U.S. patent application number 11/237299 was filed with the patent office on 2006-05-25 for venturi fan.
Invention is credited to Mark Moore, Vance M. Patterson, Thomas Salisbury.
Application Number | 20060110272 11/237299 |
Document ID | / |
Family ID | 36461101 |
Filed Date | 2006-05-25 |
United States Patent
Application |
20060110272 |
Kind Code |
A1 |
Moore; Mark ; et
al. |
May 25, 2006 |
Venturi fan
Abstract
A venturi-type fan is composed of a wire basket between front
and rear flares. The wire basket has a rear portion to which the
motor and fan blade assembly is mounted. The rear flare controls
the admission of air into the fan to reduce turbulence and allows
the flow of air to be accelerated and directed forward in a slowly
diffusing column. The openness of the sides of the present fan
reduces the noise generally associated with close-sided venturi
fans without degrading air movement characteristics
Inventors: |
Moore; Mark; (Columbia,
SC) ; Patterson; Vance M.; (Morganton, NC) ;
Salisbury; Thomas; (Columbia, SC) |
Correspondence
Address: |
MICHAEL A. MANN;NEXSEN PRUET, LLC
POST OFFICE DRAWER 2426
COLUMBIA
SC
29202-2426
US
|
Family ID: |
36461101 |
Appl. No.: |
11/237299 |
Filed: |
September 28, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60630113 |
Nov 22, 2004 |
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Current U.S.
Class: |
417/423.15 |
Current CPC
Class: |
F04D 29/545 20130101;
F04D 29/661 20130101 |
Class at
Publication: |
417/423.15 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Claims
1. A fan, comprising: a motor having a shaft; a fan blade assembly
carried by said shaft and rotatable therewith when said motor is
operating, said fan blade assembly forming a flow of air when
rotating; and a housing having a rear flare, a side wall having at
least one hole formed therein to admit air through said side wall
to join said flow of air when said fan blade assembly rotates, and
a rear portion for carrying said motor.
2. The fan as recited in claim 1, wherein said at least one hole is
a multiplicity of holes.
3. The fan as recited in claim 1, wherein said side wall is formed
of spaced apart wires.
4. The fan as recited in claim 1, wherein said side wall and said
rear portion are formed of a wire basket.
5. The fan as recited in claim 1, wherein said side wall is formed
of a helical wire having plural turns, each turn of said plural
turns being spaced apart from adjacent turns of said helical
wire
6. The fan as recited in claim 1, wherein said side wall is
frustoconically shaped.
7. The fan as recited in claim 4, wherein said wire basket is
frustoconically shaped.
8. The fan as recited in claim 1, wherein said housing carries a
front finger guard.
9. The fan as recited in claim 1, wherein said rear portion
surrounds said motor.
10. The fan as recited in claim 1, further comprising means carried
by said rear portion for mounting said motor.
11. The fan as recited in claim 10, wherein said mounting means is
a set of brackets.
Description
CROSS REFERENCE TO RELATED PATENTS
[0001] The present application claims priority to U.S. Provisional
Application Ser. No. 60/630,113, filed Nov. 22, 2004, incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to fans generally, and to fans
used in industrial and commercial settings in particular.
[0003] The purpose of a fan is move air in order to ventilate and
cool an area. In industrial and commercial environments, where air
conditioning may be impractical, fans are vital to employees'
health and comfort.
[0004] There are several types of fans used in commercial and
industrial environments. One type includes a fan blade enclosed
within a wire frame housing or "cage", sometimes mounted on a
pedestal. The shaft of a motor outside the housing may project into
the housing to turn the blades. These fans work fine in smaller
quarters. Increasing the speed of the motor and the pitch of the
blade allows this type of fan to throw more air, but increases
noise. Another type of fan is a venturi fan that has a metal,
venturi-shaped housing with a motor and a set of blades mounted
therein. The set of blades is rotated by the motor and thus
accelerates air through the housing. These fans move a large volume
of air and project it over large distances, which fact is
especially important in large industrial buildings such as
distribution centers, but they are relatively noisy.
