This invention relates generally to kitchen appliance technology and, more particularly, to an acoustic treatment and related method for insulating an under-counter kitchen appliance.
Automatic dishwashers have long been known as a particularly convenient and efficient way to clean dishes following their use. Such dishwashers generally include a washing chamber for holding the dishes and one or more streams of pressurized fluid for washing food and drink residue from the dishes. Unfortunately, the washing process generates considerable noise, which can be quite annoying to the user. In an effort to reduce this noise, it has long been known to provide dishwashers with acoustical insulation.
Conventional acoustical insulation systems for dishwashers generally comprise sound transmission barriers and sound absorption layers. Typically, acoustical insulation involves enclosing the noise source in an insulation structure. A typical form of acoustical insulation is a layer of polymer fiber insulation, such as polyester fiber insulation, wrapped around or positioned around the source of the unwanted noise. For example, a polyester blanket is usually wrapped around the sides, top and rear while separate polyester/fiberglass absorbers are usually incorporated into the front door and access panels of an under the counter dishwasher. Together, the blanket and absorbers function to reduce the transmission of unwanted sound from the source of the sound in the dishwasher to the kitchen environment.
The present invention relates to an advanced system or treatment for insulating a kitchen appliance such as a dishwasher.
To achieve the foregoing and other objects and in accordance with the purposes of present invention as described herein, a dishwasher is provided comprising a housing including a washing chamber and an access door, a plurality of legs supporting the housing, a pump and a drive motor provided in a cavity between the legs and below the housing, a plate closing a front side of the cavity, an insulator provided between the plate and the pump and drive motor and a first side shield closing a first side of the cavity. Still further, the dishwasher may include a second side shield closing a second side of the cavity and even a third shield closing a third side of the cavity.
More specifically describing the invention, the insulator includes a first layer of fibrous insulating material and a layer of barrier material. The first layer of fibrous insulating material has an airflow resistivity of between about 3,000 to about 18,000 mks rayls/m and the barrier layer has a weight per unit area of between about 0.5 to about 2.5 pounds per square foot. The first layer of fibrous insulating material is selected from a group consisting of glass fibers, polyolefin fibers, polyester fibers, polypropylene fibers, polyethylene fibers, polyethylene terephthalate fibers, polybutylene terephthalate fibers, cotton fibers, hemp fibers, jute fibers, kenaf fibers, rayon fibers, nylon fibers, acrylic fibers, copolyester fibers and mixtures thereof. If chopped fibers are used, they are chopped to a length of between about 0.635 to about 7.62 cm and have a diameter of between about 2.0 and about 60.0 microns. The first layer of fibrous insulating material may take the form of a nonwoven mat or a nonwoven veil. Further the first layer of fibrous insulating material may comprise by weight percent between about 10 to about 70% glass fibers and between about 90 to about 30% polymer fibers. The polymer fibers may include staple fibers, binder fibers or mixtures thereof.
In one possible embodiment the first layer of fibrous insulating material comprises 100% polyester fibers having a length of between about 1.2 to about 15.2 cm and a diameter of between about 5.0 to about 60.0 microns. The first layer of fibrous insulating material also has a density of between about 0.5 to about 4.0 pounds per cubic foot.
The barrier material is selected from a group consisting of ethylene vinyl acetate, barium filled rubber, asphalt and mixtures thereof. Where the plate has a width A, the barrier layer has a width B where B>A.
Still further describing the invention, the first, second and third side shields may be made from an insulating material selected from a group consisting of glass fibers, polyolefin fibers, polyester fibers, polypropylene fibers, polyethylene fibers, polyethylene terephthalate fibers, polybutylene terephthalate fibers, cotton fibers, hemp fibers, jute fibers, kenaf fibers, rayon fibers, nylon fibers, acrylic fibers, copolyester fibers and mixtures thereof and (b) have an airflow resistivity of between about 3,000 to about 18,000 mks rayls/m.
