U.S. patent application number 12/294432 was filed with the patent office on 2009-05-28 for vacuum cleaner.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Hirokazu Matsushita, Atsushi Morishita, Ritsuo Takemoto, Yoshihiro Tsuchiya.
Application Number | 20090133212 12/294432 |
Document ID | / |
Family ID | 38563410 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090133212 |
Kind Code |
A1 |
Morishita; Atsushi ; et
al. |
May 28, 2009 |
VACUUM CLEANER
Abstract
A vacuum cleaner includes an electric blower that sucks dust
through a suction connecting port, a first dust separating unit for
separating the dust and air sucked into the suction connecting port
from each other, and a pleat filter for separating the dust and air
passing through a first dust separating unit. The vacuum cleaner
further includes an external-air introducing air passage for
introducing external air toward an upstream side of the pleat
filter, a rotational fan for dropping off dust adhering to the
pleat filter by the introduced external air, and a return air
passage for returning the dust dropped off from the rotating fan
toward the upstream side of the first dust separating unit by the
introduced external air.
Inventors: |
Morishita; Atsushi; (Tokyo,
JP) ; Takemoto; Ritsuo; (Tokyo, JP) ;
Matsushita; Hirokazu; (Tokyo, JP) ; Tsuchiya;
Yoshihiro; (Tokyo, JP) |
Correspondence
Address: |
DLA PIPER LLP US
P. O. BOX 2758
RESTON
VA
20195
US
|
Assignee: |
KABUSHIKI KAISHA TOSHIBA
Minato-Ku, Tokyo
JP
TOSHIBA CONSUMER ELECTRONICS HOLDING CORPORATION
Chiyoda-ku, Tokyo
JP
TOSHIBA HOME APPLIANCES CORPORATION
Chiyoda-ku, Tokyo
JP
|
Family ID: |
38563410 |
Appl. No.: |
12/294432 |
Filed: |
March 28, 2007 |
PCT Filed: |
March 28, 2007 |
PCT NO: |
PCT/JP2007/056581 |
371 Date: |
September 25, 2008 |
Current U.S.
Class: |
15/347 |
Current CPC
Class: |
A47L 9/20 20130101 |
Class at
Publication: |
15/347 |
International
Class: |
A47L 9/10 20060101
A47L009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2006 |
JP |
2006-099864 |
Claims
1. A vacuum cleaner comprising: an electric blower for sucking dust
through a suction connecting port; a dust separating unit for
separating the dust and air sucked into the suction connecting port
from each other to thereby collect the dust; a collecting unit for
collecting the dust passing through the dust separating unit, the
collecting unit being provided separately from the dust separating
unit; a dust removal unit for dropping off the dust collected by
the collecting unit; and a return mechanism for returning the dust
dropped off from the collecting unit by the dust removal unit
toward an upstream side of the dust separating unit, the dust
returned by the return mechanism being collected by the dust
separating unit.
2. The vacuum cleaner according to claim 1, further comprising an
external-air introducing air passage provided for introducing
external air toward the upstream side of the dust separating unit,
wherein the return mechanism has a return air passage configured to
return the dust dropped off from the collecting unit by the dust
removal unit toward the upstream side of the dust separating unit
by the external air introduced through the external-air introducing
air passage.
3. The vacuum cleaner according to claim 2, wherein the collecting
unit has a pleat filter, and the dust removal unit is provided with
a rotating fan contacting the pleat filter and driven by the
external air introduced from the external-air introducing air
passage to thereby drop off dust collected by the pleat filter.
4. A vacuum cleaner comprising: an electric blower for sucking dust
through a dust suction port; a first dust separating unit for
separating the dust and air sucked into the dust suction port from
each other; a second dust separating unit for separating the dust
and air passing through the first separating unit; a first blocking
unit for blocking an air passage located on a downstream side of
the second dust separating unit and on an upstream side of the
electric blower; a second blocking unit for blocking an air passage
between the first dust separating unit and the second dust
separating unit; a detour air passage communicating an upstream
portion of the electric blower with a downstream portion of the
first dust separating unit; a third blocking unit for blocking the
detour air passage; a dust removal unit for dropping off the dust
adhering to the second dust separating unit; an external-air
introducing air passage for introducing external air toward the
upstream side of the second dust separating unit; a control unit
for controlling the first, second and third blocking units; and a
return air passage for returning the dust dropped off by the dust
removal unit toward the upstream side of the first dust separating
unit by the external air introduced from the external-air
introducing air passage so that the returned dust is collected by
the first dust separating unit.
