U.S. patent application number 14/883921 was filed with the patent office on 2016-04-21 for battery-powered, low-noise backpack blower.
This patent application is currently assigned to Mean Green Products, LLC. The applicant listed for this patent is Mean Green Products, LLC. Invention is credited to Joseph C. Conrad, Matthew C. Conrad.
Application Number | 20160108924 14/883921 |
Document ID | / |
Family ID | 55748685 |
Filed Date | 2016-04-21 |
United States Patent
Application |
20160108924 |
Kind Code |
A1 |
Conrad; Joseph C. ; et
al. |
April 21, 2016 |
BATTERY-POWERED, LOW-NOISE BACKPACK BLOWER
Abstract
A backpack blower having a fan frame with an air inlet and an
air outlet. A fan assembly is positioned within the fan frame. A
motor rotates the fan assembly to move air out the air outlet. A
controller is connected to the motor and to a battery pack, for
using power from the battery pack to energize the motor and thus
rotate the fan. A harness frame is connected to the fan frame and
has an opening in air flow communication with the air inlet, so
that, when the motor is rotating the fan assembly, air is drawn in
through the harness frame opening. Since the harness frame is
positioned in the area of an operator's back when the blower is in
use, the air flow drawn in through the harness frame opening has
the effect of cooling the operator.
Inventors: |
Conrad; Joseph C.; (Okeana,
OH) ; Conrad; Matthew C.; (Okeana, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mean Green Products, LLC |
Hamilton |
OH |
US |
|
|
Assignee: |
Mean Green Products, LLC
Hamilton
OH
|
Family ID: |
55748685 |
Appl. No.: |
14/883921 |
Filed: |
October 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62065079 |
Oct 17, 2014 |
|
|
|
Current U.S.
Class: |
417/423.7 |
Current CPC
Class: |
A01G 20/43 20180201;
F04D 17/16 20130101; A01G 20/47 20180201; F04D 25/0673
20130101 |
International
Class: |
F04D 25/06 20060101
F04D025/06; F04D 17/16 20060101 F04D017/16 |
Claims
1. A backpack blower, comprising: a fan frame, having an air inlet
of a certain area, and having an air outlet of a lesser area; a fan
assembly positioned within the fan frame; a motor having a stator,
and a motor shaft rotatable with respect to the stator, the stator
connected to the fan frame and the shaft connected to the fan
assembly so as to rotate the fan assembly within the fan frame, and
thus move air from the air inlet to the air outlet; a battery pack;
and a controller connected to the motor and to the battery pack,
for applying power from the battery pack to energize the motor and
thus rotate the fan to move air from the air inlet to the air
outlet.
2. A backpack blower as recited in claim 1 wherein the fan frame
has a bottom plate and a motor plate, the motor plate having an
opening of a certain area which functions as the air inlet, the
bottom plate and motor plate being connected to and separated by a
side wall, and both being generally ring shaped, except for the
area of the air outlet.
3. A backpack blower as recited in claim 1 wherein the fan assembly
has a bottom ring and a top ring, and vanes separating the top ring
from the bottom ring by a predetermined spacing.
4. A backpack blower as recited in claim 3 wherein the bottom ring
has a center, and wherein each vane is angled or curved with
respect to the center of the bottom ring.
5. A backpack blower as recited in claim 4 wherein the angle or
curve of all the vanes with respect to the center of the bottom
ring is the same.
6. A backpack blower as recited in claim 1, further comprising a
harness frame connected to the fan frame and having an opening in
air flow communication with the air inlet, so that, when the motor
is rotating the fan assembly, air is drawn in through the harness
frame opening, thereby cooling an operator.
7. A backpack blower, comprising: a fan frame, having a bottom
plate and a motor plate, the motor plate having an opening of a
certain area which functions as an air inlet, the bottom plate and
motor plate being connected to and separated by a side wall, and
both being generally ring shaped, except having an air outlet area;
a fan assembly positioned within the fan frame, the fan assembly
having a bottom ring and a top ring, and spaced apart from each
other by a plurality of vanes, each vane angled and curved the same
as all the other vanes with respect to the center of the bottom
ring; a motor having a stator, and a motor shaft rotatable with
respect to the stator, the stator connected to the fan frame, and
the shaft connected to the fan assembly, so as to rotate the fan
assembly within the fan frame, and thus move air from the air inlet
to the air outlet; a removable battery pack having electrical
connectors; mating electrical connectors mounted to the fan frame;
and a controller electrically connected to the motor and to the
battery pack, for using power from the battery pack to energize the
motor and thus rotate the fan to move air from the air inlet to the
air outlet.
