FIELD OF THE INVENTION
[0001] The invention relates to a floor care nozzle, and to a vacuum cleaner provided with
such a floor care nozzle.
BACKGROUND OF THE INVENTION
[0002] Some floor care nozzles appear to produce an audible rattle when used on certain
carpets.
SUMMARY OF THE INVENTION
[0003] It is, inter alia, an object of the invention to provide an improved floor care nozzle.
The invention is defined by the independent claims. Advantageous embodiments are defined
in the dependent claims.
[0004] The invention is based on the following insights. The disturbing phenomenon when
using prior art nozzles exposes itself as a vertical oscillation of the nozzle head
during backwards stroke in a single hinge nozzle, or a hopping behavior in double-hinge
nozzles. Merely adding mass to the nozzle appeared to have no effect in the disturbing
phenomenon. A further study revealed that the oscillation starts when an impulse (in
this case a starting velocity given by the carpet) is put onto the nozzle. The nozzle
starts to move away from the carpet at this velocity, but is slowed down by gravitational
pull and vacuum generated by the vacuum cleaner fan. These forces create a negative
vertical acceleration, with which the time to land can be calculated. When landed,
the nozzle will get another vertical push from the carpet, and start on its next jump.
With every landing, the nozzle is pushed into the carpet harder, creating more force
on the front rim, giving it more frictional force to create an even higher starting
velocity with the net jump. It appeared that the mass of the nozzle itself does have
no effect on this phenomenon, and that the frequency of the nozzle is dependent on
the height of the jumps (or starting vertical velocity). It also appeared that (in
combination with the increasing vertical impulse with every jump) the nozzle will
tend to start out with a high frequency jump with just small jumping height, but will
quickly move to high jumps with a low frequency. Based on these considerations, the
invention is based on the insight that by counteracting the high frequency, low amplitude
jumps at the beginning of the movement of the nozzle, it becomes possible to prevent
the high jumps, low frequency motion from occurring later on. The main element to
prevent this high frequency motion from occurring is a free mass movable with a vertical
motion component while being contained within the nozzle.
[0005] It is noted that
GB 910,697 discloses a suction cleaner nozzle having a beating device comprising a plurality
of beating elements adapted to beat surfaces, particularly carpets, over which the
suction cleaners are to work in order to loosen particles of dust, threads and the
like from the surfaces, the beating elements consisting of rubber strips arranged
parallel to one another in side by side relationship across the mouth of the nozzle,
each element being closely adjacent a neighboring element, some of the beating elements
being further away from the mouth of the nozzle than others, the arrangement being
such that the elements oscillate in a direction perpendicular to the plane of the
rim of the mouth of the nozzle when air is sucked through the nozzle. This prior art
document does not provide a solution for the rattling sound in nozzles that do not
have such a carpet beating device, and the present invention differs from this prior
art nozzle in that the motion of the movable mass is contained within the nozzle housing.
[0006] These and other aspects of the invention will be apparent from and elucidated with
reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007]
Fig. 1 illustrates the phenomenon addressed by the invention;
Fig. 2 illustrates the principle underlying the invention; and
Figs. 3A-3C and 4 show embodiments of the invention.
DESCRIPTION OF EMBODIMENTS
[0008] Fig. 1 illustrates the phenomenon addressed by the invention, by showing 4 sequential
phases in the movement of a nozzle when dragged backwards (dragging force F
drag) on a carpet. The first picture shows an impulse force F
imp (e.g. caused by an unevenness in the carpet), which results in an upwards movement
of the nozzle that is shown in the second picture. When the nozzle has fallen down
into the carpet, so that the nozzle experiences more resistance than in the first
picture, the increased impulse force F
imp shown in the third picture will result in an ever higher jump as shown in the last
picture.
[0009] Fig. 2 illustrates the principle underlying the invention. The following steps can
be identified.
Step 1: The vacuum force Fvac and gravity force Fgrav want to keep the nozzle to the ground. The nozzle mass M and the free mass m are
launched into the air by an unevenness in the carpet (impulse Imp), while the nozzle
is dragged over the carpet.
