Knob assembly

Abstract

A knob assembly for a control system, the knob assembly comprising: an outer component and an inner component which are configured to be releasably secured, the outer component comprising a main body forming an exterior surface of the assembly, the outer component and the inner component comprising corresponding mating parts which interlock to prevent separation of the outer component and the inner component when the mating parts are interlocked, wherein at least one of the mating parts is movable relative to the other mating part to release the outer component from the inner component, wherein when the outer component and the inner component are secured, the mating parts interlock at a position inwards of the exterior surface and the knob assembly is configured to provide access to the movable mating part to release the outer component from the inner component.

Description

KNOB ASSEMBLY

[0001] The present invention relates to a knob assembly and a control system comprising a knob assembly.

[0002] Manual control knobs are known in the prior art which allow a user to provide an input to a system. For example, in the context of a shower control, manual control knobs may be used to input user preference to control a characteristic of the flow of water from a shower output. For example, a user may use a control knob to adjust the temperature of the water provided by a shower and / or the flow rate of the water. A number of other systems, such as domestic appliances in particular, e.g. washing machines, dishwashers, basin taps, bath taps, etc., also generally allow for user input via a control knob.

[0003] Known control knobs may be attached to systems by fixed means, such as by using adhesive. Alternative mechanical fixing means can be used as well, such as a screw, which allows for removal of the control knob from the system. The known means are either permanent fixings and / or are visible. Control knobs are normally provided on the outside of systems so that they can be accessed by a user, for example, on a user input panel. This means that the control knob may need to be removed if access is needed to internal parts of the system, for example to carry out maintenance and / or repair. Such fixing means are beneficial in that they allow for relatively easy removal of the control knob. However, providing a screw to attach the control knob to the system can be unsightly for the user. Additionally, it may be easier for a person to tamper with such a control knob, if the screw is visible and easily removed, such as with a screwdriver.

[0004] There are benefits to providing a control knob which can be removed to allow access to other parts of a system to which the control knob is attached. Additionally, it may be preferably to provide a control knob which can be swapped so that a user can select the look and feel of the control knob.

[0005] According to an aspect of the present invention, there is provided a knob assembly for a control system, the knob assembly comprising: an outer component and an inner component which are configured to be releasably secured, the outer component comprising a main body forming an exterior surface of the assembly, the outer component and the inner component comprising corresponding mating parts which interlock to prevent separation of the outer component and the inner component when the mating parts areinterlocked, wherein at least one of the mating parts is movable relative to the other mating part to release the outer component from the inner component, wherein when the outer component and the inner component are secured, the mating parts interlock at a position inwards of the exterior surface and the knob assembly is configured to provide access to the movable mating part to release the outer component from the inner component.

[0006] According to an aspect of the present invention, there is provided a control system comprising the knob assembly described herein, and at least one shaft, wherein the at least one shaft is attached to the inner component.

[0007] The assembly of the present invention provides an inner component and outer component which can be operated as a single unit when secured together. Beneficially, the assembly can be easily assembled, and allows for easy assembly of a system when comprising the knob assembly. The assembly has the advantage that the outer component can be released from the inner component, which allows a user to replace the outer component, e.g. to select an outer component with a different look and / or feel, or to provide access to other parts of a system. The outer component can easily be removed by disengaging the interlocked mating parts. This is useful for easy disassembly of the knob assembly (or system comprising the knob assembly). The present invention provides a way of fixing which is not visible to the user, whilst also being non-permanent. The present invention may also include fewer parts than other known knob assemblies.

[0008] The present invention will now be described by way of example only, with reference to the following drawings in which:Fig. 1 is an exploded isometric view of an assembly according to an embodiment of the present invention;Fig. 2A is an alternative exploded isometric view of the assembly in Fig. 1 and Fig. 2B is an alternative isometric view of part of the assembly;Fig. 3 is an alternative exploded isometric view of the assembly in Fig. 1;Fig. 4 is a view of the assembly of Fig. 1;Fig. 5 and Fig 6. show a cross-section of part of the assembly in Fig. 1; Fig. 7 is an exploded isometric view of the assembly in Fig. 1 with a tool; Fig. 8 is a cross-section through the assembly in Fig. 1 with a tool;Fig. 9 and Fig 10. show a cross-section of part of the assembly in Fig. 1 with a tool; Figs 11-19 depict variations of the assembly shown in Figs. 1-10; andFig. 20 is an exploded isometric view of a shower control system with the assembly.

[0009] The figures show the components described below. The components depicted in the figures are not to scale. In the figures, like parts are indicated with like reference numerals.

[0010] As will be described in further detail below, the present invention provides a knob assembly, which could for example be used to provide an input to a system. For example, when attached to a system, the knob assembly can be used to rotate or move a shaft of the system. Thus, a user may turn the knob assembly to rotate a shaft of the system to indicate the user’s preference.

[0011] The knob assembly may otherwise be referred to as a control knob assembly. The knob assembly is shown in Fig.l, Fig. 2A, Fig. 2B, Fig. 3 and Fig. 4 from different angles.

[0012] The knob assembly 1 comprises an outer component 10 and an inner component 20. The outer component 10 and the inner component 20 are configured to be releasably secured, i.e. configured to be removably connected. As shown in Figs 1, 2 A and 2B, the outer component 10 and the inner component 20 are separate parts. Thus, these components can be entirely removed from one another. As will be described in further detail below, the inner component 20 can be inserted into the outer component 10. This is described further below in relation Figs 5 and 6. When the inner component 20 is inserted into the outer component 20, mating parts of the respective components engage to lock together (i.e. interlock) which then restricts the components being moved (or pulled) apart. The mating parts of the components might generally be concealed within the outer component 10 when the assembly 1 is in use, i.e. as part of a system. Thus, the mating parts may provide a hidden fixing. The assembly provides a way of accessing the mating parts, so that the mating parts can be unlocked from each other. This is described further below in relation to Figs 7, 8, 9 and 10. Variations of the assembly are shown in Figs. 11- 19. An example of a control system comprising the assembly is shown in Fig. 20.