8. A backpack blower as recited in claim 7, further comprising a
harness frame connected to the fan frame, positioned in the area of
an operator's back when the blower is in use, and having a harness
frame opening in air flow communication with the air inlet, so
that, when the motor is rotating the fan assembly, air is drawn in
through the harness frame opening, thereby cooling the
operator.
9. A backpack assembly as recited in claim 8 further comprising a
main cover connected to the motor plate and to the harness frame
and positioned over the motor plate opening.
10. A backpack assembly as recited in claim 9 wherein the main
cover has air intake openings.
11. A backpack blower, comprising: a fan frame, having an air inlet
of a certain area, and having an air outlet of a lesser area; a fan
assembly positioned within the fan frame; a motor having a
rotatable motor shaft connected to the fan assembly so as to rotate
the fan assembly with respect to the fan frame, and thus move air
from the air inlet to the air outlet; a battery pack; a controller
connected to the motor and to the battery pack, for applying power
from the battery pack to energize the motor and thus rotate the fan
to move air from the air inlet to the air outlet; and a harness
frame connected to the fan frame, positioned in the area of an
operator's back when the blower is in use, and having a harness
frame opening in air flow communication with the air inlet, so
that, when the motor is rotating the fan assembly, air is drawn in
through the harness frame opening, thereby cooling the
operator.
12. A backpack blower as recited in claim 11 wherein the fan frame
has a bottom plate and a motor plate, the motor plate having an
opening of a certain area which functions as the air inlet, the
bottom plate and motor plate being connected to and separated by a
side wall, and both being generally ring shaped, except for the
area of the air outlet.
13. A backpack blower as recited in claim 11 wherein the fan
assembly has a bottom ring and a top ring, and vanes separating the
top ring from the bottom ring by a predetermined spacing.
14. A backpack blower as recited in claim 13 wherein the bottom
ring has a center, and wherein each vane is angled or curved with
respect to the center of the bottom ring.
15. A backpack blower as recited in claim 14 wherein the angle or
curve of all the vanes with respect to the center of the bottom
ring is the same.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims priority from U.S.
Provisional Patent Application No. 62/065,079 filed on Oct. 17,
2014, which is incorporated herein by reference in its entirety for
all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to the field of
lawn, leaf and turf blowers, and specifically to battery powered
backpack blowers.
[0003] In general, backpack leaf blowers are well known, especially
in the commercial turf care industry. Most such backpack blowers
are gas powered, that is, they have a gasoline engine that powers
the blower. In such gas powered blowers, the gasoline engine needs
to be very small and light, in order to fit into the backpack form
factor. Accordingly, most such backpack blowers have air-cooled
2-cycle engines. Such blowers are often very noisy. A typical gas
backpack blower will spin a small fan at about 9,000-10,000 rpm.
Such a blower will generally deliver about 500 cfm at 150 mph out
of the tube, and will cause about a 75-84 db noise level at 50 feet
of distance. Further, 2-cycle engines run hot and emit a large
amount of air pollution, have high operating costs because of the
gasoline/oil mixture, and can be difficult to start with a pull
string and manual choke lever. Particularly in a commercial
setting, where use of such blowers can be all day long, operators
can feel sick from the odors and fumes of gas engines, and feel
fatigue from the work of starting and carrying the noisy
gas-powered blowers. Most operators will do anything they can to
avoid using the backpack blowers, in large part because the heat
from the user builds up between the user's back and the blower,
which leads to substantial discomfort.
[0004] One attempt at a solution to the heat and noise, air
pollution, hard starting, and high operating cost problems
associated with 2-cycle gas engine powered blowers, has been to try
electric powered blowers. Some weight can be eliminated if a corded
version is used, but the fact that the blower is corded so severely
limits the physical range of use that it is impractical for
commercial applications. And conventional handheld cordless
versions are much smaller, and generally have a small battery that
will only run 9-12 minutes at top speed, requiring constant
recharging with the delays and inefficiencies associated with the
charging. At the same time, even electric powered blowers have not
solved the problem of noise, as the fans they have used to move the
air have been at least as much a source of the noise as has been
the gas powered engines. Most hand-held battery-operated cordless
blowers spin a very small ducted fan at about 18,000-22,000 rpm.
