A cleaner head for a vacuum cleaner

Abstract

A cleaner head for a vacuum cleaner, the cleaner head having an agitator and a drive assembly for transmitting torque to the agitator where the drive dog and the agitator comprise a shank and a bore configured to engage the shank, and the shank has a protrusion configured to engage the bore in a predetermined orientation.

Description

[0001] 1 P004689-W001

[0002] A CLEANER HEAD FOR A VACUUM CLEANER

[0003] BACKGROUND

[0004] Vacuum cleaners are widely used household appliances designed to remove dirt, dust, and debris from various surfaces. A key component of many vacuum cleaners is the brush bar, which enhances cleaning efficiency by agitating carpet fibers and loosening embedded dirt. Traditional brush bars typically consist of bristles that rotate at high speeds to dislodge particles, but they often encounter challenges related to performance, durability, and ease of maintenance.

[0005] Existing brush bar designs face limitations in adaptability to different floor types. Many models perform well on carpets but are less effective on hard surfaces, leading to suboptimal cleaning results. Furthermore, bristle wear and entanglement with hair and debris can diminish performance over time, necessitating frequent cleaning and replacement. These issues not only impact user satisfaction but also contribute to the overall cost of vacuum cleaner maintenance.

[0006] Moreover, the need for efficient airflow through the brush bar is critical for maximizing suction power. However, many conventional designs do not adequately balance brush agitation and airflow, leading to reduced cleaning efficiency and increased energy consumption.

[0007] To address these challenges, there is a need for innovative brush bar designs that improve cleaning performance across a variety of surfaces while enhancing durability and ease of maintenance as well as efficiency of power transmission. Solutions that incorporate advanced materials and configurations can potentially offer significant improvements in the functionality and lifespan of brush bars, ultimately benefiting both manufacturers and consumers.

[0008] There is general desire to improve a cleaner head of an appliance such as a vacuum cleaner or floor sweeper which may include an agitator and a drive assembly for driving the agitator. For example, improvements may be desired in terms of size, weight, compactness, efficiency, noise, manufacturing cost, reliability, and user-friendliness. 2 P004689-W001

[0009] SUMMARY

[0010] According to a first aspect of the present disclosure there is provided a cleaner head comprising an agitator rotatably mounted about a central longitudinal axis of the agitator and a drive assembly for driving the agitator, the drive assembly comprising a main shaft having a rotation axis for transmitting torque to the agitator, a male coupler attached to the main shaft and comprising a plurality of lobes, wherein at least one of the lobes comprises a curved contact surface, and a socket configured to receive the curved contact surface, wherein, the central longitudinal axis of the agitator is at an oblique angle to the rotation axis of the main shaft, and the curved contact surface of the male coupler and the socket are configured such that rotation of the main shaft is transmitted to the agitator to cause rotation of the agitator about the central longitudinal axis of the agitator.

[0011] According to a second aspect of the present disclosure there is provided a cleaner head comprising an agitator rotatably mounted about a central longitudinal axis of the agitator and a drive assembly for driving the agitator, the drive assembly comprising a main shaft having a rotation axis for transmitting torque to the agitator, and a male coupler attached to the main shaft and comprising a plurality of lobes, wherein at least one of the lobes comprises a curved contact surface, and the agitator comprising a socket configured to receive the curved contact surface of the male coupler, wherein the central longitudinal axis of the agitator is at an oblique angle to the rotation axis of the main shaft, and the curved contact surface of the male coupler and the socket are configured such that rotation of the main shaft is transmitted to the agitator to cause rotation of the agitator about the central longitudinal axis of the agitator. 3 P004689-W001

[0012] According to a third aspect of the present disclosure, there is provided a drive assembly comprising a main shaft having a rotation axis for transmitting torque to a drive dog, wherein one of the drive assembly and the drive dog comprises a male coupler having a plurality of lobes, at least one of the lobes comprises a curved contact surface, the other of the drive assembly and the drive dog comprises a socket configured to receive the male coupler, when in use, the male coupler and the socket mate such that, rotation of the main shaft is transmitted to the drive dog about a drive dog axis that is at an oblique angle to the rotation axis of the main shaft.

[0013] The plurality of lobes of the male coupler may be projections or ridges formed on the male coupler, for example integrally formed on the male coupler. This may provide a more effective direct torque transmission from the main shaft to the agitator, without any further moving machine elements, by distributing the total rotational force among each of the plurality of lobes, thereby allowing the use of a relatively more compact male coupler in terms of component size.

[0014] The interaction between the curved contact surface of the male coupler and the socket configured to receive said curved contact surface provides for the operation of the drive assembly such that rotation of the main shaft can be transmitted to the agitator to cause rotation of the agitator about an agitator axis that is at an oblique angle to the rotation axis of the main shaft. This may allow for a degree of tolerance to misalignment between the rotating components that are in direct contact, thus simplifying the assembly process and reducing the necessity for precise alignment, enhancing the versatility of the drive assembly. At least one of the lobes may comprise a convex contact surface. The socket may comprise a corresponding concave socket contact surface in an inside wall of the socket. In examples, the socket may comprise a flat socket contact surface. The convex shape of the contact surface of the lobes may aid in distributing the load evenly across the entire contact area between the male coupler and the socket. This further minimizes stress concentration points, reducing the risk of premature wear and component fatigue. In applications with varying loads or unpredictable force distribution, the convex surface improves component integrity over a longer period of time. 4 P004689-W001

[0015] The utilization of a curved contact surface facilitates gradual engagement and dispersion of forces across the contact surfaces between transmission components (for example the male coupler and the socket), reducing abrupt loadings, augmenting the overall load-carrying capacity of the torque transmission mechanism, and subsequently enhancing the overall efficiency of torque transfer. This minimizes power losses due to friction and wear, thus optimizing performance. Furthermore, this feature may be particularly beneficial where handling of relatively higher torque loads is required.

[0016] Two principal curvatures of the curved contact surface may be equal to one another. In this context ‘principal curvature’ refers to the curvature of a surface in the direction of the maximum and minimum rates of curvature as a measure of how the surface bends by different amounts in different directions. Incorporating two principal curvatures that are equal to one another on the curved contact surface may result in a spherical segment. This may further improve uniform stress distribution, enhanced load-bearing capacity, reduced wear and friction, optimized contact geometry, improved lubrication characteristics, enhanced durability, and consistent performance.

[0017] At least one of the lobes may comprise a domed shape contact surface such that the principal curvatures of the curved surface portion are both greater than zero.

[0018] In this manner, the curved contact surface is a positively curved surface. A positively curved surface with both principal curvatures greater than zero resembles the shape of a sphere or ellipsoid and indicate that the curved surface portion is outwardly curved in both directions. This geometric form is associated with smooth, rounded contours and the outward curvature contributes to the surface bulging or protruding away from its tangent plane. The spherical or ellipsoidal shape may aid in enhancing the ability to support loads and facilitating smooth rotation of the corresponding components. Furthermore, the outward curvature contributes to a robust and stable structure, making it suitable for components or surfaces that experience external forces. 5 P004689-W001

[0019] At least one of the lobes of the male coupler may comprise a partial-cylindrical contact surface such that one of the principal curvatures of the curved contact surface portion is equal to zero, whilst the other principal curvature has a positive value.

