U.S. patent application number 12/360745 was filed with the patent office on 2009-05-21 for blower duct.
This patent application is currently assigned to HUSQVARNA ZENOAH CO. LTD.. Invention is credited to Satoshi NAKAZAWA, Takeshi Saito, Maki Yamazaki.
Application Number | 20090126147 12/360745 |
Document ID | / |
Family ID | 39316780 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090126147 |
Kind Code |
A1 |
NAKAZAWA; Satoshi ; et
al. |
May 21, 2009 |
BLOWER DUCT
Abstract
A portable-blower duct has a bendable portion whose inner
peripheral surface is a cylindrical surface without any protrusions
or recesses in a normal state or in an expanded state, that is,
unless it is greatly curved. With this construction, no turbulence
is generated in air passing through a tube, thereby making it
possible to suppress pressure loss. Thus, the flow velocity of air
guided through the duct is not reduced, thereby suppressing a
deterioration in air blowing efficiency. Even when the tube is
curved, the outer side of the curved portion is expanded, and the
corresponding portion of the inner peripheral surface remains a
smooth surface, thus making it possible to minimize the air
pressure loss.
Inventors: |
NAKAZAWA; Satoshi;
(Kawagoe-shi, JP) ; Yamazaki; Maki; (Kawagoe-shi,
JP) ; Saito; Takeshi; (Tokyo, JP) |
Correspondence
Address: |
FRISHAUF, HOLTZ, GOODMAN & CHICK, PC
220 Fifth Avenue, 16TH Floor
NEW YORK
NY
10001-7708
US
|
Assignee: |
HUSQVARNA ZENOAH CO. LTD.
Kawagoe-shi
JP
|
Family ID: |
39316780 |
Appl. No.: |
12/360745 |
Filed: |
January 27, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11584023 |
Oct 20, 2006 |
|
|
|
12360745 |
|
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Current U.S.
Class: |
15/405 ; 138/119;
138/121; 415/208.1 |
Current CPC
Class: |
F16L 11/15 20130101;
A01G 20/00 20180201; A01G 20/47 20180201 |
Class at
Publication: |
15/405 ;
415/208.1; 138/121; 138/119 |
International
Class: |
A47L 5/14 20060101
A47L005/14; F04D 29/44 20060101 F04D029/44 |
Claims
1. A blower comprising: a blower main body having an air-sending
port and being arranged to supply air to the air-sending port; a
duct comprising: a bendable portion including a flexible tube
having a smooth inner peripheral surface at least in a
non-contracted state, a plurality of protruding portions formed
along a circumferential direction of the tube and arranged at
predetermined intervals in an axial direction of the tube, and an
elbow that connects the air-sending port with the bendable portions
wherein an inner diameter of the elbow is substantially the same as
an inner diameter of the air-sending port.
2. A blower according to claim 1, wherein: the tube is a
cylindrical member made of a synthetic resin; and the protruding
portions are formed integrally with the tube so that the protruding
portions are continuous with an outer peripheral surface of the
tube.
3. A blower according to claim 1, wherein the protruding portions
are annular.
4. A blower according to claim 1, wherein the plurality of
protruding portions are connected to one another as a spiral
configuration on an outer peripheral surface of the tube, with
adjacent portions thereof being arranged at predetermined
intervals.
5. The blower according to claim 1, wherein the blower main body is
arranged to supply a predetermined amount of air to the air-sending
port.
6. The blower according to claim 1, wherein the elbow is curved in
a circular arc shape.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a Divisional Application of U.S.
application Ser. No. 11/584,023 filed Oct. 20, 2006 which is
incorporated herein by reference.
1. FIELD OF THE INVENTION
[0002] The present invention relates to a blower duct, in
particular a duct equipped with a bendable portion capable of
changing a direction of air discharged from a blower.
2. DESCRIPTION OF RELATED ART
[0003] Hitherto, there has been known a portable blower which
performs cleaning by blowing away dust, fallen leaves, etc, with
air sucked therein (see, for example, JP 2003-97493 A, FIGS. 1
through 3).
[0004] The blower disclosed in the above-mentioned publication is
equipped with a blower main body and a duct mounted to a forward
end portion of the blower main body. The duct is equipped with a
bendable portion connected to the blower, a rotary portion
connected to the bendable portion, a muffler connected to the
rotary portion and a nozzle connected to the muffler. The bendable
portion is formed in a so-called bellows-like configuration, in
which small diameter portions with a small inner diameter and large
diameter portions with a large inner diameter are alternately
connected together, and with this configuration, exhibits
flexibility. In this portable blower, the air sent out from the
blower main body passes through an elbow and the bendable portion
to be blown out through the nozzle.
