The mattress cleaner -
invention to solve/prevent dust mite allergy problems
Hobby inventor: Reinert Korsnes
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in pdf-format.
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.
Summary of advantages:
- It sucks up allergens inside the mattress and which otherwise
come out of it by normal movements and pollute
the air for the person in the bed.
- Competing nozzles do not shake loose particles so deep
into the material (and keep it loose over some time/volume)
and the air goes into these nozzles from
the side.
Hence competing nozzles has not such an effect down into the mattress.
- It is easy to clean.
One may consider a rotating brush as a competing product.
Note that hair tend to get fixed hard to a rotating brush
(in addition to that it shakes only small parts of the
mattress simultaneously and air come in from the side -
this makes a part of the upper dust in a mattress to "vibrate down"
and contribute to an accumulation of dust in the mattress).
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:
- To direct the air stream up through the mattress
into the vacuum cleaner
(to avoid air flux down into the mattress on the
side of the location of treatment).
- To eliminate uncomfortable vibrations for the user.
- To press up (locally) the surface of the mattress
(this increases the effectiveness to loosen dust
down in it).
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.