[0020] In this manner, the curved contact surface may result in a cylinder segment. Incorporating a cylinder segment as a curved contact surface may result in increased instantaneous contact surface and further improve uniform stress distribution, enhanced load-bearing capacity, reduced wear and friction, optimized contact geometry, improved lubrication characteristics, enhanced durability, and consistent performance.

[0021] The curved contact surface may aid with even distribution of contact stresses across the contact area, mitigating the risk of stress concentration at specific points. This contributes to improved component durability and longevity, reducing the likelihood of fatigue-related failures. By mitigating stress concentrations and reducing wear, the curved contact surface enhances the overall durability and resilience of the transmission components. This leads to a more robust and dependable system.

[0022] In cases where lubrication of the moving components is required, the curvature of the contact surface may promote more efficient lubricant distribution, ensuring adequate lubrication under high speed and / or high torque conditions, thus minimizing friction and wear, further contributing to the longevity of the drive assembly operation.

[0023] The curved contact surface may also facilitate smooth torque transmission which effectively dampens noise and vibration within the system, resulting in quieter and more comfortable operation. The smooth torque transmission may also aid with transmitting torque at oblique angles, maintaining a consistent and uniform output, whilst eliminating jerky or abrupt motion.

[0024] The curved contact surface may accommodate a wide range of input and output angles, thus making the drive assembly of the present disclosure versatile and adaptable to various applications requiring torque transmission at oblique angles. 6 P004689-W001

[0025] As the rotation of the main shaft causes the rotation of the agitator about an agitator axis that is at an oblique angle to the rotation axis of the main shaft, torque transmission at an intentional angle may be possible for driving various agitator arrangements. This may enable the arrangement of the agitator such that the agitator is effectively angled, towards a horizontal surface to be cleaned by the cleaner head. For example, the agitator may be effectively angled to maintain one of its sides parallel to the surface to be cleaned.

[0026] At least one of the plurality of lobes may be wider than the rest of the plurality of lobes. The wider lobe may serve as a guiding element, making it easier to achieve alignment between the male coupler and the socket. This may be valuable in situations where precise alignment can be challenging due to factors such as misalignment, vibrations, or human error. The wider lobe of the coupling member and the socket configured to mate with the coupling member may guide the components into proper alignment during engagement. This alignment may aid in forming a ‘poka-yoke’ or keyed engagement mechanism, therefore reducing the alignment errors during assembly or operation.

[0027] At least one of the plurality of lobes may comprise a lead-in chamfer. When two components come into contact, especially at an oblique angle, there is a risk of binding or jamming if not properly aligned. The lead-in chamfer may help with mitigating this risk by guiding the male coupler and the socket into alignment before they make full contact. This minimizes the chances of sudden jams or binding that can lead to operational issues or damage to the drive assembly.

[0028] The drive assembly may comprise a drive transmission member. The drive transmission member may comprise a male coupler and / or a socket. Drive transmission member may comprise an auxiliary shaft and / or a drive dog.

[0029] The auxiliary shaft may be configured to transmit the rotation of the main shaft. The auxiliary shaft may serve as a rigid and precise connection between the male coupler and the agitator. The auxiliary shaft may ensure that consistent torque transmission is achieved between the two components (for example the main shaft and the agitator), especially in situations where the components are spaced apart from each other, which may lead to misalignment between 7 P004689-W001 the components. Furthermore, by arranging a driven component of the agitator away from the main shaft, the risk of straining or breaking the torque receiving components of the agitator may be reduced. In this manner, overall system precision and reliability may be enhanced whilst operational errors may be minimised.

[0030] The auxiliary shaft may be at an oblique angle to the rotation axis of the main shaft. In further examples, the auxiliary shaft may be at an oblique angle to the central longitudinal axis of the agitator. This way, the auxiliary shaft may allow for a larger oblique angle between the main shaft and the central longitudinal axis of the agitator thus allowing for more flexibility in alignment between the main shaft and the agitator which in turn may aid in flexibility of using various sizes and shapes of agitators. By changing the size of the auxiliary shaft, the drive assembly can be adapted to various sizes and types of components, making it easier to customize the system for different applications or sizes of cleaner heads.

[0031] Auxiliary shaft may comprise a proximal end proximate to the main shaft and the socket may be at the proximal end of the auxiliary shaft such that the socket of the auxiliary shaft is configured to engage with the male coupler of the main shaft. The socket of the auxiliary shaft may be configured to receive the curved contact surface of the male coupler.

[0032] The auxiliary shaft may comprise a distal end opposite to the proximal end and the male coupler may be at the distal end of the auxiliary shaft such that the male coupler of the auxiliary shaft is configured to engage with a further socket of the drive assembly. The male coupler of the auxiliary shaft may comprise a curved contact surface configured to engage with the further socket of the drive assembly.

[0033] The drive assembly comprises a drive dog configured to couple the drive assembly to the agitator and transmit the rotation of the main shaft to the agitator. Drive dogs allow for rapid assembly and disassembly of components. Where the agitator is removable from the cleaner head, it may then be possible to removably mount the agitator to the drive dog without interfering with any further components of the drive assembly. 8 P004689-W001

[0034] One of the auxiliary shaft and the drive dog may comprise a further male coupler having a plurality of lobes, at least one of the lobes may comprise a curved contact surface, the other of the auxiliary shaft and the drive dog may comprise a further socket configured to receive the further male coupler, when in use, the further male coupler and the further socket may mate such that the rotation of the auxiliary shaft is transmitted to the drive dog.

[0035] In this manner, the drive assembly may accommodate larger oblique angles between the main shaft and the agitator, thus a wider range of input and output angles may be possible. This enables the drive assembly of the present disclosure to be more compact and fit in to a tighter or irregularly shaped areas within the cleaner head.

[0036] The auxiliary shaft may comprise the further male coupler and the socket such that the auxiliary shaft may be configured to mate to both the drive dog and the main shaft. This way, when operational requirements change, or if a component needs replacement, the auxiliary shaft that is compatible with both the driving member (e.g. main shaft) and driven member (e.g. drive dog) simplifies the reconfiguration process. This means less downtime and faster adaptation to new tasks or loads.

[0037] The socket may be identical to or the same as the further socket. Similarly, the male coupler may be identical to or the same as the further male coupler. When components share identical geometrical properties and fitting parts, the manufacturing process may be simplified. This may enable production of standard or identical parts in large quantities, reducing production costs and lead times for the final product.

[0038] The male coupler or each of the male couplers may comprise at least four lobes. This may enable the profile of the curved contact faces of the lobes, or driving contact surfaces to be a cylindrical segment, thus providing an instantaneous contact region, for example in the form of a linear cylindrical segment, on the male couplers. 9 P004689-W001

[0039] Correspondingly the linear cylindrical segment sweeps a contact region within the socket when in use. Compared to a male coupler comprising three or fewer lobes and a corresponding socket, a four-lobed male coupler / socket design enables a larger swept region for instantaneous contact within the socket, when in use. This is because when the lobes are distributed about a central longitudinal axis of the male coupler, the geometrical constraints of the corresponding features between the male coupler and the socket determine the instantaneous contact areas between these components. Thus, it is found that four-lobed male coupler-socket design may provide the optimum driving contact surfaces. This may aid with improved load distribution, torque transfer efficiency, tolerance to misalignment, resistance to wear and system durability.

