U.S. patent application number 09/727602 was filed with the patent office on 2001-06-07 for leaf blower.
Invention is credited to Doragrip, Gustaf.
Application Number | 20010002501 09/727602 |
Document ID | / |
Family ID | 20417968 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002501 |
Kind Code |
A1 |
Doragrip, Gustaf |
June 7, 2001 |
Leaf blower
Abstract
A portable leaf blower having a fan unit (10) with a fan (11)
and a combustion engine (12) for driving the fan. The fan unit (10)
is arranged in a shell (16,17) provided with a lower inlet opening
(23) through which air, during operation, flows to the fan (11).
The shell is further provided with an upper opening (24). When the
engine (12) has been cut off, air for cooling the engine (12) flows
through the shell (16,17) by means of self convection from the
lower inlet opening (23) to the upper opening (24).
Inventors: |
Doragrip, Gustaf;
(Jonkoping, SE) |
Correspondence
Address: |
PEARNE & GORDON LLP
526 SUPERIOR AVENUE EAST
SUITE 1200
CLEVELAND
OH
44114-1484
US
|
Family ID: |
20417968 |
Appl. No.: |
09/727602 |
Filed: |
December 1, 2000 |
Current U.S.
Class: |
15/344 ; 15/326;
15/339; 15/405; 417/234 |
Current CPC
Class: |
F02B 63/02 20130101;
F04D 25/02 20130101; A01G 20/47 20180201; E01H 1/0809 20130101 |
Class at
Publication: |
15/344 ; 15/326;
15/405; 15/339; 417/234 |
International
Class: |
A47L 005/12; A47L
005/24; A47L 005/14 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 1999 |
SE |
9904402-6 |
Claims
What is claimed is:
1. A portable leaf blower comprising a fan unit (10) with a fan
(11) and a combustion engine (12) for driving the fan, wherein the
fan unit (10) is arranged in a shell (16,17), said shell having a
lower inlet opening (23) and an upper opening (24), and wherein,
during operation of the fan and engine air flows through the lower
opening to the fan and, when the engine (12) has been cut off, air
for cooling the engine flows through the shell (16,17) by means of
self convection from the lower inlet opening (23) to the upper
opening (24).
2. The leaf blower according to claim 1, wherein the engine (12)
has a mainly horizontal cylinder (13) provided with vertical
flanges (13a).
3. The leaf blower according to claim 1 , wherein the engine (12)
is provided with a carburetor housing (14) that is placed at a
level that is lower than a level of warmer parts of the engine.
4. The leaf blower according to claim 1, wherein the shell
comprises a removable cover (17) and bottom part (16), the fan unit
(10) being fastened to the bottom part, which thereby forms a
chassis for the fan unit (10), the shell preventing damage to the
fan unit caused by mechanical influence during transport and
handling.
5. The leaf blower according to claim 1, wherein an inside of the
shell (16,17) is provided with a noise absorbing and noise
insulating material (22).
6. The leaf blower according to claim 2 , wherein the engine (12)
is provided with a carburetor housing (14) that is placed at a
level that is lower than a level of warmer parts of the engine.
7. The leaf blower according to claim 2, wherein the shell
comprises a removable cover (17) and bottom part (16), the fan unit
(10) being fastened to the bottom part, which thereby forms a
chassis for the fan unit (10), the shell preventing damage to the
fan unit caused by mechanical influence during transport and
handling.
8. The leaf blower according to claim 3, wherein the shell
comprises a removable cover (17) and bottom part (16), the fan unit
(10) being fastened to the bottom part, which thereby forms a
chassis for the fan unit (10), the shell preventing damage to the
fan unit caused by mechanical influence during transport and
handling.
9. The leaf blower according to claim 2, wherein an inside of the
shell (16,17) is provided with a noise absorbing and noise
insulating material (22).
10. The leaf blower according to claim 3, wherein an inside of the
shell (16,17) is provided with a noise absorbing and noise
insulating material (22).
11. The leaf blower according to claim 4, wherein an inside of the
shell (16,17) is provided with a noise absorbing and noise
insulating material (22).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a portable leaf blower
having a fan unit with a fan and a combustion engine for driving
the fan.
[0003] 2. Description of Related Art
[0004] Engine driven leaf blowers have turned out to be efficient
tools for cleaning lawns, pedestrian streets, parking places and
the like. Such leaf blowers, however, have the disadvantage that
they create a comparatively high noise level that is disturbing for
the operator as well as for the environment. For instance, the fan
creates noise of such a character that it penetrates walls and
closed windows and, hence, is difficult to shut out. For this
reason in some areas restrictions have been introduced limiting the
use of such motor driven tools. There also are limits for maximum
allowable noise level that the currently-used leaf blowers do not
fulfil.