Step 2: Nozzle & free mass fly through the air together, and experience mainly the
gravitational force Fgrav.
Step 3: When the nozzle gets closer to the ground, it will experience the vacuum force
Fvac again, which pulls it down faster. The free mass m inside the nozzle does not experience
this vacuum, hence it starts lagging behind in motion, creating a gap between the
nozzle and the free mass m.
Step 4: After touchdown of the nozzle, the nozzle is launched back into the air again
by the carpet force Imp, but quite early meets the free mass m, which was still on
its way down.
Step 5: The collision between the nozzle and the free mass m will send the nozzle
back to the ground again. In this way, the amplitude of the nozzle movement is kept
small, hence the kinetic energy the free mass needs to have can remain quite small
(since it only has to dampen out small oscillations of the nozzle).
[0010] The main advantages of this solution are:
- 1. The free masses m can be incorporated in the nozzle, without the user ever having
to see them (invisible).
- 2. The free masses m can be relatively cheap.
- 3. The free masses m are relatively simple to build into the nozzle.
- 4. The free masses m do not interact with the use of the nozzle.
- 5. The mass can be very small in comparison with the nozzle.
[0011] As to the type of the free mass, the mass can a solid or liquid form. In case of
a liquid form the containment of the liquid should be secured. The main advantage
is that the element size is rather small and best reacts on impulses. When applying
a liquid, the viscosity can be of influence. In a preferred embodiment of the nozzle,
steel spheres or rods are used as free mass m, which have a solid structure that is
easier to contain in position within a nozzle housing construction.
[0012] As to the size of the free mass m, when investigating the principle, the element
size does not seem to be very relevant. The dynamic behavior is approximately the
same in large or small members. Tests have been performed with 4 relatively big steel
spheres (diameter 12 mm, and total weight 27 g), and with about 90 small steel spheres
(diameter 3 mm, and same total weight 27 g). Both have equal performance. Therefore,
from a logistic and assembly point of view, the preference is to use a relatively
low number (e.g. 3 or 4) of relatively large free masses m.
[0013] As to the total weight of the free masses, it appeared that good results were obtained
if the total weight m of the free masses was at least about 10% of the weight M of
the nozzle, e.g. m = 27 g and M = 280 g.
[0014] As to the location of the free mass, preferably it should most far away from the
hinge point, since the movement of the free mass is then the largest. After experiments
it shows that the same weight is more effective when placed away from the hinge H,
as shown in Fig. 3A. Fig. 3A shows an embodiment of a nozzle in accordance with the
invention, in which HS indicates a nozzle housing HS.
[0015] A disadvantage of the free masses is that these can rattle when they move within
their containers. By making a container structure with the right dimensioning the
mass object can mostly move in one direction. By adding a small damping element DE
at the bottom or the top of this place it can cancel out the sounds, as shown in Fig.
3A. Another solution could be to encapsulate the mass objects themselves in a damping
layer such as rubber, as shown in Fig. 3B. The most optimal and economic execution
could be to use a steel cylinder as mass m. The benefit of this steel cylinder is
that the top and bottom surfaces are flat, and these surfaces can be equipped with
a very thin layer of absorbing material DE to reduce the audible effect of the free
masses m colliding with the plastic nozzle housing parts, as shown in Fig. 3C.
[0016] As shown in Fig. 4, in the soleplate of the nozzle, containers C are provided, within
which a free mass m can be positioned. In the embodiment of Fig. 4, the containers
C have a cylinder shape. The shape of the free masses m to be put into cylindrical
mass containers C can be a cylinder or a sphere. The top cover can seal the compartment,
securing that the free mass m will always stay in place. The number of containers
C is at least one, and preferably varies between 3 and 6, depending on the applied
masses or total weight. The containers C do not move within the nozzle housing, and
the masses m move within the containers C without touching the floor. Within these
boundaries, the containers C do not need to be fully closed; it may be possible for
a user to see the mass(es) m.