[0013] The outer component 10 may be referred to as a knob or a cover. The outer component 10 is the part of the assembly 1 which the user may interact with. In other words, user input is via the outer component 10. In this way, the outer component 10 may provide a handle part of the assembly 1 (and a handle part of whatever system the knobassembly 1 may ultimately be attached to). The inner component 20 may be referred to as a shaft connector. The inner component 10 may be used for attaching the assembly to a control system. More specifically, the inner component 20 may provide a part of the assembly 1 for being fixedly attached to the rest of a system.

[0014] The inner component 20 may be inserted into at least part of the outer component 10. Thus, the inner component 20 can be positioned within the outer component. The inner component 20 is configured to fit within at least a portion of the outer component 10. Ideally, the majority of the inner component 20 sits within the outer component 10. Preferably, a diameter of the outer component 10 is greater than a diameter of the inner component 20. Thus, when the inner component 20 sits within the outer component 10, at least part of the outer component 10 surrounds at least part, if not all, of the inner component 20.

[0015] The outer component 20 and the inner component 10 are configured to be releasably secured together. In other words, these components are removably connected. This means that these components can be secured to each other and released without damage. When secured together, the inner member and the outer member may be configured to rotate about substantially the same axis, e.g. rotational axis X. The outer component 10 and the inner component 20 can be secured together by interlocking parts of the components. Thus, the outer component 10 and the inner component 20 can be interconnected. The outer component 20 can be retained on the inner compartment 10 by corresponding mating parts. The outer component 10 and the inner component 20 can be interlocked to prevent separation of the outer component 10 and the inner component 20 when secured together. This means that the outer component 10 and the inner component 20 can be connected in a way which prevents disengagement of the components when secured. This can be provided by the relative mating parts of the components. When the components are secured together, they may feel to the user like one part.

[0016] The outer component 10 has a main body 11 with an exterior surface 12. The exterior surface 12 is preferably an exterior surface of the assembly 1 when the components are secured together, and preferably, when the assembly 1 is positioned on a shower control system. In other words, the exterior surface 12 may be an outer surface of the assembly 1. The exterior surface 12 may be the most outward surface of the assembly1. The exterior surface 12 may be part of the assembly 1 which the user interacts with, i.e. holds to adjust the position of the assembly 1.

[0017] The outer component 10 may be substantially cylindrical. The main body 11 may have an annulus 11 A (i.e. a ring-shaped wall or outer wall). The main body 11 may also have inner walls, such as inner radial walls 1 IB and 11C as shown in Fig. 3. The inner radial walls 1 IB and 11C may be provided at substantially the same radial distance inwards from the exterior surface 12. The inner radial walls 1 IB and 11C may be provided at substantially the same radial distance outward from a central axis of rotation X. The main body 11 may have inner supporting walls 1 ID which connect the annulus 11 A with the inner radial walls 1 IB and 11C. The inner radial walls 1 IB and 11C of the main body 11 may be used to interact with the inner component 20. The main body 11 may comprise an end face 1 IE, i.e. an end wall. The exterior surface 12 may be formed by the end face 1 IE and the annulus 11A. The outer component 10 has an interior surface opposite to the exterior surface 12, i.e. on an inner facing surface of the end face 1 IE and annulus 11 A.

[0018] The inner component 20 may be substantially cylindrical. The inner component 20 has an annulus 22A (i.e. a ring shaped wall or outer wall). The inner component 20 may also have an end face 22B. The inner component 20 may also have an inner wall 22C. The inner wall 22C may be specifically shaped to interact with a shaft of a control system, e.g. a shower control system. For example, the inner wall 22C may be shaped so as to fit around the shaft in the control system. The inner wall 22C may have a rotationally asymmetric cross-section (as shown in Fig. 4) such that the shaft of the control system only fits into the inner wall 22C in one orientation. Thus, as the knob assembly 1 is rotated, the shaft of the control system is rotated with the knob assembly 1. The inner component 20 may have protrusions 21 which extend radially outwards from the outer wall 22A, and which are described in further detail below.

[0019] The inner component 20 has a cavity 24 for insertion of a shaft from a control system to be installed. The inner component 20 can be fixedly installed to the shaft. For example, the inner component 20 can be screwed onto a shaft. The screw could be screwed into the shaft through the end face 22B of the inner component 20 and through the screw-hole 25.

[0020] The outer component 10 and the inner component 20 comprise corresponding mating parts. In other words, the outer component 10 and inner component20 each have a mating part which matches up with, i.e. interacts with, a mating part on the other component. These mating parts are configured to interlock to limit separation of the outer component 10 and the inner component 20 when secured together. The mating parts interlock to prevent separation of the outer component and the inner component when the mating parts are interlocked. Thus, a mating part of the outer component 10 and a mating part of the inner component 20 may provide a locking mechanism which stops the outer component 10 from being removed from the inner component 20. The mating part of the outer component 10 and the inner component 20 may automatically interact, i.e. interlock with each other, when the inner component 20 is inserted into the outer component 10.

[0021] The assembly can be configured such that the outer component 10 is secured to the inner component 20 by moving the outer component 10 relative to the inner component 20 in a first direction. The outer component 10 can be pushed onto the inner component 20 in order to connect them, or the inner part 20 can be pushed into the outer component 20. Either way, the inner component 20 is moved relative to the outer component 10 in the first direction to bring the components together. In this way, the outer component 10 and the inner component 20 can be connected via the mating parts. The first direction may be parallel to the rotational axis X. The first direction may be the downwards direction shown by arrow A in Fig 5 (when the assembly 1 has the orientation as shown in this figure). The first direction may be substantially perpendicular to a radially inwards direction. The radially inwards direction may be a second direction. The second direction is shown by arrow B in Fig 6 (i.e. to the left when the assembly has the orientation shown in Fig. 6).