[0040] The plurality of lobes may be evenly spaced about the central longitudinal axis of the male coupler and / or the further male coupler. Evenly spacing the load bearing components, for example the plurality of lobes, about the central longitudinal axis of a rotating component may aid with uniform load distribution, and therefore enhance component lifespan.

[0041] When load-bearing features are evenly spaced, the forces and loads are more uniformly distributed across the rotating member's surface. This balanced load distribution minimizes the creation of localized stress concentrations and vibrations, which are often the result of uneven forces acting on a component. As a result, the system experiences less vibration. Accordingly, uniform distribution of load-bearing components may help with dampening the vibrations and reducing overall system noise.

[0042] The agitator may comprise a first end and a second end, and the agitator may have a shape which tapers towards the first end in a direction along the central longitudinal axis of the agitator. The angle at which the tapered external surface of each agitator tapers may be equal to the angle by which the axis of the agitator is angled downwards (optionally, within + / - 20%,- or within + / - 10%). The angle at which the tapered external surface of each agitator tapers may be less than 45 degrees and may be within the range of 10 degrees to 30 degrees. The angle by which the axis of the agitator is angled downwards may be less than 45 degrees and may be within the range of 10 degrees to 30 degrees. 10 P004689-W001

[0043] The cleaner head may be arranged such that the central longitudinal axis of the agitator is inclined with respect to a horizontal surface to be cleaned on which the cleaner head is supported during use.

[0044] The agitator may further comprise an external surface and the lowermost portions of the external surface of the agitator may be parallel to the horizontal surface when the cleaner head is use. In this manner, the agitator having a tapered profile, which may be generally conical or frustoconical in shape, is at least partially compensated for. As such, a larger portion of the outer surface of each agitator may be in contact the horizontal surface during use.

[0045] The cleaner head may be arranged such that when the cleaner head is supported on a planar surface to be cleaned, the rotation axis of the main shaft is parallel to the planar surface to be cleaned. In this manner, both ends of the main shaft may be utilised for transmitting the rotation of the main shaft to the agitator in an identical manner.

[0046] The agitator may be cantilevered from a portion of the cleaner head at the second end such that first end is a free end. Accommodating the agitator in this manner may aid with encouraging any debris, such as hair or threads, which becomes wrapped around the agitator during use to travel along the length of the agitator from the first end towards the second end where it can become lose and fall from the agitator.

[0047] In use, where the cleaner is a vacuum cleaner, this wrapped debris which may have travelled along the agitator can then be sucked into the vacuum cleaner to which the cleaner head is attached. This may be particularly useful for long strands of debris which have the potential to wrap around the agitator during operation of the cleaner head. For example, strands of debris having a length which is greater than the circumference of the agitator. Examples of such wrappable debris include hair, fibres and threads.

[0048] The cleaner head may comprise a further agitator having a further central longitudinal axis, wherein the further agitator is mounted for rotation about the further central longitudinal axis 11 P004689-W001 of the further agitator. In this manner, a larger region of the horizontal surface may be agitated by the cleaner head and / or edge-to-edge cleaning may be achieved.

[0049] The further agitator may comprise a further first end and a further second end, and the further agitator has a shape which tapers towards the further first end in a direction along the further central longitudinal axis. The angle at which the tapered external surface of each agitator tapers may be equal to the angle by which the axis of the agitator is angled downwards (optionally, within + / - 20%,- or within + / - 10%). The angle at which the tapered external surface of each agitator tapers may be less than 45 degrees and may be within the range of 10 degrees to 30 degrees. The angle by which the axis of the agitator is angled downwards may be less than 45 degrees and may be within the range of 10 degrees to 30 degrees.

[0050] The agitator and the further agitator may be cantilevered from opposing sides of a hub portion of the cleaner head at their respective second ends. Each agitator and the further agitator may be arranged such that when the cleaner head is supported on a planar surface to be cleaned, the positions of the central longitudinal axes at the first ends of the agitator and the further agitator are closer to the planar surface than the positions of the central longitudinal axes at the second end of the agitator and the second end of the further agitator. The agitators are effectively angled downwards, towards the planar surface to be cleaned by the cleaner head and away from a top housing portion of the cleaner head. In this manner, the tapered profile of the agitators, which may be generally frusto-conical in shape, is at least partially compensated for. As such, a larger portion of the outer surface of each agitator will be in contact with the horizontal surface during use.

[0051] By angling the tapered agitators towards the surface in this manner, a gap which would otherwise likely be present between the lowermost portions of the two agitators at their second ends can be reduced in size. This means that a larger region of the planar surface is agitated by the cleaner head, and preferably such that there is a unitary region of contact / agitation between the horizontal surface to be cleaned and the two agitators (e.g. no gap between the respective regions agitated by the two agitator elements of the cleaner head). In examples, the central longitudinal axes of the agitator elements may be considered as being canted downwards. 12 P004689-W001

[0052] The further agitator may be identical to the agitator. Identical agitators create a symmetrical load distribution on the main shaft. This balance minimizes stress concentrations and reduces the risk of bending or warping of the shaft due to uneven loads, enhancing the overall loadcarrying capacity. Furthermore, standardizing components by using identical agitators simplifies the manufacturing and assembly processes, reducing production costs and lead times.

[0053] The drive assembly may comprise a single motor arranged to drive rotation of both the agitator and the further agitator. The single motor may be arranged to drive rotation of both agitator and the further agitator via respective first and second male couplers. In this manner, design and control of the cleaner head can be simplified. This may also aid in reducing the number of components and associated complexity, making the cleaner head easier to build and operate.

[0054] The single motor may be at least partially located inside the agitator and / or the further agitator. In examples, drive assembly may be at least partly disposed within the agitator and / or the further agitator. This provides for a compact arrangement.

[0055] In examples, the drive assembly may comprise first and second motors, the first motor being arranged to drive rotation of the agitator, and the second motor being arranged to drive rotation of the further agitator. Each motor may be disposed at least partially within the core of its respective agitator. This provides for a compact arrangement. The first and second motors may be arranged back-to-back and counter rotating, such that in use the agitator and the further agitator rotate in the same direction.

[0056] The agitator (and optionally the further agitator) may comprise a main body having a wall, and bristles mounted to the main body adjacent the wall. The wall may comprise a projection or ridge formed on the main body, for example integrally formed on the main body. The wall may project radially outwardly from the main body of the agitator. 13 P004689-W001

[0057] The agitator (and optionally the further agitator) may comprise bristle tufts, bristle strips or a surface conforming material. The bristle tufts, bristle strips or surface conforming material may be formed from any suitable material for example nylon or carbon fibre or a combination of materials. The bristle tufts, bristle strips or surface conforming material may project the same distance from the core along the full length of the agitator.

[0058] The main body may comprise an agitator channel within which the bristles are mounted, and the wall may define, and / or lead into, a wall, for example a side wall, of the agitator channel. This may be beneficial as the agitator channel may allow for more secure mounting of the bristles to the agitator. The agitator channel may be at least partly defined by regions of increased and / or decreased distance from a central longitudinal axis of the agitator relative to the main body, for example regions of increased and / or decreased radial distance. The agitator channel may be at least partly defined by opposing projections formed on the main body, for example integrally formed on the main body. The agitator channel may be at least partly defined by a recess formed in the main body.

