, second and third deflector panels defined by

deflector panels

63, 64, 66, respectively. In this figure, the

deflector panels

63, 64 are shown in cross-section, which is different from the deflector panel 66, which deflector panel 66 cannot be shown in cross-section of section a-a because of its orientation within the rear portion 22 of the housing 16. The lower edge 72 of the first deflector panel 63 and the lower end 73 of the semi-circular cylindrical panel 48 define the lower and upper boundaries, respectively, of the outlet 54 of the agitator chamber 40. The lower edge 73 of the semi-circular cylindrical panel 48 defines a plane 75 extending through the cylindrical body 44 of the agitator assembly 42. This arrangement provides sufficient clearance for dirt particles (as indicated by arrows 68) excited by the agitator assembly 42 to enter the dust channel 52 through the outlet 54 of the agitator chamber 40 to avoid or at least minimize inadvertent collisions with the semi-circular cylindrical panel 48, which could retain the dirt particles within the agitator chamber 40 and ultimately return to the floor surface.

The first deflector panel 63 includes a first concave surface 74 configured to deflect, in use, energized dirt particles from the outlet 54 of the agitator chamber 40 toward the second deflector panel 64. The first concave surface 74 curves in a vertical direction rearwardly and upwardly from a lower end 76 of the first deflector panel 63 adjacent the outlet 54 of the agitator chamber 40 to an upper end 78 of the first deflector panel 63 where it terminates above a plane 75 defined by the lower end 73 of the semi-circular cylindrical panel 48. The termination of the first concave surface 74 above the plane 75 defined by the lower edge 73 of the semi-circular cylindrical panel 48 ensures that most, if not all, of the energized dirt particles entering the dust channel 52 through the outlet 54 of the agitator chamber 40 first collide with the first concave surface 74, ensuring that they are deflected towards the second deflector panel 64. In the example shown, the first concave surface 74 extends from the lower edge 72 of the first deflector panel 63. However, the skilled reader will appreciate that the first concave surface 74 may alternatively extend from a point near the lower end 76 of the first deflector panel 63, so long as it retains its function of deflecting energized dirt particles from the outlet 54 of the agitator chamber 40 toward the second deflector panel 64.

The second deflector panel 64 comprises a second concave surface 80 configured to deflect, in use, the excited dirt particles deflected from the first concave surface 74 towards the deflector panel 66. The second concave surface 80 curves forwardly from a rear end 82 of the second deflector panel 64 adjacent the upper end 78 of the first deflector panel 63 to a front end 84 of the second deflector panel 64. In the example shown, the second concave surface 80 extends between a rear end 82 and a front end 84 of the second deflector panel 64 and connects with the first concave surface 74 above the plane 75. This arrangement means that the excited dirt particles which collide with the first concave surface 74 at the upper end 78 of the first deflector panel 63 are deflected towards the second concave surface 80.

The third deflector panel 66 includes a third concave surface 86 opposite the second concave surface 80. The third concave surface 86 is configured to deflect, in use, excited dirt particles deflected from the second concave surface 80 towards the discharge outlet 32 of the cleaner head 10. The third concave surface 86 curves downwardly from an upper end 88 of the third deflector panel 66 adjacent the front end 84 of the second deflector panel 64 to a lower end 90 of the third deflector panel 66. In the example shown, the third concave surface 86 extends between an upper end 88 and a lower end 90 of the deflector panel 66. The lower end 90 of the third deflector panel 66 terminates in a flat surface 75 providing clearance for energized dirt particles entering the dust channel 52 through the outlet 54 of the agitator chamber 40 to the first concave surface 74. The straight panel portion 92 extends in the plane 75 between the lower end 90 of the third deflector panel 66 and the lower end 73 of the semi-circular cylindrical panel 48. The straight panel portion 92 serves to direct any energized dirt particles that collide therewith towards the first concave surface 74 so that they can take the correct trajectory through the dust channel 52 towards the discharge outlet 32.

