The mattress cleaner - invention to solve/prevent dust mite allergy problems

Hobby inventor: Reinert Korsnes

Click here to get a similar presentation in pdf-format.

Photo of a mite Dust, such as dust mites (see photo) and products from them, accumulate in mattresses. Secretions and excrements from mites and dead mites are a main source of allergy. About 80 percent of a mite consists of stomach content. This media may also accommodate bacterias and mold. The allergens enter the lungs when one moves in the bed. Movements in the bed sometimes make clouds of allergens come out of the mattress. The present invention is based on this understanding. Special movements is the problem and solution. For example killing the dust mites does not solve a dust mite problem (before one has "moved out" its products - and without systematic treatments such as with this invention - this may take many years). There may be developed types of mattresses designed specially to be cleaned using this low cost invention which may be looked at as a mattress accessory. Before such mattresses are developed, this invention still can be used on many types of mattresses. Each sweep by this proposed nozzle over a location of the mattress, will bring out a significant fraction of dust below and that otherwise can enter into the lungs of those using the bed. Repeated treatments will fast bring the remaining part down to zero since the vibrations of this treatment more efficiently bring out the dust as compared to ordinary movements in the bed. This is simple mathematics.

Rotating brushes may create long term accumulation

Note that dust by normal movements in the bed penetrate down into a mattress (where it accumulates). Vibrating brushes make this worse. No current vacuum cleaner producer claims that any ordinary vacuum cleaning can solve/prevent dust mite allergy problems with origin in the mattress. Ordinary vacuum cleaning with rotating brushes may "vibrate down" (and accumulate) allergens into the mattress and hence over time contribute to create an allergen problem. Rotating brushes create such problems mainly because the air stream is not directed through the mattress - the air come into the nozzle from the side - and the brushes vibrate too small and distributed areas simultaneously so it moves dust from active/vibrating volumes and into other parts of the mattress. This invention, however, is only intended to solve allergy problems caused by dust in the mattress. No other nozzles has this design focus. A roating brush cannot homogeneously vibrate a larger area (like the present invention). Hence the concept of rotating brushes cannot in any case facilitate an optimal combination of vibration and air stream through the mattress (even with a "hat" over it like for the present invention). Note that a dust particle has sometimes to move in the oposite direction as the air stream in order to find its way out of the mattress. The vibrations makes this possible. If the vibration is too strong, the particle may "walk away" too much. If the air stream is too strong for a given air stream, the particle can be trapped in the mattress. Hence, for effective cleaning, there must be a balance between the strength of the vibration and the air stream.

Dust in general do not easily come out of porous media (for example mattresses and filters) by simple vacuum cleaning. Particles inside a mattress tend to become trapped between fibers or in pores unless they are repeatedly released and moved by shaking movements. Traditional vacuum cleaning may even not be strong enough to overcome the initial (static) friction for particles at rest down in the mattress. Mites are specially hard to "drag out" of a mattress by simple vacuum cleaning. They are specially adapted to survive by sticking to their habitat. And inside the mattress they avoid to be dried out as compared to sitting on top of the surface. Hence they will prefer to spend much time inside/down in the mattress not easily available by traditional surface vacuum cleaning.

Bang it out !


The present invention is a flapping nozzle for vacuum cleaners. It keeps dust moving within an air stream (up to the nozzle) down in the mattress over a pretty large but concentrated area. The floating dust in this way drift up to the nozzle. Controlled under-pressure below the cover can press up the mattress locally. This makes the shaking extra effective far down in the mattress, and this under-pressure also solves potential uncomfortable vibration for the user. The mattress "takes off" for the vibration. The animation below illustrates the flapping component:

To see (or download) video recording from a simple physical demonstration, click here (1.8 Mb mpeg), here (1.4 Mb AVI) or here (0.9 Mb *.rm). This demo only shows that the principle works. Do not confuse this with any design. Click here to see a possible design and here for another. These proposals are made by students at Department of Product Design at NTNU.

About technical design

Designed to clean the bed

The mattress cleaner is for cleaning flat areas such as mattresses. Carpets can in principle be cleaned by the mattress cleaner, but this may compromise hygiene, mechanical/technical design parameters and product identity. Carpets may also be washed by water or people with dust mite allergy may simply get rid of carpets. Dust mite allergens enter the lungs mainly when one moves in the bed - forget carpets this time ! And forget to compete with ordinary nozzle design ! This is a hygiene/health product solving a serious problem for many.

Designing the flapping mechanism

The strength of the air stream into a vacuum cleaner is in the range 30-60 liters per second. So if the volume behind the piston in the chamber varies one liter (from outer to inner position), it takes about 1/60 - 1/30 of a second for it to move from the outer position to the inner position (assuming the spring stiffness is small enough not significantly to affect the air stream). One can assume spring stiffness large enough and the mass of the piston/valve small enough so the piston/valve will move much faster out from the inner position. Hence the flapping frequency will be somehow smaller than 30 times a second (30 Hz) if the air stream is 30 liters per second. Note the possibility simply to regulate where the valve stops on its way into the chamber - and hence the possibility to regulate the flapping frequency. Also note that the flapping strength (momentum and energy) is independent of the strength of the vacuum cleaner - though the {\em flapping frequency} is somehow dependent on the strength of the air stream.

The function of the cover of the flapping mechanism

The regulated under-pressure below the cover of the flapping mechanism has the following function: The flapping/vibration and the air stream must be tuned together. If the flapping is too hard as compared to the air stream, then some dust will tend to vibrate down into the mattress and get stuck there. If the air stream is too hard as compared to the vibration, then some dust will tend to get stuck due to friction from being pressed to surfaces and traps into the mattress.

Last updated: 22th October 2004.