[0022] When the components are connected, the mating parts can prevent separation of the components, e.g. without the use of a tool. The mating parts may have a snap-fit which means that they automatically interact with each other to provide an interlocking connection when the inner component 10 is fully inserted into the outer component 10. This may occur when the inner component 20 is pushed into the outer component 10 so that substantially all of the inner component 20 sits within the outer component 10. In this instance, the end face 22B of the inner component 20 may be in close proximity to (an interior surface) of the end face 1 IE of the outer component 10. The inner component 20 may be considered to be fully inserted in the outer component 10 when the corresponding mating parts interlock. The inner component 20 may bepositioned near or adjacent to an inner surface of the outer component 10, the inner surface being opposite to the exterior surface. There may be a small gap between the end faces of the components, for example as shown in Figs. 8-10. The small gap may be beneficial in allowing some movement in the first direction (or opposite the first direction) between the inner component 20 and the outer component 10, e.g. when the mating parts are disengaged.

[0023] The mating parts interlock at a position inwards of the exterior surface 12. This means that the interlocking features of the mating parts are within the exterior surface 12, i.e. radially inwards of the exterior surface 12. This means that the mating parts can be secured together in a way which is not visible from outside the outer component 10 (particularly when installed on a system). The specific features of the mating parts which interlock may be the surfaces which contact each other when interlocked.

[0024] The assembly 1 is configured to provide access to the movable mating part to release the outer component 10 from the inner component 20. In other words, the assembly 1 is configured to provide access to the movable mating part to disengage the interlocking parts. In other words, the assembly is configured to allow a user input to move the movable mating part to disengage the interlocking parts. The assembly 1 can provide access due to the various configurations and variations are described below.

[0025] The inner component 20 comprises a clip 30, which is the mating part (i.e. the movable mating part) on the inner component 20 which interlocks to prevent separation of the outer component 10. This is shown in Figs 5 and 6. The corresponding mating part of the outer component (i.e. the other mating part) is an inner wall 1 IB of the outer component 10 defining an opening 40 therethrough. As shown, the opening 40 is a through-hole through the inner wall 1 IB. The clip 30 may otherwise be referred to as a catch or fastener.

[0026] The clip 30 has a connecting part 31 which connects the clip 30 to the rest of the inner component 20. The clip 30 has an arm 32 and a protruding portion 33. As can be seen in figures 2 A and 3, the protruding portion 33 of the clip 30 extends radially outward of the annulus 22 A. The protruding portion 33 may extend radially outward of any other surface of the inner component 20. The protruding portion 33 is positioned so as to align with the opening 40 in the inner wall 1 IB of the outer component 10, as can be seen in Fig. 3. As shown in Fig. 5, an upper surface of the protruding portion 33 has asubstantially angled portion 33A and a flat portion 33B, and the lower surface 33C is substantially flat. The flat portion 33B and the lower surface 33C may be substantially parallel. The flat portion 33B and / or the lower surface 33C may be substantially perpendicular to the first direction (i.e. the flat portion 33B and / or the lower surface 33C may be substantially perpendicular to the direction of relative movement between the outer component 10 and the inner component 20 when being connected). This direction of movement is shown by arrow A in Fig. 5. The angled portion 33A may be at an acute angle to the flat portion 33B. Preferably, the angled portion 33A is at an acute angle to a lower surface 1 IF of the inner wall 1 IB.

[0027] The protruding part 33 of the clip 30 may be configured to interact with the other mating part. The clip 30 may also comprise a compliant mechanism which allows the protruding portion 33 to be moved from an original position (as shown in Fig. 5) when a force is applied in a given direction (e.g. a radially inwards direction) and is configured to return the protruding portion 33 to the original position when the applied force is removed. The connecting portion 31 and the arm 32 may be flexible and may provide the compliant mechanism in this instance. In other variations (some of which are described further below), the compliant mechanism may be provided by at least one hinge, and / or alternative flexible portion and / or spring.

[0028] The clip 30 is movable relative to the other mating part, i.e. the inner wall 1 IB of the outer component 10 with opening 40. This allows the clip 30 to move radially inwards (i.e. to the left in Figs. 5 and 6) to allow insertion of the inner component 20 into the outer component 10. When the components are secured together, at least part of the clip 30 sits within at least part of the inner wall 1 IB to stop the components being separated, i.e. the mating parts are interlocked.

[0029] In further detail, when the inner component 20 is pushed into the outer component 10, the outer component 10 will move relative to the inner component 20 in the first direction (shown by arrow A). As the inner component 20 is pushed into the outer component 10, then the inner wall 1 IB of the outer component 10 is moved towards the clip 30 as shown in Fig. 6. As the inner wall 1 IB moves down and touches the clip 30, a force is applied to the clip 30 by lower surface 1 IF. Due to the shape of the protruding portion, and particularly the angled surface 33 A, as the lower surface 1 IF is moved in the first direction, at least a component part of the force applied to the clip 30 is a radiallyinward force. Thus, as the outer component 10 moves downward in Fig. 6, the protruding portion 32 is pushed radially inwards, in the second direction (shown by arrow B). This results in bending of the connecting portion 31 and / or the arm 32. As the protruding portion 33 is pushed radially inwards, the protruding portion is positioned radially inwards of the inner wall 1 IB such that the inner wall 1 IB can continue in the direction of arrow A. As the outer component 10 is pushed further in the direction of arrow A, the protruding portion 33 would be aligned with the opening 40. When the outer component 10 is pushed down far enough for the protruding portion 33 and the opening 40 to align, the inner wall 1 IB would no longer provide the inwards radial force. At this point, the protruding portion 33 moves outwards due to the resilient return force exerted by the clip 30, and particularly by the connecting portion 31 and / or the arm portion 32. The protruding portion 33 would then be positioned to interlock with the inner wall 1 IB, as shown in Fig. 9.