Most hand-held battery-operated cordless blowers move air at about
400 cfm at a maximum speed of about 130 mph, and most such cordless
blowers cause about 65-70 db of noise at 50 feet of distance.
[0005] The present invention relates to improvements over the
apparatus described above and to solutions to some of the problems
raised or not solved thereby.
SUMMARY OF THE INVENTION
[0006] The invention provides a backpack blower, having a fan
frame, with a bottom plate and a motor plate. The motor plate has
an opening of a certain area which functions as an air inlet. The
bottom plate and motor plate are connected to and separated by a
side wall, and both are generally ring shaped, except having an air
outlet area. A fan assembly, positioned within the fan frame, has a
bottom ring and a top ring, which are spaced apart from each other
by a plurality of vanes. Each vane is angled and curved
substantially the same as all the other vanes with respect to the
center of the bottom ring. A motor is provided to rotate the fan
assembly within the fan frame, and thus move air from the air inlet
to the air outlet. A removable battery pack has electrical
connectors for mating with electrical connectors mounted to the fan
frame. A controller is electrically connected to the motor and to
the battery pack, for using power from the battery pack to energize
the motor and thus rotate the fan to move air from the air inlet to
the air outlet. A harness frame is connected to the fan frame and
has an opening in air flow communication with the air inlet, so
that, when the motor is rotating the fan assembly, air is drawn in
through the harness frame opening. With the harness frame
positioned adjacent to the operator's back, the air flow through
the harness frame opening has the effect of cooling the operator. A
main cover with air intake openings is connected to the motor plate
and to the harness frame and positioned over the motor plate
opening.
[0007] Other objects and advantages of the invention will become
apparent hereinafter.
DESCRIPTION OF THE DRAWING
[0008] FIG. 1 is a perspective view of a backpack blower
constructed according to one embodiment of the invention.
[0009] FIG. 2 is a side elevation view, partially in section, of
the backpack blower shown in FIG. 1, with the hose, tubing and
control handle removed.
[0010] FIG. 3 is a perspective view of the blower shown in FIG. 2,
from the bottom left.
[0011] FIG. 4 is a perspective view of the blower shown in FIG. 2,
from the bottom right.
[0012] FIG. 5 is a perspective view of the fan of the backpack
blower shown in FIG. 1.
[0013] FIG. 6 is a perspective view of the harness frame of the
backpack blower shown in FIG. 1.
[0014] FIG. 7 is a sectional view through a motor provided in one
embodiment of the invention.
[0015] FIG. 8 is perspective view of a blower according to one
embodiment of the invention, partially in section, to show the
motor, fan and battery connector.
[0016] FIG. 9 is a side view, of a blower according to one
embodiment of the invention, partially in section, to show the
internals and air flow of the blower.
[0017] FIG. 10 is side view of an operator using a blower
constructed according to one embodiment of the invention, with the
blower shown partially in section to show the internals and air
flow of the blower.
DETAILED DESCRIPTION
[0018] Referring now to the drawing figures, the invention provides
a backpack style leaf and lawn blower 10. In the embodiment shown,
the blower 10 includes a fan frame 12. Fan frame 12 includes a
substantially flat bottom plate 14, which is generally circular
except for an outlet area 14a which will be explained below. Fan
frame 12 also includes a substantially flat motor plate 16 which is
also generally circular except for its matching outlet area 16a.
Motor plate 16 is positioned above and substantially parallel to
bottom plate 14, with the outlet areas 14a and 16a aligned over
each other. The bottom plate 14 and the motor plate 16 are
maintained at a predetermined separation from each other by a side
wall 18 mounted substantially perpendicular to, and at the
periphery of, the bottom plate and motor plate. The centers of the
bottom plate 14 and motor plate 16 form a line substantially
parallel to the side wall 18.