Fig. 6B is a cross-sectional view of the rear portion 22 of the housing 16 through the section indicated by B-B in fig. 5. Similar to the arrangement shown in fig. 6a, the rear portion 22 of the housing 16 now includes first, second and third deflector panels defining a dust channel 52. In this case, the first, second and third deflection panels are defined by the

deflection panels

61, 62, 66, respectively. The lower edge 72 of the first deflector panel 61 and the lower end 73 of the semi-circular cylindrical panel 48 define the lower and upper boundaries, respectively, of the outlet 54 of the agitator chamber 40. The lower edge 73 of the semi-circular cylindrical panel 48 terminates in a flat surface 75.

The first deflector panel 61 includes a first concave surface 74 configured to deflect, in use, energized dirt particles from the outlet 54 of the agitator chamber 40 toward the second deflector panel 62. The first concave surface 74 curves rearwardly and upwardly from a lower end 76 of the first deflector panel 61 adjacent the outlet 54 of the agitator chamber 40 to an upper end 78 of the first deflector panel 61 where it terminates above the plane 75. In the example shown, the first concave surface 74 extends from the lower edge 72 of the first deflector panel 61.

The second deflector panel 62 comprises a second concave surface 80 configured to deflect, in use, the excited dirt particles deflected from the first concave surface 74 towards the third deflector panel 66. The second concave surface 80 curves forward from a rear end 82 of the second deflector panel 62 adjacent the upper end 78 of the first deflector panel 61 to a front end 84 of the second deflector panel 62. Similar to the example shown in fig. 6a, the second concave surface 80 extends between a rear end 82 and a front end 84 of the second deflector panel 62 and connects with the first concave surface 74 above the plane 75.

The third deflector panel 66 includes a third concave surface 86 opposite the second concave surface 80. The third concave surface 86 is configured to deflect, in use, excited dirt particles deflected from the second concave surface 80 towards the discharge outlet 32 of the cleaner head 10. The third concave surface 86 curves downwardly from an upper end 88 of the third deflector panel 66 adjacent the front end 84 of the second deflector panel 62 to a lower end 90 of the third deflector panel 66. In the example shown, the third concave surface 86 extends between an upper end 88 and a lower end 90 of the third deflector panel 66. As with the arrangement shown in fig. 6a, the lower end 90 of the third deflector panel 66 terminates at a plane 75 defined by the lower end 73 of the semi-circular cylindrical panel 48. The straight panel portion 92 extends in the plane 75 between the lower end 90 of the third deflector panel 66 and the lower end 73 of the semi-circular cylindrical panel 48 and serves to direct any energized dirt particles that collide therewith towards the first concave surface 74.

Also, the structure of the rear portion 22 of the housing 16 across the

deflector panels

59, 60, 66 is similar to that shown in fig. 6b due to the symmetrical arrangement of the deflector panel 50 about the discharge outlet axis 56.

FIG. 6c is a cross-sectional view of the rear portion 22 of the housing 16 along the discharge outlet axis 56; i.e. through the section indicated by C-C in fig. 5. Despite the structural differences compared to the arrangement shown in the two previous figures, the rear portion 22 of the housing 16 now comprises first, second and

third deflector panels

61, 62, 66 defining the dust channel 52, wherein each

deflector panel

61, 62, 66 comprises a respective

concave surface

74, 80, 86. Since the discharge outlet axis 56 is located where the

deflection panels

59, 60 connect with the

deflection panels

61, 62, either set of

deflection panels

59, 60; 61. 62 may be considered to form the first and second deflector panels in fig. 6 c.