[0059] The bristles may be provided longitudinally along the agitator, and the wall may extend longitudinally along the agitator to substantially the same longitudinal extent as the bristles. This may be beneficial as the wall may prevent entanglement of debris with the bristles along substantially the entirety of the longitudinal extent of the bristles.

[0060] The wall may be integrally formed with the agitator, for example with the main body of the agitator. This may be beneficial as it may provide a simple arrangement with few component parts and may be cheaper and / or simpler to manufacture than an assembly requiring multiple component parts.

[0061] The agitator and further agitator may comprise a felt-like covering. The felt-like covering may comprise an arrangement of many fine tufts standing on end, which may for example have a fluffy texture or appearance.

[0062] The agitator and further agitator may comprise an absorbent material. In examples, the external surfaces of the agitators may comprise an absorbent material such as sponge or 14 P004689-W001 microfibre. Such agitators may be arranged to function as mop pads to absorb spilled liquids and / or to perform wet cleaning of a hard floor surface.

[0063] The agitator and further agitator may have the same overall shape. The agitators may be symmetrically shaped. The agitators may be symmetrically arranged.

[0064] According to a fourth aspect of the present disclosure, there is provided a floor cleaner, such as a vacuum cleaner or a wet floor cleaner, comprising a cleaner head according to the first aspect or a drive assembly according to the second aspect.

[0065] According to a fifth aspect of the present disclosure there is provided a cleaner head comprising an agitator; and a drive dog for transmitting torque to the agitator; wherein one of the drive dog and the agitator comprises a shank ; the other of the drive dog and the agitator comprises a bore configured to receive the shank; wherein the shank comprises a protrusion configured to engage with the bore, forming an engagement for proper assembly or operational alignment between the shank and the bore by physically preventing incorrect engagement such that; the engagement of the shank and the bore permits a predetermined operational orientation or connection between the drive dog and the agitator; and the engagement prevents the operational orientation or connection of the drive dog and the agitator in a manner other than the predetermined operational orientation or connection by rotatably and slidably guiding the drive dog and the agitator towards the same predetermined operational orientation or connection during assembly regardless of the relative orientations of the drive dog and the agitator.

[0066] Forming an engagement for proper assembly or operational alignment between the shank and the bore thus by extension between the agitator and the drive dog provides a poka-yoke mechanism or error prevention mechanism during assembly. This is enabled by physically preventing incorrect engagement of the assembly via a predefined protrusion profile and a bore profile configured to only receive said predefined protrusion profile. Such a poka-yoke 15 P004689-W001 mechanism minimizes the risk of assembly errors by allowing only the predetermined alignment orientation or orientations between components.

[0067] The shank may comprise an alignment cavity configured to receive an alignment member located near an entrance of the bore. Both the drive dog and the agitator may comprise alignment features. This may allow for enhanced the overall functionality and reliability of the poka yoke type coupling whilst providing further mitigation of misalignment issues that could lead to operational inefficiencies, component damage, or premature wear.

[0068] In this manner, the alignment cavity and the alignment feature facilitate a further axial alignment of the drive assembly and the agitator. There may be a snug-fit interaction between the alignment features of the assembly, thus ensuring that the components come together easily and fit without the need for excessive force or trial-error method for assembly of the components.

[0069] During assembly the alignment member may engage with the alignment cavity before the engagement of the protrusion and the bore. In this manner an axial alignment of the shank and the bore may be achieved, prior to the engagement of the features that provide rotational alignment. Prioritizing axial alignment over rotational alignment could facilitate easier removal and reinstallation of the brush bar by the user, promoting better maintenance habits and reducing the need for manual adjustments by the user.

[0070] The protrusion may be a helical rib formed around the shank. A helical rib may provides geometric feature that can precisely control the rotational alignment between assembly components such as the agitator and the drive dog. In this manner consistent alignment across multiple assemblies may be achieved, thus enabling standardized production and interchangeability of parts.

[0071] The helical rib design of the protrusion may also increase the contact area between components compared to straight or circumferential features. This may enhance the loadbearing capacity and distribute stress more evenly, reducing wear and prolonging the life of the components of the cleaner head. The geometry of the helical rib may provide self- 16 P004689-W001 aligning properties as components are assembled, simplifying the assembly process and reducing the risk of misalignment.

[0072] The helical rib may extend along a predetermined arc wrapped around the shank.

[0073] The arc may be centred around the shank’s central longitudinal axis, or drive dog central longitudinal axis. The angular extent of the arc may span from 5 degrees to 175 degrees, measured clockwise from the positive x-axis when the drive dog is viewed from the top. In a further embodiment, the angular extent of the arc may span from 30 degrees to 150 degrees.

[0074] The arc's predetermined length allows for controlled engagement and disengagement between components such as the drive dog and the agitator of a cleaner head, which can be critical in applications requiring partial rotation for locking or unlocking. In this manner the precise rotational movement that is needed to achieve a functional state, such as engaging a lock, activating a mechanism, or transitioning between operational modes. Limiting the helical rib to a predetermined arc may also provide for space saving, thus allowing for more compact assembly designs.

[0075] The helical rib is configured such that the helical rib completes less than one full revolution. A partial helical feature may facilitate a relatively more compact assembly in situations where a full helix is impractical due to space constraints or specific design requirements. The partial helix allows for error prevention within the constraints of the overall design.

[0076] The use of a partial helical feature may also allow for tailoring the error prevention mechanism to the specific requirements of the application. This adaptability is beneficial in diverse industries and applications with varying assembly needs, types, sizes and materials.

[0077] The bore may comprise an engagement guide formed inside the bore and configured to engage with the shank for rotatably and slidably guiding the drive dog and the agitator during assembly. Integrating the engagement guide inside the bore may allow for a more compact overall design, saving space in applications where dimensions are critical. Furthermore, having the engagement guide inside the bore may lead to a cleaner, more streamlined appearance without external protrusions or complex external features. 17 P004689-W001

[0078] The engagement guide may comprise a channel configured to receive the protrusion. The channel may be a grooved track configured to engage with the helical rib of the drive dog. In this manner the channel and protrusion arrangement ensures components are aligned with a high degree of accuracy. By adjusting the dimensions and shapes of the channel and protrusion, it may also be possible to adjust the engagement force, disengagement method, and operational characteristics to specific application requirements.

[0079] The engagement guide may comprise a lead-in tip and a lead-in shoulder arranged between the lead-in tip and the channel such that the lead-in shoulder is configured to guide the protrusion of the shank from lead-in tip towards the channel of the bore during assembly.

[0080] In this manner, the lead-in tip, lead-in shoulder, and the helical channel may work together to guide the assembly process. The lead-in tip may initiate the engagement, the lead-in shoulder may ensure proper alignment, and the helical channel guides the component smoothly along its rotational path into the predetermined operational orientation or connection. This can reduce friction, minimize stress on components, and contribute to smooth operation whilst preventing errors in the assembly process where accuracy is critical for the assembly’s functionality.

