Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02245978 1998-08-26
DUST SUCTION HEAD FOR ELECTRIC VACUUM CLEANER
FIELD OF THE INVENTION
The invention relates to an improvement in dust suction head of an
electric vacuum cleaner, and in particular, such dust suction head is
suitable for vacuum cleaning not only a hard surface such as a hard floor
and a table top but also a soft surface such as a sofa and a carpet.
BACKGROUND OF THE INVENTION
A typical electric vacuum cleaner is provided, at one end of a tube
connected with its motor, with means for collecting dust (hereinafter
referred to as dust suction head). The suction head has a rotational brush
adapted to collect dust on a floor while air is sucked by the motor from a
dust suction port of the head. The brush is driven by an electric motor or a
turbine.
However, such head is heavy and very complex in structure, so that it
not only has limited portability but also requires many parts and
complicated processes for assembly.
In a vacuum cleaner having a turbine for rotating the brush, the
turbine is normally installed in a turbine chamber formed in an air passage
en route from the dust suction port of the head to the air outlet of the head,
so that the turbine is rotated by the air flow through it. As a result, dust
can accumulate in the turbine chamber, hindering the rotation of the
turbine.
In order to overcome these problems, a new rotational brush was
disclosed in such early Japanese patent publications as No.9-28630. The
brush has two turbines mounted on the opposite ends thereof. The
turbines are rotated by fresh air taken into the chamber. The fresh air is
then taken into the vacuum chamber together with the air sucked from the
dust suction port of the head.
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In this arrangement, since the two turbines are required on the
opposite end of the rotational brush, they require a number of extra parts
and must be designed so as not to lose dust suction power even while much
air is sucked to rotate the two turbines. In other words, the turbines must
be designed so that is can rotate by a small amount of air. However, such
turbines are likely to fail to rotate at a desired speed when the head is
placed on a resistive carpeted floor, for example. Furthermore, the dust
suction port formed in the bottom of the turbine chamber is limited in
length, since it is di~cult to form a dust suction port right under the
turbines. As a result, the head, having a much smaller width than the
dust suction head, can sweep only a limited area of the floor, leaving dust
behind it.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention is to provide a dust
suction head for use in an electric vacuum cleaner, which is simple in
structure and yet capable of driving its rotational brush e~ciently
There is provided, in accordance with one aspect of the present
invention, a dust suction head for use in an electric vacuum cleaner,
comprising:
a body having in the bottom thereof an air suction port;
a brush chamber formed in said body;
a freely rotational brush mounted on a shaft within said rotational
brush chamber and having a multiplicity of blades mounted on said shaft
along the length of said shaft such that said blades extend closely to said
dust suction port; and
an opening formed in said body for taking in fresh air and guiding the
fresh air to said blades so as to rotate said rotational brush.
In this arr angement, fresh air may be introduced from the opening onto
the blades of the rotational brush to thereby rotate the brush without a
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turbine for driving the brush as in the prior art. The rotational force
provided by the fresh air may prevent the blades of the brush from sticking
on a resistive floor such as a carpet, thereby facilitating a smooth move of
the dust suction head on the floor and improving operability of the dust
suction head.
In accordance with another aspect of the invention, there is provided a
dust suction head for use in an electric vacuum cleaner, comprising:
a body having in the bottom thereof an air suction port;
a brush chamber formed in said body;
a freely rotatable brush (hereinafter referred to as rotational brush)
mounted on a shaft within said brush chamber and having a multiplicity of
blades mounted on said shaft along the length of said shaft such that said
blades extend closely to said dust suction port; and
an opening formed in said body at a position ahead of said rotational
brush, for taking in fresh air and guiding the fresh air to said blades so as
to
rotate said rotational brush.
In this example, fresh air may be introduced from the opening, as in the
preceding example, and further onto the blades of the rotational brush that
are situated ahead of the shaft, to thereby facilitating the rotation of the
brush more efficiently without resorting to a turbine for driving the brush
as in the prior art. The rotational force provided by the fresh air may
prevent the blades of the brush from sticking on a resistive floor such as a
carpet, thereby facilitating a smooth move of the dust suction head on the
floor and improving operability of the dust suction head.
In this example, an air passage may be provided for leading the fresh
air from the opening to the blades located below the shaft of the rotational
brush. Such air passage facilitates counter-clockwise rotation of the brush
when the fresh air is drawn past the downward blades into the body of the
vacuum chamber. The air passage further has an advantage that the fresh
air will blow up the dust in the stream of air into the vacuum chamber.
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At least a portion of the blades of the rotational brush may be made of a
material having poor permeability (such material will be hereinafter
referred to as non-permeable material) so that the fresh air from the
opening may be efficiently captured by the blades thereby providing a larger
torque to the rotational brush.
The blades are preferably bent or inclined in the direction opposite to
the direction of the rotation. Such bent or inclined blades may receive the
fresh air afficiently, so that they may acquire larger torques. Thus, if the
dust suction head is placed on the floor, the rotational brush can promptly
start rotation.
The opening is preferably provided in the central portion (i.e. center of
the width) of the body of the dust suction head. The fresh air, thus, taken
in from the central opening will impinges on the central portion of the
rotational brush at a high fluid velocity, since the fluid velocity of the air
is
maximum near the connection tube which is close to the central portion of
the rotational brush 11. Hence, the central opening facilitates efficient
rotation of the brush 11.
The air passage is preferably formed to lead the fresh air to the blades
ahead of the shaft of the rotational brush. In this case, the opening may be
positioned at any convenient point of the upper case, so that the body may
have a neat configuration. For example, the opening may have a
configuration which is convenient to lead the fresh air in the direction which
coincides with the rotation of the brush and onto the blades so as to prompt
the rotation of the blades.
