Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED AGITATOR BRISTLE TUFTING DESIGN
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates generally to the floor care equipment
field and, more
particularly, to a rotary agitator incorporating a new bristle tuft pattern
including a tuftless gap
that enhances the bare floor cleaning efficiency of a vacuum cleaner.
BACKGROUND OF THE INVENTION
[00021 Rotary agitators for vacuum cleaners are well known in the art. Many
such agitators
are provided with projecting bristle tufts wherein the bristle tuft pattern is
designed to ensure that
at least one bristle tuft is substantially orthogonal with the floor (i.e. at
least one bristle tuft is 90
to the plane of the floor F) at any degree of rotation of the agitator body
(see Figure 7). Thus, for
example, if the tufted agitator has two helical rows of bristle tufts, each
row extends about an are
of substantially 180 so that together the two rows of bristle tufts Ti, T2
extend fully around a
360 arc of the agitator body B. Examples of such agitator designs are
disclosed in, for example,
U.S. Patents 5,495,634 to Brundula et al and 6,574,823 to Stegens et al.
[0003] In contrast to state of the art rotary agitators of this type, the
present invention relates
to a rotary agitator having a bristle tuft pattern that extends or projects
from the exterior surface
of the agitator body about an are of less than 360 providing at least one
tuftless gap of between
about 10 and about 50 in are. When the rotary agitator is de-energized for
bare floor cleaning,
the agitator comes to rest with the tuftless gap adjacent the floor being
cleaned. Due to the fact
that the tuftless gap ensures that there are no bristle tufts extending in an
orthogonal direction
between the agitator and the underlying floor, the weight of the vacuum
cleaner and the force of
the suction provided by the vacuum cleaner combine to produce a lowering of
the nozzle
assembly of the vacuum cleaner relative to the floor. This reduces the space
between the bottom
of the nozzle assembly and the floor which in turn increases the velocity of
the suction air
stream. The increased air velocity improves the ability of the air stream to
entrain dirt and debris
which is then sucked into the suction inlet of the vacuum cleaner so as to
provide more efficient
and effective bare floor cleaning.
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SUMMARY OF THE INVENTION
[00041 In accordance with the purposes of the present invention as described
herein, a rotary
agitator is provided. The rotary agitator comprises a body having an exterior
surface. A
plurality of bristle tufts extend from the exterior surface of the body about
an arc of less than
360 thereby providing at least one tuftless gap of between about 10 and about
50 in arc. The
plurality of bristle tufts may be provided in a helical pattern, in a chevron
pattern, in an offset
chevron pattern, randomly or in any other arrangement so long as the tuftless
gap is maintained.
[00051 In one particularly useful embodiment the bristle tufts are provided in
two helical
rows wherein each of the two helical rows extends along an arc of between
about 140 to about
160 along opposing positions of the agitator body so as to provide two
opposed tuftless gaps
wherein each of the two tuftless gaps extends along an arc of between about 40
and about 20 .
[00061 In accordance with yet another aspect of the present invention a method
for
enhancing bare floor cleaning efficiency of a vacuum cleaner is provided. That
method
comprises providing the vacuum cleaner with a rotary agitator having a body
with an exterior
surface, a plurality of bristle tufts extending outwardly from that exterior
surface about an arc of
less than 360 and a tuftless gap on the exterior surface extending through an
are of about 10 and
about 50 . When the rotary agitator is stopped for bare floor cleaning, the
tuftless gap is adjacent
the floor. The weight and suction of the vacuum cleaner produces a lowering of
the nozzle
assembly of the vacuum cleaner toward the floor being cleaned. This
effectively reduces the
space between the bottom of the vacuum cleaner and the floor. This likewise
reduces the cross
section through which the suction air stream travels thereby increasing the
speed of the airstream
being drawn into the vacuum cleaner. This provides an air stream more capable
of entraining
dirt and debris for more efficient and effective bare floor cleaning.
[00071 In the following description there is shown and described several
different
embodiments of the 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.