[0081] The bore may comprise a further lead-in shoulder configured to guide the protrusion from the lead-in tip towards the helical channel such that the lead-in shoulder and the further lead- in shoulder may be arranged to guide the helical rib towards opposite directions starting from the lead-in tip. In this manner, lead-in shoulders facilitate an efficient assembly process, as the components can be brought together such that the alignment is inherently guided by the design. This simplifies the engagement procedure and helps operators or users easily identify the correct orientation for assembly.

[0082] The channel may be a single helical channel. This may aid with simplicity of the assembly as there is a clear and singular path for the engagement of the components. This simplicity can lead to faster and more efficient assembly processes, further reducing potential for errors during assembly. 18 P004689-W001

[0083] The channel may be formed around an inner wall of the bore. The channel may be a helical channel. The helical channel may be configured to receive the helical rib of the shank. In this manner, the assembly process may be simplified as the drive dog can be inserted or engaged with the agitator by a sliding motion due to the guiding nature and position of the channel. Forming the channel in this manner may aid with simpler and more cost-effective manufacturing, compared to creating complex external attachment mechanisms. This can be achieved through various manufacturing processes including but not limited to machining, casting, injection moulding or forging.

[0084] The bore may comprise an auxiliary protrusion configured to engage with the shank. The auxiliary protrusion may be a further helical rib formed inside the bore. The auxiliary protrusion may be formed around the inner wall of the bore. The auxiliary protrusion and the channel of the bore may be disposed at diametrically opposed points with respect to the central longitudinal axis of the bore.

[0085] The shank may comprise an auxiliary channel configured to receive the auxiliary protrusion. The auxiliary channel may be a further helical channel. The auxiliary channel may be formed around the shank. The protrusion and the auxiliary channel of the shank may be disposed at a diametrically opposed points with respect to a central longitudinal axis of the shank.

[0086] In this manner, the channels (the channel and the auxiliary channel) and the protrusions (the protrusion and the auxiliary protrusion) of the assembly can be mirrored for assembly on both the bore and the shank thus providing for an easier and more intuitive assembly process, reducing the risk of assembly errors. Furthermore, mirrored features can contribute to a more uniform distribution of stress and load across the interface of the shank and the bore. For products that require user assembly or interaction (i.e., a cleaner head with removable brush bars), mirrored features may enable the users to understand how parts fit together, leading to an improved user experience and reducing the need for extensive instructions or support.

[0087] The predetermined operational orientation or connection may comprise a single operational orientation or connection. In this manner, the components may be designed to fit together in 19 P004689-W001 one specific way, thus eliminating or substantially reducing the risk of incorrect assembly of the agitator on a cleaner head. Furthermore, components designed to connect in a specific manner may be optimised for wear and tear, thus improving the lifespan of the overall product. This is because the points of contact, material stress, and wear patterns can be precisely engineered and tested for a wide range of use scenarios.

[0088] The cleaner head may comprise a further agitator configured to align with a mirror image of a position of the agitator with respect to a vertical plane passing along a symmetry axis of the cleaner head and perpendicular to a horizontal surface to be cleaned. In this manner, the cleaner head can clean a larger area in a single pass compared to an arrangement having single agitator, thus potentially halving the time it takes to clean a given area. Furthermore, mirroring the agitators may provide for a balanced operation of the cleaner head, reducing strain on the user and wear on the components of the cleaner head. Mirrored agitators may be designed to extend closer to the edges of the cleaner head, thus improving the cleaner head’s ability to clean along the edges and corners of the surface being cleaned.

[0089] In an example embodiment, the agitator and / or the further agitator may be mounted on the cleaner head in a cantilevered fashion. In a further example embodiment, the agitators may perform different functions: for example, one for loosening dirt and debris via bristles and the other for suctioning or wiping the surface via a soft and felt-like material. Accordingly, mirroring the agitators may provide for a comprehensive cleaning action in a single pass. This dual functionality can be more effective than sequential cleaning or constantly needing to change the cleaner head between different cleaning operations. In this manner, by incorporating different types of cleaning technologies or materials in the mirrored members (while maintaining their mirrored disposition), it may be possible to provide a floor cleaner capable of tackling a variety of cleaning tasks effectively, from hard floors to different types of carpets.

[0090] The further agitator may comprise a further predetermined operational orientation or further connection between a further drive dog and the further agitator. The further predetermined operational orientation or further connection may comprise a single operational orientation or connection. 20 P004689-W001

[0091] The agitator and the further agitator may be arranged with a predetermined angular orientation differential with respect to a rotation axis of a motor configured to generate torque. In this manner, the cleaner head can generate a complementary action where one agitator loosens the debris while the other agitator sweeps it up. This dynamic action may be particularly effective on carpets and rugs, where deep-seated dirt can be difficult to remove. Furthermore, arranging the agitators such that there is an angular orientation differential between them may aid with balancing the wear on the agitators as well as the drive assembly of the cleaner head, thus extending their lifespan of the cleaner head whilst maintaining consistent cleaning performance over time.

[0092] Strategic orientation of the agitators may also contribute to reduced noise and vibration. By balancing the forces exerted by each agitator, the overall operation can be smoother and quieter, improving user comfort.

[0093] The predetermined angular orientation differential may be 180 degrees. The agitator and the further agitator may be identical. The agitator and the further agitator may be arranged such that both agitators rotate in the same direction. In this manner, the forces exerted by the agitators may be further balanced across the cleaner head and the effective contact surface of the agitators at any particular moment during cleaning. This may aid with reducing torque or drift that might otherwise occur with angularly aligned agitators, thus making it easier for users to control. Furthermore, 180-degree angular orientation differential may further improve the dual-functionality of the cleaner head by evenly spacing the surface features of identical agitators thus maintaining a consistent resistance with the surface to be cleaned throughout one complete rotation cycle of the agitators. In this manner, the agitators share the workload evenly, thus the wear on the agitators as well as the drive assembly is distributed more evenly.

[0094] According to a sixth aspect of the present disclosure, there is provided a floor cleaner, such as a vacuum cleaner or a wet floor cleaner, comprising a cleaner head according to the fifth aspect. 21 P004689-W001

[0095] The shank may also comprise a shank engagement guide. The shank engagement guide may comprise a shank lead-in tip and a shank lead-in shoulder arranged between the shank lead- in tip and the auxiliary channel such that the shank lead-in shoulder is configured to guide the auxiliary protrusion of the bore from the shank lead-in tip towards the auxiliary channel of the shank.

[0096] In this manner, the shank lead-in tip, shank lead-in shoulder and the auxiliary channel may work together, in a similar way the lead-in tip, lead-in shoulder, and the helical channel of the bore works, to guide the assembly process.

[0097] The shank may comprise a further shank lead-in shoulder configured to guide the auxiliary protrusion from the shank lead-in top towards the auxiliar channel such that the shank lead- in shoulder and the further shank lead-in shoulder may be arranged to guide the auxiliary protrusion towards opposite directions starting from the shank lead-in tip.

[0098] The shank may comprise a shank seating rib adjacent to the protrusion or the helical rib. The shank seating rib may be arranged such that upon assembly of the drive dog and the agitator, the seating rib rests against one of the lead-in shoulder or the further lead-in shoulder of the bore.

[0099] The bore may comprise a bore seating rib adjacent to the auxiliary protrusion or the auxiliary helical rib. The bore seating rib may be arranged such that upon assembly of the drive dog and the agitator, the bore seating rib rests against one of the shank lead-in shoulder or the further shank lead-in shoulder.