[0005] Thus there remains a need for improvements in fans,
particularly high volume industrial and commercial fans such as
venturi fans.
SUMMARY OF THE INVENTION
[0006] According to its major aspects and briefly recited, the
present invention is a venturi fan capable of producing a
significant, directed flow of air but with significantly reduced
noise compared to prior art venturi fans. The present fan has a
body comprised of a generally cylindrical wire basket for carrying
a motor and fan blade assembly, and a flared intake carried at the
rear of the wire basket. Preferably, the front of the basket
carries an exit channel, which may also have a flare but is
otherwise preferably substantially cylindrical in shape. The
rear-flared intake allows for a smooth feed of air into the basket
and past the motor and the air-accelerating fan blade assembly. The
wire basket, in a preferred embodiment, acts as a conduit for the
flow-path air but also admits additional air into the flow path and
channels the flow of air produced by the fan while allowing fan
noise to dissipate through the sides. The basket also avoids
generation of some fan noise and is a safety feature, preventing
injury in its role as both the side and rear finger guard.
[0007] An important feature of the present invention is the
relatively open sides of the present fan, compared to prior art
venturi fans. The relatively open sides contribute significantly
and in a number of ways to noise reduction, chiefly by allowing
noise to escape, while not significantly degrading the flow of air.
Indeed, the openness of the sides increases the amount of air
available to the fan.
[0008] Additionally, the combination of the rear flare intake and
the wire basket is a significant feature of the present invention.
This combination allows the flow of air generated by the fan blade
assembly to be created and directed significant distances with
little diffusion.
[0009] The use of the wire basket to support the motor and fan
blade assembly is yet another important feature of the present
invention. This arrangement reduces material, weight and
obstructions to air flow while providing a sufficiently sturdy
securement for the motor and fan blade assembly.
[0010] These and other features and their advantages will be
apparent to those skilled in the art of fan design from a careful
reading of the Detailed Description of Preferred Embodiments
accompanied by the following drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] In the drawings,
[0012] FIG. 1 is a perspective view of a fan, according to a
preferred embodiment of the present invention;
[0013] FIG. 2 is a side view of the fan of FIG. 1, according to a
preferred embodiment of the present invention;
[0014] FIG. 3 is a front view of the fan of FIG. 1;
[0015] FIG. 4 is a rear view of the Fan of FIG. 1;
[0016] FIG. 5 is a perspective view of the Fan of FIG. 1 with the
front finger guard and fan blade assembly removed to show the
mounting of the motor; and
[0017] FIG. 6 is a detailed view of the interior of the fan of FIG.
2 showing the manner in which the motor is mounted, according to a
preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is an improvement in venturi-style
fans. Venturi fans direct a significant quantity of air in a
forward direction and are suitable for large buildings such as
warehouses. Unfortunately, prior art venturi fans are relatively
noisy.
[0019] FIG. 1 illustrates in perspective the present venturi fan
10. Fan 10 has a housing 12 that is flared on both the front 14 and
the rear 16, and has a front finger guard 18. Inside housing 12 is
a motor 22 and a fan blade assembly 24.
[0020] Referring now to FIG. 2, there is illustrated a side view of
venturi fan 10 according to a preferred embodiment of the present
invention. Fan 10 is rotationally symmetric so it appears the same
from all sides. Unlike prior art venturi fans, venturi fan 10,
shown in FIGS. 1-6 in its preferred embodiment, has an opening
formed in the side wall 28, preferably a multiplicity of openings
such as perforations or an array of slots, but, most preferably, a
multiplicity of openings formed by spacing wires 34, either by
constructing a cage or basket 32, as shown. Basket 32 is
illustrated as made from circular wires 34 secured at the desired
intervals with cross supports 36, also made of wire, or,
alternatively, by forming a single helical wire secured with cross
supports to maintain the desired spacing of each turn of the
helical wire. Spacing between adjacent wires is in part dictated by
safety requirements imposed by authorities, by the requisite
strength required for fan 10, by the function of fan 10 to serve as
an airflow conduit but otherwise fan 10 is preferably open on side
26 to the greatest extent possible.