5. The vacuum cleaner according to claim 4, wherein the second dust
separating unit is provided with a pleat filter, and the dust
removal unit is provided with a rotating fan contacting to the
pleat filter and driven by the external air introduced from the
external-air introducing air passage to thereby drop off dust
collected by the pleat filter.
6. A vacuum cleaner comprising: an electric blower for sucking dust
through a dust suction port; a first dust separating unit for
separating the dust and air sucked into the dust suction port from
each other; a second dust separating unit for separating the dust
and air passing through the first separating unit; a first blocking
unit for blocking an air passage located on a downstream side of
the second dust separating unit and on an upstream side of the
electric blower; a second blocking unit for blocking an air passage
between the first dust separating unit and the second dust
separating unit; a dust removal unit for introducing external air
toward an upstream side of the second dust separating unit and
dropping off dust adhering to the second dust separating unit by
the external air; a detour air passage flowing the introduced
external air to a downstream side of the second dust separating
unit; and a third blocking unit for catching the dust passing
through the detour air passage together with the external air.
7. The vacuum cleaner according to claim 6, wherein the second dust
separating unit is provided with a pleat filter, and the dust
removal unit is provided with a rotating fan contacting to the
pleat filter and driven by the external air introduced by an
external-air introducing air passage to thereby drop off dust
collected by the pleat filter.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vacuum cleaner, and more
particularly, to a vacuum cleaner that prevents dust dropped off
from a collecting unit, such as a filter, for collecting dust, from
re-adhering to this collecting unit.
BACKGROUND OF THE INVENTION
[0002] There has hitherto been known a vacuum cleaner including a
cleaner body provided with a dust collecting container chamber
formed therein, a dust collection container detachably mounted to
the dust collecting container chamber, an electric blower provided
on the downstream side of the dust collecting container chamber, a
secondary filter, such as a pleat filter, detachably mounted to a
rear port of the dust collecting container, for collecting dust,
and a dust removal unit for dropping off dust adhering to the pleat
filter (refer to Japanese Unexamined Patent Application Publication
No. 2004-358135).
[0003] This dust removal unit includes a ring rotatably provided at
a position opposite to the pleat filter, and a projection provided
to a ring so as to abut against the pleat filter.
[0004] In this conventional vacuum cleaner, when a cord reel is
rewinding a power cord, the ring is rotated, and under the rotation
of the ring, the protrusion moves getting over mountain portions of
pleats of the pleat filter, to thereby give vibration to the pleat
filter so as to drop dust adhering to the pleat filter.
[0005] However, in such a vacuum cleaner, a problem was posed such
that dust dropped off from the pleat filter adheres again to the
pleat filter when the electric blower is driven.
DISCLOSURE OF THE INVENTION
[0006] Accordingly, it is an object of the present invention to
provide a vacuum cleaner that prevents dust dropped off from a
collecting unit, such as a secondary filter, for collecting dust,
from re-adhering to the secondary filter.
[0007] To achieve the above described object, a vacuum cleaner
according to one embodiment of the present invention includes: an
electric blower that sucks dust through a suction connecting port;
a dust separating. unit for separating the dust and air sucked into
the suction connecting port from each other to thereby collect the
dust; a collecting unit for collecting the dust passing through the
dust separating unit, the collecting unit being provided separately
from the dust separating unit; a dust removal unit for dropping off
the dust collected by the collecting unit; and a return mechanism
for returning the dust dropped off from the collecting unit by the
dust removal unit toward an upstream side of the dust separating
unit, the dust returned by the return mechanism being collected by
the dust separating unit.
[0008] According to the present invention, since the dust dropped
off from the collecting unit such as a secondary filter is returned
to and collected by the dust separating unit, it is possible to
prevent the dropped-off dust from re-adhering to the collecting
unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [FIG. 1] a perspective view showing an appearance of a
vacuum cleaner according to a first embodiment of the present
invention.