[0100] Features described above in connection with one aspect of the disclosure is equally applicable to and may be incorporated into other aspects of the present disclosure. 22 P004689-W001

[0101] BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Figure l is a schematic cross-sectional view of a cleaner head used in a vacuum cleaner;

[0103] Figure 2 is a schematic view of a motor of the cleaner head shown in Figure 1;

[0104] Figure 3 is a schematic view of drive assembly of the cleaner head shown in Figure 1;

[0105] Figure 4 is a schematic front view of the drive assembly shown in Figure 3 with and without brush bar attached;

[0106] Figure 5 is a schematic exploded view of one half of the drive assembly and brush bar;

[0107] Figure 6a is a schematic view of a male coupler of the drive assembly shown in Figure 3;

[0108] Figure 6b is a schematic view of a male coupler of the drive assembly shown in Figure 3;

[0109] Figure 7a is a schematic view of the socket of the drive assembly shown in Figure 3;

[0110] Figure 7b is a schematic front view of the socket of the drive assembly shown in Figure 3;

[0111] Figure 7c is a schematic view of A-A cross-section annotated in Figure 7b;

[0112] Figure 8a is a schematic side view of a further male coupler comprising 3 lobes;

[0113] Figure 8b is a schematic front view of a further socket configured to receive the male coupler shown in Figure 8a;

[0114] Figure 8c is a schematic view of B-B cross-section of the socket shown in Figure 8b;

[0115] Figure 9a is a schematic isometric view of an auxiliary shaft of the drive assembly shown in Figure 3;

[0116] Figure 9b is a schematic front view of an auxiliary shaft of the drive assembly shown in Figure 3;

[0117] Figure 10a is a schematic view of a drive dog forming part of the cleaner head shown in Figure 1;

[0118] Figure 10b is a further schematic isometric view of the drive dog shown in Figure 10a;

[0119] Figure 10c is a schematic rear view of the drive dog shown in Figure 10a;

[0120] Figure lOd is a schematic side view of the drive dog shown in Figure 10a;

[0121] Figure 1 la is a schematic isometric view of a drive dog socket forming part of the cleaner head shown in Figure 1;

[0122] Figure 1 lb is a schematic cross-sectional view of the drive dog socket shown in Figure I la; Figure 12a is a schematic cross-sectional isometric view of an interaction between the drive dog shown in Figure 10a and the drive dog socket shown in Figure I la.

[0123] Figure 12b is a schematic cross-sectional isometric view of a further interaction between the drive dog shown in Figure 10a and the drive dog socket shown in Figure 1 la. 23 P004689-W001

[0124] Figure 13 is a schematic isometric view of a handheld vacuum cleaner.

[0125] DETAILED DESCRIPTION

[0126] A cross-sectional view of a cleaner head 10 according to the present invention is shown in Figure 1.

[0127] The cleaner head 10 comprises a neck 12, a cover 14. The cleaner head further comprises, disposed within the cover 14, agitators 20, 20’ and a drive assembly 30.

[0128] As shown in Figure Ithe cleaner head 10 comprises a first agitator element 20 and a second agitator element 20’. The first and second agitators 20, 20’ are each mounted for rotation about their respective axes 22, 22’ (as shown in Figure 1). Each agitator element 20, 20’ comprises a first, free end 24, 24’ and a second end 26, 26’ at which they are mounted to the cleaner head 10. Each agitator element has a shape which tapers towards the first end 24, 24’ in a direction along the axis of rotation 22, 22’ . In the illustrated implementation, the agitator elements 20, 20’ are generally frusto-conical in shape. However, it should be appreciated that a portion of one or both agitator elements 20, 20’ may not be tapered. For example, the shape of one or both agitator elements 20, 20’ may comprise a cylindrical portion combined with a frusto-conical portion, a cylindrical portion, or any other suitable cross-section.

[0129] With reference to Figures 2 and 3, the drive assembly 30 comprises a motor 32 for driving rotation of the agitators 20, 20’. The motor 32 is shown schematically in isolation in Figure 2. The motor 32 comprises an output shaft 34, 35. In general, the motor 32 is configured to generate a rotational motion of the output shaft 34, with such rotational motion being considered an output of the motor 32. It will be appreciated that the precise configuration of the motor 32 is immaterial to the present disclosure and that the rotational motion of the output shaft 34 can be brought about in a variety of manners.

[0130] In example embodiments, output shafts can terminate at the second ends of the agitator, such that the agitator elements support themselves in a cantilevered fashion without the first end being connected to the output shafts. 24 P004689-W001

[0131] In an example embodiment, the motor 32 may include an integrated transmission in the form of a gearbox (not shown), which steps down or up the angular rotation rate and outputs the motor’s drive via output shaft 34, 35.

[0132] The motor 32 is at least partially disposed within the cores of the agitators 20, 20’. In an alternative implementation, each of the agitators 20, 20’ can have its own motor, optionally including an integrated transmission. In a further alternative implementation, one or more motors can be provided outside of the space defined by the inside of agitators 20, 20’, and the drive provided from the motor(s) to the agitators 20, 20’ by way of one or more drive shafts, linkages, gears, chains, pulleys, or other transmission means. In such implementations, agitators 20, 20’ can be supported by, for example, a central hub (not shown) instead of a drive shaft. Optionally, such a hub can form part of the drive transmission means, including providing support to one or more transmission components such as driveshafts, linkages, gears, chains, pulleys bearings and the like.

[0133] Alternatively, one or more motors can be provided outside of the space defined by the inside of agitators 20, 20’, and the drive provided from the motor(s) to the agitator 20, 20’ by way of one or more driveshafts, linkages, gears, chains, pulleys, or other transmission means. In such implementations, agitators 20, 20’ can be supported by, for example, a central hub (not shown) instead of the drive shafts. Optionally, such a hub can form part of the drive transmission means, including providing support to one or more transmission components such as driveshafts, linkages, gears, chains, pulleys, bearings, septic and the like.

[0134] The first and second agitators 20, 20’ are cantilevered from opposite sides of the motor 32 at their respective second ends 26, 26’. In the illustrated implementation, the motor 32 is at a laterally central position with respect to the overall cleaner head 10, although this may not always be the case. For example, if the first and second agitator elements 20, 20’ have different lengths, then the motor 32 (or any other hub from which the agitator elements are cantilevered in other implementations) can be offset laterally relative to the laterally central part of the cleaner head 10. 25 P004689-W001

[0135] As is most clearly illustrated in Figure 1, which is a lateral sectional view of the cleaner head 10, each agitator 20, 20’ is arranged such that when the cleaner head 10 is applying suction to the horizontal surface 16 to be cleaned (e.g. hard flooring or carpet), the position of the axis 22, 22’ at the first end 24, 24’ of each agitator element 20, 20’ is closer to the surface 16 than the position of the axis 22, 22’ at the second end 26, 26’ of each agitator 20, 20’. Therefore the agitators 20, 20’ are effectively angled downwards (e.g. canted downwards), towards the surface 16 to be cleaned by the cleaner head 10.

