CN118613196A - Vacuum cleaner head for a vacuum cleaner - Google Patents

Abstract

A cleaner head (40) for a vacuum cleaner (10) is described. The cleaner head (40) includes a main body having a suction chamber and a roller (81) rotatably mounted to the main body at a front position or a rear position of the suction chamber. Then, when the cleaner head is maneuvered over the cleaning surface in one of the forward and rearward directions, the roller (81) is configured to rotate in a first direction, and when the cleaner head is maneuvered over the cleaning surface in the other of the forward and rearward directions, the roller is prevented from rotating in a second, opposite direction.

Description

Vacuum cleaner head for a vacuum cleaner

Technical Field

The present invention relates to a cleaner head for a vacuum cleaner.

Background

There is a continual effort to improve the pick-up performance of vacuum cleaners.

Disclosure of Invention

The present invention provides a cleaner head for a vacuum cleaner, comprising: a main body having a suction chamber; and a roller rotatably mounted to the main body at a front position or a rear position of the suction chamber, wherein the roller is configured to rotate in a first direction when the cleaner head is maneuvered over the cleaning surface in one of the forward direction and the rearward direction, and the roller is prevented from rotating in a second, opposite direction when the cleaner head is maneuvered over the cleaning surface in the other of the forward direction and the rearward direction.

When mounted in front of the suction inlet, the roller is configured to rotate as the cleaner head is maneuvered in a forward direction over the cleaning surface. Thus, when a relatively large dirt is present on the cleaner head during the forward stroke, the dirt is allowed to pass under the rotating roller and into the suction chamber. This reduces the shovel plow (snowplough) of large dirt. When the cleaner head is maneuvered in the rearward direction, the roller is prevented from rotating. Thus, dirt within the suction chamber is hindered from escaping from under the now stationary roller. Accordingly, the residence time of the dirt in the suction chamber increases, and thus more dirt can be sucked into the vacuum cleaner.

When installed behind the suction inlet, the opposite behavior is observed. In particular, the roller is configured to rotate when the cleaner head is maneuvered in a rearward direction and to be stationary when the cleaner head is maneuvered in a forward direction. Thus, the plow of large dirt can be reduced during the forward stroke of the cleaner head, and dirt in the suction chamber can be hindered from escaping during the forward stroke.

By reducing the shovel plow of dirt in one direction of travel while blocking the escape of dirt in the opposite direction of travel, the pick-up performance of the cleaner head can be improved.

Many conventional cleaner heads focus on improving pick-up performance only during the forward stroke. In some examples, the cleaner head may comprise a plastic, rubber or fleece strip located behind the suction chamber. During use, the strip contacts and forms a seal with the cleaning surface. This ensures that dirt in the suction chamber is blocked from escaping during the forward stroke of the cleaner head. However, a disadvantage of this arrangement is that the strip scoops dirt during the forward stroke.

With the cleaner head of the invention, improved pick-up performance during the backward stroke can be achieved (e.g. by positioning the roller behind the suction chamber) without significantly affecting the pick-up performance during the forward stroke. Thus, the overall pick-up performance of the cleaner head can be improved.

The rollers may create a restriction or seal with the cleaning surface. Therefore, the pressure in the suction chamber can be improved, which in turn can improve the pickup performance. Conversely, if there is a significant gap between the roller and the cleaning surface, air will be drawn into the suction chamber below the roller, compromising the negative pressure within the suction chamber.

The roller may comprise an elongate body covered by a compressible material. In an example, the elongated body may be covered with pile fibers. In other examples, the elongated body may be covered with a solid foam (such as a closed cell foam), felt, nonwoven fabric, or the like. In some examples, the compressible material may include a composite of a compressible core (e.g., formed of foam, felt, nonwoven, etc.) surrounded by a flexible outer sleeve (e.g., formed of rubber). By covering the body with a compressible material, a relatively good restriction or seal between the roller and the cleaning surface can be achieved. However, relatively large dirt can pass under the rotating roller without adversely affecting the pressure within the suction chamber.