[0010] [FIG. 2] a longitudinal sectional view showing a structure
of a cleaner body shown in FIG. 1.
[0011] [FIG. 3] a perspective view showing a dust collecting unit
of the vacuum cleaner.
[0012] [FIG. 4] a perspective view showing a main part of the dust
collecting unit.
[0013] [FIG. 5] a cross-sectional view showing a structure of the
dust collecting unit shown in FIG. 4.
[0014] [FIG. 6] a perspective view of the dust collecting unit (in
FIG. 3), as viewed from a different direction.
[0015] [FIG. 7] a diagram showing an orientation of blades of a
rotating fan of a dust removal unit in the vacuum cleaner.
[0016] [FIG. 8] a conceptual diagram showing air passages in the
cleaner body shown in FIG. 1.
[0017] [FIG. 9] a longitudinal sectional view showing a structure
of the cleaner body according to a second embodiment of the present
invention.
[0018] [FIG. 10] a conceptual diagram showing air passages in the
cleaner body according to the second embodiment of the present
invention.
REFERENCE NUMERAL
[0019] 24 - - - electric blower [0020] 27a - - - suction connecting
port [0021] 52 - - - dust separation portion [0022] 55 - - - first
dust separation unit [0023] 104 - - - pleat filter [0024] 640 - - -
return air passage [0025] 650 - - - outside air introduction
passage [0026] 800 - - - rotating fan
BEST MODE FOR EMBODYING THE INVENTION
[0027] Hereunder, embodiments of a vacuum cleaner according to the
present invention will be specifically described with reference to
the accompanying drawings.
FIRST EMBODIMENT
[0028] FIG. 1 shows a vacuum cleaner according to a first
embodiment of the present invention. A vacuum cleaner 10 in the
first embodiment includes: a cleaner body 11; a dust collecting
hose 12 having one end detachably connected to a connection port
11a of the cleaner body 11 and the other end provided with a hand
operating tube 13; an extension tube 14 detachably connected to the
hand operating tube 13; and a suction port body 15 detachably
connected to the front end of the extension tube 14. The hand
operation tube 13 has an operating portion 13A, which includes a
drive/stop changeover switch 13a for switching between the drive
and the stop of the electric blower 24, and a strong/weak
changeover switch 13b for controlling the power of the electric
blower 24, described below. The cleaner body 1 has a body case 20,
which incorporates a dust collecting unit 50 and the electric
blower 24 (refer to FIG. 2). These dust collecting unit 50 and
electric blower 24 will be described hereinlater.
[0029] The suction port body 15 includes a dust suction port, not
shown, opened in the bottom surface of the suction port body 15 so
as to suck dust lying on a floor or the like, and a suction chamber
(not shown) communicating with the dust suction port. The suction
chamber communicates with a suction connecting port 57a of the dust
collecting unit 50 (refer to FIG. 3) provided within the cleaner
body 11, via the extension tube 14, the dust collecting hose 12,
and the connection port 11a.
[0030] A shutter 600 is provided within the connection port 11a of
the cleaner body 11, as shown in FIG. 2. The shutter 600 is
configured to block or open the connection port 11a.
[0031] As shown in FIG. 2, a dust collecting unit chamber 22 is
provided inside a front portion of the body case 20. The dust
collecting unit 50 is located in the dust collecting unit chamber
22.
[0032] The electric blower 24 is located inside a rear portion of
the body case 20 (i.e., on the left side in FIG. 2). In front of
the electric blower 24, a large-diameter connection air passage
portion 25 having a front opening 25B is provided. In a rear wall
25A of the connection air passage portion 25, there is formed a
connection opening 25b, which is connected with an air passage tube
500 having a small-diameter. The air passage tube 500 communicates
with a suction opening 24A of the electric blower 24. The air
passage tube 500 incorporates a first blocking unit, which is
constituted of, for example, a shutter 501. By the opening/closing
of the shutter 501, the suction opening 24A of the electric blower
24 and the inside of the connection air passage portion 25 takes a
communication state or a non-communication state.
[0033] Between the shutter 501 and the suction opening 24A, the air
passage tube 500 connects with one end of the detour air passage
tube 502, to thereby communicate with the detour air passage tube
502.
