This invention relates to composite components and in particular, though not solely, to components made from at least two sub-component parts that are bonded together by an adhesive, in particular by a cyanoacrylate adhesive or cyanoacrylate-based adhesive.
Components of modern devices such as electrical appliances may be formed in a variety of different ways. For example, certain components may be machined out of a larger block of material or may be moulded from a molten material as is the case with injection-moulded thermoplastics components. Some components are formed by combining two or more sub-components into a composite component in which the separate sub-components must be reliably secured together. For example, the sub-components may be attached by interlocking features of the parts, by separate fasteners or clips or they may be bonded by welding or by an adhesive.
A well-known adhesive which is suitable for bonding most materials is cyanoacrylate, for example Permabond® 737 toughened cyanoacrylate manufactured by Permabond Engineering Adhesives or Loctite® 454® cyanoacrylate manufactured by Henkel Corporation. Such cyanoacrylate adhesives are normally a “one-part” adhesive whereby curing occurs by a reaction to traces of surface moisture on the parts being bonded. A known issue with cyanoacrylate adhesives is a phenomenon known as “blooming” or “frosting” that occurs when uncured adhesive evaporates or vaporises off a part and either:
The resulting appearance is unsightly, particularly when it occurs on parts or surfaces of a component that are cosmetic or decorative in nature.
Blooming has conventionally been reduced by ensuring adequate ventilation over an assembly area, applying less adhesive and/or curing the adhesive faster. These options are often not workable, for example when once the parts are assembled the still-to-be-cured adhesive is within a partially enclosed space which is difficult to ventilate but from which adhesive vapour/bloom may still escape and then cause blooming to occur on external surfaces of the assembled part. Also, accurately and repeatedly controlling the amount of adhesive applied to a surface can be difficult in assembly-line situations, particularly when the adhesive is manually applied.
It is therefore an object of the present invention to provide a composite component, a composite lid or an electrical appliance incorporating a composite lid which will go at least some way towards overcoming the above disadvantages, or which will at least provide the public or industry with a useful choice.
In a first aspect, the invention may broadly be said to consist in a composite component, comprising:
Preferably, the adhesive is a cyanoacrylate adhesive or cyanoacrylate-based adhesive.
Preferably, the depression is a continuous or semi-continuous groove or channel.
In a second aspect, the invention may broadly be said to consist in a lid, the lid being a composite component according to the first aspect.
In a third aspect, the invention may broadly be said to consist in an electrical appliance comprising:
Preferably, the electrical appliance is a laundry appliance such as a laundry clothes washing machine, in particular a top-loading laundry clothes washing machine.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only. The following description will concentrate on the incorporation of embodiments of the invention within a top-loading or “vertical-axis” laundry clothes washing machine however, it will be readily appreciated by those of ordinary skill in the art that the invention is not limited to such applications. The invention is applicable generally to any glued composite components, irrespective of whether they are incorporated in an electrical/home appliance. In general, the invention is applicable to articles made by gluing opposing article sub-components using an adhesive susceptible to the aforementioned blooming problem, wherein when the sub-components have been glued and connected, the adhesive is within a fully or partially enclosed hollow volume of the article.
Preferred forms of the invention will now be described with reference to the accompanying drawings in which:
An exemplary laundry clothes washing machine 1 of the top-loading or “vertical-axis” type is illustrated in
Although not essential to the present invention, the major components within wrapper 2 will now be briefly described. An outer bowl assembly is mounted beneath assembly 3 via a suspension system such as suspension rods. A spin tub (sometimes referred to as a laundry basket) is located within the outer bowl assembly, mounted on a shaft which extends through the base of the outer bowl assembly. The spin tub receives a laundry load, via the opened lid 4, during operation of the machine. An agitator or wash plate is ordinarily provided within the spin tub, connected to the upper end of the shaft which passes through seals in the bases of both the outer bowl assembly and the spin tub. The lower end of the shaft may be driven directly by an electric motor which may be an electronically commutated external-rotor motor wherein the stator is mounted to the base of the outer bowl assembly with the rotor directly connected onto the end of the shaft. Examples of such laundry clothes washing machines are our own SMARTDRIVE™-powered top-loading laundry clothes washing machines variously sold under the trade marks CLEANSMART, WASHSMART, AQUASMART, FABRICSMART and QUICKSMART.
Lid 4 is a composite component manufactured in accordance with a preferred embodiment of the present invention. Sub-components of lid 4 may be formed by an injection moulding operation preferably utilising a thermoplastics material such as ABS (Acrylonitrile Butadiene Styrene). As shown in
Lid 4 also includes side walls 23 between the upper 20 and lower 30 surfaces. As will be appreciated from
It will be appreciated from
Referring now in particular to
The lower side 41 of upper lid sub-component 40, as shown in
Alignment of the upper 40 and lower 50 lid sub-components is assisted, during assembly of the composite lid 4, by the provision of a number of pins or posts 46 projecting substantially perpendicularly from underside 41 of upper lid sub-component 40 near its rear edge 45. Each post 46 has a corresponding opening 54 provided in lower lid sub-component 50 near its rear side 25. Posts 46 could of course alternatively be provided on lower sub-component 50 with openings 54 on upper sub-component 40. Preferably the edges of openings 54 are bevelled or curved inwardly to assist with alignment and insertion of the posts within the openings when the lid sub-components are being assembled to form the composite lid component 4.