The roller may be configured to move vertically relative to the body between a lower position and an upper position, and the roller may be biased to the lower position. In an example, the roller may be pivotally mounted to the body such that the roller pivots between a lower position and an upper position. By configuring the roller such that it is free to move vertically, a relatively good restriction or seal between the roller and the cleaning surface can be achieved. When contacting large dirt, the rollers may be moved vertically to allow the dirt to pass under the rollers. Thus, the plow for the dirt can be reduced without adversely affecting the pressure in the suction chamber. Furthermore, by biasing the roller to the lower position, a good negative pressure can be maintained in the suction chamber without large dirt or when the roller is stationary.

The suction chamber may be defined by a roller. Thus, relatively large dirt can pass under the roller and immediately enter the suction chamber, thereby improving the pick-up of the dirt. Furthermore, the roller may provide an effective seal or restriction with the cleaning surface along one side of the suction chamber and thus a good negative pressure may be achieved in the suction chamber.

The cleaner head may comprise an agitator rotatably mounted to the main body and a drive assembly for driving the agitator, and the agitator may be rotatable independently of the roller. In an example, the agitator may comprise a brush bar having bristle tufts or bristle bars and/or the drive assembly may comprise a motor and a transmission for transmitting torque generated by the motor to the agitator. The agitator may agitate the dirt on the cleaning surface, thereby improving the pick-up of the dirt. For example, the agitator may include shorter, stiffer bristles for agitating dirt from a carpet surface and/or longer, more flexible bristles for agitating or sweeping dirt from a hard surface (e.g., a wooden or tile surface). The agitator rotates independently of the roller. Thus, the speed of the agitator is independent of the speed at which the roller rotates or the speed at which the cleaner head is maneuvered over the cleaning surface.

The agitator may be driven (and thus rotated) by the drive assembly as the cleaner head is maneuvered over a cleaning surface in a forward and rearward direction. This then has the following advantages: during both the forward and backward strokes of the cleaner head, dirt can be agitated from the cleaning surface.

The roller may be located behind the agitator. During use, the user is typically concerned with the forward stroke of the cleaner head. By positioning the roller behind the agitator, the cleaner head may be provided with features at the front of the cleaner head which preferentially pick up dirt during the forward stroke. For example, the front portion of the body may include a slot or opening through which large dirt may enter the suction chamber during the forward stroke. Such grooves often compromise the pressure in the suction chamber, resulting in reduced pick-up performance. However, the roller may be used to create a restriction or seal in the rear of the suction chamber and thus good negative pressure may be achieved in the suction chamber despite the groove in the front of the body.

The diameter of the agitator may be greater than the diameter of the roller. Furthermore, the diameter of the agitator may be at least twice that of the roller. The advantage of having a larger agitator is that dirt from the cleaning surface can be agitated at a lower peak electrical power. For example, the agitator may comprise a brush bar having one or more bristle bars helically arranged around the brush bar. As the diameter of the agitator increases, the number of bristles that are in contact with the cleaning surface at any time decreases. Thus, the peak electric power required to drive the agitator can be reduced. Another advantage of having a larger agitator is that the drive assembly can be housed within the agitator. In addition, the entanglement of hair and fibers around the agitator can be reduced. In contrast, the rollers are not intended to agitate the cleaning surface. Thus, by employing a small diameter roller, the cost, weight and/or size of the cleaner head can be reduced.

The roller may be mounted to the body by a clutch bearing. This provides a relatively convenient means for ensuring that the roller is free to rotate in a first direction but is prevented from rotating in a second direction.

The outer surface of the roller may have a relatively low coefficient of friction. For example, the roller may be covered with pile fibers. In this way, the roller does not generate excessive drag and/or noise when the roller is prevented from rotating. However, when the cleaner head is maneuvered over a hard surface, such as a wooden or ceramic tile surface, the roller may not be able to rotate or rotate unevenly. This may then result in an increased plow for the soil. Thus, the cleaner head may comprise a wheel mounted to the main body. Then, the wheel is freely rotated in the first direction and the second direction with respect to the main body, and the roller is mounted to the wheel through the clutch bearing. When the cleaner head is placed onto a cleaning surface, the wheels contact the cleaning surface and rotate in both directions as the cleaner head is maneuvered forward and backward. The roller is mounted to the wheel by a clutch bearing. When the wheel rotates in a first direction, the clutch bearing receives and transfers torque from the wheel to the roller. Thus, the roller moves with the wheel in the first direction. Conversely, when the wheel rotates in the second direction, the clutch bearing disengages and no torque is transferred from the wheel to the roller. Thus, the roller is stationary without any force acting on the roller.