[0005] Another problem in connection with leaf blowers is that they
are often exposed to rough treatment especially under transport,
which means that damages might occur for example, to the air
filter, carburetor or fuel tank.
SUMMARY OF THE INVENTION
[0006] A purpose of the present invention is to minimize or
eliminate the aforementioned inconveniences that are found in the
prior art, and to achieve a leaf blower which, when compared to
such prior-art tools, emits less disturbing noise and also stands
rough treatment without the risk for damages. In accordance with
the present invention, a leaf blower has a fan unit arranged in a
shell, the shell having a lower inlet opening and an upper opening.
When the engine and fan are operating, air flows through the lower
inlet opening to the fan. When the engine and fan are shut off, air
for cooling the engine flows through the shell, from the lower
inlet opening to the upper inlet opening, by means of self
convection, thereby cooling the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and further features of the present invention will be
apparent with reference to the following description and drawings,
wherein:
[0008] FIG. 1 is a side view, partly in section, of the leaf blower
according to the present invention; and,
[0009] FIG. 2 is a front view of the leaf blower shown FIG. 1
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] The leaf blower shown in the drawing has a portable,
motor-driven fan unit 10 comprising a centrifugal fan 11 that is
driven by a combustion engine 12. As is best shown in FIG. 2, the
engine 12 is provided with a cylinder 13, a carburetor housing 14
and silencer or muffler 15.
[0011] The fan unit 10 is arranged in a shell consisting of a
bottom part 16 provided with a removable cover 17. A dividing or
separation line between the bottom part 16 and the cover 17 is
shown with dotted lines 18 in FIG. 1. In order to more clearly show
the fan unit 10, the leaf blower is illustrated in FIG. 2 with the
cover 17 removed. The fan unit 10 is, by spring means that damp the
vibrations, supported at the bottom part 16. Accordingly, the
bottom part 16 serves as a chassis for the fan unit 10.
[0012] The bottom part 16 is, at its upper end, provided with a
fuel tank 20 and a supporting handle 21. The fan unit is arranged
to be supported on the back of an operator and for this purpose the
bottom part 16 is provided with supporting belts (not shown). The
cover 17 is removably secured at the bottom part 16 by means of
fastening devices (not shown) of some suitable conventional type,
which means that the fan unit 10 is easily accessible for
maintenance and repair. At its inside the cover 17 is provided with
a noise insulating and noise absorbing material 22.
[0013] As shown in FIG. 1, a lower end of the bottom part 16 has an
inlet opening 23 through which air flows into the fan 11 when the
fan is operating. The air flow to the fan 11 also gives the
necessary cooling of the engine 12 and especially the cylinder
13.
[0014] An upper end of the cover 17 has an opening 24 and a noise
damping screen 25. The noise damping screen 25 is arranged outside
and spaced a distance from the opening 23. The upper opening 24 is
designed and provided to admit an air flow through the shell 16, 17
when the engine has been shut off in order to cool the hot parts of
the engine, especially the cylinder 13 and the muffler 15. The air
flow through the shell 16, 17 is created by means of self
convection whereby air, which has been heated up by the engine,
rises upwards and flows out through the upper opening 24 at the
same time as cold air is drawn in through the lower inlet opening
23.
[0015] In order to achieve a good cooling efficiency and flow of
cooling air through the shell 16, 17 the cylinder 13 of the engine
is arranged horizontally and provided with vertical cooling flanges
13a. The cooling air flows along the cooling flanges 13a (FIG. 2)
as the cooling air traverses the interior of the shell 16, 17 from
the lower inlet opening 23 to the upper opening 24. Since the
cooling air flow is directed upwards, the carburetor housing 14,
which is placed at a lower level than the warmer parts, will not be
overheated when the engine has been shut off. The carburetor is
disposed in the carburetor housing 14, which also serves as a
shield to prevent warming up of the carburetor (not shown) as a
result of heat radiation from the warmer parts of the engine.
[0016] In FIG. 1 the air flow direction to the fan 11 during
operation and the cooling air flow between the lower inlet opening
23 and the upper opening 24 after the engine has been shut off is
shown by arrows. During operation, the upper opening 24 can also
serve as a secondary air inlet, which is indicated in FIG. 1.
Because of the self convection effect that takes place when the
engine has been shut off, excessively high temperatures, which
otherwise may damage the shell 16, 17 or the noise damping
insulation 22, are avoided.
[0017] Thus, the shell 16, 17 makes it possible to achieve an
effective noise reduction of the engine and the fan unit 10,
especially if the shell is at its inside provided with noise
absorbing and noise insulating material. The shell is also an
efficient protection against damages of the fan unit caused by
mechanical influence during transport and handling.
[0018] While the preferred embodiment of the present invention is
shown and described herein, it is to be understood that the same is
not so limited but shall cover and include any and all
modifications thereof which fall within the purview of the
invention.
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