[0034] As shown in FIGS. 3 to 6, the dust collecting unit 50
includes a dust separation unit 400 and a dust collecting container
410.
[0035] The dust separation unit 400 includes a dust separation
portion 52 capable of separating the dust and air and collecting
the dust, and a collecting unit for collecting dust that has passed
through the dust separation portion 52. The collecting unit is
composed of, for example, a filter unit 80 and a lid case 21A
provided on the filter unit 80. The dust separation portion 52 is
configured to swirl air containing dust and separates the dust and
the air by virtue of inertia force. Details of these dust
separation portion 52 and filter unit 80 will be described
later.
[0036] The dust collecting container 410 is composed of a
transparent dust collecting portion 70 made of a resin and a lid
case 21B provided on the dust collecting portion 70.
[0037] As shown in FIG. 4, the dust separation portion 52 includes
a separating chamber 54 cylindrically formed by an outer peripheral
wall 53, a substantially conical first dust separating unit 55
provided in the separating chamber 54 along the axis line thereof,
a suction air passage portion 56 provided outside a right side wall
54A of the separating chamber 54, and a guide air passage tube 57
for guiding air to the separating chamber 54 from the suction
connecting port 57a through which the dust is sucked.
[0038] As shown in FIG. 2, the suction connecting port 57a
communicates with the connection port 11a of the cleaner body 11
via the shutter 600.
[0039] As shown in FIG. 5, in an upper portion of the outer
peripheral wall 53 of the separating chamber 54, there is provided
an introducing opening 53A for introducing the dust separated from
the air to the dust collecting portion 70.
[0040] Further, in the right side wall 54A of the separating
chamber 54, as shown in FIG. 4, a circular opening 154A and a
fan-shaped opening 154B are provided. To the opening 154A, the
first dust separating unit 55 is mounted, and to the opening 154B,
a net filter NF2 (not shown) is mounted. In the right side wall
54A, there is provided a connection opening 54Aa, to which a guide
air passage tube 57 is connected. Thus, the separating chamber 54
and the guide air passage tube 57 are communicated with each
other.
[0041] The first dust separating unit 55 is composed of a plurality
of frames 55a and a net filter NF1 bonded to the periphery of the
frames 55a. The suction air passage portion 56 communicates with
the separating chamber 54 via the opening 154A in the right side
wall 54A and the net filter NF1 (refer to FIG. 5), and also
communicates with the separating chamber 54 via the net filter NF2
(not shown) of the opening 154B in the right side wall 54A.
[0042] The suction air passage portion 56 communicates with the
inside of an accommodating case 81 of the filter unit 80 and also
communicates with a dust collecting chamber 73 (described later) of
a dust collecting case portion 74 via a connection opening 56A
formed in a right side wall portion 156 (refer to FIG. 5) of the
suction air passage portion 56.
[0043] The bottom of the suction air passage portion 56 is
connected with the other end of the detour air passage tube 502,
and the suction air passage portion 56 and the air passage tube 500
of the cleaner body 11 communicate with each other via the detour
air passage tube 502. On the other end side of the detour air
passage tube 502, there is provided a third blocking unit, which is
constituted of, for example, a solenoid valve 503. This solenoid
valve 503 serves to block or open the detour air passage tube
502.
[0044] As shown in FIG. 5, the dust collecting portion 70 includes
a communication case portion 72 having a communicating passage 71
which laterally extends in an upper portion thereof and a dust
collecting case portion 74 having the dust collecting chamber
portion 73 which extends downward from the right end of the
communication case portion 72 so as to collect the dust.
[0045] In the left bottom surface of the communication case portion
72, there is provided an opening 72A, which is communicated with
the introducing opening 53A of the dust separation portion 52 as
shown in FIG. 5. A connection opening 75 is provided in a left side
wall portion 74A of the dust collecting case portion 74, and a net
filter NF3 is mounted to the connection opening 75.
[0046] A cover plate 170 is mounted on the outer wall portion of
the dust collecting case portion 74 to a position located outside
the net filter NF3 and apart from the net filter NF3 by a
predetermined distance, a. An opening 170A is provided in a lower
portion of the cover plate 170.
[0047] The opening 170A of the cover plate 170 is connected to the
connection opening 56A of the suction air passage portion 56.