When the device described in the preceding paragraph is used on a carpeted surface, the wheel may sink into the cleaning surface. Then, when the clutch bearing is disengaged, friction generated between the roller and the cleaning surface may be sufficient to rotate the roller in the second direction. Thus, the roller may be mounted to the body at a first end by a first clutch bearing and the roller may be mounted to the wheel at a second end by a second clutch bearing. The first clutch bearing is then engaged when the roller attempts to rotate in the second direction. Thus, the roller is prevented from rotating in the second direction. On the other hand, when the wheel rotates in the first direction, the second clutch shaft engages. Thus, the roller is also rotated in the first direction.

The invention also provides a vacuum cleaner comprising a cleaner head according to any one of the preceding paragraphs.

Drawings

Embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of a vacuum cleaner;

figure 2 is a front isometric view of a cleaner head of a vacuum cleaner;

Figure 3 is a rear isometric view of the cleaner head;

figure 4 is an underside view of the cleaner head;

figure 5 is a side view of a cleaner head;

figure 6 is a cross-sectional slice through the cleaner head in the plane A-A shown in figure 4; and

Figure 7 is a section through the cleaner head in the plane B-B shown in figure 4.

Detailed Description

The vacuum cleaner 10 of figure 1 comprises a hand-held unit 20 attached to a cleaner head 40 by means of a wand or tubular duct 30.

The hand-held unit 20 includes a vacuum motor (not shown) which, during use, generates suction at the cleaner head 40 such that dirty air is drawn through the cleaner head 40, and a dirt separator 22. From there, the dirt-laden air is conveyed via a rod 30 to the dirt separator 22. The dirt is then separated from the dirt-laden air and the cleaned air is exhausted from the hand-held unit 20.

Referring now to figures 2 to 7, the cleaner head 40 comprises a head unit 50 and a neck 100.

The head unit 50 includes a main body 60, an agitator assembly 70, and a roller assembly 80.

The main body 60 includes: a suction chamber 61; a plurality of inlets 62, 63, 64; and an outlet 65. In use, dirty air is drawn in through the inlets 62, 63, 64 and into the suction chamber 61. From there, the dirty air is sucked out through the outlet 64. In this example, the inlet includes a suction opening 62 provided on the underside of the main body 60, a side discharge 63 provided on the side of the main body 60, and a debris slot 64 provided in front of the main body 60.

The body 60 also includes a door 66 that can be raised and lowered to open and close the debris slot 64, and an actuator 67 that is movable to raise and lower the door 66. In this example, the actuator 67 takes the form of a mechanical slide that can be moved to the right or left to open or close the door 66. When the door 66 is raised and the debris slot 64 is opened, large debris can pass through the slot 64 and into the suction chamber 61. Thus, the plow of dirt can be reduced during the forward stroke of the cleaner head 40. However, due to the size of the debris slot 64, a negative pressure loss in the suction chamber 61 is generated, which may reduce the pickup performance. When the door 66 descends and the debris slot 64 is closed, a negative pressure gain occurs in the suction chamber 61, and thus pickup performance can be improved. However, a large dirt shovel plow may increase during the forward stroke.

The agitator assembly 70 includes an agitator 71 and a drive assembly 72.

The agitator 71 is rotatably mounted to the main body 60 in the suction chamber 61. In this example, the agitator 71 takes the form of a brush bar and includes a cylindrical body 73 and a plurality of bristle bars 74, 75 arranged helically around the body 73. The bristle bars 74, 75 include a first bristle bar 74 and a second bristle bar 75. The first 74 and second 75 strips are intended to agitate dirt from different surface types. The first bristles 74 are stiffer and shorter and are intended to agitate dirt from the carpet surface. The second bristles 75 are longer and more flexible and are intended to agitate or sweep dirt from a hard surface such as a wooden or ceramic tile surface.

The drive assembly 72 is responsible for driving the agitator 71 (i.e., rotating the agitator 71 within the suction chamber 61). In this particular example, the drive assembly 72 is located inside the agitator 71 and includes an electric motor and a transmission for transmitting torque generated by the motor to the agitator 71. In other examples, the drive assembly 72 may be located external to the agitator 71. Further, the drive assembly 72 may include alternative means, such as an air turbine, in addition to the motor, for generating the torque required to drive the agitator 71.