The arrangement shown in figure 6c is substantially similar to the arrangement of the rear portion 22 of the housing 16 shown in the two previous figures. That is, the first concave surface 74 is configured to deflect, in use, dirt particles that collide therewith towards the second deflector panel 62. The first concave surface 74 curves rearwardly and upwardly from a lower end 76 of the first deflector panel 61 adjacent the outlet 54 of the agitator chamber 40 to an upper end 78 of the first deflector panel 61 where it terminates at the discharge outlet 32. The second concave surface 80 is configured to deflect, in use, the energized dirt particles deflected from the first concave surface 74 towards the third deflector panel 66. The second concave surface 80 curves forwardly from a rear end 82 of the second deflector panel 62 adjacent the discharge opening 32 to a front end 84 of the second deflector panel 62. The third concave surface 86 is opposite the discharge outlet 32 and is configured to deflect, in use, energized dirt particles deflected from the second concave surface 80 to the discharge outlet. The third concave surface 86 curves downwardly from an upper end 88 of the third deflector panel 66 adjacent the front end 84 of the second deflector panel 62 to a lower end 90 of the third deflector panel 66. In the example shown, the third concave surface 86 extends between an upper end 88 and a lower end 90 of the third deflector panel 66. The straight panel portion 92 extends in the plane 75 between the lower end 90 of the third deflector panel 66 and the lower end 73 of the semi-circular cylindrical panel 48 and serves to direct any energized dirt particles that collide therewith toward the first concave surface 74 or the discharge outlet 32.

In the three examples described above, the rear portion 22 of the housing 16 is configured such that the excited dirt particles that generally enter the dust channel 52 from the agitator chamber 40 first collide with the first concave surface 74. This collision directs them toward the second concave surface 80, and they then deflect from the second concave surface 80 to the third concave surface 86. Finally, the collision with the third concave surface 86 directs them to the discharge port 32. This trajectory is achieved by grouping points on the first concave surface 74 with corresponding points on the second and third

concave surfaces

80, 86 such that a majority of the energized dirt particles that strike a point on the first concave surface 74 will be directed to corresponding points on the second and third

concave surfaces

80, 86. The local curvature of the first, second and third

concave surfaces

74, 80, 86 at their respective points is such that the angle at which the dirt particles strike these points relative to the respective lines perpendicular to these points is equal to the angle at which the dirt particles are deflected. 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.

Turning to fig. 7, which is a cross-sectional view of the dust channel 52 in a horizontal plane, the first concave surfaces 74 are inclined such that their axially outer edges 94 are located forwardly of their respective axially inner edges 96 relative to the discharge outlet axis 56. Although not shown in this figure, the second concave surfaces 80 of the

deflector panels

58, 60, 62, 64 are similarly arranged with their axially outer edges forward of their axially inner edges relative to the discharge outlet axis 56. Similarly, an axially outer edge 98 of the third concave surface 86 is positioned forward of its center point 99 on the discharge outlet axis 56 relative to the discharge outlet axis 56. At each portion of the dust channel 52, the first and second

concave surfaces

74, 80 are inclined so as to diverge from the third concave surface 86 toward the discharge port 32. This diverging arrangement between the first and

second concavities

74, 80 and the third concavity 86 serves to widen the cross-section of the dust channel 52, providing sufficient space for the energized dirt particles to reach the discharge outlet 32 without colliding more than once with each

concavity

74, 80, 86. For example, in the trajectory defined by arrow 97, the energized dirt particles enter the dust channel 52 through the outlet 54 of the agitator chamber 40 in a direction substantially parallel to the outlet opening axis 56 and first collide with the first concave surface 74 at point I. The first concave surface 74 directs the energized dirt particles toward the second concave surface 80 and, due to its inclination, introduces an axial component into its trajectory to direct it axially inward away from its original trajectory toward the discharge outlet axis 56. The excited dirt particle collides with the second concave surface 80 at point II, from where it is directed toward the third concave surface 86. The second concave surface 80 is sloped to add an additional axial component to the trajectory of the energized dirt particles, further directing them axially inward toward the discharge outlet axis 56. The excited dirt particles collide with the third concave surface 86 at point III, which is configured to add a further axial component to their trajectory to direct them to the discharge outlet 32.

As mentioned above, the object of the present invention is to take advantage of the initial energy of the excited dirt particles entering the dust channel 52 through the outlet 54 of the agitator chamber 40 to direct them towards the discharge outlet 32 by a series of successive purposeful collisions with the deflector panel 50, whilst avoiding any accidental collisions which would cause them to be inadvertently trapped within the dust channel 52 and even return to the floor surface unless they are entrained in the airflow through the dust channel 52. The collision with the deflector panel 50 dissipates the energy of the dirt particles so that they are more easily entrained by the airflow in the dust channel 52. Thus, the present invention not only improves the pick-up performance of the head 10, but also reduces the flow rate of air through the dust channel 52, thereby reducing the energy consumption of the motor-driven fan unit 6 of the vacuum cleaner 2.