[0048] Upon mounting the dust collecting container 410 to the dust
collecting unit chamber 22 of the cleaner body 11, as shown in FIG.
5, the introduction opening 53A of the dust separation portion 52
is connected to the opening 72A of the dust collecting container
410, and the opening 170A in the cover plate 170 of the dust
collecting container 410 is connected to the connection opening 56A
of the suction air passage portion 56 in the dust separation unit
400.
[0049] As shown in FIGS. 3 to 6, the filter unit 80 is opened in
the rear surface, and includes a cylindrical accommodating case 81
and a pleat filter portion 100 mounted therein. On the front
surface of a front wall portion 84 of the accommodating case 81,
the dust separation portion 52 is integrally mounted. The pleat
filter portion 100 has a pleat filter 104 having a plurality of
mountain portions extending radially.
[0050] The front wall portion 84 (refer to FIG. 2) of the
accommodating case 81 has a connection opening 84A (shown in FIG.
6), which is connected to the suction air passage portion 56 (refer
to FIG. 5). The inside of the accommodating case 81 and the suction
air passage portion 56 are communicated with each other via the
connection opening 84A. The connection opening 84A has a second
blocking unit, which is constituted of, for example, a shutter 700.
The shutter 700 is operative to block or open the connection
opening 84A.
[0051] Further, the accommodating case 81 has therein side a return
mechanism for returning air in the accommodating case 81 to the
dust separation portion 52. This return mechanism is constituted
of, for example, a return air passage 640 constituting an air
passage. One end of the return mechanism is connected to a lower
portion of the front wall portion 84 of the accommodating case 81,
while the other end thereof is connected to the guide air passage
tube 57 of the dust separation portion 52. To the other end of the
returning air passage 640, there is provided, for example, a
solenoid valve 641, which is operative to block or open the return
air passage 640.
[0052] An external-air introducing air passage 650 (refer to FIG.
2) for introducing external air into the accommodating case 81 is
formed at an upper portion of the accommodating case 81. The
external-air introducing air passage 650 includes, for example, a
solenoid valve 651, which serves to to block or open the
external-air introducing air passage 650.
[0053] A dust removal unit for removing dust from the pleat filter
portion 100 is disposed inside the accommodating case 81. As shown
in the illustration of the embodiment, the dust removal unit is
located between the pleat filter portion 100 and the front wall
portion 84 of the accommodating case 81 and constitutes a rotating
fan 800 that pivots on a central axis 101A of the pleat filter
portion 100. The rotating fan 800 is configured to be rotated, for
example, by external air introduced from the external-air
introducing air passage 650. A frame 801 of the rotating fan 800
has at least one protrusion 802 in contact with one of the mountain
portions of the pleat filter 104.
[0054] Upon rotating the rotating fan 800, the protrusion 802 gets
over the mountain portions of the pleat filter 104, and
accordingly, it is possible to provide vibrations to the pleat
filter 104 to thereby shake off dust adhering to the pleat filter
104. As shown in FIG. 7, the orientation of the blades 803 of the
rotating fan 800 is set so as to receive the external air
introduced from the external-air introducing air passage 650 to
thereby flow the external air toward the pleat filter portion 100.
As described above, the dust removal unit is configured to remove
the dust from the pleat filter by means of the rotating fan 800
that is rotated by the external air introduced from the
external-air introducing air passage 650. The present invention is,
however, not limited to this way of removing the dust. For example,
the dust may be removed by rotating the pleat filter portion 100 by
a motor (not shown) or the like, and the dust is dropped off from
the pleat filter portion 100, for example, by bringing a fixed leaf
spring (not shown) into contact with the mountain portions and
causing the leaf spring to pick these mountain portions. In this
case, since it is not necessary to rotate the fan 800, the more
smooth air flow from the external-air introducing air passage into
the filter unit may be achieved.
[0055] The control of the closing/opening operations of the
shutters 501, 600, and 700, or the solenoid valves 503, 641, and
651 is performed by a control unit, which is not shown in the
figure.
[Operation]
[0056] Hereunder, the operations of the vacuum cleaner of the
structure mentioned above will be described with respect to FIG. 8
as a conceptual diagram.