The roller assembly 80 is rotatably mounted to the main body 60 at a position rearward of the suction chamber 61 (and thus also rearward of the agitator 71). In this particular example, the roller assembly 80 defines a rear portion of the suction chamber 61. That is, the suction chamber 61 is defined in part by the roller assembly 80.

The roller assembly 80 includes a roller 81 and a pair of wheels 82, 83. Roller 81 includes an elongated body 84 covered by a compressible material 85. In this example, the roller 81 comprises a cylindrical body covered with pile fibers. In other examples, the body 84 may be covered by a solid foam (such as a closed cell foam), felt, nonwoven fabric, or the like. In some examples, the compressible material 85 may include a composite of a compressible core (e.g., formed of foam, felt, nonwoven, etc.) surrounded by a flexible outer sleeve (e.g., formed of rubber). Wheels 82, 84 are located on opposite sides of roller 81 and have an outer diameter similar to the outer diameter of roller 81.

The body 60 includes a first shaft 68 to which a first end of a roller assembly 80 is rotatably mounted. More specifically, a first one 82 of the wheels is rotatably mounted to the first shaft 68 by means of a plain bearing, and a first end of the roller 81 is rotatably mounted to the first shaft 68 by means of a first clutch bearing 91 (i.e. a one-way bearing). The roller assembly 80 includes a second shaft 88 extending outwardly from the second end of the roller assembly 80. A second one 83 of the wheels is rotatably mounted to the second shaft 88 by a second clutch bearing 92, and the roller 81 is fixedly mounted to the second shaft 88. The second shaft 88 is then rotatably mounted to the body 60 by means of a sliding bearing.

The first clutch bearing 91 ensures that the roller 81 is allowed to rotate relative to the main body 60 in only one direction. More specifically, the first clutch bearing 91 ensures that the roller 81 is allowed to rotate relative to the main body 60 in a first direction and prevents the roller 81 from rotating relative to the main body 60 in a second, opposite direction. Referring to the example shown in fig. 6, the roller 81 is allowed to rotate in the clockwise direction, and the roller 81 is prevented from rotating in the counterclockwise direction. Accordingly, when the roller 81 rotates in the second direction (counterclockwise in fig. 6) with respect to the first shaft 68, the first clutch bearing 91 is engaged with the first shaft 68. Since the first shaft 68 is stationary and forms part of the main body 60, engagement of the first clutch bearing 91 prevents rotation of the roller 81 relative to the main body 60 in the second direction. Conversely, when the roller 81 rotates in the first direction (clockwise in fig. 6), the first clutch bearing 91 is disengaged from the first shaft 68. Thereby, the roller 81 is free to rotate in the first direction with respect to the main body 60.

The second clutch bearing 92 ensures that the second wheel 83 is allowed to rotate in the second direction relative to the roller 81 and prevents the second wheel 83 from rotating in the first direction relative to the roller 81. When the second wheel 83 rotates in the first direction (clockwise in fig. 6), the second clutch bearing 92 is engaged with the second shaft 88. Because the second shaft 88 is fixed to the roller 81, the roller 81 is also rotated. Accordingly, the second clutch bearing 92 transmits torque from the second wheel 83 to the roller 81. Thus, the second wheel 83 and the roller 81 move together in the first direction. Conversely, when the second wheel 83 rotates in the second direction (counterclockwise in fig. 6), the second clutch bearing 92 is disengaged from the second shaft 88. The second wheel 83 is thus free to rotate in a second direction relative to the roller 81. Accordingly, even when the roller 81 is prevented from rotating relative to the main body 60 by the first clutch bearing 91, the second wheel 83 can freely rotate in the second direction relative to the main body 60 by the second clutch bearing 92.

The roller assembly 80 is mounted to the body 60 such that the roller assembly 80 is free to move vertically relative to the body 60. In particular, the roller assembly 80 is free to move vertically between a lower position and an upper position. The roller assembly 80 is then biased to the lower position. In this embodiment, the body 60 includes a housing 93 and a pair of support arms 94, the pair of support arms 94 being mounted to the housing 93 to pivot about a pivot axis 95. The roller assembly 80 is then mounted to the support arm 94 in the manner described above. The body 60 also includes a pair of torsion springs (not shown), each biasing a respective support arm 94 into a lower position. In this example, vertical movement of the roller assembly 80 is achieved by pivoting. In other examples, the roller assembly 80 may translate (i.e., move linearly) up and down.