An air guide may also be formed to guide the fresh air from the opening
to a point below the shaft of the rotational brush so that all of the fresh
air
impinges on the blades from below thereby driving the blades in the
direction of rotation of the brush. Thus, when the fresh air is drawn into
the vacuum chamber together with the air taken in from the dust suction
port, it facilitates the rotation of the blades.
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The blades of the rotational brush may be mounted on the shaft in a helical
configuration to spiral in one direction, for example. At the same time the
opening
may also be formed in the form of a spiral which spirals in the opposite
direction of
the blades. The blades and the flow of fresh air then cross each other so that
many of
the blades receive the fresh air evenly while the fresh air is delivered to
them. This
also contributes to the efficient rotation of the brush.
The brush chamber preferably has a round transverse cross section (in a plane
perpendicular to the axis of the shaft of the rotational brush). Such simple
design of
the brush chamber renders the configuration of the dust suction head simple
and
compact.
The rotational brush is preferably movable in the vertical direction. Then the
tips of the rotational brush may be adjusted in height in response to
protrusions and
recesses on the floor, so that the rotational brush always acquires an optimum
level
and may carry out efficient brushing of the floor.
The shaft of the rotational brush may be provided with additional blades for
receiving the fresh air to help the rotation of the brush. The additional
blades will
function as a turbine to promote the rotation of the brush.
In another aspect of the invention, there is provided a dust suction head for
use
in an electric vacuum cleaner, comprising: a body having in the bottom thereof
an
air suction port; a brush chamber formed in said body; a freely rotatable
rotational
brush mounted on a shaft within said brush chamber and having a multiplicity
of
flexible blades mounted on said shaft along the length of said shaft; and an
opening
formed in an upper portion of said body for taking in fresh air and guiding
the fresh
air to said blades so as to assist rotation of said rotational brush.
In a further aspect of the invention, there is provided a dust suction head
for use
in an electric vacuum cleaner, comprising: a body having in the bottom thereof
an
air suction port; a brush chamber formed in said body; a freely rotatable
rotational
brush mounted on a shaft within said brush chamber and having a multiplicity
of
flexible blades helically mounted on said shaft along the length of said
shaft; and an
opening formed apart from said suction port, for taking in fresh air, said
opening
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extending at an angle with said blades such that the fresh air is constantly
provided
obliquely to said blades regardless of the angular position of said rotational
brush.
In yet a further aspect of the invention, there is provided a dust suction
head
for use in an electric vacuum cleaner, comprising: a body having in the bottom
thereof an air suction port; a brush chamber formed in said body; a freely
rotatable
rotational brush mounted on a shaft within said brush chamber and having a
multiplicity of flexible blades mounted on said shaft along the length of said
shaft;
and an opening formed in said body for taking in fresh air and guiding the
fresh air
to said blades so as to assist rotation of said rotational brush, wherein said
blades are
formed such that said blades are bent away from a radial direction from said
shaft so
that said blades do not touch a floor to be cleaned when said rotational brush
is not
rotated, and said blades are extended by centrifugal force to touch the floor
when
said rotational brush is rotated.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the present
invention will be apparent from the following detailed description of the
preferred
embodiments of the invention reference being made to the accompanying drawings
in which like reference numerals indicate like parts throughout the figures
and in
which:
Fig. 1 is a side view of the first example of a dust suction head according to
the
invention.
Fig. 2 is a longitudinal cross section of the first dust suction head shown in
Fig.
1.
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Fig. 3 is a horizontal cross section of the first dust suction head shown
in Fig. 1.
Fig. 4 is a plan view of the first dust suction head shown in Fig. 1.
Fig. 5 is a vertical cross section of the first dust suction head shown in
Fig. 1.
Fig. 6 is a transverse cross section of the rotational brush of the first
dust suction head of Fig. 1, showing the condition of the rotational brush at
rest.
Fig. 7 is a transverse cross section of the rotational brush of the first
dust suction head of Fig. 1, showing the condition of the rotational brush in
rotational motion.
Fig. 8 is a transverse cross section of the second rotational brush for use
in a dust suction head according to the invention.
Fig. 9A and 9B show transverse cross sections of another exemplary
rotational brush of the invention when the brush is at rest (Fig. 9A), and
when the brush is in operation (Fig. 9B). Fig. 9C shows a detailed cross
section of the blades 15 of the rotational brush.
Fig. 10 is a transverse cross section of a still another rotational brush
for use in a dust suction head in accordance with the invention.
Fig. 11 is a longitudinal cross section of another dust suction head
according to the invention.
Fig. 12 is a plan view of the dust suction head shown in Fig. 11.
Fig. 13 is a longitudinal cross section of still another dust suction head
according to the invention.
Fig. 14 is a plan view of the dust suction head shown in Fig. 13.
Fig. 15 is a longitudinal cross section of a still another dust suction
means according to the invention.
Fig. 16 is a bottom view of the dust suction head shown in Fig. 15.
Fig. 17 is a partial cross section of the dust suction head taken on line
B-B of Fig. 16.
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Fig. 18 is a partial cross section taken on line C-C of a front part of the
dust suction head of Fig. 16.
Fig. 19 is a longitudinal cross section of a still another dust suction
means according to the invention.
Fig. 20 shows, in detail, the cross section of the rotational brush for use
in the dust suction head shown in Fig. 19 at rest (Fig. 20A) and in rotational
motion (Fig. 20B).
Fig. 21 is a longitudinal cross section of a still another dust suction
head according to the invention.
Fig. 22 is a plan view of the dust suction head of Fig. 21.
Fig. 23 is a longitudinal cross section of a still another dust suction
means according to the invention.
Fig. 24 is a horizontal cross section of the dust suction head of Fig. 23.
Fig. 25 is a plan view of the dust suction head of Fig. 23.
Fig. 26 is a longitudinal cross section of a still another dust suction
means according to the invention.
Fig. 27 is a front view of the dust suction head of Fig. 26.