[0057] First, as shown in FIG. 2, the dust collecting unit 50 is
mounted to the dust collecting unit chamber 22 of the cleaner body
11, and the dust collecting hose 12 is connected to the connection
port 11a of the cleaner body 11, and the suction port body 15 is
also connected to the hand operation tube 13 via the extension tube
14 as sown in FIG. 1. At this time, the shutters 501, 600 and 700
are each in an opened state, and the solenoid valves 503, 641 and
651 are each in a closed state.
[0058] Upon operating the switch 13b of the operation portion 13A,
the electric blower 24 is driven. When this electric blower 24 is
driven, air is sucked from the suction opening 24A of the electric
blower 24. As a result, a negative pressure operates on the inside
of the accommodating case 81 of the dust collecting unit 50 via the
air passage tube 500 and the connection air passage portion 25, and
further operates on the inside of the dust collecting case portion
74 or the separating chamber portion 54 of the dust separation
portion 52 via the suction air passage portion 56. This negative
pressure acts to the dust collecting hose 12, the extension tube 14
and the suction port body 15 via the guide air passage tube 57 to
thereby suck the dust through the suction port body 15 together
with air.
[0059] The thus sucked dust and air are guided into the suction
connecting port 57a of the dust collecting unit 50 via the
extension tube 14 and the dust collecting hose 12. The dust and the
air that have been sucked into the suction connecting port 57a are
introduced into the separating chamber 54 of the dust separation
portion 52 through the guide air passage tube 57, and the dust and
air are then counterclockwisely rotated in the separating chamber
54 as shown in FIG. 4.
[0060] Under the rotation of the air, the dust and the air are
separated from each other by inertias, and the air is sucked into
the accommodating case 81 of the filter unit 80, through the net
filter NF1 (refer to FIG. 5) of the first dust separating unit 55
or the net filter NF2 (not shown) of the opening 154B and further
through the suction air passage portion 56.
[0061] On the other hand, the separated dust is introduced into the
communication case portion 72 in the dust collecting portion 70 of
the introducing opening 53A in the separating chamber 54 by an
inertia force, together with a part of air. These introduced dust
and air are sucked into the dust collecting chamber 73 through the
communicating passage 71 in the communication case portion 72, and
the dust is collected into the dust collecting chamber 73.
[0062] The air that sucked into the dust collecting chamber 73 is
then sucked into the suction air passage portion 56 through the net
filter NF3 and the opening 170A located below the cover plate 170,
and further sucked into the accommodating case 81 of the filter
unit 80.
[0063] The air sucked into the accommodating case 81 is then sucked
into the connection air passage portion 25 of the cleaner body 11
through the pleat filter 104 of the pleat filter portion 100, and
further sucked into the suction opening 24A of the electric blower
24.
[0064] The air sucked into the suction opening 24A of the electric
blower 24 is then exhausted from an exhaust port 20H of the cleaner
body 11 shown in FIG. 2, through the inside of the electric blower
24. That is, the air flows as indicated by a chain line with arrows
in FIG. 8.
[0065] Upon completing the cleaning and operating of the switch 13a
of the hand operation tube 13, the shutters 501, 600 and 700 are
closed and the solenoid valves 503, 641 and 651 are opened. The
electric blower 24 is driven at a predetermined power for a
predetermined time period.
[0066] By closing the shutters 501, 600 and 700 and opening the
solenoid valves 503, 641 and 651, the external air is introduced
from the external-air introducing air passage 650 into the
accommodating case 81 (refer to FIG. 2) of the dust collecting unit
50 as shown in FIG. 8. Under such introduction of the air, the
rotating fan 800 is rotated, and the vibration is caused to the
pleat filter 104 by the location of the protrusion, thereby
dropping off dust adhering to the pleat filter 104.
[0067] Further, since the external air abutting against the blades
803 of the rotating fan 800 flows toward the pleat filter 104, the
dust adhering to the pleat filter 104 can be effectively dropped
off.
[0068] As indicated by broken lines with an arrow in FIG. 8, the
external air introduced into the accommodating case 81 is sucked
into the upstream side of the dust separating portion 55, that is,
into the guide air passage tube 57 (refer to FIG. 2) of the dust
collecting unit 50 through the return air passage 640, and further
sucked into the separating chamber 54 of the dust collecting unit
50 shown in FIG. 5.