[0019] The motor plate 16 has an opening 20 at its center which is
generally round, the diameter of which about half of the diameter
of the motor plate itself, except that there are motor mounting
arms 21 extending generally radially inward from the inner edges of
the opening.
[0020] The embodiment shown includes a centrifugal fan assembly 22
with forward curved vanes 32. The fan assembly 22 is positioned
within the fan frame 12, that is, between the bottom plate 14 and
the motor plate 16, and within the side wall 18. The fan assembly
22 includes a bottom ring 24, and a top ring 26. The rings 24, 26
have similar diameters. Top ring 26 has a top ring opening 30 at
its center, the diameter of which opening is about 70% of the
outside diameter of the top ring. The plane of the top ring 26 is
spaced apart from and parallel to the plane of the bottom ring 24,
held at a predetermined spacing by a number of the vanes 32, spaced
generally equally about the circumference of the rings. The
embodiment shown in FIGS. 2 and 5 has 11 vanes, but other numbers
of vanes could also work well. In the embodiment shown in isometric
isolation in FIG. 5, each of the vanes 32 is connected to both
rings 24, 26. From the inner edge of top ring 26, each vane 32
tapers down to a point of connection to the bottom ring 24 at a
point about 75% of the distance from the outer circumference to the
center. The outer 30% of each vane 32 is curved or angled in the
direction of the rotation of the fan assembly, that is, forward, at
an angle of about 35 degrees.
[0021] As shown in FIG. 2, the invention provides a motor 34 to
rotate the fan assembly 22. In the embodiment there shown, the
motor 34 is an outrunner-type motor, which is advantageous because
such a motor runs at a lower speed, eliminating the weight and
complexity of a gearbox or reducer, while at the same time
producing more torque than an inrunner-style motor. As shown in
more detail in FIG. 7 but also in some of the other drawing
figures, motor 34 has a motor body 36 that is connected to and
rotates with a motor shaft 38, and a motor stator 39 mostly inside
the motor body. Motor stator 39 is rigidly affixed to a motor
mounting bracket 40 which, as shown best in FIG. 2, has motor
bracket arms 41 extending generally radially outward, the ends of
which are bolted or otherwise removably attached to the motor
mounting arms 21. Since motor mounting arms 21 are part of the
motor plate 16, the stator 39 of motor 34 is thus non-rotatably
connected to the motor plate 16. The motor shaft 38 is rigidly
connected to the bottom ring 24 of the fan assembly 22 by means of
a fan hub 42. Bottom ring 24 may have a one or more bottom ring
openings 28, to accommodate attachment of the fan hub 42. Thus when
the motor shaft 38 is rotated with respect to the motor mounting
bracket 40, the fan assembly 22 is rotated with respect to the
motor plate 16 and the fan frame 12 in general.
[0022] The side wall 18 does not entirely enclose the fan assembly
22, instead having an outlet 44 which allows escape of the air
being moved by the fan assembly, and in fact, use of the blower 10
as a blower. The area of the outlet opening is about 25% of the
area of the motor plate opening 20, so as to provide proper air
flow and pressure. As shown in FIG. 1, to the outlet 44 is
removably attached one end of a hose or flexible tube 46. The other
end of the flexible tube 46 has a blower tube 48 attached to it.
Any suitable flexible or non-flexible tubes or nozzles may be used
to accomplish the various operations for which the blower 10 will
be used. To the blower tube 48, or the end of the flexible tube 46
nearest the blower tube, is attached a control handle 50, which can
be used to direct the flow of air out of the nozzle as desired when
the blower 10 is in use. The control handle 50 may also be provided
with a power switch 50a to turn the power ON and a lever 50b to
adjust the airflow from "low" to "high." There may also be a
momentary trigger switch 50c for "boost" or maximum speed. Such
controls would make the blower 10 very easy to start and stop
compared to taking the blower off the user's back and pulling a
rope to start a gas blower.