Fig. 28 is a plan view of the dust suction head of Fig. 26.
Fig. 29 is a longitudinal cross section of a still another dust suction
head according to the invention.
Fig. 30 is a plan view of the dust suction head of Fig. 29.
Fig. 31 is cross section of a still another dust suction head according to
the invention.
Fig. 32 is a horizontal cross section of the dust suction head of Fig. 31.
Fig. 33 shows, in detail, a transverse cross section of the dust suction
head of Fig. 31.
Fig. 34 is a plan view of the dust suction head of Fig. 31.
Fig. 35 is a side view of the dust suction head of Fig. 31.
Fig. 36 illustrates a hand-held type dust suction head according to the
invention, in longitudinal cross section (Fig. 36A); in cross section taken on
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line D-D of Fig. 36A (Fig. 36B); and in cross section taken on line E-E of
Fig.
36A (Fig. 36C).
Fig. 37 illustrates another hand-held type dust suction head according
to the invention, a side view (Fig. 37A); and in front view as seen in the
direction of arrow F shown in Fig. 37A (Fig. 37B).
Fig. 38 illustrates still another hand-held type dust suction head
according to the invention, in longitudinal cross section (Fig. 38A); in cross
section taken on line G-G shown in Fig. 38A (Fig. 38B); and in cross section
taken on line H-H shown in Fig. 38A (Fig. 38C).
Fig. 39A and 39B show respectively a side view and a front view, as
seen in the direction of arrow I, of the dust suction head of Fig. 38.
Fig. 40 is a longitudinal cross section of a still another dust suction
head according to the invention.
Fig. 41 is a plan view of the dust suction head of Fig. 40 with its cover
removed.
Fig. 42 is partial longitudinal cross section of the dust suction head of
Fig. 40.
Fig. 43 is a bottom view of the dust suction head of Fig. 40.
Fig. 44 is a plan view of the dust suction head of Fig. 40.
Fig. 45 is a side view of the dust suction head of Fig. 40.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figs. 1-7, there is shown a first exemplary dust suction
head 1. The dust suction head 1 includes an upper case 2, a lower case 3, a
lid 4 which is removably mounted on the upper case 2 and the lower case 3,
a rotatable tube 5 which is supported in vertically movable condition
between the upper case 2 and the lower case 3, and a connection tube 6
rotatably supported by rotatable tube 5.
The body 1 is provided in the bottom thereof with an air suction port 7,
a brush chamber 8 for accommodating a rotational brush 11 inside the body
H
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1.
Located on the opposite sides of the body 1 are shaft supports 9, which
rotatably support wheels 27 as described later.
A pair of partitioning ribs 10 are formed to extend from the upper and
the lower cases 2 and 3, respectively, for partitioning the chamber 8 from
the shaft supports 9, so as to prevent air from being drawn into the brush
chamber 8 through the shaft supports 9.
The freely rotational brush 11 is installed in the brush chamber 8,
facing the air suction port 7. The rotational brush 11 consists of a shaft 12,
two pairs of spiral blades 15 and 16 mounted on the shaft 12 with the bases
14 of the blades inserted in spiral grooves 13 formed along the length and on
the surface of the shaft 12.
Formed at the opposite ends of the shaft 12 of the rotational brush 11
are protruding arbors 112. Holding caps 111 are secured on the protruding
arbors 112 for keeping the first and the second blades 15 and 16,
respectively, in position. The protruding arbors 112 are rotatably supported
by respective bearings 113 mounted on the partitioning ribs 10.
In the example shown herein, each of the first pair of blades 15 has a
form of brush. Each of the second pair of blades 16 is composed of a fabric
17 and a plastic base 18 molded at one end of the fabric 17. The base 18 is
secured in the spiral groove 13. Stitched on the other end of the base 18 is
a brush member 19. The base 18 is inserted in the spiral groove 13. The
fabric 17 is deformable, so they can bend along the length of the shaft 12.
The blade 16 is mounted on the shaft 12 in such a way that the tip of the
blade 16 is bent or curved in the direction opposite to the rotational
direction of the brush 11, that is, the blade 16 (or brush member 19) is bent
so as to capture air in the concave section thereof and to facilitate the
rotation of the brush 11.
Accordingly, each of the second blades 16 is bent towards the direction
of rotation of the brush 11 when the brush 11 is at rest or in motion at a low
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speed, as shown in Fig. 6. When the second blade 16 is rotated at a high
speed, it will stretch straight in the radial direction due to a centrifugal
force, as shown in Fig. 7.
Blades 15 and 16 are designed not to touch the floor when they are at
rest. The radii of the blades 16 are larger than those of blades 15 when
they are rotated at a high speed and fully extended in the radial direction.
In order to distribute fresh air in the brush chamber 8, the lid 4 is
provided with an opening 20 that extends the entire length of the blades 15
and 16. The lid 4 is also provided with a first rib 21 at the front side of
the
opening 20, a second rib 22 defining the bottom of opening 20, and a cover
24 above the second rib 22, with these members together defining the air
passage 26.
Afresh air induction port 23 is formed at the end of the air passage 26
in such a way that it projects downwardly and directly above the upper
front part of the circular locus of the blades 16.
A cover 24 is mounted on the hd 4 with latching pawls 25 so as to cover
and hide the fresh air induction port 23.
The air passage 26 formed by the first and the second rib 21 and 22,
respectively, and the cover 24 narrows as it extends from the opening 20 to
fresh air induction port 23.
A pair of front wheels 27 are mounted on the shaft supports 9. The
wheels 27 have substantially the same radius of the body 1 of the dust
suction head. Rear wheels 28 are mounted at the rear end of the body 1 of
the dust suction head.