[0017] In summary, the invention provides a floor care nozzle comprising a nozzle housing
HS, within which a mass m is vertically movable. Preferably, the nozzle housing HS
is provided with a damping element DE at a place where the mass m collides with the
nozzle housing HS, or the mass m is provided with a damping element DE. Preferably,
a total weight of the mass m is at least about 10% of a weight of the nozzle. Preferably,
the mass m comprises a plurality of masses m distributed over a width of the nozzle
housing HS, wherein the number of masses m could be at least 3 and at most 6. Preferably,
the nozzle housing HS comprises a plurality of containers C in which respective masses
m can move, which are advantageously placed at a front end of the nozzle housing HS.
No air is needed to make the masses move; the masses are set in motion by sudden (vertical)
motions of the nozzle. The sole purpose of the masses is to counteract this vertical
dynamic behavior of the nozzle. A vacuum cleaner is advantageously provided with the
nozzle of the present invention.
[0018] It should be noted that the above-mentioned embodiments illustrate rather than limit
the invention, and that those skilled in the art will be able to design many alternative
embodiments without departing from the scope of the appended claims. For example,
instead of cylindrical containers C, other containment structure shapes are alternatively
possible, such as square, hexagon, etc. with contact ribs defining the degrees of
freedom for this mass. Any such containers contain the mass inside a pre-defined space,
giving it much less room to move around compared to a mass that is free to move inside
the nozzle. Additionally, if the masses are not spheres, but cylinders (or the like),
they will not be able to roll along the walls of the container when the side of the
container is close to horizontal, but they will then tend to slide. This sliding makes
the masses significantly less mobile when the nozzle is moved, hence this results
in much less rattling when the nozzle is handled off the floor.
[0019] The mass m should be allowed to move with a vertical motion component. In a straightforward
embodiment, the mass m moves vertically. However, deviations from a purely vertical
movement are perfectly possible (and even desired if this results in making the container
C better fit in within a desired overall outer shape of the nozzle design), as long
as it is ensured that the mass m is able to counteract undesired movements of the
nozzle, i.e. the movement of the mass m has a sufficiently large component in a direction
of an undesired movement of the nozzle. In an alternative embodiment, the mass m could
be mounted to an arm that may rotate around e.g. the hinge H: this will still result
in that the mass m can move with a vertical motion component so as to counteract undesired
movements of the nozzle. A rotating movement of the mass m may be the best way to
counteract a hopping undesired movement of a double-hinge nozzle.
[0020] The drawings are drafted so as to illustrate the essential features of the present
invention. In reality, the nozzle will have various ribs and other structures to ensure
that it is strong enough.
[0021] In the claims, any reference signs placed between parentheses shall not be construed
as limiting the claim. The word "comprising" does not exclude the presence of elements
or steps other than those listed in a claim. The word "a" or "an" preceding an element
does not exclude the presence of a plurality of such elements. In the device claim
enumerating several means, several of these means may be embodied by one and the same
item of hardware.
1. A floor care nozzle comprising a nozzle housing (HS), characterized in that the nozzle housing (HS) comprises at least one container (C) that is provided with
a mass (m) that is movable in the container (C) with a vertical motion component,
whereby the mass (m) is contained within the nozzle housing (HS).
2. A floor care nozzle as claimed in claim 1, wherein the nozzle housing (HS) is provided
with a damping element (DE) at a place where the mass (m) collides with the nozzle
housing (HS).
3. A floor care nozzle as claimed in claim 1, wherein the mass (m) is provided with a
damping element (DE).
4. A floor care nozzle as claimed in any of the preceding claims, wherein a total weight
of the mass (m) is at least about 10% of a weight of the nozzle.
5. A floor care nozzle as claimed in any of the preceding claims, wherein the mass (m)
comprises a plurality of masses (m) distributed over a width of the nozzle housing
(HS).
6. A floor care nozzle as claimed in claim 5, wherein the number of masses (m) is at
least 3 and at most 6.