[0023] Mounted to the outer surface of the motor plate 16 is a main
cover 52. Considering as the front of the blower 10 the outlet 44,
and that the direction of air flow from the outlet is out the front
of the blower, the bottom end of the main cover 52 is connected to
the motor plate 16 at the back of the blower. The main cover 52
acts as a guard, rising at a forward angle and thereby covering the
motor 34 and the larger motor plate opening 20, and being
perforated with small openings 52b so as to still permit entry of
air into the motor plate opening, as shown by arrows 53 (FIGS. 9
and 10). The sides of the main cover 52 are connected to the motor
plate 16 by side plates 54 and 56 and are generally closed. Side
plate 54 (FIG. 3) is on the left, is generally triangular in shape,
and is connected along a bottom edge to the motor plate 16, and
along one side edge to the main cover 52. Side plate 56 (FIG. 4) is
on the right, is also generally triangular in shape, and is
connected along a bottom edge to the motor plate 16, and along one
side edge to the main cover 52.
[0024] A harness frame 58 (shown in isometric isolation in FIG. 6)
is connected to the opposite side edge of each of the side plates
54, 56, and to the motor plate 16, as well as, at the top thereof,
to the main cover 52. Thus the entire motor plate opening 20 is
covered by the assembly of the main cover 52, the side plates 54
and 56, and the harness frame 58. When the blower 10 is in use,
harness frame 58 fits in the area of the back of the user or
operator 59. Harness frame 58 also has openings 60, so as to allow
air to be drawn in around the user when the blower 10 is in use and
the fan assembly 22 rotating. A handle opening 61 near the top of
the harness frame 58 permits the harness frame to be used as a
handle, by which to carry the blower 10. Shoulder straps 62 are
provided, connected to the harness frame 58, to permit the user to
carry the blower 10 on the user's back. The air flow resulting from
the openings 60 in the harness frame 58, as shown by arrows 63, has
a beneficial cooling effect, relieving some of the heat build-up
that results for a user of conventional backpack blowers, making
the blower 10 much more pleasant to use.
[0025] The power source for the blower 10 is a battery pack 64
which is easily removable and replaceable, in an opening 52a
provided for that purpose in main cover 52. Some of the drawing
figures show the opening 52a with the battery pack 64 having been
removed, so as to show the battery pack support plates 66, 68 under
the main cover 52. As shown in FIG. 8, a battery connector 70 is
provided near the bottom of the battery pack 64 goes, such as on
the battery pack support plate 86, so as to connect with the
battery pack when inserted in the opening 52a. The battery
connector 70 is electrically connected and provides power to a
controller 74, which is in turn connected to the motor 34 to
provide power. The control handle 50 may also be connected to the
controller 74, to enable the operator to control the blower 10,
such as by varying the speed of the blower in ways known to persons
of skill in the art.
[0026] Given the generally horizontal orientation of the fan
assembly 22 and the straight-line orientation between the outlet 44
and the hose 46, the invention provides a blower 10 that produces
higher static pressure and has much quieter operation than prior
backpack leaf blowers, but still has very good air flow. Blower 10
generally has a top speed of about 4700 rpm, compared to, as
described above, 9,000-10,000 rpm for commercial gas backpack
blowers and about 18,000-22,000 rpm for most hand held cordless
blowers. Fan assembly 22 will deliver 504 CFM at 150 mph out of the
tube with 58 db noise level at 50' distance. As stated above, a
typical gas backpack blower that delivers 500 cfm at 150 mph out of
the tube causes about a 75-84 db noise level at 50' distance. Since
noise doubles for every 6 db change, blower 10 is about 3-4 times
quieter than a conventional gas blower. Most handheld
battery-powered cordless blowers move about 400 cfm of air at a
maximum of about 130 mph, and cause about 65-70 db of noise--still
2-3 times louder than blower 10, with much less air movement
performance. As described above, these hand held blowers also have
a disadvantage in that their small battery will only run 9-12
minutes at top speed. With its large battery pack 64, blower 10
will run over 60 minutes at the best speed of the handheld blowers,
or about 45 minutes at its top speed of 150 mph. Run time such as
that is about the same as in a commercial gas backpack blower using
a full tank of gasoline. Further, as shown in FIG. 10, based upon
the orientation of the outlet 44, operation of the blower will
cause a reaction where the blower is lifted slightly in the
direction of arrow 76, making it feel lighter on the user's
shoulders.
[0027] While the apparatus hereinbefore described is effectively
adapted to fulfill its intended objects, it is to be understood
that the invention is not intended to be limited to the specific
preferred embodiments set forth above. Rather, it is to be taken as
including all reasonable equivalents to the subject matter
described.
* * * * *