Provided at the front and the rear ends of the air suction port 7 are a
pair of suction keepers 29. The suction keepers 29 are made of a resilient
material such as soft rubber. The suction keepers 29 prevent suction of air
from outside of air suction port 7, to thereby enhance suction of air from a
space between air suction port 7 and a carpet, for example, and sucking the
dust which has fallen deep in the carpet.
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In this arrangement, a free end of the connection tube 6 may be
connected to the body of the vacuum cleaner a via resilient hose and an
extension tube. If an electric blower, connected with the connection tube 6,
is operated, air is taken in from air suction port 7. When the body 1 is
lifted upward from the floor, most of air is taken in from suction port 7
since
then the suction port 7 is open free and the air flow resistance through the
suction port 7 is small. Under this condition, the velocity of air taken in
through the suction port 7 is relatively low and little air is introduced from
the opening 20, so that the rotational brush 11 is not rotated by the air
flow.
If the body 1 is placed on a floor such as tatami mat or a flooring to be
cleaned, a small gap is formed between the floor and the air suction port 7,
through which the air is drawn by the electric motor at a high speed,
creating a high speed air flow that impinges on the first and the second
blades 15 and 16, thereby rotating the brush 11 in the counter-clockwise
direction as shown in Fig. 2 and 5.
When the rotational brush 11 is at rest or in motion at a low speed, the
blades 16 is accelerated efficiently by the air taken in through the suction
port 7 and impinging thereon, since the blades 16 are curved towards the
direction of its rotation as shown in Fig. 6.
As the rotational brush 11 is rotated at a high speed, the blades 16 are
stretched to their full length by centrifugal forces, as shown in Fig. 7.
Under this condition, the blades 16 may touch a tatami mat or floor,
brushing it without hurting the floor, since the tips of the blades 16 are
brush member 19 stitched on the soft resilient fabric 17.
On the other hand, when cleaning a soft floor such as a carpet, the
suction port 7 is covered almost completely with the soft floor, increasing
the flow resistance of air that passes through the suction port 7, resulting
in
an increase in the air flow through the opening 20. The fresh air induction
port 23 has an extremely small cross section as compared with the suction
port 7, so that the air flow through the fresh air induction port 23 is passed
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onto the first and the second blades 15 and 16 of the rotational brush 11,
causing the brush 11 to be rotated in the counter-clockwise direction as
shown in Fig. 2 and 5.
Since the first and the second ribs 21 and 22, respectively, forming the
fresh air induction port 23, extend downwardly close to the circular locus of
the tips of the blades 16, the air taken in through the fresh air induction
port 23 will impinges on the blades 15 and 16, and then drawn into the
connection tube 6. Furthermore, since the fresh air induction port 23
extends straight in parallel with the shaft 12, the fresh air is induced to
various sections of the helical extending blades 15 and 16, irrespective of
the angular positions thereof, so that the blades 15 and 16 are accelerated
accordingly, and get rotated efficiently by the air.
The air flow generates noise as it is lead in a passage if the cross section
of the passage varies abruptly. Therefore, it would be appreciated that the
narrowing passage 26 only suppresses noise of the air flow as it leads the
fresh air from the opening 20 to the fresh air induction port 23. In addition,
the narrowing passage 26 increases the speed of air flow toward the air
induction port 23. Hence, the narrowing passage 26 provides an
accelerated air flow to the first and the second blades 15 and 16,
respectively, which facilitates efficient rotation of the brush 11.
The flow of air from the opening 20 may prevent the dust suction head 1
from adhering to the floor, thereby increasing the operability of the dust
suction head 1.
When the dust suction head is in operation on a carpet, frictional
resistance of the carpet can hinder the motion of the rotational brush 11 and
lower the speed of the bush 11. As the rotational brush is slowed down,
the centrifugal force acting on the blades 16 is reduced, so that the blades
16 begins to contract by restoring their original configurations, thereby
reducing the rotational radii thereof and hence the frictional resistance.
As a result, the rotational brush 11 restores its speed. Repeating these
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steps continuously, the rotational brush 11 may substantially maintain a
constant speed.
It would be remembered that each of the blades 16 has a brush member
19 stitched on the fabric 17. The brush member 19 may bend easily, and
its weight generates significant centrifugal force to extend the blade 16,
facilitating keeping the constancy of the rotational speed of the brush 11.
It would be apparent that the blades 16 may alternatively be formed of
an elastic material such as a rubber, instead of the fabric member 17, the
base 18 and the brush member 19.
In the example shown hereinabove, the air passage 26 is an elongate
slit. However, the air passage 26 may be divided into a multiplicity of
smaller slits in order to prevent the blades 15 and 16 from contacting the
first and the second ribs 21, and 22, respectively, when the lid 4 is bent
towards the inside of the brush chamber 8 caused by a negative pressure in
the brush chamber 8, especially when the strength of the lid 4 has lowered
after a long period of use.
It will be apparent to those skilled in the art that the rotational brush
11 is not limited to the example shown above: it may have many different
forms. For example, the first blade 15 may be formed by: a relatively hard
fabric member 31 which is bent at one end thereof, inserted in one of two
helical grooves 13 formed in the shaft 12, and secured therein by glue, for
example, thereby forming a base 14 of the blades; and a brush member
implanted at the free end of the fabric member 31, as shown in Fig. 8. The
second blade 16 may be formed and secured in one of another pair of helical
grooves 13 in the same manner as in the aforementioned example, but
without bending it.
In this case, the first blades 15 are mounted on the shaft 12 with their
tips inclined in the direction opposite to the rotational direction so that it
can be rotated easily by the air flow when it is at rest. Consequently, as
the brush 11 is rotated, the first blades 15 tend to stand upright on the
shaft
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12. Thus, the first blades 15, as shown in Fig. 8, play the same role as the
second blades 16, as described in the preceding example, in keeping the
rotational brush 11 at substantially a constant speed.
Fig. 9 shows another example of a rotational bush 11 of the invention.