[0069] The dust dropped off from the pleat filter 104 passes
through the return air passage 640, moves with the flow of the
external air, and is carried into the separating chamber 54 of the
dust collecting unit 50.
[0070] The dust is separated from the external air in the
separating chamber 54 and carried into the dust collecting chamber
73, while the external air is sucked into the suction air passage
portion 56 through the net filter NF1 (refer to FIG. 5) of the
first dust separating unit 55, or the net filter NF2 (not shown) of
the opening 154B.
[0071] As indicated by the broken lines each with arrow in FIG. 8,
the external air introduced into the suction air passage portion 56
is sucked into the downstream side portion of the shutter 501,
i.e., the air passage tube 500 shown in FIG. 2 through the detour
air passage tube 502 and further sucked into the suction opening
24A of the electric blower 24. Then, the drive of the electric
blower 24 is stopped after a predetermined time period.
[0072] In this manner, the dust dropped off from the pleat filter
104 is carried into the separating chamber 54 of the dust
collecting unit 50. Therefore, when the electric blower 24 is
driven for performing cleaning, the dust that has been dropped off
from the pleat filter 104 is prevented from being sucked up and
re-adhering to the pleat filter 104.
SECOND EMBODIMENT
[0073] FIGS. 9 and 10 show a vacuum cleaner according to a second
embodiment of the present invention. In the vacuum cleaner of the
second embodiment, the air passage tube 500 and the inside of the
accommodating case 81 are communicated through the detour air
passage 900 constituting a detour passage, and the detour air
passage tube 900 has a third dust separating unit. The third dust
separating unit includes, for example, a filter 901 and a solenoid
valve 902.
[0074] In the vacuum cleaner of the second embodiment, when the
cleaning is performed; the shutters 501 and 700 are opened and the
solenoid valve 902 is closed, air flows as indicated by a chain
line with arrows in FIG. 10, and dust is collected into the dust
collecting chamber portion 73 as in the case of the first
embodiment.
[0075] When the switch 13a (refer to FIG. 1) of the operation
portion 13A is operated by using the hand operation tube 13, the
shutters 501 and 700 are closed, and the solenoid valves 902 is
opened. The electric blower 24 is driven at a predetermined power
for a predetermined time period.
[0076] When the shutters 501 and 700 are closed, external air is
introduced from the external-air introducing air passage 650 into
the accommodating case 81 of the dust collecting unit 50. This
introduction of the air causes dust adhering to the pleat filter
104 to drop off therefrom as in the case of the first embodiment.
The external air introduced into the accommodating case 81 is
sucked into the air passage tube 500 through the detour air passage
900, and further sucked into the suction opening 24A of the
electric blower 24, as indicated by the broken lines each with
arrow in FIG. 10.
[0077] The dust dropped off from the pleat filter 104 passes
through the detour air passage 900 and moves with the flow of the
external air, as in the case of the first embodiment. Because the
detour air passage tube 900 has a filter 901, the dust is caught by
the filter 901, and only the air is sucked into the air passage
tube 500.
[0078] In this way, the dust dropped off from the pleat filter 104
is carried into the detour air passage tube 900 and caught by the
filter 901. Therefore, when the electric blower 24 is driven for
performing cleaning, the dust that has been dropped off the pleat
filter 104 is prevented from being sucked up and re-adhering to the
pleat filter 104.
[0079] According to the second embodiment, the shutter 600, it is
not necessary to locate the return air passage 640 or the solenoid
valve 641.
[0080] The present invention is not limited to the above-described
first and second embodiments, and a vacuum cleaner of a type using
a paper pack filter may be utilized instead of the dust separation
portion 52 and the dust collecting portion 70.
[0081] It is to be noted that the present invention is not limited
to the described embodiment and many other changes and
modifications may be made without departing from the scopes of the
appended claims.
[0082] In the above-described embodiments, although the present
invention has been applied to a vacuum cleaner, the present
invention is not restricted thereto. For example, the present
invention is also applicable to an air-conditioning system and the
like in such a way as to drop off dust from a filter in the
air-conditioning system and the like.
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