[0005] In the related art blower as disclosed in the
above-mentioned publication, the bendable portion has on its outer
surface and inner surface a plurality of protrusions and recesses
formed between the small diameter portions and the large diameter
portions. When there are protrusions and recesses on the inner
surface of the bendable portion, turbulence is generated in the
airflow from the blower, resulting in generation of air pressure
loss. Thus, as a result of the pressure loss due to this air
turbulence, the wind pressure becomes so much the lower, resulting
in a deterioration in air blowing efficiency of the blower.
SUMMARY OF THE INVENTION
[0006] It is a principal object of the invention to provide a
blower duct helping to achieve an improvement in air blowing
efficiency.
[0007] A blower duct according to an aspect of the invention
includes: a bendable portion composed of a tube, whose inner
peripheral surface is a smooth surface at least in a non-contracted
state, and which exhibits flexibility; and protruding portion,
which are each formed substantially in an annular configuration
extending in a circumferential direction of the tube, and are
arranged at predetermined intervals in an axial direction of the
tube.
[0008] According to the aspect of the invention, when the flexible
tube is not greatly contracted, that is, when it is in a normal
state in which no external force is being applied thereto, or when,
even if an external force is applied thereto, it is expanded due to
that external force, the inner peripheral surface of the flexible
tube is a smooth surface, so no turbulence is generated in the air
passing through the tube, and pressure loss is prevented. In a
state in which the tube is curved, contraction occurs on the inner
side of the curved portion of the tube, and the inner peripheral
surface of the contracted portion exhibits protrusions and
recesses. However, on the outer side of the curved portion, the
tube is expanded, and the inner peripheral surface of this expanded
portion reliably provides a smooth surface, so it is possible to
reduce the pressure loss.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a general schematic view of a portable blower
according to an exemplary embodiment of the invention; and
[0010] FIG. 2 is a sectional view of a bendable portion of the
exemplary embodiment taken along the axis thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)
[0011] In the following, an exemplary embodiment of the invention
will be described with reference to the drawings. FIG. 1 is a
general plan view of a blower according to the exemplary
embodiment. FIG. 2 is a sectional view of a part of the duct of the
exemplary embodiment taken along the axis thereof.
[Construction of the Portable Blower]
[0012] In FIG. 1, numeral 100 indicates a portable blower. The
portable blower 100 is formed in a size and weight allowing the
operator to carry it on operator's back, with operator's hand, etc.
The portable blower 100 is equipped with a blower main body 10 and
a duct 20 connected to the blower main body 10. Air sucked in by
the blower main body 10 is supplied to the duct 20, and with the
air blown out of the duct 20, it is possible to blow away dust,
fallen leaves, etc.
[0013] The blower main body 10 is equipped with an air sending port
11 to which the duct 20 is connected, a volute 12 supplying air to
the air sending port 11, and a throttle 13 for adjusting an amount
of air supplied by the volute 12. The volute 12 has a rotary fan
(not shown). This rotary fan receives a drive force transmitted
from an engine (not shown) provided inside the blower main body 10,
and rotates at a rotating speed according to an amount by which the
throttle 13 is operated. Through the rotation of the rotary fan,
outside air is sucked in through an intake port 12A, and is
supplied to the air sending port 11. Instead of the engine provided
inside the blower main body 10, it is also possible to provide an
electric motor.
[0014] The duct 20 is equipped with an elbow 21 connected to the
air sending port 11 of the blower main body 10, a bendable portion
22 connected to the elbow 21, an operation pipe 23 connected to the
bendable portion 22, and an air outlet 24 connected to the
operation pipe 23.
[0015] The elbow 21 is curved in a circular arc shape. The inner
diameter of the elbow 21 is substantially the same as the inner
diameter of the air sending port 11. With this construction, the
air introduced from the air sending port 11 passes through the
elbow 21 without involving any pressure loss, and is supplied to
the bendable portion 22.
[0016] As shown in FIG. 2, the bendable portion 22 is equipped with
a substantially cylindrical tube 221, a plurality of protruding
portions 222 provided so as to extend in the circumferential
direction of the tube 221, a blower connection portion 223
connected to the elbow 21, and an operation connection portion 224
connected to the operation pipe 23; the bendable portion 22 is
formed of a flexible member made of a synthetic resin such as PP
(polypropylene).