The rotational brush 11 includes an extruded aluminum shaft 12 having
four helical grooves which are cut along the length of the shaft 12 and are
angularly spaced apart by 90" about the axis of the shaft 12. The
rotational brush also includes the first and the second sets of blades secured
alternately in the grooves. Thus, the blades have the same helical
configuration as the grooves. In addition, the first pair of the blades 15 are
disposed on the opposite sides of the shaft 12 to keep them in good balance,
and so are the second pair of the blades, thereby providing smooth rotation
of the rotational brush 11.
The first blades 15 are each made of a soft resilient impermeable
matex2al such as soft polyvinyl chloride (PVC) or soft rubber (e.g. urethane
rubber) integral with the base 14. Formed on both sides near the tips of
the first blades 15 are a multiplicity of projections 15a and 15b extending
along the length thereof, as shown in more detail in Fig. 9C. The length of
the first blades 15 between the root and the tips thereof is a little smaller
than the corresponding length of the second blades 16 and is about the same
as the length of long plush of a carpet sucked into the rotational bush.
On the other hand, each of the second blades 16 is formed of a non-
permeable soft fabric 17, a molded plastic base 18 at one end of the fabric 17
and a blush member 19 stitched at the other end of the fabric 17. The
fabric 17 having the molded base is soft enough to bend and waves along the
shaft 12 together with the stitched brush member 19 . The second blade 16
is secured on the shaft 12 such that it is generally bent in the direction of
the rotational of the brush 11 (counter-clockwise direction) as shown in Fig.
9A when it is at rest. When the rotational brush 11 is at rest, the first and
the second blades 15 and 16 will not touch the floor if the dust suction head
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is placed on the floor.
The second blade 16, which is bent as described above when it is at rest
or in rotation at a low speed, will be straighten in the radial direction when
it is rotated at a high speed due to centrifugal force, as shown in 9B, so
that
the tip of the second blade 16 extends beyond the circular locus of the first
blades 15 and touches the floor.
In the example shown in Fig. 9, the first blades 15 are mounted upright
on the shaft while the second blades 16 are bent when the brush 11 is
stopped. However, the first blades 15 may alternatively bent and the
second blades 16 are upright as shown in Fig. 10. Further, both the first
and the second blades 15 and 16 may be bent and inclined on the shaft.
Figs. 11 and 12 illustrate another example of a dust suction head 1 of
the invention. The example shown in Figs. 11 and 12 differs from the
preceding one in that an opening 20 is formed in a case of the dust suction
head 1 at a position ahead of the shaft of the rotational brush 11.
In this arrangement, the rotational brush 11 may operate in just the
same manner as in the preceding example when the dust suction head 1 is
placed on or removed from a flat soft floor such as a carpet. However, in
this example, the opening 20 provides fresh air to the front end of the
rotational brush 11, so that the air flows in the same direction as the
rotational direction of the rotational brush 11 before it is drawn into a
connection tube 6, which facilitates efficient rotation of the rotational
brush
11.
It would be appreciated that the case of the dust suction head 1 has a
simple structure to cover the rotational brush 11 with a case having an
inner diameter which is substantially the same as the radii of the blades.
Referring to Figs. 13 and 14, there is shown a still another example of
the invention. The example shown in Figs. 13 and 14 differs from the
aforementioned example in that the upper potion of the case 2 extends
below the level of the shaft for the rotational brush 11, and a rib 32 is
CA 02245978 1998-08-26
provided to depend from the cover 2 in front of the rotational brush 11 to
allow the fresh air to reach a fresh air induction port 23 between the rib 32
and a front wall 33 of the case 2.
In this arrangement, although the rotational brush 11 operates in the
same manner as in the preceding examples, the fresh air entering the brush
chamber from the fresh air induction port 23 is allowed to impinge on the
floor in front of the rotational brush 11 at a high speed, blowing the dust
off
the floor, and at the same time driving the blades 15 and 16 in the counter-
clockwise direction, thereby leading the dust into the connection tube 6.
In this manner, by providing fresh air through the opening 20 and the
fresh air induction port 23, the dust suction head 1 is prevented from
adhering to the floor if the air suction port 7 is completely covered with a
carpet, for example. Furthermore, the fresh air facilitates removal of dust
off the floor as described above.
Referring now to Figs. 15, 16 and 17, there is shown still another
example of the invention.
In Figs. 15-17, mounted on the front end of the dust suction head 1 is a
bumper 35, made of a resilient material such as soft rubber, for protecting
furniture and the like and the dust suction head itself from being dented in
case the dust suction head bumps against the furniture.
The shaft 12 of the rotational brush 11 is provided at the opposite ends
thereof with protruding arbors 112, which are supported by respective
bearings 113. The bearings 113 are each mounted in vertical grooves 114
formed in the partitioning ribs 10, so that the rotational brush 11 is allowed
to slide vertically
Each of the bearing 113 has an upward protrusion 115 which opposes a
protrusion 116 formed on the back of the lid 4 so as to hold a coil spring
117.
The coil spx2ngs 117 bias the bearings 113 downward, as shown in Fig. 17.
The springs 117 are hard enough to support the weight of the rotational
brush 11 and soft enough to be contracted when they are pushed by
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CA 02245978 1998-08-26
protrusions on the floor and adjust the vertical level of the rotational brush
11 in the grooves 114.
Each of the bearings 113 also has a downward protrusion having a
length substantially equal to that of the first blades 15. The protrusion
has, at the lower end thereof, an abutment face 118 that barely touch the
floor when the bearing 113 is forced to the lowest position in the groove 114
by the associated coil spring 117.
Fig. 17 depicts a condition in which the lower end of the protrusion 118
is slightly lifted by plush of a carpet, for example. However, when the dust
suction head is placed on a hard flat floor and hence the bearings 113 are
lowered to the lowest position, the blades 15 then touch the floor and brush
up and/or polish the floor.