The neck 100 is rotatably attached at one end to the head unit 50 and removably attached at an opposite end to the wand 30 of the vacuum cleaner 10. In this example, the neck 100 is hinged and includes a front portion 101 rotatably attached to the body 60 of the head unit 50 and a rear portion 102 pivotally attached to the front portion 101. The neck 100 further comprises a pair of dome-shaped wheels 103, which dome-shaped wheels 103 are rotatably attached to the front portion 101 and converge below the front portion 101.

In use, the cleaner head 40 is maneuvered over a cleaning surface by the wand 30. For example, the cleaner head 40 can be maneuvered forward and backward by pushing and pulling the wand 30. In addition, the cleaner head 40 can be turned to the left and right by twisting the lever 30. The hinge in the neck 100 and the rotatable connection between the neck 100 and the head unit 50 help ensure that the head unit 50 maintains a horizontal profile with the cleaning surface when the cleaner head 40 is maneuvered over the cleaning surface. The wheels 103 serve to support the neck 100 and help prevent the head unit 50 from lifting off the cleaning surface, particularly when a pushing force is applied to the wand 30.

As the cleaner head 40 rotates forward and backward, the agitator 71 rotates to agitate dirt from the cleaning surface. The agitated dirt is then entrained with the moving air drawn into the suction chamber 61. The wheels 82, 83 of the roller assembly 80 contact the cleaning surface and rotate during the forward and rearward strokes of the cleaner head 40. However, as will now be explained, the roller 81 of the roller assembly 80 rotates only during the forward stroke of the cleaner head 40.

The first clutch bearing 91 prevents rotation of the roller 81 relative to the main body 60 in the second direction (anticlockwise in figure 6) during the forward stroke of the cleaner head 40. Thus, the roller 81 does not rotate when the cleaner head 40 is maneuvered forward over a cleaning surface. This then has the advantage that dirt in the suction chamber 81 is hindered from escaping from below the roller 81. Accordingly, the residence time of the dirt within the suction chamber 61 increases, and more dirt may be entrained by the air moving through the suction chamber 61. Conversely, if the roller 81 rotates during the forward stroke of the cleaner head 40, dirt within the suction chamber 61 may pass under the rotating roller 81. In practice, the roller 81 may actively push dirt out of the rear of the cleaner head 40.

During the rearward stroke of the cleaner head 40, the first clutch bearing 91 is disengaged and thus the roller 81 is free to rotate relative to the main body 60. Further, the second clutch engagement 92 and thus the roller 81 rotates together with the second wheel 83 in the first direction (clockwise in fig. 6). The roller 81 rotates as the cleaner head 40 is maneuvered rearwardly over the cleaning surface. Thus, when the cleaner head 40 encounters large dirt during the backward stroke, the dirt is allowed to pass under the rotating roller 81 and into the suction chamber 611. This then reduces the shovel plow for large dirt.

The roller 81 extends substantially across the width of the suction chamber 61. In addition, the rollers 81 form a restriction or seal with the cleaning surface. Therefore, a good negative pressure can be achieved in the suction chamber 61, which in turn can improve the pickup performance. Conversely, if there is a significant gap between the roller 81 and the cleaning surface, a significant air flow will be drawn under the roller 81 and in the suction chamber 61, thereby compromising the pressure within the suction chamber 61. By ensuring that the roller 81 forms a restriction or seal with the cleaning surface, improved pick-up can be achieved during the backward stroke without adversely compromising the pressure within the suction chamber 61. Thus, a net improvement in pickup performance can be achieved.

In the present embodiment, the suction chamber 61 is defined by the roller 81. Accordingly, relatively large dirt can pass under the roller 81 and immediately enter the suction chamber 61, thereby improving the pickup of the dirt. Further, the roller 81 may provide an effective restriction or seal with the cleaning surface along one side of the suction chamber 61 and thus a good negative pressure may be achieved within the suction chamber 61. However, in other examples, the roller 81 may be spaced apart from the suction chamber 61.

The roller 81 includes a body 84 covered by a compressible material 85 such as wool fibers, closed cell foam, felt, or the like. By covering the main body 84 with the compressible material 85, dirt can pass under the rotating roller 81 while maintaining a relatively good restriction or seal with the cleaning surface.