Preferably the openings are rectangular or oval in shape rather than circular so that they allow limited relative movement in a preferred direction, although it is also preferred that the longer dimension of the respective openings are not all aligned. That is, it will be appreciated that the central opening 54 shown in
With reference now in particular to
Adhesive is preferably also applied to the upper surfaces of inwardly-directed projections 51 on either side of lower lid sub-component 50 to bond them to a corresponding projecting tab 42 on upper lid sub-component 40. Adhesive is also preferably applied to substantially planar rear flange surface 70 and substantially planar front flange surface 71 of the lower lid sub-component, both of which also form bonding regions for bonding those surfaces to adjacent regions of surface 41 of the upper lid sub-component 40 when aligned and assembled.
The longitudinal path has a much greater length than width and provides a suitable surface area to which adhesive may be applied from a nozzle of an adhesive dispenser. For example, a user or robotic device would place the tip of the dispenser at a starting position at or near one end of a bonding region, commence squeezing or dispensing adhesive whilst moving the tip of the dispenser along the longitudinal path and stop moving and dispensing adhesive once the other end of the path is substantially reached. A guide or stencil may be provided, covering most of the area of the lower lid sub-component 50 but having openings formed as slots above the bonding regions 57 to assist a user to manually apply adhesive in the correct locations. To assist in placement of the tip of the adhesive dispenser at the start of the adhesive application path a depression 61 may be formed within the bonding region 57, at or near an end of the longitudinal path. The shape/area and/or depth of the further depression 61 should be sufficient to enable the tip of the adhesive dispenser to be at least partially received therein. The depressions 61 are preferably positioned laterally near the centre line of the longitudinal path to assist centering of the adhesive application path. Further depressions 61 could also be provided at or near the completion end of the adhesive application path. As may be best seen in
It will be appreciated that when the upper and lower lid sub-components are assembled together, the composite lid component 4 thus produced will be substantially hollow such that the sub-components at least partially enclose a central volume of air. As mentioned above, it is difficult to control adhesives curing within an enclosed space so that blooming will occur, particularly where excess uncured cyanoacrylate adhesive is present on a surface which is not in contact with or adjacent to another surface which the adhesive may contact. The surface of such excess uncured adhesive is therefore exposed to the atmosphere and may easily evaporate or vaporise, particularly in a warm ambient environment. As the lid sub-components are not hermetically sealed, some of the adhesive vapour will inevitably find its way out of the composite lid and can result in blooming on external, potentially cosmetic, surfaces.
To avoid or reduce blooming on external surfaces of the composite lid component 4 the bonding regions 57 may be partially or completely bounded on their periphery by a further depression 60 which may be formed as a trench, channel or groove in the substantially planar upper surface of rib 56. Groove 60 is provided to receive excess or overflowing adhesive that has been applied to bonding region 57. Compared to the situation where uncured adhesive on a surface is completely exposed (for example, if excess adhesive overflowed the edge of the substantially planar upper surface of a rib 56 and ran down towards or onto surface 55), adhesive received by groove 60 has only a limited exposed surface area, being the width of the groove, from which any uncured adhesive may evaporate or vaporise. Accordingly, any adhesive received in groove 60 will eventually cure without significantly evaporating, thereby reducing or avoiding the occurrence of blooming. The width of the bonding region, between grooves 60 on either lateral side of the longitudinal path, is chosen to allow the uncured adhesive to spread sufficiently so that the width of bond created between the sub-components will provide adequate strength to the composite component. As shown in
Once adhesive has been applied to the bonding regions 57, and before the adhesive has completely cured, the upper 40 and lower 50 lid sub-components are aligned and clipped together. This process will result in an adhesive interface being formed between the sub-components, the interface including the bonding regions 57 of the lower lid sub-component and adjacent regions of underside 41 of the upper lid sub-component. The opposed surfaces meeting at the interface may be in contact or slightly spaced, provided that the adhesive layer is sufficiently thick to span the gap between the sub-components and thereby bond them together. Pressure may be applied between the sub-components during curing for a period of, for example, 10 to 30 seconds to ensure that a strong bond is achieved.
Although the grooves are described above as bounding a bonding region 57, a reduction in blooming will still occur if the bonding region is not completely surrounded by groove 60. For example, it can be seen in
To further reduce or control the occurrence of blooming on external surfaces of the lid component seals may be formed between the two sub-components, preferably along peripheral edges thereof. For example, a lip 48 may be provided at the rear of the upper lid sub-component 40 which partially overlaps with the rear edge 25 of the lower sub-component. The clearance between the lip and rear edge 25 is minimal to reduce or resist vapour, particularly originating from flange 70, from exiting the composite lid component and forming bloom on the console 5. A similar constriction may be provided at the front edge to control vapour, particularly from flange region 71, from exiting the lid component between the front edge of lower sub-component 50 and the adjacent surface of handle region 21. The sides of the lid may be similarly sealed, for example by providing a recess or groove along the length of the side edges of one of the sub-components and a correspondingly-shaped ridge provided along the length of the side edges of the other side component. For example, upper lid sub-component 40 is provided with side grooves 49 while the side edges 73 of lower lid sub-component 50 have a profile that fits within corresponding groove 49 with minimal clearance therebetween. When assembled, the gap between groove 49 and side edges 73 provide a substantially u-shaped tortuous path in cross-section, resisting vapour flow from the sides of the lid component to the adjacent surface of top deck 3.
In the exemplary embodiment shown in the drawings, the lateral width of the grooves 60 between substantially parallel side walls may be between about 0.25 mm and about 1.0 mm, preferably about 0.5 mm and the depth at least about 0.25 mm, preferably at least about 0.5 mm with a lateral bonding region 57 width of between about 5 mm and about 10 mm. The specific dimensions of the grooves are of course not essential to the invention and it is also not essential that all of the grooves in a particular sub-component, or even all of the grooves associated with a particular bonding region 57, have the same dimensions or that they all be associated with the same groove pattern.
Number | Date | Country | Kind |
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709626 | Jul 2015 | NZ | national |