[0030] When the protruding portion 33 is positioned within the opening 40, as shown in Fig. 9, the clip 30 prevents removal of the outer component 10 from the inner component 20 because the protruding portion 33, is positioned within the opening 40. If a user tried to remove the outer component 10 from the inner component 20, the clip 30 , and particularly the protruding portion 33 positioned in the opening 40 would prevent this.This is due to the shape of the surface of the protruding portion 33 and the inner wall 1 IB which interact. In particular, the lower surface 33C of the protrusion is substantially perpendicular to the first direction and so is the part of the surface of the inner wall 1 IB in contact with the lower surface 33C. Thus, there is no inward radial force to move the clip 30 out of the way of the inner wall 1 IB, so the clip 30 prevents the removal of the outer component 10. The part of the surface of the inner wall 1 IB in contact with the lower surface 33C is a lower edge of the opening 40, as can be seen in Fig. 9.

[0031] The clip 30 is configured to move relative to the other mating part in a radially inward direction (i.e. a second direction, perpendicular to the first direction), to disengage the mating parts to release the outer component 10 from the inner component 20. In order to release the interlocking mating part, at least part of the clip 30 can be moved relative to the other mating part, i.e. the inner wall 1 IB, and particularly the opening 40, to release the outer component 10. Specifically, at least part of the clip 30 can be moved (e.g. in a radially inwards direction) so that it is no longer blocking movement ofthe inner wall 1 IB. Thus, the corresponding mating parts can be disengaged to release the components.

[0032] As will be understood, when the inner component 20 and outer component 10 are connected, access to the mating parts which limit or prevent separation of the components is restricted. This is made more difficult still when an assembly 1 is positioned on a system for use. Even so, the assembly 1 is configured to provide access to the movable mating part to release the outer component 10 from the inner component 20. The access could be direct or indirect. Thus, in the present invention, users may access the movable mating part to release the outer component 10 from the inner component 20 in a number of different ways, some of which are described below.

[0033] The outer component 20 may have a through -hole 13 with an opening 14 on the exterior surface 12. The through-hole 13 going from the exterior surface 12 to an inner surface of the outer component 10. The outer component 10 may be shaped to form the through-hole 13. The through-hole 13 may be configured to provide access to at least one of the mating portions. As described in further detail below, to disengage the interlocking parts, a tool, button or structure may be pushed via the opening 14 towards the inside of the assembly 1, e.g. in a direction from the exterior surface 12 towards the inner surface. The through-hole 13 may extend through the end face 1 IE of the outer component 10. The opening 14 and / or through-hole 13 can be circular in cross-section. Although this is not a necessity as any appropriate shape could be used (e.g. square, triangular, hexagonal, etc.). The opening 14 and / or through-hole 13 could be a slot which extends to the edge of the outer component 10.

[0034] Although the assembly 1, and particularly the through-hole 13, may be of any appropriate size, the through-hole 13 is preferably big enough to allow for tools to be provided through the through-hole 13. Different types of tool may be used. Any rigid elongated device or object might be appropriate for use as the tool. For example, a pin or needle may be used. Preferably the through-hole 13 is of the order of a few millimetres in diameter / width. Although the through -hole 13 could be larger, it would be preferable to provide a through-hole 13 of this size to reduce ingress of water inside the assembly. The through-hole 13 could be tens of millimetres in diameter / width.

[0035] Preferably, the through-hole 13 provides an indicator. Thus, the through- hole 13 can be used to allow access to the mating parts, and to indicate a position of theassembly 1 to a user. The through -hole 13 could, for example, line up with a scale or markings (on a system) radially outwards of the outer component 10 to indicate to a setting to a user.

[0036] When the outer component 10 and the inner component 20 are connected, the assembly 1 may provide a passageway from the opening 14 to at least one of the mating parts, in this case, the clip 30. The passageway may allow for insertion of tool 100 as shown in Figs 7 and 8. Thus, when the outer component 10 and the inner component 20 are connected, the assembly 1 may provide a passageway suitable for the tool 100 to be inserted to access at least one of the mating parts, in particular the mating part which is movable relative to the other mating part. In this case, the passageway can be used to allow insertion of the tool 100 to interact with the clip 30. Preferably the passageway is linear. This allows for insertion of a rigid tool which can be used to interact with the clip 30.

[0037] The passageway is a space formed between at least one component of the assembly 1. For example, the passageway could be formed between parts of the outer component 10. The passageway could be formed between two or more components of the assembly 1. For example, the passageway could be formed between the outer component 10 and the inner component 20 as shown in figure 6. The passageway may otherwise be referred to as a cavity, space or void. The passageway itself does not need to be linear, however, the passageway preferably includes a linear space through which the tool can be inserted into the assembly 1.

[0038] The opening 14 may provide an opening to the passageway within the assembly 1. This provides access to the mating part from outside the assembly 1. In particular, this provides access to the mating part from a front of the device, i.e. a part of the assembly 1 which is accessible when the assembly 1 is positioned, for example, on a control system.

[0039] The passageway may allow access to the movable mating part using a tool inserted into the through-hole 13. In particular, the passageway may be empty to allow passage of the tool. Thus, the passageway may allow access to the movable mating part by using a tool to directly contact (and apply a force to) the movable mating part.