[0021] Safety requirements relate to the size of the openings
between wires 34 that, when properly set, the likelihood that
someone will inadvertently stick fingers into the interior of
basket 32 in the vicinity of fan blade assembly 40 is minimized.
Consequently, the spacing will take into account the age of those
likely to come into contact with fan 10 and the proximity of fan
blade assembly 24 to basket 32. Thus, the spacing will be wider if
wires 34 are farther from fan blade assembly 24 and narrower closer
to fan blade assembly 24, and can include both spacings in the same
basket 32, as best seen in FIG. 2.
[0022] Basket 32 must also be rigid enough to support fan blade
assembly 24, a motor 22 and a rear flare 16. Rear flare 16 is the
solid portion of housing 12. The term "flare" simply means that the
cross sectional area taken at right angles with respect to the
direction of air flow increases toward the end of housing 12, as in
the flare of a trumpet. Optionally, front flare 14 is added to fan
10 to give the present fan 10 a symmetric, finished look. Front
flare 14 includes an optional front finger guard 18, best seen in
FIG. 3. Basket 32 is made to be basket-shaped so that it's rear
portion 50 contiguous with side wall 28 and best seen in FIG. 5,
acts as a finger guard for the rear of fan 10.
[0023] Rear flare 16 helps to control the flow of air into fan 10
is because it minimizes turbulence and increases laminar flow. Rear
flare 16 is significant from an airflow standpoint; front flare 14
is much less so and is essentially an optional feature of the
invention, provided essentially for appearances.
[0024] In addition to acting as a rear finger guard, rear portion
50 provides a surface on which motor 22 can be mounted. Rear
portion 50 has a central opening through which motor 22 is
partially inserted. Brackets 54, that run along the side of basket
32 across rear portion 50 and thence into the interior of basket 32
where they form loops 58 and then return, are used to support motor
22. Threaded posts 60 on the front of motor 22 extend through loops
58. Nuts 62 are then threaded to posts 60 to secure motor 22 to
brackets 54.
[0025] Motor 42 has a central shaft 68 to which fan blade assembly
40 is attached. Blade assembly may have three or more paddle blades
70.
[0026] The present fan 10 is much quieter than prior art venturi
fans. While not wishing to be bound by theory, it is believed that
this result has been achieved by a number of different factors
working in combination. First, although fan 10 controls and directs
airflow in much the same way as a prior art venturi fan, sound now
can disperse over a greater angle because side wall 28 of fan 10 is
open and is not channeled with the airflow. Second, in the prior
art venturi fan, the tips of its blade assembly normally pass
closer to the housing than in the present fan 10 and the turbulence
that arises sets up vibrations in the solid housing. Those
vibrations are reflected throughout the housing and may resonate.
Turbulence is reduced in the present fan 10. Indeed, the tips of
fan blade assembly 24 are farther from wires 34 at least for safety
reasons alone, and are no longer as starved for air, as air is
admitted freely through side wall 28 between wires 34. Furthermore,
vibrations created by the movement of fan blade assembly 24 in the
vicinity of wires 34 are weaker and less easily reflected by wires
34. The prior art side wall mounted bracket has been removed in
favor of mounting motor 22 directly onto rear portion 50, thus
eliminating a structure on the interior of the fan that causes
additional turbulence and noise. It is believed that these changes
result in less noise and "whiter" noise, that is, noise spread more
evenly over the audible frequency spectrum.
[0027] The shapes of the front and rear flares 14, 16 may be the
same and may be symmetrical with respect to each other, but may
alternatively be different if desired for packaging efficiency. For
example, rear flare 16 may have a smaller diameter where it fits
onto basket 32 than front flare 14 in order that basket 32 may have
a slightly frustoconical shape, as shown best in FIG. 2, so that it
nests better with other baskets 32 in shipping or storing.
[0028] Many modifications and substitutions will be apparent to
those skilled in the art of fan manufacture from the foregoing
description of the preferred embodiments without departing from the
spirit or scope of the present invention. It is intended that the
scope of the present invention include all modifications that
incorporate its principal design features, and that the scope and
limitations of the present invention are to be determined by the
appended claims.
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