The rotational brush 11 shown in the example operates in the same way
as the preceding ones. In addition, the bearings 113 are held so that the
abutment surfaces 118 are always in touch with the floor. As a result, tips
of the first and the second blades 15 and 16 are respectively positioned at
the most preferable height for sweeping lint and dust on the floor and at the
same time preventing the dust suction head from adhering to the floor.
That is, the tips of the blades are kept to lightly touch the floor.
On the other hand, if the floor is carpeted, the abutment surfaces 118
are lifted a little by the plush of the carpet. As a result, the blades are
kept
at an appropriate depth in the carpet to remove lint and dust therein while
preventing the blades 15 and 16 from being caught by excessive friction in
the carpet.
Thus, the rotational brush 11 may be held at an optimum height for a
particular type floor and may prevent cluttering noise caused by hard
vertical vibrations of the rotational brush 11 during its operation, since the
bearings 113 are biased downward by the coil springs 117.
It will be understood that the invention is not limited to the coil springs
117 and that it can be replaced by any biasing means such as resilient
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CA 02245978 1998-08-26
members mounted in any arbitrary manner.
Referring now to Fig. 18, there is shown a still another example of the
invention. The dust suction head shown in Figs. 15-17 differs from the
preceding ones in that the rotational brush 11 is biased downward by the
weight of the rotational brush 11 itself without using coil springs 117 in
biasing the bearings 113 of the rotational brush 11.
In this arrangement, the protrusions 115 and 116 and the coil springs
117 are advantageously eliminated so that the dust suction head is
simplified in structure and becomes less costly.
It will be noted that the advantages of the preceding examples are also
attained in this example. That is, the height of the rotational brush 11
may be appropx2ately adjusted for a particular type of floor without the coil
springs 117, if the weight of the rotational brush 11 is appropriately
increased. Therefore, cluttering of the rotational brush 11 due to its
irregular vibrations in the groove may be prevented.
Referring now to Figs. 19 and 20, there is shown a further example of
the invention. In this example, the shaft 12 is provided with four helical
rotor blades 12b extending between two neighboring blades 15 and 16.
These rotor blades 12b may be fabricated integral with the shaft 12 when
the shaft 12 is fabricated, or fabricated independently of the shaft 12 and
later secured in respective four helical grooves formed along the length of
the shaft 12. These rotor blades 12b are adapted to receive the air flow that
impinges on the rotational brush 11 and facilitate the rotation of the brush
11. The shaft 12 is acted on by an extra rotational force by the rotor blades
12b.
Thus, the dust suction head 1 may operate in the same way as in the
preceding example, but in a more efficient way owing to the rotor blades 12b
since the rotational blades 12b act as a turbine.
Referring now to Figs. 21 and 22, there is shown a still further example
of the invention. The example shown herein differs from the previous one
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CA 02245978 1998-08-26
in that ribs 41 and 42 are provided at the front end of the upper case 2.
The ribs 41 and 42 together forms a nozzle shaped opening 40 for the fresh
air. A guide 43 is formed on the lower cover 3, facing the opening 40, so as
to lead the fresh air from the opening 40 to the rotational brush 11.
In this example, if the dust suction head 1 is placed on a floor as shown
in Fig. 22, the fresh air is guided by the guide 43 from the opening 40 to the
blades 15 and 16 depending downward from the shaft 12, thus, providing
the rotational brush 11 with a large torque.
Other features of the dust suction head shown in the Figures are the
same as those described in conjunction with the preceding Figures.
Referring to Figs. 23-25, there is shown a still further example of the
invention. This example has a feature that a set of turbines 50 are
provided on the shaft 12 at the opposite ends of the rotational brush 11, as
shown in Fig. 24. The rotor blades 51 of the turbines 50 are designed to
receive the fresh air delivered from an air passage 56, as described in more
detail later, so as to rotate the brush 11 in the clockwise direction as
viewed
in Fig. 1.
An elongate slit or opening 53 for taking in the fresh air is formed in the
lid 4. The elongate opening 53 extends along substantially the entire
length of the rotational brush 11 and the turbines 50. Formed at the front
and rear ends of the opening 53 are the first and the second ribs 54 and 55,
respectively, forming together an air passage 56 for guiding the fresh air
taken in from the elongate opening 53 to the blades 15 and 16 of the brush
as well as to the rotor blades 51 of the turbines 50. The ribs 54 and 55
depend downward from the lid 4 to a point which is a little ahead of the
shaft 12 and above the locus of the blades 15, 16 and 51.
The lid 4 may be removed from the body by pulling buttons 4a, as
shown in Fig. 25, for an access to the rotational brush 11 and the turbines
50 for maintenance thereof.
The front wheels 27, mounted on a front shaft support 9, have
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CA 02245978 1998-08-26
substantially the same radius as the substantially round body of the dust
suction head 1. Mounted at the rear end of the dust suction head 1 are
rear wheels 28 having a smaller diameter.
A connection tube 6 is connected with the dust suction head 1 via a
flexible hose and an extension tube. When the dust suction head 1 is
placed on a floor, the vacuum cleaner operates substantially in the same
manner as in the previously described examples.
When cleaning a soft floor such as a carpet, the air suction port 7 is
covered with the floor, which increases air friction through the air suction
port 7, which in turn increases the amount of fresh air taken in from the air
passage 56 of the upper lid 4. Since the air induction port 57 has a much
smaller aperture than the air suction port 7, the fresh air from the fresh air
induction port 57 acquires a much higher fluid velocity than through the air
suction port 7 and impinged with that speed on the rotational rotor blades
51 of the turbine 50 as well as to the blades 15 and 16, driving them to move
in the clockwise direction as seen in Fig. 1. The blades 15 and 16 and the
rotational brush 11 are accelerated by the force acting thereon, in addition
to a rotational force acting on the turbine 50. Thus, the rotational brush
acquires a desirable rotational force necessary for cleaning a soft,
frictional
floor.