[0040] The tool 100 may be pushed into the assembly via the opening 14. The tool100 can be inserted through the opening 14 and the through-hole 13 to the passageway, asshown in Figs 7 and 8. When the tool 100 is pushed into the passageway it will interact with the clip 30. Specifically, the tool 100 will touch the arm 32 of the clip 30, and particularly the surface 32A. This will be described with reference to Figs. 9 and 10.

[0041] The tool 100 can be pushed into the passageway in the first direction (shown by arrow C). The arm 32 of the clip 30 is angled with respect to the first direction. Specifically, the surface 32A of the arm 32 is at an acute angle with respect to the first direction. As the tool 100 is pushed into the passageway in the first direction (shown by arrow C), the arm 32 is pushed radially inwards (i.e. in the second direction) by the tool 100. As the protruding portion 33 is connected to the arm 32, the protruding portion 33 moves radially inwards as the tool 100 is pushed into the assembly as shown in Fig. 10.

[0042] When the tool 100 reaches the protruding portion 33, the base of the tool 100 reaches the flat portion 33B. The flat portion is substantially perpendicular to the direction of movement of the tool 100. When the tool 100 reaches the flat portion 33B, the tool 100 abuts the flat portion 33B and does not travel further into the assembly 100.

[0043] When the tool 100 is abutting the flat portion 33B, the clip 30 is in a radially inwards position as shown in Fig 10. As the clip 30 has been moved radially inwards, the protruding portion 33 has been moved radially inwards and is no longer sitting within the opening 40. In other words, the tool 100 can be used to disengage the clip 30 from the outer component 10. Thus, the protruding portion 33 no longer prevents movement of the first component 10 in the direction of the rotational axis away from the inner component 20, i.e. in a direction shown by arrow D. Thus, the outer component 10 can be moved in a direction opposite the first direction. In this way, the outer component 10 and inner component 20 can be separated. Thus, the tool 100 can be used to move the clip 30 to release the outer component 10 from the inner component 20.

[0044] In addition to the above, the components 10 and 20 may optionally have engaging parts which means that they only fit together in one orientation. This may be beneficial in ensuring that the corresponding mating parts line up. The engaging parts can interlock to limit rotation between the inner component 20 and the outer component 10. For example, the inner component 20 may form a recess 23 A which extends from end face 22B as shown in Fig. 2 A. The outer component 10 may have a corresponding projection 23B which fits within the recess 23 A. The projection 23B of the outer component 10 may be shaped to fit within the recess 23 A. For example, the projection 23B from the outercomponent 10 may be a cylindrical projection extending inwardly from the interior surface of the outer component 10 (opposite to the exterior surface 12). The diameter of the projection 23B may be slightly smaller than a diameter of the recess 23 A. When the outer component 10 is pushed onto the inner component 20, as long as the outer component and the inner component are correctly oriented, the projection 23B will fit within the recess 23 A. When the outer component 10 and the inner component 20 are connected together, these engaging parts substantially prevent rotational movement between the outer component 10 and the inner component 20 around rotational axis X. The rotational axis may be a central axis, e.g. which is positioned roughly in the centre of the inner component 20 and / or the outer component 10 and / or the assembly 1. The central axis may be the same for the inner component 20 and the outer component 10.

[0045] Although relative rotational movement between the outer component 10 and the inner component 20 about the rotational axis X may be reduced or prevented by the interlocking mating parts and / or the engaging parts, further benefit can be found in the use of interference fit between the inner component 20 and the outer component 10 to resist relative movement between the components.

[0046] In particular, an interference fit between the components 10 and 20 may be beneficial in resisting linear movement between the outer components 10 and the inner component 20 in the first direction and in the direction opposite the first direction. In particular, the interference fit can limit the separation of the components 10 and 20 by making it harder for the user to remove the first component 10 from the second component 20. An interference fit between the components may be beneficial in resisting rotational movement between the components 10 and 20 about the rotational axis. This may be beneficial in reducing movement between the components 10 and 20 when the user provides as input to a system via the knob assembly 1. Thus, the interference fit may assist in the components 10 and 20 being secured together without relative movement. The main function of the interference fit is to keep the outer component 10 and the inner component 20 fastened together in such a way that they move as one unit. This may provide a smoother experience for the user. However, it is noted that the interface fit may not prevent separation of the outer component 10 from the inner component 20, for example, if a user pulls hard on the outer component 10.

[0047] As described below, the interference fit can be provided based on the shape of relevant connecting parts of the outer component 10 and the inner component 20, i.e. parts of the components 10 and 20 which are in contact when secured.

[0048] As shown in at least Figs 1-4, the inner component 20 comprises ribs 21 which extend radially outwards of the inner component 20. When the outer component 10 is pushed onto the inner component 20, the ribs 21 of the inner component 20 are at least partially crushed by the outer component 10, and particularly the inner walls 1 IB and 11C of the outer component 10. When the ribs 21 are crushed this provides a tolerance fit between the outer component 10 and the inner component 20 which provide friction between the components 10 and 20 to limit relative movement between the components. Although the interference (and / or tolerance fit) of the outer component 10 and the inner component 20 is beneficial in reducing relative movement between the outer component 10 and the inner component 20, the user would still be able to remove the outer component 10 from the inner component 20 without the presence of the corresponding mating parts.

[0049] In further detail, the inner component 20 may have ribs 21 (i.e. crush ribs) which extend radially outwards from the outer wall 22A. There may be multiple ribs 21. The inner component 20 may have four ribs 21 as shown in Fig. 4, however any appropriate number of ribs may be provided. There may only be a single rib 21, or two, three or more than four. Preferably, the ribs 21 are radially spaced around the outside of the inner component 20. The ribs 21 can be shaped and positioned so as to interact with the inside of the outer component 10.