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BRIEF DESCRIPTION OF THE DRAWINGS
[00081 The accompanying drawings incorporated herein and forming a part of the
specification, illustrate several aspects of the present invention and
together with the description
serve to explain certain principles of the invention. In the drawings:
[0009] Figure 1 is a perspective view of a rotary agitator constructed in
accordance with the
teachings of the present invention including two helical rows of bristle
tufts;
[0010] Figure 2 is an end elevational view of the rotary agitator of Figure 1
illustrating two
helical rows of bristle tufts extending through an arc of 160 and two opposed
tuftless gaps each
extending through an arc of 20 ;
[0011] Figure 3 is an end elevational view similar to Figure 2 but showing an
alternative
embodiment wherein the two helical rows of bristle tufts extend through an are
of 140 each and
the two opposed tuftless gaps extend through an arc of 40 each;
10012] Figures 4a and 4b are perspective views of an alternative embodiment of
the present
invention wherein two bristle tuft rows are each provided in a chevron pattern
and two opposed
tuftless gaps each extend through an arc of 30 ;
[0013] Figures Sa and 5b are perspective views illustrating an alternative
embodiment of the
present invention wherein the agitator body includes two rows of bristle tufts
both provided in an
offset chevron pattern and two tuftless gaps therebetween;
[00141 Figures 6a and 6b are respective end elevational views of (a) a prior
art agitator
including two helical rows of bristle tufts wherein each row extends through
an are of 180 so as
to provide bristle tufts around the full 360 are of the agitator and (b) the
rotary agitator of the
present invention including two helical rows of bristle tufts as illustrated
above in Figures 1 and
2. These figures illustrate how the rotary agitator of the present invention
allows the nozzle
assembly to more closely hug the floor and thereby increase the air stream
velocity to produce
enhanced cleaning efficiency; and
[0015] Figure 7 is an end elevational view illustrating a prior art rotary
agitator including two
bristle tuft rows wherein each row extends along an arc of 180 so as to
provide bristle tufts
around the full 360 arc of the rotary agitator.
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[0016] Reference will now be made in detail to the present preferred
embodiment of the
invention, examples of which are illustrated in the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0017] Reference is now made to Figures I and 2 illustrating one possible
embodiment of
the rotary agitator 10 of the present invention. In the illustrated
embodiment, the rotary agitator
comprises a tubular body 12 having an exterior surface 14. A plurality of
bristle tufts 16
extend or project from the exterior surface 14 of the body 12 about an arc of
less than 360
thereby providing at least one tuftless gap 18 of between about 10 to about
50 along the
exterior surface 14.
[0018] In the embodiment particularly illustrated in Figures 1 and 2, the
bristle tufts 16 are
provided in two, opposed helical rows 20, 22 with each row extending through
an arc of
approximately 160 . This creates two opposed tuftless gaps 18 with each such
gap extending
through an arc of about 20 (see particularly Figure 2 showing one tuftless
gap 18 between two
rows 20, 22, the other gap being hidden on the opposite side of the agitator).
[0019] In the alternative embodiment illustrated in Figure 3, the bristle
tufts 16 extend
through two opposed helical rows 24, 26 each having an are of 140 . This
produces two opposed
tuftless gaps 28 each having an are of 40 .
[0020] In yet another embodiment illustrated in Figures 4a and 4b, the bristle
tufts 16 are
provided in two rows 30, 32 wherein each row defines a chevron pattern. This
produces two
opposed tuftless gaps 34 wherein each of the gaps extends through an arc of
between about 10
and about 50 .
[0021] In yet another embodiment illustrated in Figures 5a and 5b, the bristle
tufts 16 are
provided in two separate rows 36, 38 wherein each of the rows defines an
offset chevron pattern.
Two tuftless gaps 40 are provided between the rows 36, 38 and extend through
an arc of between
about 10 and about 50 .
[0022] While the rotary agitators 10 of the present invention are illustrated
as having tubular
bodies 12 with circular cross sections, it should be appreciated that the
agitator bodies may also
be of solid construction if desired. Further, the agitator bodies themselves
do not have to be
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circular in cross section even though the arc described by the bristle tufts
16 is semi-circular in
shape.