[0136] In the illustrated implementation, the downwards angling of the agitators 20, 20’ is such that the lowermost portion of the external surface of each agitator 20, 20’ is parallel to the horizontal surface 16 when the cleaner head 10 is applied thereto. Furthermore, there is substantially no gap between the lowermost portions of the agitators 20, 20’ at their second ends 26, 26’, i.e. the lowermost portions of the agitators 20, 20’ are in contact at their second ends 26, 26’. This means that there is very little, if any, unagitated region of the surface 16 between the two agitators 20, 20’.

[0137] In this implementation the respective regions on the floor agitated by the two agitators touch each other so that there is effectively a single unitary (elongate) region agitated by the cleaner head on the floor at any given time. In general, this condition (the lowermost portions of the agitators being parallel to the floor) will be achieved when the agitators 20, 20’ are angled downwards by an angle a which is equal to around half the cone angle of the frusto-conical agitators 20, 20’. The tapering of the conical shape of the external surface of each agitator element has a taper angle which is equal to half the cone angle and thus in the illustrated implementation the same as the angle a by which the axis of the agitator is angled downwards. Given that the external surface of each agitator element may have some resilience / deformability and that surfaces to be cleaned in practice are rarely perfectly flat, it will be appreciated that the lowermost portion need not be exactly parallel, in the strict mathematical sense, to the horizontal surface for the agitator element to cause agitation of the surface to be cleaned along substantially the entire length of the external surface of the element arranged to perform such agitating. 26 P004689-W001

[0138] It should be appreciated that the agitators may not necessarily be angled downwards by an angle corresponding to half the cone angle of the agitator elements. In implementations, the agitator elements may have different lengths and / or different cone angles.

[0139] Accordingly, the first and second agitator may be angled downwards by different angles. In some implementations, the cleaner head 10 comprises a sole plate in which a suction opening is formed. The lowermost portion of the external surface of each agitator may be parallel to the sole plate.

[0140] The drive assembly 30 is shown schematically in isolation in Figures 3, 4 and 5. The drive assembly 30 comprises a male coupler 40 mounted to the output shaft 34 or protrude as an extension of the output shaft 34. The male coupler 40 is configured to engage with the agitator 20. This engagement can be directly or indirectly via intermediary components, for example any one or a combination of a socket 50, an auxiliary shaft 60, a drive dog 70 and a drive dog socket 80. The male coupler 40 is transmits the torque generated by the motor 32 to the agitator 20.

[0141] The male coupler 40 is shown schematically in isolation in Figures 6a and 6b. The male coupler 40 comprises a narrow lobe 42 and a wide lobe 44 protruding radially and defining a channel therebetween. The narrow lobe 42 and the wide lobe 44 comprise a narrow lobe lead-in chamfer 43 and a wide lobe lead-in chamfer 45 respectively. The lead-in chamfer may aid in ease of assembly of the drive assembly.

[0142] In embodiments each of the narrow lobe 42 and the wide lobe 44 comprise a top curved contact surface 46 and at least one side curved contact surface 48. In this manner, the top curved contact surface 46 facilitate smoother alignment of parts and more precise component assembly during installation. The side contact surface 48 comprises a cylindrical segment and in use a portion of the cylindrical segment is an instantaneous contact surface 49, for example linear sub-segment of the cylindrical segment. 27 P004689-W001

[0143] As illustrated in Figure 6a and Figure 6b, in embodiments there is a plurality of narrow lobes 42 (for example three narrow lobes 42) and at least one wide lobe 44 arranged about a central longitudinal axis (not shown) of the male coupler 40.

[0144] The socket 50 is shown schematically in isolation in Figures 7a, 7b, and 7c. The socket 50 comprises cavities configured to receive the narrow lobes 42 and at least one wide lobe 44 of the male coupler 40. The socket 50 further comprises, for example in the cavities, at least one socket contact surface 52. When in use, at least one side contact surface 48 of the male coupler 40 rests against at least one socket contact surface 52. In this manner, the male coupler 40 engages with the socket 50 for transmitting torque generated by the motor 32 to the agitator 20.

[0145] In use, due to the oblique angle between the rotation axes of male coupler 40 and the socket 50, the instantaneous contact surface 49 dynamically sweeps a sub-segment of the contact surface 52 of the socket 50. This dynamic sweep region is defined by the socket instantaneous contact region 54 as shown in Figure 7c. The sweeping action of the instantaneous contact surface 49 within the socket instantaneous contact region 54 enhances the system's performance by mitigating wear, reducing friction, and promoting a more controlled and stable engagement between the rotating components.

[0146] In a further example, the drive assembly 30 comprises a 3-lobed male coupler 140 as shown in Figure 8a. In this arrangement, the corresponding component is a 3-lobed socket 150 as shown in Figure 8b and 8c. When in use, at least one instantaneous contact point 142 of the 3-lobed male coupler 140 rests against at least one 3-lobed socket contact surface 152. In this manner, the 3-lobed male coupler 140 engages with the 3-lobed socket 150 for transmitting torque generated by the motor 32 to the agitator 20.

[0147] In use, due to the oblique angle between the rotation axes of 3-lobed male coupler 140 and the 3-lobed socket 150, the instantaneous contact point 149 dynamically sweeps a curved line segment along the 3-lobed socket contact surface 152 of the 3-lobed socket 150. This curved line segment is defined by the 3-lobed socket instantaneous contact line 154 as shown in Figure 8c. The sweeping action of the instantaneous contact point 149 within the 3-lobed 28 P004689-W001 socket instantaneous contact line 154 enhances the system's performance by mitigating wear, reducing friction, and promoting a more controlled and stable engagement between the rotating components.

[0148] The design of the rotating components is not limited to a male coupler comprising a specific number of lobes such as 3-lobed or 4-lobed designs. Rather, the drive assembly 30 is adaptable to various numbers of lobes. The selection of the optimum number of lobes is driven by the overarching goal of improving power draw efficiency of the cleaner head and minimizing component wear.

[0149] The auxiliary shaft 60 is shown schematically in isolation in Figure 9a and Figure 9b. The auxiliary shaft 60 comprises a male coupler portion 64 and a socket portion 65. The male coupler portion 64 comprises a plurality of narrow lobes 642 and at least one wide lobe 644. The plurality of narrow lobes 642 and the wide lobe 644 are identical to the corresponding features of the male coupler 40. Correspondingly, the socket portion 65 of the auxiliary shaft 60 comprises cavities, contact surface and instantaneous contact surface that are identical to the socket 50.

[0150] The auxiliary shaft 60 comprises an auxiliary shaft rotation axis 62. The Auxiliary shaft rotation axis 62 may be at a further angle P with respect to the central longitudinal axis 22 of the agitator 20.

[0151] The drive assembly 30 comprises a drive dog 70. The drive dog 70 s shown schematically in isolation in Figures 10a, 10b, 10c and lOd. The drive dog 70 is responsible for transmitting the torque generated by the drive assembly 30 to the agitator 20. The details of the drive assembly 30 are not pertinent to the details of the drive dog 70 described herewith.

[0152] A more detailed explanation will now be provided of the drive dog 70, the end of the agitator 20 that engages with the drive dog 70, and how the drive dog 70 and the agitator 20 engage in order to transmit torque. 29 P004689-W001

[0153] As illustrated in Figures 10a- lOd, the drive dog 70 comprises a head 72 and a shank 74 that extends from the head 72. The drive dog 70 further comprises at least one helical rib 76 and at least one recessed channel 78 helically formed around the shank 74.