[0050] Each rib 21 is shown as extending substantially the same radial distance from the surface of annulus 22 A (i.e. having the same thickness) along its length. However, the ribs 21 could be provided to extend a different amount along their length. For example, each rib 21 may not extend out of the surface at one end, e.g. at the end near the end face 22B, and may increase the amount that the rib extends from the surface towards the other end of the rib 21. In this case, the rib may be substantially triangular. It may be easier to push the inner component 20 into the outer component 10 in this case, due to the smaller size of the ribs when the inner component 20 is first introduced into the outer component 10.

[0051] Although ribs are described above and shown in the figures, the interference fit may be provided in alternative ways, i.e. by having at least a part of the externaldimension of the inner component 20 exceed a corresponding internal dimension of the outer component 10. The interference fit may be provided by having zones in which the space between the inner component 20 and the outer component 10 is slightly smaller than the relative parts of the component such that the contacting part of the component is pressed as the inner component 20 is inserted into the outer component 10.

[0052] The interference fit may be provided by small crush nibs / balls instead of ribs. The interference fit may be provided by a tolerance fit between the annulus 22A of the inner component 20 and the inner walls 1 IB and 11C of the outer component. This may be referred to as a standard tolerance push fit.

[0053] Additionally or alternatively, the interference fit may be provided by having a connector. In this case, the interference fit is provided by friction between the outer component 10 and the connector and the inner component 20 and the connector. The connector could be an O-ring or an over mould soft material band, such as a rubber band.

[0054] The position of the parts providing the interreference fit may be switched between components. For example, instead of the ribs 21 being provided on the inner component 20, the ribs could instead be provided on an inner surface of the outer component 10. Alternatively, at least one rib could be provided on the inner component 20 and at least one rib could be provided on the outer component 10.

[0055] Additionally, or alternatively, the assembly 1 may comprise a friction forming fluid positioned between the outer component 10 and the inner component 20 to resist relative movement between the components. Although the friction forming fluid would not prevent separation of the outer component 10 and the inner component 20, this may be beneficial in reducing movement between the first component 10 and the second component 20. The friction forming fluid could be a sealant, e.g. a silicone sealant. The friction forming fluid could be a non-permanent adhesive, e.g. a non-curing adhesive.

[0056] In the above embodiment, the compliant mechanism is provided by the clip 30, and particularly the connecting portion 31 and the arm 32. The arm 32 may be flexible and may bend radially inwards when the protruding portion is moved radially inwards. The arm 32 will also provide a moment about the connection portion 31 which may also have some flexibility to allow the arm 32 to bend about the connection portion 31. Although not shown, an alternative could be provided with a rigid arm and a hinge connection, with the hinge being configured to allow rotational movement whilst returningthe arm to its original position when no user input is applied to the clip 30. In this case, a spring may be provided to push the protruding portion radially outwards, i.e. back to its original position when the tool is removed.

[0057] In the above embodiment, the clip 30 and internal wall 1 IB with opening 40, are used to provide the corresponding mating parts. Other variations are also possible.

[0058] In a variation, the opening 40 could be a recess 41 rather than a through- hole 40, such that the protruding portion 33 of the clip 30 sits within a recess 41 as shown in Fig. 11. In a variation, instead of an opening 40, the internal wall 1 IB comprises a ledge 42. In this variation, the ledge 42 prevents the outer component 10 from being removed from the inner component 20. The tool 100 can be used to push the clip 30 away from the internal wall 1 IB to disengage the mating parts.

[0059] In a variation, the arm 32 is provided at an angle such that when the tool 100 is inserted, the clip 30 is moved radially inwards. However, at least part of the arm 32 could be substantially parallel to the axis of rotation X. For example, the clip 30 could have an arm 32, at least part of which, is substantially parallel to the outer wall 22A of the inner component 20. In this case, the protruding portion 33 may have an angled upper surface which is configured to interact with tool 100 such that when the tool 100 is pressed into the upper surface of the protruding portion 33, the protruding portion is pushed radially inwards. An example of such a configuration is shown in Fig. 13.

[0060] In a variation, a protruding portion could be connected to the inner component via a spring 34, rather than arm 32, for example as shown in Fig 14. Thus, when the tool 100 is pushed into the assembly, the protruding portion is pushed radially inwards which compresses the spring 32. When the tool is removed, the spring 34 extends to push the protruding portion radially outwards. In this instance, the inner component 20 provides a supporting portion 35 on which the protrusion can move back and forth. This is useful for keeping the protruding portion aligned with the opening when the tool 100 is pressed down on the protruding portion. The supporting portion 35 could be attached to, or part of the outer component 10 instead of the inner component 20 as shown.

[0061] In the above embodiment, the assembly 1 is configured such that a tool can be inserted into the passageway to move the movable mating part. Other variations are possible.

[0062] In a variation, the assembly 1 comprises a structure 50 positioned in the passageway, for example as shown in Fig. 15. The structure 50 may interact with the clip 30 in a similar way to tool 100. However, the structure 50 may be part of the assembly 1. In other words, the structure 50 may be positioned within the assembly 1 when assembled. The structure 50 may be positioned between the outer component 10 and the inner component 20. The structure 50 is an object shaped to fit between the components and interact with the movable mating part. The structure 50 may be configured to move the movable part, e.g. the clip 30. The structure 50 may be positioned within a slot, for example in the outer component 10 to limit movement of the structure 50 in the first direction (or the direction opposite the first direction). The assembly 1 may comprise a spring 51. The spring 51 can be positioned between at least part of the structure 50 and a part of the outer component. The spring 51 can be attached to the structure 50 and the outer member 51. When no external force is applied to the structure 50, the spring 51 may be in an extended state and the structure 50 may be at an uppermost position, as shown in Fig 15. When the structure 50 is pressed toward the outer component 10, i.e. in the first direction, the spring 51 is compressed and the structure 50 pushes the clip 30 inwards which disengages the mating parts. In particular, an angled inner surface 50A of the structure 50 contacts the arm 32 of the clip 30. The angled inner surface 50A may have an acute angle with respect to the first direction, i.e. the direction in which the structure 50 is moved. The angled inner surface 50A and the surface of the arm 32 of the clip 30 contacted by the structure 50 may be substantially parallel.