In addition, the dishwasher may include an insulation blanket covering a top wall, a rear wall, a first side wall and a second side wall of the housing. That insulation blanket may be constructed from a material selected from a group consisting of polyester, polyolefin, polyethylene, rayon, nylon, acrylic, hemp, kenaf, cotton, fiberglass and combinations thereof. Still further, the dishwasher may also include an insulating element provided in the access door of the housing. Additionally, at least one shield of the first, second and third side shields may include a barrier layer.
In the following description there is shown and described several embodiments of this invention simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The accompanying drawings incorporated in and forming a part of this specification, illustrate several aspects of the present invention, and together with the description serve to explain certain principles of the invention. In the drawings:
Reference is now made to the drawing figures illustrating the dishwasher 10 of the present invention that incorporates a unique insulating system including the insulator 12, first side shield 14, second side shield 16, third or rear shield 18 and insulating blanket 20.
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The first layer 60 of fibrous insulating material is selected from a group of materials consisting of glass fibers, polyolefin fibers, polyester fibers, polypropylene fibers, polyethylene fibers, polyethylene terephthalate fibers, polybutylene terephthalate fibers, cotton fibers, hemp fibers, jute fibers, kenaf fibers, rayon fibers, nylon fibers, acrylic fibers, copolyester fibers and mixtures thereof. In one possible embodiment the fibers in the layer 60 are continuous and have a diameter of between about 2.0 to about 60.0 microns. In another possible embodiment the fibers in the layer 60 are chopped to a length of between about 0.635 to about 7.62 cm and have a diameter of between about 2.0 and about 60.0 microns.
Typically the first layer 60 of fibrous insulating material is a nonwoven mat or a nonwoven veil. In one particularly useful embodiment the first layer 60 of fibrous insulating material comprises by weight percent between about 10 to about 70% glass fibers and between about 90 to about 30% polymer fibers. Typically those polymer fibers are stable fibers, binder fibers or combinations thereof. In another particularly useful embodiment, the first layer 60 of fibrous insulating material comprises 100% polyester fibers having a length of between about 1.2 to about 15.2 cm and a diameter of between about 5.0 to about 60.0 microns. In any of the embodiments the first layer 60 of fibrous insulating material may have a density of between about 0.5 to about 4.0 pounds per cubic foot. This construction provides desirable acoustic characteristics for absorbing relatively low frequency noise in a range of approximately 100 to 400 Hz as commonly associated with pumps and drive motors 40 of dishwashing equipment.
The material used to make the barrier layer 62 may be selected from a group consisting of ethylene vinyl acetate, barium filled rubber, asphalt and mixtures thereof. The thickness of the barrier layer 62 may be varied to provide the desired transmission barrier and cooperate with the sound absorption characteristics of the first layer 60 to provide the most efficient and effective noise suppression for a particular application.
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In a particularly useful embodiment the shields 14, 16, 18 are made from the same material as the first insulating layer 60 of the insulator 12. As a consequence, any pump and motor noise reflected by the barrier layer 62 away from the plate 46 is directed toward the shields 14, 16, 18 that muffle and absorb that noise and prevent the noise from exiting the cavity underneath the housing 22 of the dishwasher 10. Of course, for maximum effectiveness the shields 14, 16, 18 must extend continuously from the bottom wall 26 of the housing 22 to the floor F. Further, the shields 14, 16, 18 and the insulator 12 must also meet at the corners where they may be joined by tape or other means if desired. In this way, the cavity beneath the housing 22 is subjected to an “acoustic seal.”
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The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, the blanket 20 or any portion 52, flap 54, 56, 58 may incorporate a barrier layer if desired. Any or all of the shields 14, 16, 18 may also incorporate a barrier layer. Further, while three shields 14, 16, 18 are shown, less than three could be provided. A layer of open cell foam material might also be used as a substitute for fibrous insulating layer 60 so long as the foam material exhibits an air flow resistivity of between about 3,000 to about 18,000 mks rayls/m.
Further, while a two layer insulator 12 has been illustrated and described, the insulator could include three, four or more layers. Possible constructions include but are not limited to a three layer insulator having a layer of barrier material sandwiched between two layers of fibrous insulating material and a four layer insulator including alternating layers of fibrous insulating material and barrier material.
The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way.
Number | Date | Country | |
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60777199 | Feb 2006 | US |