Since the first rib 54 is arranged to depend downwardly from the front
end of the fresh air induction port 57 as described above, it prevents the
fresh air from escaping out into a front space ahead of the rotational brush
11 and guides the fresh air directly onto the blades 15 and 16, thereby
facilitating the rotation of the brush 11.
Similarly, since the second rib 55 depends from the rear end of the fresh
air induction port 57 as described above, it prevents the fresh air from
escaping out into a space above the rotational brush 11 without interacting
therewith and guides the fresh air directly onto the blades 15 and 16,
thereby, facilitating the rotation of the brush 11.
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CA 02245978 1998-08-26
It is noted that the brush chamber 8 has a substantially cylindrical
cross section to prevent the fresh air impinging on the blade 15 and 16 from
diverging away therefrom, thereby facilitating continuous rotation of the
brush 11.
The air passage 56 extends over the length of the turbine 50 on the
opposite ends of the rotational brush 11, so that no extra air suction port is
necessary for the turbine 50. This is an advantage in manufacturing the
dust suction head 1 at low cost.
Since the air passage 56 is provided in the top end of the body 1, it is
not blocked by a wall while cleaning the floor close to the wall, so that a
rotational force on the blades 15 and 16 of the rotational brush 11 is always
available.
As an ancillary aspect of the invention, fresh air from the air passage 56
may prevent the head 1 from excessively adhering to the floor, and hence,
improve mobility of the body 1.
As in the previous example, the rotational brush 11 of this example may
also be stretched or bent smoothly even when the rotational speed of the
rotational brush 11 fluctuates.
Figs. 26 through 28 show another example. In this example, an
opening 58 is formed on the front end of the body 1, in contrast to the
previous examples in which the opening 53 is formed in the top section of
the lid 4. In particular, the opening 58 can be a slit having substantially
the same length as the rotational brush 11 plus the turbine 50, and is
formed in the front end of the lower case 3 below the bumper 35.
The lower case 3 has a thick wall section at its front end. An upper
wall 59 and an bottom wall 60 extend from the front opening 58 in
substantially parallel relationship towards the inside thereof. A fresh air
induction port 62 is formed inside the brush chamber 8. The upper wall 59
and the bottom wall 60 correspond to the first rib 54 and the second rib 55 of
the preceding example. They guide the fresh air taken in from the air
21
CA 02245978 1998-08-26
passage 61 to the front of the rotational brush 11 and then onto the lower
blades 15 and 16 of the rotational brush 11.
The advantages discussed in the preceding example may be obtained
with this dust suction head 1. In particular, when the fresh air from the
air passage 61 impinges on the blades 15 and 16 which are in contact with
the floor such as a carpet, the air forces the blades in the rotational
direction, thereby preventing loss of rotational speed of the rotational brush
11.
It would be understood that the projecting bumper 35 ensures suction
of air through the opening 58 while cleaning the floor adjacent a wall if the
opening 58 is formed in the front end of the lid 4 as described above.
Figs. 29 through 30 show a still further example of the invention.
In this example, no air suction port is provided, but an air passage 64 is
formed under the lower front end of the head 1 in the form of a wide gap
such that the gap is not blocked by long plush of a carpet, for example, even
when the head 1 is placed on the carpet. A guide is formed at the front
edge of the air suction port 7 for guiding the air sucked from the front gap
(air passage 64) to the lower blades 15 and 16.
Specifically, the air suction port 7 is formed with its front edge 65
shorter than the rear edge of the air suction port 7 and with the tip of the
front edge 65 pointing to a lower section of the rotational brush 11. As a
result, the lower front end 66 of the lower case 3 is positioned at a higher
level than those of conventional ones, so that a gap (air passage 64) is
always formed by the front edge 65 and an air guide is formed under the
curved front end 66 for leading the air to the lower blades 15 and 16 even
when the dust suction head 1 is placed on a carpet having long plush.
In the example shown here, perforated openings 4b for a turbine 50 (Fig.
30) are provided on the opposite ends of the rotational brush 11 in order to
take advantage of the air guide formed at the front end of the air suction
port 7. Formed on the back of these perforated openings 4b are air guides
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CA 02245978 1998-08-26
(not shown) for guiding fresh air onto the rotor blades 51 of the turbine 50
(forward).
In this arrangement of the body 1, the same effect may be obtained as
in the preceding examples. In particular, fresh air taken in from the air
passage 64 impinges on the blades 15 and 16 which are in contact with the
floor such as a carpet. The air forces the blades to rotate in the forward
direction (i.e. natural rotational direction of the blades), thereby
effectively
preventing loss of rotational speed of the brush 11 that can arise from the
friction of the carpet.
It is noted that this design requires no opening in the body 1, so that
the head 1 may be manufactured at a lower cost. In addition, the openings
4b provides fresh air for efficient acceleration of the turbine 50 and hence
the rotational brush 11.
Figs. 31 through 35 show a still further example of the invention.
This example is similar to the preceding one shown in Fig. 23 in that an
opening 53 is formed in the upper lid 4 and depending ribs 54 and 55 formed
at the front and the rear ends of the opening 53, respectively. The ribs 54
and 55 together form an fresh air induction port 57 for guiding fresh air
from the air passage 56 into the brush chamber 8. But this example differs
from the preceding one in that the opening 53 has only a limited length
which is equal to the length of the rotational brush 11 as shown in Fig. 34.
In this example, an extra opening 53 is provided on both sides of the
body 1, instead of forming an elongate opening along the entire length of the
rotational brush 11 and the turbine 50 or providing an opening 4b at the
upper front ends of the lid 4 as in the previous example.