[0154] The head 72 is generally cylindrical and comprises a drive dog socket portion 75 as shown in Figure 10b. Drive dog socket portion 75 comprises cavities, contact surface and instantaneous contact surface that are identical to the socket 50.

[0155] The shank 74 extends from the head 72 and is generally cylindrical in shape. The helical rib 76 and shank seating ribs 77 and 771 are parallel and helically wrapped around the shank 74.

[0156] The recessed channel 78 is helically wrapped around the shank 74. The helical wrap of the recessed channel 78 follows a constant pitch along the length of the shank 74. The helical wrap of the recessed channel 78 follows a constant depth along the length of the shank 74.

[0157] The drive dog 70 further comprises a lead-in tip 79 and at least one lead-in shoulder 791 wherein the lead-in shoulder 791 is helically wrapped around the shank 74. The lead-in shoulder 791 is configured as a guide for guiding a component that comes in contact with the lead-in shoulder 791, along a desired path and into the recessed channel 78.

[0158] The drive dog 70 may comprise a further lead-in shoulder 792 wherein the further lead-in shoulder is helically wrapped around the shank 74 in an opposite direction to the lead-in shoulder 791. Both lead-in shoulder 791 and the further lead-in shoulder 792 are configured such that a component comprising corresponding mating features is guided along a desired path and into the recessed channel 78, regardless of the mounting orientation of the said component.

[0159] The said component may be an agitator 20. The agitator 20 may comprises a drive dog socket 80 either as an integrated part of the agitator 20 or as a removable component. 30 P004689-W001

[0160] The drive dog socket 80 is shown schematically and in isolation from the rest of the assembly, in Figures I la and 1 lb. The drive dog socket 80 is configured to engage with the drive dog 70 and transmit the torque generated by the drive assembly 30 to the agitator 20. In order to engage with the drive dog 70, the drive dog socket 80 comprises mating features formed around an inner wall 84 of a bore 82 configured to compliment the features of the drive dog 70. More specifically, the drive dog socket 80 comprises further helical rib 86 and bore seating ribs 87 and 871, helical channel 88, bore lead-in tip and bore lead-in shoulders 891, 892.

[0161] The interaction between the drive dog 70 and the drive dog socket 80 is shown schematically in isolation in Figures 12a and 12b. When mounting the agitator 20 to the drive assembly 30, the features of the drive dog 70 and the drive dog socket 80 may be misaligned. The lead in shoulder 891 and the further lead-in shoulder 892 of the bore 82 are configured to receive the corresponding mating feature helical rib 76 and guide the helical rib 76 of the shank 74 to the helical channel 88 of the bore 82, regardless of the initial engagement orientation of the agitator 20 and the drive assembly 30. Consequently, a user need only push the agitator 20 towards the drive assembly 30 in order to bring the mating features of the drive assembly 30 and the agitator 20 into a preferred alignment.

[0162] In embodiments, the drive dog 70 comprises an alignment cavity 73, configured to receive an alignment feature 83 of the drive dog socket 80. The ends of the alignment cavity 73 and the alignment feature 83 are tapered. This aids the user in mounting the agitator to the drive assembly. In particular, the end of the alignment feature 83 is guided by the tapered portion of the alignment cavity 73 towards the centre of the bore 82.

[0163] Figure 13 shows a hand-held floor cleaner 90 according to an implementation of the disclosure and comprising a main body 92, a wand 94 and a cleaner head 10. The wand 94 is attached at one end of the main body 92 and at the other end to the cleaner head 10. The wand 94 provides fluid communication between the cleaner head 10 and the main body 94, and supports the cleaner head 10 during use. 31 P004689-W001

[0164] It should be appreciated that the arrangements described with respect to the first agitator 20 and the drive dog 70 are equally applicable for the second agitator 20’ and a second drive dog 70’ configured to drive the second agitator 20’, and vice versa. Where terms such as “sphere”, “arc”, “ellipsoid” and “helical” are used, the skilled person will appreciate that these refer to a general shape rather than any strict mathematical definition associated with such terms. For example, the angle of the or each rib can follow any suitable angular path along the outer surface of the shank 74, including a path over which the angle changes, while still being generally “helical”.

Claims

32 P004689-W001CLAIMS1. A cleaner head comprising an agitator; and a drive dog for transmitting torque to the agitator; wherein one of the drive dog and the agitator comprises a shank; the other of the drive dog and the agitator comprises a bore configured to engage the shank; wherein the shank comprises a protrusion configured to engage with the bore in a predetermined orientation.

2. A cleaner head as claimed in claim 1, wherein the shank comprises an alignment cavity configured to receive an alignment member of the bore.

3. A cleaner head as claimed in claim 2, wherein the alignment member engages with the alignment cavity before the engagement of the protrusion and the bore.

4. A cleaner head as claimed in any preceding claim, wherein the protrusion is a helical rib formed around the shank.

5. A cleaner head as claimed in claim 4, wherein the helical rib extends along a predetermined arc around the shank.

6. A cleaner head as claimed in claim 4 or claim 5, wherein the pitch of the helical rib is configured such that the helical rib completes less than one full revolution.

7. A cleaner head as claimed in claim 4 or claim 5, wherein the pitch of the helical rib is configured such that the helical rib completes more than one full revolution.

8. A cleaner head as claimed in any preceding claim, wherein the bore comprises an engagement guide formed inside the bore and the engagement guide is configured to engage with the shank to guide the drive dog and the agitator during engagement.33 P004689-W0019. A cleaner head as claimed in claim 8, wherein the engagement guide comprises a channel configured to receive the protrusion.

10. A cleaner head as claimed in claim 8, wherein the engagement guide comprises a lead- in tip and a lead-in shoulder arranged between the lead-in tip and the channel such that the lead-in shoulder is configured to guide the protrusion from lead-in tip towards the channel during assembly.

11. A cleaner head as claimed in claim 8 or claim 9, wherein the channel is a single helical channel.

12. A cleaner head as claimed in any of claims 8 to 10, wherein the channel is formed around an inner wall of the bore.

13. A cleaner head as claimed in any preceding claim, wherein the bore comprises an auxiliary protrusion configured to engage with the shank.

14. A cleaner head as claimed in claim 13, wherein the auxiliary protrusion is a further helical rib formed inside the bore.

15. A cleaner head as claimed in claim 12 or claim 13, wherein the shank comprises an auxiliary channel configured to receive the auxiliary protrusion.

16. A cleaner head as claimed in claim 14, wherein the auxiliary channel is a further helical channel formed around the shank.

17. A cleaner head as claimed in any preceding claim, wherein the predetermined operational orientation or connection comprises a single operational orientation or connection.

18. A cleaner head as claimed in any preceding claim, wherein the cleaner head comprises a second agitator and a second drive dog.34 P004689-W00119. A cleaner head as claimed in claim 18, wherein the agitator and the second agitator are arranged with a predetermined angular orientation differential with respect to a rotation axis of a motor configured to generate torque.

20. A cleaner head as claimed in claim 19, wherein the predetermined angular orientation differential is 180 degrees.

21. A floor cleaner comprising a cleaner head of any one of the preceding claims.

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