7. A floor care nozzle as claimed in any of the preceding claims, wherein the nozzle
housing (HS) comprises a plurality of containers (C) in which respective masses (m)
can move.
8. A floor care nozzle as claimed in claim 7, wherein the containers (C) are placed at
a front end of the nozzle housing (HS).
9. A vacuum cleaner comprising a floor care nozzle as claimed in any of the preceding
claims.
1. Bodenpflegedüse, die ein Düsengehäuse (HS) umfasst, dadurch gekennzeichnet, dass das Düsengehäuse (HS) mindestens ein Fach (C) umfasst, das mit einer Masse (m) versehen
ist, die sich mit einer vertikalen Bewegungskomponente im Fach (C) beweglich ist,
wobei die Masse (m) innerhalb des Düsengehäuses (HS) enthalten ist.
2. Bodenpflegedüse nach Anspruch 1, wobei das Düsengehäuse (HS) mit einem Dämpfungselement
(DE) an einer Stelle versehen ist, an der die Masse (m) mit dem Düsengehäuse (HS)
zusammenstößt.
3. Bodenpflegedüse nach Anspruch 1, wobei die Masse (m) mit einem Dämpfungselement (DE)
versehen ist.
4. Bodenpflegedüse nach einem der vorstehenden Ansprüche, wobei ein Gesamtgewicht der
Masse (m) mindestens etwa 10 % eines Gewichts der Düse beträgt.
5. Bodenpflegedüse nach einem der vorstehenden Ansprüche, wobei die Masse (m) eine Vielzahl
von Massen (m) umfasst, die über eine Breite des Düsengehäuses (HS) verteilt sind.
6. Bodenpflegedüse nach Anspruch 5, wobei die Anzahl von Massen (m) mindestens 3 und
höchstens 6 beträgt.
7. Bodenpflegedüse nach einem der vorstehenden Ansprüche, wobei das Düsengehäuse (HS)
eine Vielzahl von Fächern (C) umfasst, in denen sich jeweilige Massen (m) bewegen
können.
8. Bodenpflegedüse nach Anspruch 7, wobei die Fächer (C) an einem vorderen Ende des Düsengehäuses
(HS) platziert sind.
9. Staubsauger, der eine Bodenpflegedüse nach einem der vorstehenden Ansprüche umfasst.
1. Buse pour nettoyage de sol comprenant un boîtier de buse (HS), caractérisée en ce que le boîtier de buse (HS) comprend au moins un contenant (C) qui est doté d'une masse
(m) qui est mobile dans le contenant (C) avec un composant de mouvement vertical,
moyennant quoi la masse (m) est contenue dans le boîtier de buse (HS).
2. Buse pour nettoyage de sol selon la revendication 1, dans laquelle le boîtier de buse
(HS) est doté d'un élément d'amortissement (DE) à un emplacement où la masse (m) entre
en collision avec le boîtier de buse (HS).
3. Buse pour nettoyage de sol selon la revendication 1, dans laquelle la masse (m) est
dotée d'un élément d'amortissement (DE).
4. Buse pour nettoyage de sol selon l'une quelconque des revendications précédentes,
dans laquelle un poids total de la masse (m) représente environ 10 % d'un poids de
la buse.
5. Buse pour nettoyage de sol selon l'une quelconque des revendications précédentes,
dans laquelle la masse (m) comprend une pluralité de masses (m) distribuées sur une
largeur du boîtier de buse (HS).
6. Buse pour nettoyage de sol selon la revendication 5, dans laquelle le nombre de masses
(m) est d'au moins 3 et d'au plus 6.
7. Buse pour nettoyage de sol selon l'une quelconque des revendications précédentes,
dans laquelle le boîtier de buse (HS) comprend une pluralité de contenants (C) dans
lesquels des masses respectives (m) peuvent se déplacer.
8. Buse pour nettoyage de sol selon la revendication 7, dans laquelle les contenants
(C) sont placés à une extrémité avant du boîtier de buse (HS).
9. Aspirateur comprenant une buse pour nettoyage de sol selon l'une quelconque des revendications
précédentes.