Each of the front wheels 27 has a radial air suction port 27a similar to
that shown in Fig. 35. Openings 9a and 10a are also formed through the
bearing 9 of the head 1 and partitioning ribs 10 as shown in Fig. 32.
Mounted on the opposite ends of the rotational brush 11 are propeller
fan type turbines 50a whose rotor blades 51a are adapted to rotate in the
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CA 02245978 1998-08-26
clockwise direction as seen in Fig. 33 when fresh air is taken through the
openings 27a, 9a, and 10a.
This arrangement has the same advantages as the previous ones. It is
suited for smooth rotation of the propeller fan type turbines 50a and of the
rotational brush 11.
Figs. 36 and 37 show a still further example of the invention.
The invention shown herein is a hand-held type dust suction head
suited for cleaning a sofa, for example.
A dust suction head 100 includes a main case 101, a connection tube
106 rotatably supported at one end thereof by the main case 101. In
contrast to the previous examples which require a rotatable tube 5 for
rolling the dust suction head over a floor forward and backward, this
example needs no such rotatable tube since this dust suction head is moved
in the longitudinal direction of the head.
An air suction port 107, similar to the preceding one, is formed in the
bottom of the dust suction head 100 (main case 101) for the rotational brush
11. A substantially cylindrical brush chamber 108 is formed inside the
main case 101 for accommodating the rotational brush 11.
The rotational brush 11 is rotatably supported in the brush chamber
108. A propeller fan type turbine 50a is mounted on one end of the
rotational brush 11.
In order to provide the turbine 50a with fresh air, an opening lOla is
formed in one end of the main case 101 facing the turbine 50a.
The rotor blades 51a of the turbine 50a are adapted to rotate in the
clockwise direction as seen in Fig. 36C while sucking air through the
opening lOla. As shown in Fig. 36A, the blades 15 and 16 are also
arranged to rotate together with the turbine 50a when it is accelerated by
the fresh air coming from the opening lOla and the air suction port 107.
That is, the blades 15 and 16 are curved to spiral along the shaft of the
brush 11 such that they are acted on by a rotational force by the air
24
CA 02245978 1998-08-26
streaming from the opening lOla to the connection tube 106.
As a result, in addition to the rotational force applied by the turbine 50a,
the rotational brush 11 acquires a desirable rotational force acting on the
blades 15 and 16 themselves. The rotational forces on the blades
effectively facilitate rotation of the brush 11, especially, when it is
operated
on a very resistive floor such a sofa.
Figs. 38 and 39 show a still further example of the invention, which has
the same feature of the example described in conjunction with Fig. 36 and
37. In this example, the invention further comprises an air passage 126
connected with an upper opening or slit 122. The slit 122 has a length
along the entire length of the rotational brush 11, in just the same manner
as in the preceding example. The slit 122 is formed in the main case 101
and offset a little from the very top of the case 101 in the rotational
direction
of the brush 11. The first and the second ribs 123 and 124 are respectively
formed on both sides of the air passage 126 for guiding the fresh air from
the air passage 126 to the blades 15 and 16 to assist the rotation thereof.
An outlet mouth 125 is formed at the tips of the ribs 123 and 124.
The dust suction head 1, having this arrangement, has an advantage
over the preceding one in that this head can provide a further enhanced
torque on the rotational brush 11.
Figs. 40 through 45 show a still further example of the invention,
applied to a general dust suction head for cleaning a floor. This example
differs from the ones shown in Figs. 23 through 35 in that the brush
chamber 8a has a non-cylindrical configuration and that the front wheels
27a are smaller and the rear wheels 28a are larger than previous ones,
respectively. This dust suction head, however, has the same basic
structure as the previous ones in that this also has a turbine 50 on the
opposite ends of the rotational brush 11.
A feature of this example lies in the fact that, as shown in Fig. 42, a
brush member 15a is mounted on each of the rotational rotor blades 51 of
CA 02245978 1998-08-26
the turbine 50, and that an air suction port 7a extends over the entire
length of the rotational brush 11 plus the turbine 50 as shown in Fig. 43.
Like the blades 15 mounted on the rotational brush 11, each of the brush
member 15a may be formed of nylon or polyethylene. The tip portion of the
brush member 15a stretches straight so as to sweep dust on a floor due to
centrifugal force acting on it as the turbine 50 is rotated at a high speed.
It is noted that an elongate opening or slit 53a is formed in the lid 4 of
the body and along substantially the entire length of the rotational brush 11.
As in the previous examples, the first and the second ribs 54a and 55a are
respectively formed at the front and rear ends, respectively, of the slit 53a
for guiding the air taken in from the slit 53a to the blades 15 and 16 of the
rotational brush 11. The xzbs 54a and 55a together define an air passage
56a. The air passage 56a ends with a fresh air induction port 57a.
Perforated openings 4b are formed at the opposite ends of a lid 4. On
the back of each perforated opening 4b is a guide 4c formed for guiding fresh
air drawn through the opening 4b to the rotor blades 51 (forward) of the
turbine 50 as shown in Fig. 42.
Thus, the rotational force acting on the blades 15 and 16 themselves as
well as the rotational force of the turbine may together provide a torque
needed for the rotational brush 11 to clean a frictional floor such as a
carpet.
Since the elongate air suction port 7a extends over the turbine, the dust
swept by the brush member 15a mounted on the turbine 50 may be well
removed.
In the example shown herein, the brush members 15a may be replaced
by blades, or by a combination of the brush members 15a and the rotor
blades 51.
Also, the rotational brush 11 may have only the blades 15 or the blades
16. If the rotational brush 11 is formed solely of non-permeable blades 16,
the rotational force will be further enhanced, but the blades 15 made of a
permeable material will normally be adequate in acquiring a required
26
CA 02245978 1998-08-26
rotational force to clean a carpet for example, because the blades 15 are
assisted by the turbine 50.
z7