[0063] The structure 50 can protrude from the exterior surface 12, as shown in Fig 15. This may be beneficial in that the structure 50 can be pressed to disengage the mating parts without the need for a tool 100. This might facilitate easier removal of the outer component. However, the structure 50 could be substantially flush with the exterior surface or recessed from the exterior surface (i.e. with a top surface positioned in the through-hole in the end face). This might be more aesthetically pleasing. In this case, a tool 100 could be used to push the structure 50 inwards. This may be beneficial in that a user may not accidentally press the structure and disengage the mating parts.

[0064] The structure 50 may be beneficial in providing a more reliable mechanism. For example, it may be preferable to a tool 100, which might be inserted at an incorrect angle. The structure 50 may allow for tighter tolerances within the assembly 1.Additionally, the structure may be beneficial in reducing or preventing the ingress of water through the opening 14. Additionally or alternatively, the structure 50 could be translucent or transparent and may be used as a light guide. For example, if a light source was to be included as part of the assembly 1 or a part of the system to which the assembly 1 could be attached, lining up the light source with the structure 50 could allow the light to be seen at the opening 14 via the structure 50.

[0065] An alternative structure 50 is shown in Fig. 16. In this instance, the structure 50 directly contacts a protruding portion 33 of the clip 30. The structure 50 may be more similar in shape to the tool 100 as described above. In this instance, the structure may comprise an arm 50B which is positioned in a slot in the outer component 10 to limit movement of the structure in the first direction (or a direction opposite the first direction). Although the structure in Fig. 6 is shown as flush, it could be recessed or protruding as described above.

[0066] The structure 50 is shown as a separate part in Fig 16. However, the structure could be attached to, or integral with the clip. In this case, when the structure is pushed downwards, the clip 30 (including the arm 32, protruding portion 33 and structure 50) would rotate around the connecting part 31, such that the protruding portion 33 would move radially inwards and disengage from the other mating part.

[0067] In the embodiment and variations, the through-hole 13 in the outer component 10 to provide access for the tool 100 extends through the end face 1 IE. However, the through-hole 13’ could instead be positioned around the outer edge of the outer component 10. In other words, the through-hole 13’ could extend through the annulus 11 A. In this case, the tool 100 would move in a direction substantially perpendicular to the first direction, i.e. in the second direction. In this case, the tool 100 would move in a radially inwards direction to move the protruding portion 33 to disengage the mating parts.

[0068] In an embodiment, the assembly may comprise a structure, for example formed as a button 60 as shown in Fig. 18. In this case, the through-hole 13’ is provided in the annulus 11 A, as described above. However, a button is positioned within the through- hole 13’, the button being configured to move the clip 30. The button 60 may have a clip engaging part 61. The button 60 may be attached to the outer component 10 by springs 62. Although two springs are indicated, only one or multiple springs may be used. The button61 is shown as flush with the outer component 10, but could be protruding or recessed as described above. The button 60 can be pressed via opening 14’. The button 60 can be pressed radially inwards, in a direction substantially perpendicular to the first direction, i.e. in the second direction. In this case, the button 60 would move in a radially inwards direction to move the protruding portion 33 to disengage the mating parts. The button 60 may be any shape. For example, the button 60 may be circular, rectangular, oval or any other shape.

[0069] In an embodiment, the movable mating part may be provided as a button 70 as shown in Fig 19. In this instance, the other mating part is provided by the annulus 11 A with opening 14’. The button 70 and the annulus 11 A can have an interlocking shape wherein the shape of the button 70 interlocks with internal surfaces 80 of the annulus 11 A. For example, the button 70 may be step-shaped as shown in Fig 19. The movable mating part may comprise compliant arms 90, which can be compressed when the button 70 is moved radially inwards, i.e. in the second direction. The button can be attached to the compliant arms 90 via connection 91, or the button and the compliant arms 90 could be integral or could be interlocked via connection 91. The button 70 could be pushed inwards when the second component 20 is pushed into the first component 10. In this case, when the button is released, the compliant arms 90 would push the button 70 radially outwards such that as the second component 20 is pushed into the first component 10, the button 70 slots into the opening 13’. In this way, the button 70 interlocks with the annulus 11A and prevents separation of the outer component 10 and the inner component 20. To disengage the mating parts, the button 70 could be pressed radially inwards (i.e. in the second direction) via the opening 14’ in the annulus 11 A. The button 70 may be pressed such that the button 70 is positioned radially inwards of the annulus 11 A to allow the outer component 10 to move in a direction along the rotational axis (i.e. to move in a direction opposite the first direction) to separate the outer component from the inner component 20. The button 70 is shown as flush with the external surface 12, but could be protruding or recessed as described above. The button 70 may be any shape. For example, the button 60 may be circular, rectangular, oval or any other shape.

[0070] In variations with a structure and / or button, this may provide an indicator if visible at the external surface 12. This may particularly be the case, when a part of the structure or button is flush or protruding from the external surface 12.

[0071] In the above embodiment and variations, the movable part of the interlocking mating parts (i.e. the clip 30) is provided as part of, or connected to, the inner component 20. However, the mating parts could be swapped such that the movable part of the interlocking mating parts is provided on the outer component 10. For example, the clip 30 could be provided in place of at least part of the inner wall 1 IB comprising opening 40 and at least part of the inner wall 1 IB of component 10 comprising opening 40 could be replaced with the clip 30.