The roller assembly 80 is free to move vertically relative to the body 60. Thus, upon contacting particularly large dirt, the roller 81 may move upward to pass the dirt under the roller 81. After the dirt passes under roller 81, roller assembly 80 is biased downwardly so that a restriction or seal is again established between roller 81 and the cleaning surface. Thus, the plow of dirt during the backward stroke can be further reduced without adversely affecting the pressure within the suction chamber 61. In spite of the foregoing advantages, the roller assembly 80 may be mounted to the body 60 in a manner that does not allow vertical movement.

The roller 81 is prevented from rotating relative to the main body 60 by the first clutch bearing 91. The clutch bearing provides a relatively convenient means for ensuring that the roller 81 is free to rotate in a first direction, but preventing the roller 81 from rotating in a second direction. Although convenient, clutch bearings can be relatively expensive. Accordingly, the cleaner head 40 may comprise alternative means for ensuring that the roller 81 is allowed to rotate in a first direction and that the roller 81 is prevented from rotating in a second direction. As an example, the roller 81 and the body 60 may include ratchet-like features that allow rotation only in a first direction. For example, the roller 81 may include teeth at an end of the roller, and the body 60 may include pawls that engage with the teeth to prevent rotation in the second direction. In another example, the roller assembly 80 may be mounted to the body 60 in a manner that allows for small horizontal translations of the roller assembly 80 relative to the body 60. When the cleaner head 40 is maneuvered forward over a cleaning surface, the roller assembly 80 translates rearward relative to the main body 60 and the roller 81 engages the main body 60 to brake the roller 81. Conversely, when the cleaner head 40 is maneuvered rearwardly over a cleaning surface, the roller assembly 80 translates forwardly relative to the main body 60, and the roller 81 disengages from the main body 60 and rotates freely.

In the above example, the roller assembly 80 includes a pair of wheels 82, 83. Further, the roller 81 is mounted to one of the wheels 83 by a clutch bearing 92. It is contemplated that wheels 82, 83 and/or clutch bearing 92 may be omitted. However, as will now be explained, there are advantages in using the wheels 82, 83 and the clutch bearing 92. In this example, the roller 81 includes a body 84 covered with pile soft fibers 85. Accordingly, the outer surface of the roller 81 has a relatively low coefficient of friction. This then has the advantage that the roller 81 does not generate excessive drag and/or noise when the roller 81 is stationary during the forward stroke of the cleaner head 40. However, if the wheels 82, 83 and the second clutch bearing 92 are omitted, the roller 81 may not be able to rotate or not rotate smoothly when the cleaner head 40 is maneuvered rearwardly over a hard surface, such as a wooden or ceramic tile surface. This can then result in an increase in the shovel plow of the soil. By mounting the roller 81 to one of the wheels 83 by means of the clutch bearing 92, the roller 81 is rotated together with the wheel 83 during the backward stroke. While this benefit may be achieved by providing a single wheel, providing two wheels 82, 83 on opposite sides of the roller 81 helps ensure that the roller 81 has a more consistent interference with a hard cleaning surface. In addition, the arrangement of the two wheels 82, 83 better guides the cleaner head 40 in a straight line during the forward and rearward strokes. In the above example, only the second wheel 83 is clutched (i.e., mounted to the roller 81 by the clutch bearing 92). In other examples, both wheels 82, 83 may be clutched. Accordingly, the roller 81 is actively driven in the first direction by the two wheels 82, 83. This then has the advantage that if one of the wheels 82, 83 is slid over the cleaning surface, the roller 81 continues to be driven by the other of the wheels 82, 83.

One or more of the wheels 82, 83 and/or clutch bearings 92 may be omitted, despite the advantages described in the preceding paragraphs. If the wheels 82, 83 and/or the second clutch bearing 92 are omitted, the roller 81 may include features that increase the surface friction of the roller 81. For example, instead of or in addition to pile fibers, the roller 81 may include foam or felt on which rubber dots are provided to achieve the desired friction with the cleaning surface.