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.

Claims

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

a rotatable agitator assembly (42);

a main body (12) defining an agitator chamber (40) within which is supported an agitator assembly (42), the agitator chamber (40) including a suction inlet (28) through which a portion of the agitator assembly (42) projects to engage a surface to be cleaned and an outlet (54) through which, in use, when the agitator assembly (42) sweeps an excited dirt particle rearwardly from the surface, the excited dirt particle exits the agitator chamber (40) to enter a rear portion (22) of the main body (12), wherein the rear portion (22) includes a plurality of deflector panels (50) defining a dust channel (52) extending between the outlet (54) of the agitator chamber (40) and an exhaust outlet (32) of the cleaner head (10) through which the excited dirt particle is drawn from the dust channel (52), and wherein the plurality of deflector panels (50) include respective concave surfaces (74, 54), 80. 86) configured to deflect the activated dirt particles from the outlet (54) of the agitator chamber (40) towards the discharge outlet (32) by a series of successive collisions.

2. The cleaner head (10) of claim 1, wherein the plurality of deflector panels (50) includes a first deflector panel (63), and wherein the outlet (54) of the agitator chamber (40) is defined by a lower edge (72) of the first deflector panel (63).

3. The cleaner head (10) of claim 2, wherein the first deflector panel (63) comprises a first concave surface (74) configured to deflect, in use, excited dirt particles from the outlet (54) of the agitator chamber (40) towards a second deflector panel (64) of the plurality of deflector panels (50).

4. The cleaner head (10) of claim 3, wherein the first concave surface (74) curves rearwardly and upwardly from a lower end (76) of the first deflector panel (63) adjacent the outlet (54) of the agitator chamber (40) to an upper end (78) of the first deflector panel (63).

5. The cleaner head (10) of any one of claims 3 or 4, wherein the second deflector panel (64) comprises a second concave surface (80) configured to deflect, in use, excited dirt particles deflected from the first concave surface (74) towards a third deflector panel (66) of the plurality of deflector panels (50).

6. The cleaner head (10) of claim 5, wherein the second concave surface (80) curves forwardly from a rear end (82) of the second deflector panel (64) adjacent the upper end (78) of the first deflector panel (63) to a front end (84) of the second deflector panel (64).

7. The cleaner head (10) of claim 5 or 6, wherein the third deflector panel (66) comprises a third concave surface (86) configured to deflect, in use, excited dirt particles deflected from the second concave surface (80) towards the discharge outlet (32) of the cleaner head (10).

8. The cleaner head (10) of claim 7, wherein the third concavity (86) is configured to deflect, in use, excited dirt particles deflected from the second concavity (80) towards a focal point located on the longitudinal axis (56) of the discharge opening (32).

9. The cleaner head (10) of claim 7 or 8, wherein the third concavity (86) curves downwardly from an upper end (88) of the third deflector panel (66) adjacent the front end (84) of the second concavity (80) to a lower end (90) of the third deflector panel (66).

10. The cleaner head (10) of any one of claims 3 to 9, wherein the rear portion (22) of the main body (12) further comprises a semi-circular cylindrical panel (48) defining the agitator chamber (40), and wherein a lower end (73) of the semi-circular cylindrical panel (48) defines a plane (75) above which the first concave surface (74) terminates.

11. The cleaner head (10) of claim 10, wherein the planar surface (75) extends through the discharge opening (32).

12. The cleaner head (10) of any one of claims 3 to 11, wherein the recessed surfaces (74, 80, 86) are inclined towards the discharge outlet (32) such that an axially outer edge (94) of each recessed surface (74, 80, 86) is located forwardly of an axially inner edge (96) thereof relative to the longitudinal axis (56) of the discharge outlet (32).

13. The cleaner head (10) of any one of claims 7 to 12, wherein the first and second concavities (74, 80) are configured to diverge from the third concavity (86) towards the discharge outlet (32).

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