[00231 The agitator body 12 may be made from substantially any appropriate
material
including, but not limited to, plastic, metal, composite and/or wood.
Similarly, the bristle tufts
16 may be made from substantially any appropriate material including, but not
limited to,
plastics such as nylon.
[00241 In accordance with an additional aspect of the present invention a
method is provided
for enhancing the bare floor cleaning efficiency of a vacuum cleaner. The
method comprises
providing the vacuum cleaner with a rotary agitator 10 having a body 12 with
an exterior surface
14, a plurality of bristle tufts 16 extending outwardly from the exterior
surface about an arc of
less than 360 and a tuftless gap 18 on the exterior surface extending through
an arc of about 10
and about 50 .
[00251 Most vacuum cleaners manufactured today include a switch for de-
energizing the
rotary agitator 10 during bare floor cleaning. This is because the air
turbulence generated by the
bristle tufts of the rapidly rotating agitator can interfere with the cleaning
efficiency of a vacuum
cleaner when attempting to clean a bare floor. More specifically, the
turbulence can push dirt
and debris away from the suction inlet.
[00261 When a vacuum cleaner equipped with the rotary agitator 10 of the
present invention
is de-energized, that rotary agitator will stop with a tuffless gap 18
adjacent to the floor F being
cleaned (see Figure 6a). This is because the absence of tufts in the gap 18
causes the gap to be
least resistant to stopping in the bottom dead center position. When in this
position, no bristle
tufts 18 are orthogonal to the floor. Accordingly, the bristle tufts 16 bend
much more easily and
the weight of the vacuum cleaner and the force of the suction being generated
combine to draw
the nozzle assembly N of the vacuum cleaner toward the floor F. This reduces
the height or
space H2 between the bottom B of the nozzle assembly N and the floor F.
Accordingly, the cross
sectional area through which the vacuum air stream flows is reduced. This
results in an increase
in air velocity toward the suction inlet S of the vacuum cleaner. The
increased air velocity more
efficiently and effectively entrains dirt and debris which is drawn into the
suction inlet S of the
vacuum cleaner thereby enhancing bare floor cleaning efficiency (see action
arrows A).
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[0027] As best illustrated in Figure 6b, such an efficiency enhancement is not
provided when
the same vacuum cleaner nozzle N is fitted with an agitator R of prior art
design incorporating
two opposing rows of bristle tufts T wherein each row extends through an arc
of 180 so as to
provide bristle tufts extending from the body of the agitator R through a full
360 arc of the
agitator. Such a bristle tuft arrangement effectively presents at least one
bristle tuft T orthogonal
to the floor F in any position of the rotary agitator R. Bristle tufts T in
such a substantially
orthogonal position resist bending. Accordingly, the bristle tufts T resist
any significant
lowering of the nozzle assembly due to the weight of the vacuum cleaner and
the suction air
stream. Thus, for bristle tufts T of the same height, the prior art agitator R
supports the bottom B
of the nozzle assembly N at a height Hi above the floor F. This is
substantially higher than the
height H2 discussed above and illustrated in Figure 6a. Accordingly, with the
prior art agitator R
there is no lowering of the height/narrowing of the space between the bottom B
of the nozzle
assembly N and the floor F and no increase in air stream velocity to provide
enhanced cleaning
action.
[0028] The foregoing description of the preferred embodiments of the present
invention have
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, while the rotary
agitator 10 of the present
invention is described above as having two rows of bristle tufts 16,
substantially any number of
rows may be provided so long as a tuftless gap 18 of appropriate are is
provided. Similarly, the
rotary agitator 10 may alternatively include only randomly spaced bristle
tufts 16 so long as a
tuftless gap 18 of appropriate arc is provided.
[0029] 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
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preferred embodiments do not and are not intended to limit the ordinary
meaning of the claims in
their fair and broad interpretation in any way.
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