The cleaner head 40 comprises a debris slot 64 in front of the main body 60, which debris slot 64 can be opened to receive large debris during the forward stroke of the cleaner head 40. As described above, when the debris groove 64 is opened, there is a loss of negative pressure in the suction chamber 61. Dirt entrainment and pick-up may be adversely affected. However, the restriction or seal created by the roller 81 at the rear of the suction chamber 61 helps ensure that relatively good pressure can be achieved within the suction chamber 61 despite the opening of the debris slot 64.

In the above example, the cleaner head 40 comprises two very different mechanisms (the debris slot 64 and the roller 81) for allowing large debris to enter the suction chamber 61 during the forward and rearward strokes. The main reason for this is that during use, the user will typically be concerned with the forward stroke of the cleaner head 40. The debris slot 64 depicted in this particular example is generally more efficient than the roller 81 when large dirt is allowed to enter the suction chamber 61. However, the debris slot 64 results in a greater pressure drop within the suction chamber 61. By having the chip pocket 64 at the front of the body 60 and the rear mounted roller 81, large chip pickup can be prioritized for the forward stroke. However, it is also achieved that large debris is picked up during the backward stroke, while maintaining a good pressure within the suction chamber 61. Thus, especially when considering user behavior, a net improvement in soil pick-up can be observed.

The debris slot 64 at the front of the main body 60 may be omitted and the cleaner head 40 may include a further roller assembly located in front of the suction chamber 61 for receiving large debris during the forward stroke. The additional roller assembly then operates in a similar manner to the roller assembly 80 located behind the suction chamber 61. However, in comparison to the roller 81 located behind the suction chamber 61, the roller located in front of the suction chamber 61 is configured to rotate when the cleaner head 40 is maneuvered in a forward direction over a cleaning surface and is prevented from rotating when the cleaner head 40 is maneuvered in a rearward direction.

In further examples, the cleaner head 40 may comprise a single roller assembly located in front of the suction chamber 61, i.e. the roller assembly 80 located behind the suction chamber 61 may be omitted. Then, the rear portion of the main body 60 (i.e., the rear portion of the suction chamber 61) may be similar to the rear portion of a conventional cleaner head. While this arrangement may result in a plow that adds large debris during the backward stroke, it may still be advantageous to provide a roller assembly in front of suction chamber 61. For example, a roller assembly located in front of the suction opening may achieve a better seal with the cleaning surface and thus a higher negative pressure in the suction chamber 61 than the debris slot 64.

In the above example, the roller assembly 80 includes a single roller 81 that is cylindrical in shape. In other examples, the roller assembly 80 may include more than one roller and/or each roller shape may be non-cylindrical. Thus, different behaviors and profiles can be achieved. For example, the roller assembly 80 may include two rollers arranged in series. Each roller is independently vertically movable relative to the body. When the first roller is in contact with large debris, the first roller may move vertically to allow dirt to pass under the roller. However, the second roller does not move vertically and remains effectively restrained or sealed with the cleaning surface. Therefore, the pressure in the suction chamber 61 can be increased. In another example, the roller assembly 80 may include a plurality of rollers arranged in series. The rollers may then be spaced apart such that a debris slot is created between adjacent rollers. In this manner, the roller assembly 80 may simulate the debris slot 64 located at the front of the body 60. In another example, the roller assembly 80 may include two or more tapered rollers arranged in series such that the lowermost surface of the rollers is flush with the cleaning surface. Hair and long fibers that might otherwise become entangled on the roller may then migrate to and fall off the smallest end of the roller. In other examples, roller 81 may include a discontinuous outer surface. For example, the roller 81 may include a central body from which a plurality of flexible paddles extend radially outward. The paddles may extend linearly or helically along the length of the body. Alternatively, the paddles may be arranged in other patterns along the length of the body. For example, the paddles may be arranged in a chevron shape. A roller with paddles has the following potential benefits: rollers with smaller diameter bodies may be used to catch large dirt.

In another example, the paddle may be in the form of a bristle assembly that includes a plurality of bristles or bristle bars (not shown). The bristle bars provide the advantage of not leaving a streak of dirt as the tool is swept across the cleaning surface. The bristle sub-assembly may include bristle bars formed of nylon, which have the potential benefit of additional agitation of the carpet surface. Alternatively, the bristle sub-assembly may include bristle bars formed from carbon fibers. Carbon fibers allow for relatively soft and thin bristles, which helps reduce the speckle of the cleaning surface. Furthermore, carbon fibers have good antistatic properties, which means that the bristles can sweep across a clean surface without charging the surface.