[0072] In the above embodiments and variations, the assembly is configured to provide access to the movable mating part via an opening in the exterior surface 12. However, the assembly may also provide access via a base of the assembly, for example, via a gap as shown in Fig 8, wherein some sort of tool could be used to push the protruding portion radially inwards via the gap between the protruding portion and the annulus 12 A.

[0073] In the above embodiments and variations, only one set of corresponding mating parts are included in the assembly 1. However, it will be understood that multiple sets of mating parts could be included. For example, 2, 3, 4, 5, 6 or more sets of mating parts, e.g. clips and corresponding openings. Preferably, multiple sets of mating parts may be radially spaced around the assembly, e.g. with even spacing between the clips around the outside of the inner component 20.

[0074] Any appropriate material can be used for the relevant parts of the assembly. For example, plastic and / or metal may be preferred, but other materials, such as composites, wood and / or ceramics could be used. For example, flexible parts may be relatively thin plastic or metal (e.g. of the order of a few mm) so that the part can be bent and will return to its original position. For example only, preferred metals may be aluminium alloys and / or steel alloys. For example only, preferred plastics may include any thermoplastics or thermoset plastics, and more particularly, ABS (acrylonitrile butadiene styrene), PC (polycarbonate) / ABS, PP (polypropylene) or any combination thereof.

[0075] In an embodiment, a control system may be provided with a knob assembly as described in any of the above embodiments or variations. The control system comprises at least one shaft which is attached to the inner component. Such a shower control assembly 200 is shown in figure 20. Rotation of the knob assembly may be used to rotatethe shaft of the control assembly. Alternatively, movement of the knob assembly, e.g. along a linear slider, may be used to move the shaft of the control assembly. The control assembly, if used as part of a shower system, may be used to control the temperature and / or flow rate of water following shower output based on position of the shaft.

[0076] For example only, rotation of the shaft of the shower control system may control the opening of a valve to increase the flow rate of water from a shower head, or the closing of a valve to decrease the flow rate of water from a shower head. The mechanism could be used to control flow rate and / or temperature and / or an another characteristic of flow from a shower control system. The assembly could be used to turn on and / or off the flow from a shower control system.

[0077] Although the control assembly as described above in relation to the shower control device, the knob assembly can be used as a control knob for any appropriate system or appliance. For example instead of a shower control system, any other control system may be used. The assembly could be used as part of a number of other systems, such as domestic appliances in particular, e.g. washing machines, dishwashers, basin taps, bath taps, etc., which also generally allow for user input via a control knob.

Claims

CLAIMS1. A knob assembly for a control system, the knob assembly comprising: an outer component and an inner component which are configured to be releasably secured, the outer component comprising a main body forming an exterior surface of the assembly, the outer component and the inner component comprising corresponding mating parts which interlock to prevent separation of the outer component and the inner component when the mating parts are interlocked, wherein at least one of the mating parts is movable relative to the other mating part to release the outer component from the inner component, wherein when the outer component and the inner component are secured, the mating parts interlock at a position inwards of the exterior surface and the knob assembly is configured to provide access to the movable mating part to release the outer component from the inner component.

2. The knob assembly of claim 1, wherein the inner component is for attaching the assembly to the control system.

3. The knob assembly of either of claims 1 or 2, wherein the assembly is configured such that the outer component is secured to the inner component by moving the outer component relative to the inner component in a first direction4. The knob assembly of claim 3, wherein the movable mating part is configured to move relative to the other mating part in a second direction, perpendicular to the first direction, to disengage the mating parts to release the outer component from the inner component.

5. The knob assembly of any one of the preceding claims, wherein the outer component comprises a through-hole with an opening on the exterior surface6. The knob assembly of claim 5, wherein to disengage the interlocking parts, a tool, structure or button is pushed via the opening towards the inside of the knob assembly.

7. The knob assembly of either of claims 5 or 6, wherein the knob assembly provides a passageway from the opening to the at least one of the mating parts.

8. The knob assembly of claim 7, wherein the passageway is configured to allow access to the movable mating part using a tool inserted into the through-hole.

9. The knob assembly of claim 7, further comprising a structure positioned in the passageway, the structure being configured to move the movable mating part.

10. The knob assembly of claim 9, wherein the structure is: a) recessed from the exterior surface; or b) substantially flush with the exterior surface; or c) protruding from the exterior surface.

11. The knob assembly of any one of claims 5-10, wherein the opening provides an indicator.

12. The knob assembly of any one of the preceding claims, wherein the movable mating part comprises a compliant mechanism attached to a protruding portion, wherein the compliant mechanism allows the protruding portion to be moved from an original position when a force is applied in a given direction to the protruding portion and is configured to return the protruding portion to the original position when the applied force is removed.

13. The knob assembly of claim 12, wherein the compliant mechanism comprises: a) an arm and connection portion, wherein the arm and / or connection portion is flexible; and / or b) a spring.

14. The knob assembly of any one of the preceding claims, wherein the other mating part comprises a ledge and / or an opening, preferably wherein the opening is a through-hole or a recess.

15. The knob assembly of any one of the previous claims, further comprising an interference fit between the outer component and the inner component to resist relative movement between the components.

16. The knob assembly of claim 15, wherein the outer component and / or the inner component comprises crush ribs and / or crush nibs.

17. The knob assembly of either of claims 15 or 16, further comprising a connector, wherein the interference fit is between the inner component and the connector and the outer component and the connector.

18. The knob assembly of claim 17, wherein the connector is a rubber band or O-ring.

19. The knob assembly of any one of the preceding claims, further comprising a friction forming fluid between the outer component and the inner component to resist relative movement between the components.

20. A control system comprising the knob assembly of any one of the previous claims, and at least one shaft, wherein the at least one shaft is attached to the inner component.

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