[0017] In the normal state in which the tube 221 is not greatly
contracted, or if not in the normal state, in a state in which the
tube 221 is expanded by an external force applied thereto, an inner
peripheral surface 221A of the tube 221 is a smooth cylindrical
surface without any protrusions or recesses. The protruding
portions 222 provided on the outer peripheral surface of the tube
221 are formed integrally with the tube 221. The protruding
portions 222, which protrude as continuous ring-like portions
extending in a circumferential direction of the tube 221, are
arranged at predetermined intervals in an axial direction of the
tube 221. The portions between the protruding portions 222 are
formed as groove portions 225 adapted to be recessed toward the
axis when the tube 221 is contracted.
[0018] In the tube 221, constructed as described above, the groove
portions 225 between the protruding portions 222 are deflected and
recessed toward the axis of the tube 221, whereby the tube 221 as a
whole can be contracted and curved, thereby generating protrusions
and recesses on the inner peripheral surface 221A. However, when
the tube 221 is in the normal state or in the expanded state, the
inner peripheral surface 221A is a cylindrical surface without any
protrusions or recesses, so no turbulence occurs, and no air
pressure loss is generated. Even when the tube 221 is in the curved
state, the groove portions 225 of the tube 221 are recessed toward
the axis to generate protrusions and recesses in the portion of the
inner peripheral surface 221A on the inner side (contracted side)
of the curved portion. However, on the outer side (expanded side)
of the curved portion, the groove portions 225 are not recessed, so
the corresponding portion of the inner peripheral surface 221A is
kept as a smooth surface, thus making it possible to minimize the
air pressure loss.
[0019] The operation pipe 23 is connected to the bendable portion
22 and the air outlet 24, and causes the air from the bendable
portion 22 to be blown out of the air outlet 24. Further, the
operation pipe 23 is equipped with an operating grip 231. The
operating grip 231 is a portion grasped by the operator when the
portable blower 100 is to be operated; while grasping the operating
grip 231, the operator directs the duct 20 in a desired direction
in which air is to be blown out. It is also possible for the
operating grip 231 to be equipped, for example, with an operation
control lever for controlling the operation and stopping of the
blower.
EFFECTS OF EXEMPLARY EMBODIMENT
[0020] As described above, in the portable blower 100 of the
exemplary embodiment, the inner peripheral surface 221A is a
cylindrical surface without any protrusions or recesses when the
tube 221 of the bendable portion 22 is in the normal state or in an
expanded state. Thus, unless the tube 221 is greatly curved, no
turbulence is generated in the airflow passing through the tube 221
thus making it possible to suppress pressure loss. Thus, the flow
velocity of the air guided through the duct 20 is not lowered by
pressure loss, thereby making it possible to suppress a
deterioration in air blowing efficiency.
[0021] When the bendable portion 22 is curved, the inner peripheral
surface 221A is contracted to generate protrusions and recesses on
the inner side of the curved portion of the tube 221. In contrast,
on the outer side of the curved portion of the tube 221, the inner
peripheral surface 221A is expanded and reliably provides a smooth
curved surface. Thus, even when the tube 221 is curved, due to the
presence of the above-mentioned smooth surface, it is possible to
reduce the air pressure loss as compared with that in the bendable
portion of the related art blower duct, thus making it possible to
achieve an improvement in air blowing efficiency.
MODIFICATIONS OF EXEMPLARY EMBODIMENT
[0022] The invention is not restricted to the above-described
exemplary embodiment but allows the following modifications as long
as they help to achieve the object of the invention.
[0023] For example, while in the above-described exemplary
embodiment a plurality of protruding portions 222 are provided as
annular members extending along the outer peripheral surface of the
tube 221 and arranged at predetermined intervals, this should not
be construed restrictively. For example, the protruding portion may
be one formed in a spiral configuration extending along the outer
peripheral surface of the tube 221.
[0024] Further, while in the above-described exemplary embodiment
the bendable portion 22 with a smooth inner peripheral surface is
only provided between the elbow 21 and the operation pipe 23, this
should not be construed restrictively. For example, it is also
possible for the bendable portion 22 to be directly attached to the
air sending port 11; it is also possible for the air outlet 24 to
be directly attached to the bendable portion 22; further, it is
also possible for the bendable portion 22 and the air outlet 24 to
be formed integrally.
[0025] Apart from the above, the specific construction and
procedures for carrying out the invention allow appropriate
modifications as long as they help to achieve the object of the
invention.
[0026] The basic application Number JP2005-255469 upon which this
patent application is based is hereby incorporated by
reference.
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