The cleaner head 40 comprises an agitator 71 in the form of a brush bar which is driven (i.e. rotated) during both the forward and rearward strokes. Thus, dirt can be better agitated from the cleaning surface, thereby improving pickup performance. The brush bar is larger than the roller 81 and in an example may be at least twice the diameter of the roller 81. The advantage of having a relatively large brush bar is that dirt can be agitated from the cleaning surface with a low peak electrical power. In particular, as the diameter of the brush bar increases, the number of bristles that are in contact with the cleaning surface at any time decreases. Thus, the peak electric power required to drive the brush bar is reduced. Another advantage of having a large brush bar is that the drive assembly 72 can be housed within the brush bar, as in this example. In addition, the entanglement of hair and fibers around the brush bar can be reduced. In contrast, the roller 81 is not intended to agitate the cleaning surface. Thus, by employing a small diameter roller, the cost, weight and/or size of the cleaner head 40 can be reduced.

In the above example, the agitator 71 comprises a brush bar that rotates about an axis parallel to the cleaning surface. In other examples, the agitator 71 may take alternative forms. For example, the agitator 71 may comprise one or more discs or pads that carry bristles or other cleaning elements and rotate about an axis perpendicular to the cleaning surface. In further examples, the agitator may be omitted entirely, thereby reducing the cost, weight and/or size of the cleaner head 40.

Although the vacuum cleaner 10 shown in figure 1 is a stick vacuum cleaner, the cleaner head 40 may equally be used with other types of vacuum cleaners, such as canister, upright or robotic vacuum cleaners. In the above example, the cleaner head 40 comprises a neck 100, which neck 100 helps ensure that the head unit 50 maintains a horizontal profile with the cleaning surface as the cleaner head 40 is maneuvered forward and backward. However, the neck 100 is not relevant to the present invention and alternative designs of the neck are possible. Furthermore, the neck 100 may be omitted, particularly if the cleaner head 40 forms part of an upright or robotic vacuum cleaner.

While particular examples and embodiments have been described, it should be understood that these examples and embodiments are illustrative only and that various modifications may be made without departing from the scope of the invention as defined by the claims.

Claims (13)

1. A cleaner head for a vacuum cleaner, comprising:

a main body having a suction chamber; and

A roller rotatably mounted to the main body at a front position or a rear position of the suction chamber;

wherein the roller is configured to rotate in a first direction when the cleaner head is maneuvered over a cleaning surface in one of a forward direction and a rearward direction, and to be prevented from rotating in a second, opposite direction when the cleaner head is maneuvered over the cleaning surface in the other of the forward direction and the rearward direction.

2. The cleaner head of claim 1, wherein the roller forms a seal with the cleaning surface.

3. A cleaner head according to claim 1 or 2, wherein the roller comprises an elongate body covered by a compressible material.

4. A cleaner head according to any preceding claim, wherein the roller is configured to move vertically relative to the body between a lower position and an upper position, and the roller is biased to the lower position.

5. A cleaner head according to any one of the preceding claims, wherein the suction chamber is defined by the roller.

6. A cleaner head according to any preceding claim, wherein the cleaner head comprises an agitator rotatably mounted to the main body and a drive assembly for driving the agitator, and the agitator rotates independently of the roller.

7. The cleaner head of claim 6, wherein the agitator is driven by the drive assembly when the cleaner head is maneuvered over the cleaning surface in the forward and rearward directions.

8. A cleaner head according to claim 6 or 7, wherein the roller is located behind the agitator.

9. A cleaner head according to any one of claims 6 to 8, wherein the agitator has a diameter at least twice the diameter of the roller.

10. A cleaner head according to any preceding claim, wherein the roller is mounted to the main body by a clutch bearing.

11. A cleaner head according to any one of the preceding claims, wherein the cleaner head comprises a wheel mounted to the main body, the wheel being free to rotate relative to the main body in the first and second directions, and the roller is mounted to the wheel by a clutch bearing.

12. The cleaner head of claim 11, wherein the roller is mounted to the body at a first end by a first clutch bearing and the roller is mounted to the wheel at a second end by a second clutch bearing.

13. A vacuum cleaner comprising a cleaner head according to any one of the preceding claims.